ML20082H892
| ML20082H892 | |
| Person / Time | |
|---|---|
| Site: | Hope Creek  |
| Issue date: | 10/31/1978 |
| From: | Fischer J, Szymanski J, Werner M DAMES & MOORE |
| To: | NRC |
| Shared Package | |
| ML20082H873 | List: |
| References | |
| NUDOCS 8312010314 | |
| Download: ML20082H892 (80) | |
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Technical Bookshelf Article i
A New Approach to Dividing the Northeastern United States into Tectonic Provinces by J.A. Fischer, J.C. Szymanski and M.L. Werner 4
dated October,1978 e
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A NEW APPROACH TO DIVIDING THE NORTHEASTERN UNITED STATES INTO TECTONIC PROVINCES O
O 4
INTRODUCTION The division of the northeastern United States into
" geologic" provinces is not new.
Generally, the physiographic cycle and geomorphic history of the area have been major con-tributing factors in this decision, and geologic structures have been considered only to a limited degree.
However, for the pur-II) poses of adhering to certain government regulations it is necessary to utilize geologic structural similarities in a man-ner not previously contemplated.
This discussion, and the provincial subdivision of the Appalachians utilizes the concept of plate tectonics.
In plate L-tectonics, the earth's crust is divided into large nearly rigid r
L segments (plates) which move about relative to one another.
These movements may be either divergent (where two plates part l
l and new oceanic crust forms at the spreading center), convergent (plate collision) or translational (bypassing along a shared I
boundary).
Consequently, this division of the Appalachian oro-gen has considered not only the convergent orogenies (Taconic, l
Acadian, and Allegheny), but also the preceding (Proto-Atlantic) t and subsequent (modern North Atlantic) divergent movements.
This approach synthesizes the available knowledge of the Appalachian orogen, and the dynamics of plate tectonics theory through geologic time and may be summarized as follows:
i 1.
Recognition of four major stages in the evolution of the Appalachian orogen:
crustal divergence (Late Precambrian-Early Paleozoic); convergence i*
l
~
(1) NRC (formerly AEC) 10 CFR Part 100 Appendix A
(Early to Late Paleozoic); crustal translation (Late Paleozoic); and final crustal divergence (Mesozoic);
2.
Partitioning of the Appalachian orogen into a part characterized by structural and petrographic assemblages specific of only the convergent stage (craton) and a part characterized by assemblages related to all four stages (mobile belt);
3.
Division of the craton into tectonic provinces based on characteristic assemblages of struc-tural geologic features; 4.
Division of the mobile belt into tectonic pro-vinces based on structural and petrographic assemblages specific of different tectonic settings; 5.
Division of the mobile belt and craton into northern and southern-sections on the basis of a transverse element which formed during the initial divergence and was functional in the subsequent stages.
The application of this approach results in the rec-ognition of eleven tectonic provinces within the orogen's north-ern section.
They have been named as follows (Figure 1) :
Stable Interior
. Fold.and Thrust Belt Conestoga Valley
\\
r 2
E
f Highlands Ottawa Basin Inner Piedmont Coastal Plain Central New England Avalon Platform St. Albans Thrust Belt Quebec-Vermont Piedmont o
e t
e
- e I
e O
e 3
.o.
GEOLOGIC HISTORY AND TECTONIC EVOLUTION Studies of the inherent characteristics of the region-al and subregional geology (the structure, petrographic assem-blages'and faunal zones), together with plate tectonic theory, allow us to distinguish four major stages in the evolution of 1
the Appalachian orogen and its individual components - the tec-tonic provinces.
These stages are:
(1) initial crustal diver-gence in Late Precambrian - Early Paleozoic tir.e; (2) crustal convergence in Ordovician to Carboniferous time; (3) crustal translation in Carboniferous time, and (4) renewed crustal di-vergence in Mesozoic time.
The tectonic framework of the Appalachian provinces C
appears to have been founded in Late Precambrian time when crustal divergence created a northeasterly trending linear sym-metric scheme of a medial depositional trough flanked by cra-tonic margins and cratons.
Subsequent convergence created fold and thrust structures parallel to this symmetry.
Still later, the cratonic margins, as the most fundamental and profound structures, served as the loci for translational and final di-vergent plate movements.
INITIAL DIVERGENCE The initial crustal divergence occurred in Late Pre-cambrian time, following the completion of the Grenvillian Oro-genic cycle.
This process caused the separation of the North American and African plates and resulted in the formation of 4
the Proto-Atlantic Ocean (Williams and Stevens, 1974; Wilson, 1966; and Rankin, 1975).
In the initial rifting phase, an east-ward thickening wedge of clastic sediments (graywackes, arkoses, and shales), interbedded with volcanic rocks, were deposited un-
~
conformably on the Grenvillian basement in water-filled basins within the ancient continental margin (Hadley,1970).
These rocks are presently exposed on the eastern side of the Blue Ridge-Reading Prong as the basal Ashe and Lynchburg Formations, and probably the lower portions of the Wissahickon Formation (Rankin, 1975; Hadley, 1970).
Recent radiometric age determina-tions suggest that the Yonkers Gneiss of the Manhattan Prong, and the Dry Hill Gneiss (Pelham domes of western Connecticut) are northern equivalents of these rocks (Naylor, 1975;- Long,
~
1969).
f As rifting progressed, the Proto-Atlantic ocean opened and the previous system of isolated rift basins gave way to a long depositional trough underlain by oceanic crust.
This trough was located primarily between the ancient margin of east-ern North America, and the ancient western margin of the Avalon platform (Wilson, 1966; Williams and Stevens, 1974).
This later phase of the initial divergence is marked by two rock assemblages representing the continental margin and oceanic trough:
1.
A miogeosynclinal wedge, developed either as a great carbonate bank over the stabilized ancient continental margin, or as a Middle-to-Late c
9 5
O Cambrian basal clastic sequence lying transgres-sively.cn1 Grenvillian basement; and 2.
An ophiolitic sequence, remnants of which are known only from the northeastern portion of the orogen, south of Logan's line, and possibly as the Baltimore-State Line gabbro-peridotite com-plex (St. Julien and Hubert, 1975; Rankin, 1975).
Otherwise, the oceanic crust was largely consumed by subduction during the subsequent convergent stage.
Although the lines of rift and trough development were generally linear, there appears to have been a primary bend in the orogen in southeastern Pennsylvania (the Pennsylvania Elbow).
The existence (or, at least, the initiation) of this curvature in Eocambrian-early Paleozoic time is suggested by Cambro-Ordovician facies boundaries in the Conestoga Formation, and by the distributions of clastic sediments and volcanic rocks in an Eocambrian embayment west of the Susquehanna River (Wise and Werner, 1969).
Additionally, a transverse trough (transverse to the ancient continental margin) formed in the area from Ottawa to northern New Hampshire (Wilson, 1946; Cady, 1969; Rickard, 1973).
CONVERGENT STAGE i
The history of the closing of the Proto-Atlantic is l
reflected in the convergent stage of Appalachian Orogen.
During this stage the tectonic provinces began to develop their indi-e<
a
viduality, and by its close all but one of the provinces is distinguished.
This stage begins in ordovician time with the onset of the Taconic orogeny.
The earliest phases of this stage are evidenced by a pre-Middle Ordovician unconformity (Rodgers, 1971, unconformity C), which extends throughout the orogen (Colton, 1970), followed by the influx of detrital sediments (flysch) over the previous carbonate bank, along the cratonic margin.
At the height of the Taconic orogeny, ophiolitic rocks (presumably oceanic crust) were obducted from the eugeosyncline, and the mio-geosynclinal cover (detritial and carbonate alike) were thrust i
onto the craton.
This sudden loading of the cratonic margin, in turn, resulted in the development of an exomiogeosyncline which
[
was the depocenter for additional flysch grading to molasse (Martinsburg and equivalents).
The close of the Taconic orogeny marked the destruc-tion of the ancient continental margin and the development of the mature arc-trench-subduction zone system.
The subsequent Acadian orogeny represents continent-continent collision and shortening, and limited metamorphism.
It resulted in the final closure of the already contracted Proto-Atlantic Ocean in the northern Appalachians.
The culmination of the closing of the Proto-Atlantic Ocean in the southern Appalachians occurred in Carboniferous time.
It appears, based on available evidence, i
I that the Carboniferious period had the character of convergence only in the southern portion of the Appalachians (Al'legheny 0
?
I
o orogeny); in the north, it was a period of translational move-ments.
Odom and Fullagar (1973) have interpreted the 300 million-year old (Allegheny) orogeny in North Carolina to be the result of the ultimate convergence of the North American and African continents, and the full demise of the Proto-Atlantic.
In this context, they regard the preceding Taconic phase as the collision between the North American continent and an island arc system that lay between the two continents.
During both the Taconic and Acadian orogenies the pre-viously mentioned transverse trough from Ottawa to northern New Hampshire became a zone of greater tectonic mobility (Cady,
1969).
(Cady has named this northwest-trending trough and rela-tively more mobile zone the "New England Salient", which name is adopted here).
This unusual mobility is indicated by early Taconic cross-folds (Cady, 19 6 9 ; Beland, 1967; St. Julien, 1967) and late Taconic and Acadian rotation of longitudinal structural elements about pivots on the southern flank of the Salient.
Similarly, the geometry of the Pennsylvania Elbow tended to con-trol the trends of the exogeosynclinal troughs and the Allegheny orogeny (Drake and Woodward, 1963; Woodward, 1968; Wise and Werner, 1969).
TRANSLATIONAL STAGE The translational stage followed the final closure of the Proto-Atlantic in the north and was contemporaneous with the final process of convergence in the south.
This stage of the e
- 1 8
l
' c orogen's evolution is recognized only in the northern Appalachi-ans where it caused the development of a series of Carboniferous to Lower Permian sedimentary basins stretching from Rhode Island 4
4 to northern Newfoundland.
These basins are filled with clastic sedimentary rocks, in places as thick as 4000 meters.
These in-clude graywacke, shale, conglomerate, and coal, and are inter-bedded with mildly alkalic volcanic rocks.
In Rhode Island and Massachusetts, these sediments are intruded by granitic plutons and dikes of aplitic granite.
The basins are interpreted to have developed by dextral rifting (Belt, 1968; Ballard and Uchupi, 1975).
Ballard and Uchupi (1975)' noted that the translation 4
may have resulted frem an oblique collision of the North Ameri-can and North African continents.
Since translation, as recog-nized only in the northern Appalachians, was contemporaneous with final convergence in the southern Appalachians, it is pos-sible that the two represent the same process of localized con-vergence.
FINAL DIVERGENCE The Post-Middle Triassic development of the orogen, that is, the final divergence initiated the opening of the North Atlantic Ocean, annexed the last individual province and inten-sified the provisional uniqueness of the others.
l The last stage has recently been shown to be more com-plex than was formerly believed (deBoer,1967; Sanders, 1963; Bain, 1957; Ballard and Uchupi, 1975; Brown et. al., 1972; e
9
Kumarapeli and Saull, 1966; May, 1971 and Dames & Moore, 1974, 1975).
The following discussion is an attempt to summarize these recent structural analyses in a regionally homogeneous tectonic scheme.
This structural development, which is the youngest, regionally recognizable diastrophism in the northeast-ern United States (about 250 to 80 m.y.), is characterized by vertical movements (basining) and related continental and marine sedimentation, transcurrent faulting along pre-existing planes of crustal weakness, and extrusive and intrusive igneous activi-ty.
Thus, it corresponds to a rift structure or taphrogen like the East African Rift.
Based on available geologic evidence, it is possible to subdivide the development of this " Appalachian Rift" into Middle to Late Triassic, Trio-Jurassic, and Cretace-ous phases.
MIDDLE TO LATE TRIASSIC PHASE The most important phase of the rift development oc-curred in Middle to Late Triassic time.
In general, this phase is characterized by the development of a northeast trending rift valley, more than seventy miles wides, in which a thick series of continental rocks was deposited.*.The rift extended from the Bay of Fundy to the Carolinas.
Several periods of diabase ex-trusion and intrusion accompanied the sedimentation and are in-dicative of syn-sedimentary basin development.'
The majority of the Triassic basins have faulted bor-ders toward which the beds dip.
The presence of the border j
faults along the down-dip margin of the basins, and the exist-e 10 i
~.
ence of fanglomerates along this faulted margin, led to the con-cept (Barrell, 1915;'McLaughlin, 1953; and Sanders, 1963) that fa~.'.ing and basin filling were contemporaneous and that the bas ~.a were either half grabens or a single large graben which later experienced central uplift and erosion.
.The shapes of the individual basins and groups of basins, as well as the positions of the diabase sills within them, are strongly concordant to the structural grain of the o
pre-existing orogen.
This is suggestive of a utilization of the old structural framework in the development of the rift system.
the positions of the basins immediately cratonward of In fact, the cratonic margins (west of the basin in Connecticut, New Jersey and Pennsylvania and east of the one in the Gulf of Maine) suggest that these most fundamental divisions of the or-ogen persisted into Mesozoic time.
TRIO-JURASSIC PHASE The Juro-Triassic phase of rift development is char-acterized by the intrusion of diabase dikes and alkaline plu-tons, continued tectonization of the previously formed basins, and limited, if any, s'edimentation on the Coastal Plains of North Carolina and New Jersey (Brown, et. al., 1972).
This phase is equivalent to the early opening of the North Atlantic Ocean when North America and Europe began to move independently of North Africa (Pitman and Talwani, 1972; LePichon and Fox, 1971).
9 11
The diabase dikes, as mapped throughout the Appalachi-ans from Maine to Alabama, are concentrated in a relatively nar-row zone trending northeast from below the southernmost basin into and following the area occupied by the Triassic basins.
The remnant magnetic directions of the dikes coincide with nei-ther Late Triassic nor Early Cretaceous directions (DeBoer, 1967).
This, together with available field evidence (dikes cut the youngest rocks of the Newark basins and post-Newark sedi-ments in the Coastal Plain of North Carolina) and absolute age determinations of dike rocks (Dames & Moore, 1974) indicate a Jurassic age for the intrusions.
In contrast to the Triassic basins and sills, dike trends are discordant to the Appalachian structural grain.
Fur-thermore, dike orientations show remarkable variation within their areas of occurrence.
However, it is possible to distin-guish three domains in which the dikes have relatively consist-ent orientations.
In New England, the dike trends are consist-ently north-northeast.
Assuming that dike trends are indicative of lines of first-order extension fractures, May (1971) and deBoer (1967) showed that the dike swarms were intruded during application of a compressive stress.
To account for differences in dike trends, both authors postulated differentiation of the tectonic stress along the length of the orogen.
It is likely that this Jurassic differentiation of the tectonic stress system along the
~
12
- length of tha Appalachiens, likn the differencas in tectonic character that were noted during Carboniferous time, is reflec-tive of a fundamental difference between the northern and south-ern Appalachians.
The eastern edge of the North American plate at the start of the opening of the North Atlantic Ocean, 180 million years ago has been variously described as the magnetic quiet zone boundary (Drake and Woodward,1963), magnetic anomaly E (Rabinowitz, 1974), the continental slope (Bullard, et. al.,
1965), and a synthetic 180 million year isochron (Pitman and Talwani, 1972).
Offsets in all of these features suggest that i-a transform fault was initially present in the spreading axis in the vicinity of the present Kelvin seamounts.
Reconstruc-h tions'of the Canary and Kelvin fracture zones (LePichon and Fox, 1971) suggest that the transform was a broad zone.
Although it
.b may have developed along a Paleozoic fault zone (like the postu-lated Kelvin-Cornwall fault; Drake and Woodward, 1963), it did ~
not extend into the continent beyond the offset segments of the spreading ridge.
The clear absence of gross transcurrent offset along either the Kelvin-Cornwall trend or the postulated Boston-Ottawa trend (Diment, et. al., 1972) is in accord with the nature of transform faulting (Wilson, 1970).
As noted, continental tectonism in the northern Appa-lachians during the Trio-Jurrasic phase occurred along northeast trending fractures and was accomplished by sinistral simple shear.
This is compatible with either transform movement 13
c parallel to the Kelvin-Cornwall trend, expected movement along the Appalachians where they lie diagonal to the spreading axis, or transcurrent movement between Europe. iud North Afri'ca (Carey, 1958; Pitman and Talwani, 1972).
In this context, the north-south trend of the White Mountain plutons might represent exten-sional fracturing, however, these bodies were emplaced passive-ly (Chapman, 1968 ) and display a complete lack of structural I
control (Billings, 1945).
The White Mountain alkaline intru-l sions are predominantly Late Triassic and Jurassic in age, although they include Cretaceous ages (Stone & Webster,1975)
~
implying reutilization during the Monteregian magmatic event.
The absence of structural control suggests that the White Mountains (and the Monteregian Hills) represent localization of magmatism by a larger tectonic element, such as the New England Salinet (Cady, 19 6 9 ).
CRETACEOUS PHASE The third phase of Mesozoic crustal divergence was I
characterized by igneous activity and subsidence.
The subsi-dence occurred in the form of regional subsidence of the Atlan-l tic continental margin, and development of a miogeosycline.
The igneous activity consisted of the emplacement of alkaline plutons in the faulted terrain of the St. Lawrence River Valley I
in Quebec Province.
These events were a continuation of the i
processes acting throughout the Mesozoic and are related to continued opening of the North Atlantic Ocean.
e i
14
Subsidence during the Cretaceous affected the Appala-chian orogen only along the continental margin from New York to Florida and in the Gulf of Maine.
Boring data and geophysical studies show that Triassic, Jurassic and Cretacccus sediments have been down-dropped into faulted basins.
The Cretaceous sediments of the Coastal Plain have been rotated seaward in
(' ith a hinge in the response to subsidence along the margin w
general vicinity of the ancient continental crust-oceanic crust boundary) with the resulting development of a miogeosynclinal depocenter (Brown, et. al., 1972).
The timing of this subsi-dence varied along the coast, but it began prior to the Creta-ceous and continued into at least the Early Cretaceous.
The
- deformation may be characterized as block faulting, with the more fractured a'reas dropping into grabens.
The block faulting pattern of the present continental margin may be due to larger-scale faulting in the basement (Sheridan, 1975).
The faults cut-ting the Cretaceous rocks may be the result of sinistral shear along major transverse fracture zones.
This sense of movement is in agreement with the clockwise rotation suggested for the
(' itma'n and Talwani, 1972).
North American continent P
In the area of the present St. Lawrence River Valley, the Creataceous phase of divergence was marked by intrusion of rocks of alkaline affinity.
The most evident of these are the Monteregian plutons, but the alkalic dixes and sills of the Champlain Valley, the kimberlite dikes at the north end of the Timiskaming graben, the lamprophyre dikes in northeastern c
e 15
- s Newfoundland, and the alkaline dikes along the west margin of
-the Belle Isle trough should also be included (Kumarapeli, 1970; Doig and Barton, 1968).
All of these lie within a br'anching system of faulted. valleys which Kumarapeli and Saull (1966) have argued is a rift system.
The Monteregian plutons, which lie along an east-southeast trending line in the vicinity of Montreal, have been dated as Middle Cretaceous (Fairbairn, et. al., 1963; Gold, 1967; Lowdon, 1961).
This alignment is paralleled by several normal faults.
Recent studies (Dames & Moore, 1974) have shown that the plutons are tectonized by east-southeast trending frac-tures, suggesting the same stress system was operative before, during, and after the emplacement of the plutons.
The differ-ence in trend between the Monteregian Hills and the White Mountains may be due either to control by an older fracture (Doig and Barton, 1968), failure of the northeast shear regime with time, and/or an areal change in stress orientations such as exists today (Sbar and Sykes, 1973).
During Late Cretaceous-time, about 80 million years ago, there appears to have been a reorganization of the North Atlantic spreading scheme and a change in the position of the rotational pole of the plates (Pitman and Talwani,19 72; LePichon and Fox, 1971).
At this time, Europe separated from North America and moved eastward at a slower rate than North Africa.
Magnetic profiles across the North Atlantic suggest that the previously mentioned transform zone (Kelvin-Canary)
I
- 1 16
- s was eradicated from the spreading ridge at this time.
LePichon and Fox (1971) have suggested that a shift in the rotational pole would have caused unusual stress concentrations at the ends of the pre-existing transform zones beyond the spreading ridges, which may account for the extrusion of the Kelvin Seamounts at about this date.
TECTONIC DIFFERENTIATION OF THE APPALACHIAN OROGEN Considering the tectonic evolution of the Appalachian orogen, as conceptualized in this paper, the Appalachian orogen can be subdivided into two fundamental regions: the craton, which was affected by only convergent diastrophism and the mobile belt which was affected by all four major events in the orogen's evolution, that is initial divergence, convergence, translation and. final divergence (Figure 1).
The mobile belt,
~
as defined here, is situated east of the great anticlinoria cored by Grenvillian rocks, i.e. east of the Long Range (Nova Scotia), the Green Mountains, the Berkshire Highlands, the Hudson-New Jersey Highlands-Reading Prong, and the Blue Ridge.
The mobile belt thus corresponds to the Appalachian "eugeosyn-cline" and includes the quasi-cratonic margins.
The western edge of the mobile belt parallels and lies to the west of the eastern edge of the North American continent during Cambro-Or-dovician time as defined by Rodgers (1968).
The terrain to the north and west of this boundary, the " craton", was not affected by the initial divergent, translational or final divergent
- stages, i
c 17 L
4 There appears to be a profound difference between the northern and southern portions of the' Appalachian orogen as evidenced by three stages of the orogen's developmentt 1.
In the intial rifting stage, the Appalachian rift developed with a bend, offsetting the northern and southern salients; 2.
In the final portion of the convergent stage, which was coincident with the translational stage, the Allegheny orogeny was pronounced only in the South.
Translation was restric-ted to the northern Appalachians; and 3.
In the Jurassic phase of the final divergent l
stage, different stress regimes prevailed in the northern and southern portions.
Therefore, for simplicity, the following discussion leads to definition of the tectonic provinces only in the north-ern Appalachian orogen.
TECTONIC DIFFERENTIATION OF THE CRATON The cratonic portion of the Appalachian orogen is underlain by continental crust composed of approximately one billion year old crystalline rock, which was deformed during the Grenvillian orogenic cycle.
The craton can be divided into two main areas based on gross geologic structure; (1) an eastern l
belt of anticlinoria; and (2) a western, elongated basin.
ed 18
s The eastern portion, termed here the Highlands (Figure 1), constitutes one tectonic province and is character-
~
ized by Grenvillian rocks deformed during the Paleozoic conver-gence stage (dermal or thick-skinned deformation).
The western portion is characterized by the absence of basement involvement in the deformation.
It can be divided into two tectonic pro-vinces, termed here the Stable Interior and the Fold and Thrust Belt.
The Stable Interior tectonic province, is characterized by the absence of intense deformation and the presence of shelf-delta type Paleozoic sediments.
The Fold and Thrust Belt tec-tonic province is characterized by tightly folded and thrust-faulted Paleozoic sediments developed as flysch or molasse.
The western boundary of this tectonic province is the western limit of Paleozoic trusting; the eastern boundary is the western edge of the Highlands tectonic province.
The Stable Interior and Fold and Thrust Belt provinces may be further subdivided by the New England Salient (the base-anticlinoria of the Highland province effectively terminate ment at the southern flank of the Salient, as defined by Cady, 1969).
The extension of the New England Salient into the Stable Inter-ior, termed here the Ottawa Basin tectonic province, is charac-terized by the development of a Cambro-Ordivician basin along an older zone of crustal weakness.
This basin was subsequently broken by a branching system of normal faults.
The southwestern limit of the Ottawa Basin province is the southern flank of the New England Salient; its eastern border is Logan's Line.
C e
19
Similarly, the intersection of tha New England Salient with the Fold and Thrust Province may be distinguished as a separate province, here termed the St. Albans Thrust Belt tec-tonic province.
This province is distinguished from the rest of the Fold and Thrust province by the incursion of the shale basin into the normal carbonate-quartzite miogeosyncline (Shaw, 1958) and by counter-clockwise rotation of the thrusts origina-ting from the Middlebury-Hinesburg-St. Albans synclinorium (Cady, 19 69 ).
The eastern limit of the province generally co-incides with the Sutton Mountain anticlinorium.
The tectonic differentiation of the cratonic portion of the Appalachian orogen, as outlined above, largely follows the tectonic subdivisions proposed by Rodgers (1970) with only a modification of the eastern boundary of the Highlands tecton-ic province and consideration of the New England Salient.
TECTONIC DIFFERENTIATION OF THE MOBILE BELT i
The mobile portion of the Appalachian orogen is under-lain partially by a continental crust of Grenvillian age and partially by a thick, dense, presumably mafic crust (Williams and Stevens, 1974).
In addition, in Newfoundland, New Bruns-wick, the Gulf of Maine, and southeastern Massachusetts, the mobile belt is underlain by the Late Precambrian carbonate and clastic rocks interbedded with, and intruded by volcanic rocks.
I These latter rocks of the Avalon Platform are less than 600 million years ago.
1 i
[
20 l
p
's
~
Thus, the mobile portion of the Appalachian orogen may be divided, on the basis of the underlying crust, into three areas:
1.
The eastern cratonic margin which is underlain by continental crust of predominantly Grenvil-lian age.
2.
The Central New England tectonic province which has no known Precambrian basement (Naylor, 1975) and which is presumed from i
geophysical evidence to be underlain by mafic crust (Williams and Stevens, 1974),
3.
The Avalon Platform tectonic province, in-cluding its western margin, which is under-lain by continental crust younger than Grenvillian.
TECTONIC DIFFERENTIATION OF THE EASTERN CRATONIC MARGIN 4
The eastern cratonic margin is bounded on its western side by the Highlands tectonic province and on its eastern side by the easternmost extent of Grenvillian basement.
This eastern boundary is interpreted principally from a line of gneiss domes of one billion-year old continental crust including the Pine Mountain belt, the Sauratown Mountains anticlinorium, the Balti-more Gneiss domes, and possibly, the Chester dome of Vermont.
This boundary corresponds to the eastern limit of the ancient continental margin of North America (Williams and Stevens,1974; Rankin, 1975).
It also coincides with several structural and 21 r
a
geophyoical changes (Williams and Stevena,1974) as follow:
1.
It parallels the main gravity high of the Appalachians (Mayhew, 1974);
2.
It is marked by contrasting seismic refrac-tion and reflection profiles that indicate deep crustal contrast; and 3.
It is a zone of faulting, contrasting struc-ural ctyle and contrasting metamorphic facies.
Within the eastern cratonic margin, the Grenvillian basement is overlain by three rock assemblages indicative of three distinctive geologic settings:
1.
Clastic sedimentary rocks of Late Precambrian age with associated mafic dikes and extrusions reflecting the rifting phase of the initial divergent stage; 2.
A miogeosynclinal assemblage (representing the advanced phase of initial crustal divergence) unconformably overlain by exomiogeosynclinal clastic rocks (from the start of the convergent stage); and l
3.
A eugeosynclinal assemblage of the convergent stage.
Since assemblage 3 above was deposited primarily over assemblage 1 the cratonic margin is properly divided into two tectonic prcvinces:
The Conestoga Valley province and the Inner Piedmont province (Figure 1).
The boundary between the e
22 e-w--
r--
s
.c--y-
,-r-
-..s
- s Conestoga Valley province and the Inner Piedmont province cor-responds to the Martic Line in Pennsylvania (Wise, 1970) and the southward extension of Cameron's Line in western Connecti-cut (Stanley, 1966).
The Conestoga Valley tectonic province is characterized by a miogeosynclinal assemblage overlapping an older clastic assemblage.
The Inner Piedmont tectonic province is characterized by eugeosynclinal assemblage over an older clastic assemblage.
Additionally, the intersection of the New England Salient with the Inner Piedmont (an area here termed the Quebec-Vermont Piedmont tectonic province) is distinguished from the rest of the Inner Piedmont by the following character-istics; 1.
The lower and middle Paleozoic sedimentary sequence in the Quebec-Vermont Piedmont reaches 80,000 to 100,000 feet in thickness, whereas it is 3u,000 to 50,000 feet thick in the Inner Piedmont (White and Jahns, 1950; Cady, 1969);
i 2.
Early Taconic cross-folds are common in the
(
Quebec-Vermont Piedmont but are uncommon to i
(
the south (Cady, 1969; St.-Julien, 1967; Beland, 1967);
3.
Mafic volcanic rock types predominate in the Quebec-Vermont Piedmont whereas both mafic and felsic activity was common elsewhere (Cady, 1969) ;
6 C
e 23 i
s I
4.
Within the Quebec-Vermont Pieduont, the usual upward and cratonward movement of the.
southeasterly anticlinal tracts was accompanied by counter-clockwise rotation of all longitu-dinal structures about pivots on the south flank of the Salient (Cady, 1969).
The Central New England Tectonic Province and CoEstal Plain Tectonic Province The Central New England tectonic province (Figure 1) is characterized by thick, dense, probably mafic crust (Sheridan and Drake, 1968), as indicated b'y a pronounced gravity gradient i
(King, 1964).
This crust is overlain by eugeosynclinal sedi-c i
ments specific of the convergent stage.
It is further charac-terized by intense deformation and large areas.in which Acadian metamorphism overprints ths Taconic pecrystallization.
The eastern boundary of this province corresponds to the western edge of the Avalon platform an'd is marked by a pronounced i
gravity and magnetic anomaly (Mayhew,1974).
The province is bounded on the. west by the Inner Piedmont and Vermont-Quebec Piedmont tectonic province.
The Coastal Plain tectonic province, which is essen-tially developed on the Central New England tectonic province, is characterized by the development of a miogeosynclinal wedge during the advanced phases of final crustal divergence.
i e
9 24
- Tho Avalon Platform Tcctonic Provinca The Avalon Platform tectonic province is characterized by crystalline continental crust which is younger than the Gren-villian orogeny.
These rocks are intruded by dioritic and gab-broic plutons which range in age from Ordovician to Devonian.
In addition, the province contains rocks characteristic of the translational and final divergent stages.
The eastern boundary of this province is the western flank of the Meguma geosyncline (Ballard and Uchupi, 1975).
Further Possible Subdivisions Since Cady's (1969) synthesis is restricted to north-western New England and adjacent Quebec, and because there has been no comparable detailed tectonic synthesis in New Hampshire or southwestern Maine, it is presently uncertain whether the
'New England Salient should be extended across the Central New England and Avalon Platform tectonic provinces.
As conceived by Cady, the New England Salient stems from a transverse weak-ness or variation in the Grenvillian crust which was enhanced by, and acquired a distinctive geometry through orogenesis.
It is reasonable to theorize that this distinctive geometry intlu-enced the form of the island arc-subduction zone system that ex.'.sted between the proto-Inner Piedmont and the proto-Central New England, and would have affected the deformation of the Central New England province.
Therefore, it would not be sur-prising if future tectonic syntheses indicated a southeastward continuation of the Salient.
25
- s On tho othsr htnd, strcightforward continuation of ths New England Salient (sensu stricto) into the Avalon Platform is unlikely for two reasons.
First, the Avalon Platform was not involved in the previously mentioned island arc-subduction zone system.
Second, the Platform probably did not reach its posi-tion relative to the Salient until Permian time (Ballard and Uchupi, 1975) long after the completion of the Taconic and Acadian events on which the recognition of the Salient is based.
1 It should be noted at this time, that although the i
boundaries of the provinces are drawn as thin black lines, in many cases the boundary is not that clear.
However, it is believed that the concepts used in this division and the general vicinity of the boundary are valid.
As more work is completed in this region of the Appalachian Orogen and ambiguities are eliminated, the tectonic boundary lines can become more defini-O tive.
e e
26
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TECTONIC PROVINCES OF THE
- M NORTHERN APPALACHIANS
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-l REFERENCES
- Bain, G.W., 1957, Triassic Age Rift Structure in Eastern North America, New. York Acadamy of Science Section Meeting,
- p. 489-502.
Ballard, R.P.
and Uchupi, E.,
1975, Triassic Rift Structure in Gulf of Maine:
Am. Assoc. Petroleum Geologists Bull. v.
59, p. 1041-1072.
- Barrel, J., 1915, Central Connecticut in the Geologic.Past, Connecticut State Geol. National History Survey Bulletin 23.
Bayley, R.W.
and Muehlburger, W., 1968, Basement Rock Map of the United States, United States Geological Survey.
- Beland, J., 1967; Contributions from Systematic Studies of Minor Structures in the Southern Quebec Appalachians; in Clark,
~~
T.H.,
(ed.), 1967, p. 48-56.
Belt, E.S.,1968, Post-Acadian Rif ts and Related' Facies in East-ern Canada:
in Zen, et. al. (eds. ), Studies of Appalachian Geology:
NortEern and Maritime, John Wiley & Son, Inc.,
N.Y., p.95-116.
a
- Billings, M.P., 1945; Mechanics of Igneous Intrusion in New Hampshire:
Am. Jour. Sci., v. 243-a, p. 40-68.
- Brown, M.V., Miller, J.A. and Swain, F.M.,
1972, Structural and Stratigraphic Framework, and Spatial Distribution of Per-meability of the Atlantic Coastal Plain, North Carolina to New York:
U.S.G.S. Professional Paper 796.
- Bullard, E.C.,
- Everett, J.E.,
and Smith, A.G.,
1965, The Fit of the Continents Around the Atlantic; in Blackett, P.M.S.,
- Bullard, E.C.,
- Runcorn, S.K.,
(eds. )7~A Symposium on Con-tinental Drift:
Royal Soc. London Philos. Trans., sec. A,
- v. 258, p. 41-51.
- Cady, W.M., 1969; Regional Tectonic Synthesis of Northwestern New England and Adjacent Quebec:
Geol. Soc. Amer. Memoir 120, 181 p.
in
- Carey, S.W., 1958, A Tectonic Approach to continental Drift;
- Carey, S.W., (ed.), Continental Drift; a symposium:
- Hobart, Tasmania Univ., p. 177-355.
Chapman, C. A., 1968, A Comparison of the Marine Coastal Plutons and the Magmatic Central Complexes of New Hampshire; in Zen, et. al.,
(eds.), Studies in Appalachian Geology:
c Northern and Maritime, John Wiley & Son, Inc., N.Y.,
p.
385-396.
27
7 _..
s REFERENCES (Continued)
- Colton, G.W.,
1970, The Appalachian Basin - Its Depositional sequences and Their Geologic Relationships; in Fisher, et.
al. (eds.), Studies in Appalachian Geology: Central and Southern, John Wiley & Son, Inc., N.Y.,
p.
5-48.
Dames & Moore, 1974, Geologic Report, Limerick Generating Station, Limerick, Pennsylvania.
Dames & Moore,1974; Seismo-Tectonic Conditions in the St.
Lawrence River Valley Region; Report to New York State Atomic and Space Development Authority.
Dames & Moore, 1975, Geologic Investigation, Indian Point Generating Station.
- DeBoer, J., 1967, Paleomagnetic-Tectonic Study of Mesozoic Dike Swarms in the Appalachians:
Jour. Geophys. Res., v. 72, no. 8, p. 2237-2250.
- Diment, W.H.,
- Urban, T.C.,
- Revetta, F.A.,
1972, Some Geophysical Anomalies in the Eastern United States: Nature of the Solid Earth, McGraw-Hill, New York, p. 552-582.
l Dnig, R.
and Barton, J.M.,
1968, Ages of Carbonatites and Other Alkaline Rocks in Quebec:
Can. Jour. Earth Sci., v. 5, p.
1401-1407, Drake, C.L. and Woodward, H.P.,
1963, Appalachian curvature Wrench Faulting and Offshore Structures: Trans. New York Acad. Sci., Ser. II, v. 26, p 48-63.
Fairbairn, H.W.,
- Faure, G.,
- Pinson, W.H.,
Hurley, P.M. and l
- Powell, J.L.,
1963; Initial Ratio of Strontium 87 to Strontium 86, Whole-Rock Age, and Discordant Brotite in the Monteregian Province, Quebec: Jour. Geophys. Res.,
- v. 68, p. 6515-6522.
l
- Gold, D.P.,
1967; Alkaline Ultrabasic Rocks in the Montreal i
Area, Quebec, p. 288-302 in Wyllie, P.J.
(ed.), Ultramafic, l
and Related Rocks: John WIIey & Sons, Inc., New York, 464 pp.
- Hadley, J.B., 1970, The Ocoee Series and Its Possible Correla-tives; in Fisher, J., Pettijohn, F., Weaver, K.,
Reed, J.
(eds. ) 5tudies of Appalachian Geology: Central and Southern, John Wiley & Son, Inc., N.Y., p. 247-259.
- King, P.B., 1964, Further Thoughts on Tectonic Framework, South-eastern United States, V.P.I. Department of Geological and Earth Sciences, Mem. 1, p. 5-31.
P 28
~
REFERENCES (Continued)
Kumarapeli, P.S.,
1970, Monteregian Alkalic Magmatism and the St. Lawrence Rift System in Space and Time: Canadian Mineralogist, v. 10, p. 421-431.
Kumarapeli, P.S. and Saull, V.A.,
1966, The St. Lawrence Valley System: A North American Equivalent of the East African Rift Valley System: Can. Jour. Earth Sci. v.
3, p. 639-657.
LePichon, X. and Fox, P.J.,
1971, Marginal Offsets, Fracture Zones and the Early Opening of the North Atlantic:
Jour.
Geophys. Res., v. 76, no. 26, p. 6294-6308.
- Long, L.E.,
1969, Whole-Rock Rb-Sr. Age of the Yonkers Gneiss, Manhattan Prong:
Geol. Soc. America Bull., v. 80, no.
10, p. 2087-2090.
- Lowdon, J.A.,
1961; Age Determinations by the Geological Survey of Canada, Rept. 2: Geol. Sur. Canada, Paper 61-17, 127 pp.
- May, P.R.,
1971, Pattern of Triassic-Jurassic Diabase Dikes around the North Atlantic in the Context of Predrift Position of the Continents:
Geol. Soc. America Bull.
v.
82, p. 1285-1292.
- Mayhew, M.A.,
1974, Geophysics of Atlantic North America:
in Burk, C.A. and Drake, C.L.,
(eds.), The Geology of Con-tInental Margins, p. 409-427.
McLaughline, D.,
1953, Triassic Basin in Pennsylvania and New Jersey:
Geol. Soc. America Bull. v.
64, no. 12, p.
452-453.
- Naylor, R.S.,
1975, Age Provinces in the Northern Appalachians, Annual Review of Earth and Planetary Sciences, v. 3, p.
387-400.
- Odam, A.L.
and Fullager, P.D.,
1973, A Major Discordance Between U-Pb Zircon Ages and Rb-Sr Whole-Rock Ages of Blue Ridge Province (abs. ) :
Geol. Soc. America Program with Abstracts,
- v. 7.
Pittman, W.C.
III, and Talwani, M.,
1972,. Sea-Floor spreading in.the North Atlantic:
Geol. Soc. America Bull., v. 83,
- p. 619-646.
Rabinowitz, P.D., 1974, The Boundary Between Oceanic and Conti-
~
nental Crust in the Western North Atlantic:
in Burk, C.A.,
and Drake, C.L.,
(eds.), The Geology of Continental Margins,
- p. 67-84.
29
v:-
REFERENCES (Continued) 4
- Rankin, D.W.,
1975, The Continental Margin of Eastern North America in the Southern Appalachians, Am. Jour. Science,
- v. 275-A, p. 298-330.
- Rickard, L.V.,
1973; Stratigraphy and Structure of the Subsur-face Cambrian and Ordovician Carbonates of New York: Cor-relation of the Cambro-Ordovician Carbonates Within New York State, Extending into Adjacent States and Canada; N.Y. State Mus, and Sci. Serv., Map and Chart Ser. No. 18, 26 p.
- Rodgers, J.,
1968, The Eastern Edge of the North American Conti-nent during the Cambrian and Early Ordovician:
in Zen, E-an, White, W.S.,
- Hadley, J.B.,
and Thompson, J.B.
(eds.)
Studies of Appalachian Geology: Northern and Maritime, John Wiley & Son. Inc., New York, p. 141-149.
- Rodgers, J.,
1970, The Tectonics of the Appalachians; Witey-In-terscience.
- Rodgers, J.,
1971, The Taconic Orogeny:
Geol. Soc. America Bull., v. 82, p. 1141-1178.
Sanders, J.E., 1963, Late Triassic Tectonic History of North-eastern United States:
Am. Jour. Science, v. 261, p. 501-524.
Sbar, M.L.
and Sykes, L.R.,
1973, Contempcrary Compressive Stress and Seismicity in Eastern North America.
An Example of Intra Plate Tectonics:
Geol. Soc. America Bull., v.
84, p. 1861-1882.
- Shaw, A.B.,
1958; Stratigraphy and Structure of the St. Albans Area, Northwestern Vermont:
Geol. Soc. America Bull., v.
69, p. 519-568.
- Sheridan, R.E.,
1975, Atlantic Continental Margin of North America:
in Burk, C.A., and Drake C.L.,
(eds. ), The
, Geology of~ Continental Margins, p. 391-447.
Sheridan, R.E. and Drake, C.L.,
1968, Seaward Extension of the Canadian Appalachians, Canadian Jour. of Earth Science:
- v. 5, p. 337-373.
St. Julien, P.,
1967; Tectonics of Part of the Appalachian Region of Southeastern Quebec (Southwest of the Chaudiere River):
in Clark, T.H.,
(ed.) of Appalachian Tectonics, Royal Society of Canada, Special Publication, #10 Toronto Press, p. 41-47.
p 30
REFERENCES (Continued)
St. Julien, P. and Hubert, C.,
1975, Evolution of the Taconic Orogen in the Quebec Appalachians: Am. Jour. Science, v.
275-A, p. 337-362.
3
- Stanley, R.S.,
1969, Comments on the Geology of Western Connec-ticut:
in Alexandrov, E.A.,
(ed.), a symposium on the New York City Group of Formations, p. 11-15.
Stone & Webs'.tr, 1975, The White Mountai.n Plutonic-Volcanic series
.f New England.
- White, W.S.,
and Jahns, R.H.,
1950; Structure of Central and East-Central Vermont; Jour. Geology, v. 58, p. 179-220.
Williams, H.
and Stevens, R.K.,1974, The Ancient Continental Margin of Eastern North America: in Burk, C.A. and Drake, C.L.
(eds. ), The Geology of Continental Margins, Springer-Verlag, p. 781-796.
Wilson, A. E., 1970, Geology of the Ottawa-St. Lawrence Lowland, Ontario and Quebec:
Geol. Surv. Canada, Mem. 241, 66 p.
- Wilson, J.T.,
1966, Did the Atlantic Close and then Reopen?,
Nature, v.
211, no. 5050, p. 676-681.
- Wise, D.U., 1970, Multiple Deformation, Geosynclinal Transitions and the Martic Problem in Pennsylvania:
in Fisher, et. al.
(eds. ), Studies of Appalachian Geology:
Central and Southern, John Wiley & Son, Inc.,
N.Y.,
- p. 317-334.
Wise, D.U.
and Werner, M.L.,
1969, Tectonic Transport Domains and the Pennsylvania Elbow of the Appalachians, (abstr.)
Progr. Amer. Geophys. Union Mtgs.
- Woodward, H.P., 1968, A Possible Major Fault Zone' Crossing Cen-tral New Jersey:
Bull. New Jersey Acad. Sci., v. 13, no.
l 1, p. 40-46.
l 31
25 COPY NO.
3
~.
l ENCLOSURE 2 t
~
e rwu set.3 3
1(
\\W W,
/ 2.)
l M \\T \\
~/. / Z r' W
Dames a mooses l
ENGINEER'S GUIDE TO THE t
SOIL LA.BORATORY DECEEBER 1978 i
l D
Prepare 1
/
6 l
Herbert H. Chan Laboratory Services Manager j
Approved:
@d
)
Charles W.INewlin Professional Coordinator Soils & Foundation Engineering
/-
i l
N.
TABLE OF C0h'IENTS PAGE PREFACE............................................................
ix SECTION I - MOISTURE-DENSITY RELATIONSHIPS CHAPTER 1 Chunk Density De t ermination (CD)..................... 1-1 CHAPTER 2 Compaction Test (Comp)............................... 2-1 CHAPTER 3 Moisture Determination (M)........................... 3-1 CHAPTER 4 Moisture Content Determination of Organic Materials (M0)....:.................................. 4-1 CHAPTER 5 Mois ture-Density De termination (MD).................. 5-1 CHAPTER 6 Moisture-Density Determination of Organic Materials (MD0)...................................... 6-1 CHAPTER 7 Quick Determination of Moisture-Density (QD).................................................7-1 CHAPTER 8 Re la tiv e De ns i ty (RD )................................ 8-1 SECTION II - INDEX TESTS CHAPTER 9 Atterberg' Limits (AL)................................ 9-1 CHAPTER 10 Specific Gravity (Gs)...............................
10-1 CHAPIER 11 F r ee Swe ll ( F S )..................................... 11-1 CHAPTER 12 Amount of Material Finer Than the #200 Sieve (-200).12-1 CHAPTER 13 Grain-Size Distribution - Sieve Analysis (S A).......13-1 CHAPIER 14 Hydrome te r Analysis (HA)............................ 14-1 l
CHAPIER 15 Combined Mechanical Analysis of Soil (MA)........... 15-1 1
l CHAPTER 16 Shrinkage Factor.of Soil (SF)....................... 16-1
\\an.
i i
$U e
S i
9 PAGE
/
SECTION III - VOLUMETRIC TESTS CHAPTER 17 One-Dimensional Consolidation Properties of Soil (C)......................................... 17-1 1
CHAPTER 18 Percent Collapse for Cohesionless Soils (COL)....... 18-1 CHAPTER 19 Expansion Pressure (EP).............................
19-1 CHAPTER 20 Percent Expansion for Cohesive Soils (EXP)..........
20-1 CHAPIER 21 Swell Load (SL)..................................... 21-1 CHAPIER 22 Shrink-Swell (SS)................................... 22-1 SECTION IV - PERMEABILITY DETERMINATION CHAPTER 23 Permeability Test By Back Pressure-Constant Head (Pbp).......................................... 23-1 CHAPTER 24 Permeab'ility Test by Consolidation,(P ).............
24-1 i
CHAPTER 25 Permeability Test by Constant Head (Peh)............ 25-1 CHAPTER 26 Permeability Test by Falling Head (Pfh)............. 26-1 SECTION V - SHEAR AND COMPRESIVE STRENGTH TESTS CHAPTER 27 Direct Shear / Unconsolidated-Undrained (DS/UU)....... 27-1 CHAPTER 28 Direct Shear / Consolidated-Undrained (DS/CU)......... 28-1 CHAPTER 29 Direct Shear / Consolidated-Drained (DS/CD)........... 29-1 CHAPTER 30 Friction /Unconsolida ted-Undrained (F/UU)............ 30-1 CHAPTER 31 Friction / Consolidated-Undrained (F/CU).............. 31-1 CHAPTER 32 Friction / Consolidated-Drained (F/CD)................ 32-1 CHAPTER 33 Triaxial /Unconsolida ted-Undrained (TX/UU)........... 33-1 CHAPTER 34 Triaxial /Isotropically Consolidated-Undrained (TX/ICU)............................................ 34-1 x) ii
PAGE
, 3, CHAPTER 35 Triaxial /Isotropically Consolidated-Undrained with Pore-Pressure Measurement (TX/ICU/PP)...............: 33-1 CEAPTER 36 Triaxial /Isotropically Consolidated-Drained (TX/ ICD).36-1 CEAPTER 37 Laboratory Vane Test (LV).......................... 37-1 CHAPTER 38 To rva ne She ar ( TV ).................................. 3 8-1 CHAPTER 39 Pocket Penetrometer Test............................ 39-1 CHAPTER 40 Unconfined Compressive Strength of Cohesive Soil
( U C )................................................ 4 0-1 i
SECTION VI - DYNAMIC PROPERTY EVALUATION INTRODUCTION TO DYNAMIC TESTING OF S01LS...........................VI-1 CHAPTER 41 Resonant Column Test (RC)........................... 41-1 CHAPTER 42 Strain-Controlled Cyclic Triaxial Test (TX/ICU/CY or TX/ACU/CY)............................
42-1
\\-
GRAPTER 43 Stress-Controlled Cyclic Triaxial Test (TX/ICU/ LIQ or TX/ACU/ LIQ).......................... 43-1 f
APPENDICES APPENDIX A-1 Standard Test Symbols...............................A-1 APPENDIX A-2 Definition of Terms and Symbols..... <............... A-4 APPENDIX B Soil Classification Chart and Key to Test Data................................................B-1 APPENDIX C Data Acquisition by Computer Permeability Test with Back Pressure EP73..........C-1 Consolidated Drained Triaxial Test EP74............C-7 Unconsolidated Undrained Triaxial Test EP75........C-19 Consolidated Undrained Triaxial Test with Fore Pressure Measurement EP 7 6..................... C-2 6 k Computation EP77................................C-41 i r.,
' _a iii
PAGE
)
APPENDIX C (Cont.)
Stress Controlled Cyclic, Triaxial Test EP78.......C-49 Resonant Column Test EP79.........................C-58 Dynamic Properties EP80...........................C-68 Hardin Resonant Column EP81.......................C-78 APPENDII D Table of Contents - Soils Laboratory Manual of Technical Practices................................D-1 e
O O
iv
. ~.
LIST OF FIGURES FIGURE PAGE 1
Dames & Moore Soil Laboratories Testing Capabilities.....xiii 2
Jo b Te s ting Prog ram ( S ample ).............................xiv, xv l-1 Chunk De ns ity De t e rmina tion.............................. 1-2 2-1 Compaction. Test Data..................................... 2-4 2-2
, Compaction Test Data Plotted on Zero-Air Voids Curve..... 2-5 2-3 Typical Moisture De nsity Curve s.......................... 2-7 3-1 Hoisture Content Dete rmination Data Sheet................ 3-3 4-1 Moisture Content Determination of Organic Materials...... 4-3 5-1 Mois tur e-Dens ity Da ta Sheet.............................. 5-4 5-2 Mo is tur e-De ns i ty Gr a ph................................... 5-5 6-1 Moisture and Dens ity De terainations...................... 6-3 6-2 Moisture-Density Plotted on Zero-Air Voids............... 6-4 7-1 Quick Moisture and Density Determinations................ 7-6 8-1 Rela tive De ns ity Test Da ta She et......................... 8-2 8-2 Graphical De te rnination of Relative Density.............. 8-3 9-1 Atterberg Limits Test Data............................... 9-3 10-1 Work Sheet - Specific Gravity Tests..................... 10-3 s_j 11-1 Fr e e-Swell Te s t Da ta.................................... 11-2 12-1 Amount of Material Finer than the #200 Sieve (-#200)....12-3 13-1 Mechanical Analysis - Sieve Tes t Data................... 13-4 13-2 Grain-Siz e Di s tr ibu tio n................................. 13-5 14-1 Combined Mechanical Analysis............................ 14-3 14-2 Grai n-S iz e Di s tribu tio n................................. 14-4 14-3 Hydrometer Analysis Data Reduction by Graph............. 14-5 15-1 Gr ai n-S iz e Di s tribu tion................................. 15-2 16-1 Sh rinka g e Lim 1 t s........................................ 16-2 17-1 Consolida tion Te s t Data She e t........................... 17-7 17-2 Consolidation Test Data Sheet (cont. )................... 17-8 17-3 Consolidation Tes t Da ta Plo t............................ 17-9 17-4 Time-Deformation Curves (5-cycle semilog paper).........17-10 17-5 Time-Deformation Curves (square root of time paper).....17-ll 17-6 Void-ra tio Compu tat ion.................................. 17-12 17-7 Swell Index versus Liquid Limit......................... 17-13 17-8 Consolidation Characteristics of Fine Grained Soils.....17-14 18-1 Collapse Test Data Sheet................................ 18-3 18-2 Criterion for Evaluating Looseness and Probability of S ub s id e nc e.............................................. 18 -4 19-1 Expansion Pres sure Test 'Da ta Sheet...................... 19-4 E/
V
FIGURE PAGE s
20-1 Pe rcent Expans ion Test Data Sheet....................... 20-4 i
21-1 Swell Load Test Data Sheet.............................. 21-3 1
l 22-1 Shrink-Swell Te s t Da ta She e t............................ 22-4
~
23-1 Permeability Test Data Sheet............................ 23-3 23-2 Saturation and Consolidation Test Da ta She e t............ 2 3-4,5 23-3 Permeability Test by Back Pressure Constant Head (Pbp).. 23-6
{
23-4 Coef ricient of Pe rmeability - Void Ratio Flot........... 23-7 l
24-1 Summa ry of comput a tions................................. 2 4-3 24-2 Plot of k versus e...................................... 24-4 25-1 Cons tant Head Pe rmeability Test Da ta Sheet.............. 25-3 26-1 Fallink Head Pe rmeability Test Da ta Sheet............... 26-3 l
27-1 Direct Shear /UU Test Data Sheet......................... 27-3 28-1 Direct Shear Te s t Da ta Sheet............................ 2 8-3 28-2 Consolida tion Da ta She e t................................ 2 8-4 28-3 Dire ct Shear /CU Test Data Sheet w/ Plot.................. 28-5 1
29-1 Dire ct She a r Te s t Da t a She e t............................ 2 9-4 I
29 -2 Conso lid a tion Da t a Shee t................................ 29-5 29 -3 Direct Shear Test Data Sheet w/ plot..................... 29-6 29-4 Di re c t Shear Tes t Data Summary.......................... 29-7 29-5 Strength Parame ter for Granular Materials............... 29-8
_,) l r
30-1 Fri c t io n Te s t Da t a S he e t................................ 3 0-3 30-2 UU Friction Test Data Sheet w/ plot...................... 30-4 31-1 Friction Test Data Sheet................................ 31-3 32-1 Friction Test Data Sheet................................ 32-3 32-2 CD Friction Test w/ Plot................................ 32-4 32-3 Friction Test Data Summary............................ 32-5 33-la Triaxial Compre s sion Test Data Sheet.................... 33-6 33-lb Recorder Data Plot......................................
33-7 33-2a Compressive Strength Test Data Sheet.................... 33-8 33-2b Compressive Strength Test Data Sheet.................... 33-9 33-2c Compressive Strength Test Data Summary & Plot........... 33-10 33-3 St rengt h Envelope s (Mohr 's Circle )...................... 33-11 34-la S a tu r a t i on Da t a......................................... 3 4-8 34-lb Co n s o lid a tio n Da ta...................................... 3 4-9 34-2a Triaxial Compression Test Data Sheet.................... 34-10 34-2b Recorder Data Plot...................................... 34-11 34-3a Compres sive Strength Test Da ta Sheet.................... 3 4-12 34-3b Compressive Strength Test Data Sheet.................... 34-13 34-3c Compressive Strrength Test Data Summa ry & Plot.......... 34-14 34-4 S trength Envelopes (Mohr 's Circle )...................... 34-15 e
vi
i FIGURE PAGE 35-1 Triaxial compression Test Data Sheet.................... 35-6 35-2 Recorder Data Plot...................................... 35-7 35-3 Saturation Data......................................... 35-8 35-4 Consolidation Data...................................... 35-9 35-5 Triaxial Compression Test Data Sheet.................... 35-10 35-6 Triaxial Compres si on Te s t Repo rt........'................ 35-11 l
35-7 Pictorial Representation of Sample Failure.............. 35-12 36-1 Triaxial Te st Da ta Sheet with plots..................... 36-6 36-2 Sa turat ion Da ta she e t................................... 3 6-7 36-3 Consolidation Data...................................... 36-8 36-4 Consolidation Plots..................................... 36-9 36 -5 TX/CD Data Computation Sheet............................ 36-10 36-6 Triaxial Compression Test Report........................ 3 6-11 36-7 Pictorial Repres entation of Sample Failure.............. 36-12 37-1 Laboratory Vane Shear Test Data Sheet................... 37-2 l
37-2 Moisture-Density Results Plotted on Zero-Air Voids Curve................................................... 37-3 38-1 To rvane Shear Te st Data Shee t........................... 3 8-2 39-1 Pocke t Penet rome te r Te s t Data........................... 39-2 40-1 Triaxial Compression Test Data Sheet.................... 40-3 40-2 Triaxial Compression Test Data Plot w/ Pictorial Representatio'.......................................... 40-4 n
VI-l Hysteretic Stress-Strain Relationships at Different Strain Amplitudes........................................VI-5 VI-2 Field and Laboratory Tests Showing Approximate Strain Ranges of Test Procedures................................VI-5 41-la Reques t for Resonant Column Tests....................... 41-4 41-lb Request for Dynamic Tests:
Pa g e 2...................... 41-5 41-2 Resonant Column Tests Computer Printout................. 41-6 42-la Request for Strain-Controlled Cyclic Triaxial Tests..... 42-3 42-lb Request for Dynamic Tests:
Pa ge 2...................... 4 2-4 42-2 Dynamic Soil Property Test Computer Printout............ 42-5 43-la Request for Stress-Controlled Cyclic Triaxial Tests..... 43-4 43-lb Request for Dynamic Tests:
Page 2...................... 43-5 43-2 Stress-Controlled Cyclic Triaxial Test Computer Printout.43-6 43-3 Stress-Controlled Cyclic Triaxial Test Computer Plot.... 43-7 g
v11
m LIST OF TABLES N
../
TABLE PAGE 2-1 Methods of Perf o rming Compaction Tests.................... 2-2 2-2 Typical Maximum Dry Densities obtained by Modified Co mp a c t i o n................................................ 2-9 5-1 Density calculation Factors for D&M Standard Size S a m p l e s................................................... 5 -3 5-2 Volume & Weight Relationships............................. 5-6 7-la Quick Density Determination - Specific Gravity =
2.65..... 7-3 7-lb Quick Density Determination - Specific Gravity - 2.70..... 7-4 7-lc Quick Density Determination - Specific Gravity =
2.75..... 7-5 10-1 Typical Specific Gravity Va1ues..........................
10-4 12-1 Criteria of Test Sample Size.............................
12-2 13-1 ASTM Approved Criteria of Test Sample Size............... 13-2 25-1 Coef ficient o f Pe rmeability.............................. 25-4 viii
I CPAPTER 34 TRIAIIAL/ISOTROPICAll.! CONSOLIDATED-UNDFAINED (TI/ICU)
Sco?E This test deternines the undrained shear strength parameters of soils.
The test sanple is first consolidated toder an isotropic confining pr essur e.
(Anisotropic consolidation vill be discussed later in this chapter.)
~
SAMPLE Because of the difficulty in the laboratory to si=uiate field like tha TX/UU test, (Caapter 33), this test is nere conditions, ef fectively performed on cohesive soils than on granular soils.'
1.A30R TIME is as follows:
- 1. abor time required to perforn this tes:
1.
Standard tes: - one and one-half hours 2.
Extras sa=ple saturation by back pressure - one boc
- computing and plotting stress-strain curve - one hour e
Special data - consuir vi:b the lab
'3.
c.
EQUI?". INT TIME Four bours for each ~ day the :riaxial equipment.is used for the test.
TURN-AROUh*D TIME two addirional work days Three work days for a standard test; for back pressure satu ation of the sa=ple.
IIST PROCEDURI once the triaxial equipmen is checked and prepared and all tools are ready, the sanple is prepared.
The sample, encased in a Ibe sanple is is placed into the triaxial chamber.
rubber membrane, allowed to consolidate fully under an isotropic confining pressure before 1: is sheared at a strain rate of about 2 per =inute.
The sample volume change after consolidation is calculated by the amounttime of c.. amber fluid displaced.
If requested, S
34-1
'~
e consolidation; other. rise, s.
can be obtained and plotted to assure 100::
standard duration of consolidation is approximately 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> with the sufficient readings taken to indicate that essentially all primary After th'e sample is ' sheared, it is consolidation has taken place.
removed from the triaxial chanber and the after-test vet weight is The sa=ple is then for. noistures and density conputation.
obtained inspected and classified.
Failure condition of the sanple will Unless otherwise specified, the either be sketched or photographed.
entire sample will be used for water-content deter =ination.
vill saturation is required, a filter paper jacket If sa=ple be placed around the sample before applying the ne=brane.
The filter paper jacket s-ill increase the rate of water flow and thus time required to saturate the sample.
Saturation is help reduce the It is done before the consolidation phase of the test.
carried out by first-running water through the soil and the equi;xnent assembly (entering from the bottom and out from the top) to flush out Water is then forced into the soil from entrapped air in the system.-
both top and bottom by a back pressure to fill the voids and dissolve any entrapped air bubbles in the soil.
During the flushing and-saturating process, the chamber pressure is always nainta than the back pressure.
10 psi in an interval of about an hour.
When the maximu:n is left on until Skempton's 3 toavailable back pressure is reached, it paranater of 0.95 or higher is attained:
3 42--
- 3 For stiff soils,' high 3 para =eter is of ten difficult to atain due to high consolidation ratio.
Therefore, a plot of 3 vs back in determining whether the sample has reached pressure is helpful In which case, rather than 3 = 0.95 or higher, as the saturation or not.
soon as 3 is leveling or dropping with increasing back pressure,See Black &
sample has probably attained saturation.
full discussion..
the 3 parameters are checked and the sample
.During saturation, volume change is observed.
If the sanple tends to expand, the difference between chamber pressure and back pressure (the effective consolidation pressure) vill be increased in order to prevent the sample from expanding.
To go from saturation to consolidation, all the drainage valves are closed, the cha=ber pressure is increased to the level at full effective consolidation pressure is realized, and the At no time should which the drainage valves are opened to beg.tu consolidation.
l i the back pressure be reduced, otheritise air s-ill cone out of so ut on and cause the sample r.o desaturate.
O 34-2
s j
1 t
..c-- p DATA.PRESENIATIONe...
.. o, ;:. -
The following data vill be reduced and provided by the laboratory for a standard test:
1.
Sa=ple identification 2.
Soil classification with description of failure 3.
Initial and final moisture and dry de-nsity 4.
laitial and final void ratio and degree of saturation 5.
Consolidation daa 6.
Voltme change calculation, which includes:
6 *d due to consolidation A V due to consolidation (sanple area af ter consolidation)
Ag V
e A
- i~
c c
e (sa=ple volume after consolidation)
V c (sanple height after consolidation)
E (vben recorde:r is used) or load and 7.
Load-deformation curve deformation data with manually-plotted Icad-deformation curve (when recorder is not used) str-n and corrected deviator stress at d
8.
Percent of axial peak:
b.Sc c: -
' x 100 Ec
^
, or Og " % load X load factor in psf Z P
g Af where:
c% = % of axial strain AEf = defor:ation at failure t
%~
34-3 m
P t.
3 4.....
~;.
c s
. ~.
J
= sa=ple height af ter consolidation H
e
= deviator s:ress ed
= 4.6 sq in or 0.0319 sq f t, initial D&M sanple area.
A Ac area of sample at failure = 1-c A
=
f
= axial load applied af ter correction for buoyancy corresponding AEf P
and friction effects, in pounds at A, = area of. sa=ple c.frer consolidation II/UU (Chapter 33) includes details of percent load, load fae:or, and other infor=ation.
j The s:ress and strain may also be conpuited and plotted by i
labora:ories.
e conputer in sene surch as c and sa=ple All basic da:a required in the test 3
9.
.m dinensions
'O data are presentedi in a form similar standard es:
(Recorderr data); or 34-3A, above The 34-11, 34-13, 34-2A, and 34 to Figures 34-33, and 34-3C (nanual data).
is requested, the inbora:ory vill also
- saturation (Figure If sa=ple saturation furnish the data on attaining back pressure 3/4-1A).
all load and defornation' data shown in Colu=ns A and F, will be reduced and the cu special request, Upon Figure 34-33, in Figuare 34-3C.
plotted with percentinstead of load versus defornation as shown Also, upon request, a plo: of an envelespe of~ Nohr circles (Figure 34-4) vill be provided.
ENGINEER'S INFUT_
Confining pressure (o3) is noted.
saturation is required,. please keep in nind nus no: exceed the line Vben back pressure and back pressures that the sun of c3 The limitation of line presscre differs fron one pressure available.
laboratory to another.
5 e
V
.s r.
,... e.,. 3 4.
3.
, g..a,. :..,.. _,
M'# '"
Any special data or any deviation from the standard test',musti v
- w. a.
?
be specified at the time the test program is subnitted.
(Data such as sample saturation and ultimate strength cannot be obtained af ter a certain stage of the test is cocpleted.)
The' specific gravity used for all computations vill be 2.70, unless others-ise specified or determined.
DISCUSSION In addition to the discussion below, also refer to TI/UU (Chapter 33).
Nearly all triaxial loading equipment in D&M laboratories is built s-ith dual controls:
strain-control, and stress-control.
An ordinary test should be performed by strain-control, because this method vill provide a definite peak value', whereas, i:n a stress-control test, peak value cannot be obtained accurately.
The main r'eason for having the stress-control tas: available is to enable the laboratory to perform triaxial tests under anisotropically consolidated conditions., The procedure for TI/ACU is identical to the TI/ICU, with the exception that the consolidation stresses are not equal. An estimate of K, is nade, and the major and ninor principal stresses are ev aluated and applied to the sa=ple.
The usual procedure is to consolidate the sample by increasing the g,
stresses acting on the sa=ple in stages, while always mai=1taining the This procedure vill provide the best method to value of.It constant.
evaluate tSe in situ undrained shear strength of undir=urbed soils when the in situ stresses are reapplied during consolidation.
Other occasions where anisotropic consolidation procedures are warranted occur. during the consolidation of embanienen=s when the i
ground surface is not lev el..
Lee concludes that, in the case of granular drained strengths, essentially the same results.are obtained fron isotropically and anisotropically censolidated samples.
- dovev er,
for undrained conditions, - the test results are highly dependent on the magnitude of'the confining pressures.
the ACD streEgths are of the same At low confining pressures, form as the ICU strengths...At high confining pressures, general the peak undrained strengths of anisotropically consolidated
- however, triaxial samples of saturated sand are considerably higher than ICU j
strengths.
For co=pacted clays involving maximu:n strength-related ICU tas:s are easier problems, either ACU or ICU tests can be run.
P.ovever, f or load-deformation-related problems., dif ferences
. to run.
in stress-strain relationships and pore pressure changes occ~ur which i
should not be ov erlooked..
An excellent sun =ary on this subject is given in a research report by C.C. Ladd and J. Varallyay (1965).
- (\\
t 34-5 I
?.-.,.2.
.n; a.,.
. /..
Since the anisotropically consolidated trimv'=1 test has not been a popular test in the D&M laboratories, a separate chapter for this test vill not be prepared at this time.
For information reg'arding the perfornance of this test, the laboratory may be consulted.
POSSI31.E ERRORS those, listed in TI/UU (Chapter 33), the In additior. to f ollowing errors are conr.on:
test equipment will affect the 1.
Improper de-airing of the sample saturation and consolidation.
2.
Improper de-airing of the chamber flu:id, noncurrent calibration data of chamber expansio %
and piston displacement vill result in inaccurate measurement of volume change.
Inaccurate volune-change seasurement vill. affect all and 3.
results-the s aller the test sample, the m: ore significant the error.
4.. If inproperly removed from the triaxial chamber after testing, the sample vill pick up extra water--hence an inaccurate final vater content.
REFERENCES In. addition to those given in Chapters '53 and 35, the following references are added:
Casagrande, A., and others, 1951, The Effect of Rate of Loading on Strength of Clays and Shales at Constant Water Co ntent.
Geotechnique, Vol. II, No. 3, pp. 251-263.
- Duncan, J.M.,
and other s, 1966, Strength Variation Along Failure Surfaces in Clays.
Journal of the Soil Mechanics and Youndations Division, Anerican Society of Civil. Engineers,
+
Vol. 92, No. SM6.
- Eansen, J.B.,
and others, 1949, Undrained Shear Strengths of Anisotropically Consolidated Clays.
Geotect=21gue, Vol.
I, pp. 189-204 Hvorslev, M.J.,1960 The " Physical Components of The Shear Strengths Proceedings of The American Society of of Saturated Clays.
Civil E.ngineers Research Conference on the Shear Strengths of Cohesive Soils, Boulder, Colorado.
34-6 j
... ~
~: :. : ~..;4.c.. g,: r.'.;?a:.y.:it. :.,
..: *: > :.r.
,.s, mt
- Ladd, C.C., 1965, na Influence of Stress Syste=s on The Behavner of Saturated Clays During Undrained Shear.
Research Report 165-11, Soils Publication no. 177, M.I.T.
- Lambe, T.V., 1951, Soil Testing for Engineers. John Wiley and Sons,
Inc., New York.
- Lee, K.L., 1970, 'Undrained Strength of Anisotropically Consolidated Sand.
Journal of the Soil Mechanics and Foundaxions Division, American Society of Civil Engineers, Vol. 96, yo.
SM2, Proceedings Paper 7136, pp. 411-428.
- Skempton, A.W.,
- 1954, De Pere pressure Coefficient A and 3.
Geotechnique, Vol. 4, pp. 143-147.
Ske=pton, A.W., and others,- The Behavior of Saturated Clays Ihcring Sa=pling and Testing.
Geotechnique, Vol. 13 No. 4 pp.
269-290.
e e
34-7
TICURE 34-1.A DAM ES 8. MOORHE SATURATION DATA
=,.
....y...
...... :.... t. :
.,n.
~! !
C
/~~
NO.:
LOCATION:
)ROJECT:
!I 7[
(ft.l.:r )
Set up: _M
/
f Sample:
Depth:
. Boring N2.:_
Tyh of Test:D ' A ce!!No.:
b~1 Dial No.: -
//
/O.
sai
/f00
- prf.
g3 -
YuSr"YTs' rear-es a ssa sacx
^
'"'5"'
'" '5 " '
oi d"oc.
'"?!!!"'
c^ "
CLOSED OPEN CMIN.)
- (
[f14 1030 10 6
ft t/fz.9
/
\\
Ilbo 11 01 Zo
/6
/6. 1 /14. 6
/
19.3/19.T
/
liff 11SG So 2 f.
/Sof
/Bo9 40 M
23 o[2s./ mf 9/27. 2 S.9
.39 1411 1423
[O 46 2L 7/2r.9 l 36.cl4/.4l C. 9
. [4 tr1r IT14 So l
SG 18.I/z 8. z-l % clC z. C 6. T l 45 15 B!~
1656 70 64
- 29. T/29.Tl [& !/63. 5 74-74 17.1 1729 80 76 l30.M30.7 66 //7 9. 3 8 2.
. g 2.
SllJ 095%
ofB9 90 l6
%I.r/St. Cl 76. ;It C. C
- 9. 4 94 i
/- llb :.l95. 8 9.C 94 10 0 C t os e D IB os
/
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P,ROJECT:
g 3
ig (y
K n/74
/-
Bor ng N3.t Sam;ie:
Depth:
m./7.) Consit. by:
{5. s -(G*o o f5.5 = l0. 0 j
~
~
N
-F-CONSOLID AT!ON D ATA'
(-
EXTERNAL ELAPSED CHAMBER SACK BACK BU RETTE INTERN AL PORE DATE TIME TIM E PRESSUR E PRESS 1 PR ESS 2 OR BURET 7E PR ESSURE (MIN)
IPSI)
(PS.Il IPSil DI AL RDG.
(C.*)
(psg)
ICC)/IIN.1
~3 / r7 I Isor I o
I 16.4 I
86 I
I
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ws 1
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SAMPLE HEIGHT AREA AND VOLUME CORRECTIONS AFTER CONSOLIDATION
' INITI AL MPLE HEIGHT (H I Ih O
0I th INITIAL DIAL
- E OO FINAL DIAL, MO CH AN G E I N H EI GHT (A H)........................
ID FINAL HEIGHT AFTER CONSOLIDATION (H I c
O tr i N m A L SAM P L E A R EA ( A,)................................................'..........
~
b*
- E C I N Iil A L S AMP L E V O L U M E (V,).........................................................
7-O C O
FIN AL BURR.i i c/DI AL 3 CH AN G E I N VO L (b V)..........
INITIAL BUR:a e s/ DIAL C
A N AL V O LU ME AFT E R CO N SO LI D AT I O N (V )............................................
g
/l W C WATER ADDED:
6 Burette Y / H, A
e c
. o.3 c
. 4.I 7 8 50.iN.
e n e,n.i 3u,e11e Fissen ois,i.
/7 i :
A Volume fro m e: to c:
h psi
/50 i
Call Exp. @
Dial Conversion Factor:
1.i Net t. Volume in. =
c TIGUF.E 34-13 34-9
TRIAX1AL COMPRE551CH TEST DATA SHEET Joo s 0185-131, i
cwnta CC SF LocAriew SF, CALIF.
ser-m.5 n: s.,
15 ft soCTypt
. BROWN S;SDICI.AY og,vs sAwatt 3
sawatto ' MS 52f 76 s tT.u, WL 5.16 7.6 itsTro WL 5,18 76 i 03 orrict3 f
f sATu=AvtoitsT 0 ritto uoisTuat Test O rtsv 'ATraat==tssuar 1500
- sr fA TX CU 3
Type or itsT 2 42 911 l1004. 0 Net diemeter D,
in.
Weight soil & dish no.
! 821 1 freo (0.7E5 D,2)
A, 4. 6 0sg,in.
Dry weight soil & dish Net loss of moisture 118.3 182.9 g,;ght H,
6. 0 0,,,
107.8 Volume (A,H,)
- 1723 V[
ev.h.
weight of dish only Het weight of dry soil.
713.3 713.3 Volume (A H,) = 16.4 V,
' re Moisture. T. el dry -eight 16.6' 25.6 specir;c gre ;ty.1 sol;g, c,2.70 assumed
- '*** *I
- IId* # ~O Y
5 s
s 831.6 896.2 (V,
V, ) - V, 4;
Wt. solids. moisture W_.._ _ g m s.
W, - 454 W,'
lb s.
Initiet burette reeding ec Surette reeding under pressure ec W
gms.
Weight sol'ds 115.2l
,,g gy, y,), y,
wet density Wl-V '
p 98 8' pei Dry density NOTES:
Void Ratio & Final Drv Densitv:
t Initial Final I
452.28 449.38 vt
=
264.19 264.19 v s'
=
188.09 185.19 I
l vv
=
.712
.701 e
=
63%
99%
s
=
98.8 x 452.28/449.38 Ydf
=
99.4 ocf
=
Maximtm Deviator Stress:
10.85%
c
=
cd =
2678 esf FIGURE 34-2A 1339 psf T
=
34-10
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N 34-n i
COMPRESSIVE STRENGTH TEST Type e,f Tcst
~".' s O TX/uu- -
.W c.,,......
. : i., *
' N' /
O TX/CU (field moisturel 2 TX/CU (saturated)
O uc (unconfined compression)
C/Ba'- /3 /
SF CA 33i Location:
Pr: ject:
8 Boring !
Soil Cassification:
~S BR oco N SANhv CL A V Samene r
/f Depts (ft.:
I /S '75 Computed By:
/ / [dChecked By: NO b Z I 7 5 ffice:
0I b
/ /
0 b
/ /
Tested By:
initial Final SAMPLE TYPE:
Wet Weight of Soil + Tare (gm) l
/00 4 0 D Undisturbed I
g 2,/. /
O Remolded to -
Dry Weight of, Soil + Tate (gm)
' Net Loss of Moisture (gm)
/ / 8.3
/ [2.9
% De
/07.8
% Compaction Tare Weight (gml Ory Weigns of Soil (gm) 7 /3.3 7td.3 PR ESSUR E~C Moisture (w ),% of Dry Weight
/6,6 7.f. 6 r
e Wet Weight of Sample (gm)
$ 51. [a 3 96,1
"'[#
bp
- ps:/ psf Dry Weight of Sample (gm) 7/3,3 l
7f3,3
,3 j' BOO psil.a J.
=
Wzt Dens:ty'of Sample - ym* (PCII
//I 1 l
e Dry Density of Sample - yd' (PCII SO*h hh Y ~
7df " Ydo x (Vg/Vtt )
- Sam'ple Height
( Je/ C ff ) - H h,00 l*
RATE OF SHEARING:
a.v Sample Diameter ( f#C pf ) - 0 2,4.2 l
@. / O
' in/ min o
Sample Area
( $Q (N )- A d, [:;c l~
in/hr,
~
482.28 l 4 4 { J[
Lead Controlled Sampfe Volume (cc) - Vt M 4,/q l 2 6 M, / $
9ECWC MAVR Volume of Solid (cc) - V3 Voiume of Void (cc) - V,
/8{,C$ l
/ 8 f, f h Assumed 2'70 7/1 l
70/
Void Ratio - e f 3 */,
77 '/
Degree of Saturation - :
SUMMARY
OF TEST RESULTS 5%
1 20 %
l tS%
1 20 %
1 PEM Axial Strain (%) -E Nl
/O,85~
26'78 Devister Stress (psf) es
's l
/33h Shear Stress (psf)
T lN
[ ki #
R EMAR KS:
C
- l ke
- ' Q. 5 7 8 3&. M.
.r N
FIGUR.E 3'5-3A EQUIPMENT:
7 Lead Frame f Cell i Saturation Consol ( _
~
ar
/11 276_ m u
mewamanmmanrum
]
Tvoe ef Ten O TX/uu O TX/Cu (tilld moisture)
N.TX/CU. (saturated)
O UC (une:.nfined compression).
~
p......:. s.
/,.N.
5F G
o / s T - /3 i aos,
Location:
Preje;.:
I Sample !
Depth (ft.)
/f Office 68
" Coring (
/ [5 7b ompmed By:
03l-8 / /f //8 Checked By:
OO 8 / 2/ f7g S
/
C Tes:ed Sy:
Load Range:
[o; O 00 psf Lead Factor =
7pp psi /*A f
AREA CHANGE AX1AL LOAD AXIAL DEFLECTION DEVIATOR STRESS 1
D ai as A,
E%
in, 2 Alat
% Rante i
ce..ene:
in g uncor; eye Reading i
psi i
erf e
f.00 0.00 O
4.578
/. M[
O o
Q
!. of 0.05
.83 4.6 in 99G 10.0 (doo IB9C,
l 0.1ol1.GJ(4.656 928 l18.0 (800
/778
{
1 10 i
/ Zo~
O.2o l 3.Sf 4.734 97/
13.0 15m u.39
=
i
- l. Bo C 30 5.0s ! 4.819
.95+
, 26.I 2G to 24 91 I
t.
/.40 0.40 6.68 l ?.906 968 l 27 7 Go 26o7
/. fo O. fo 3.Bf 4.99f 1.92. /
18'.9 18'Jo z662.
- f. So
- 0. Go 10.02.
5.098 9C4
- 29. b 2960 2676
~~
- 1. GC
- o. & T l0. 9[
C.l35
. 196 2 ').4 2890
.1679
- 0. 7 0 l / /. 6 9 ll f./24 EP7 Bo.1 Solo zG 7I 1
l 1 70
/. 7f o. 7 I
, I z. f :.
- f. z 53
.S79 30,2 so2o grr i
/.8o
- 0. 8o
, /3. 36 f.2.g d
. C7 /
l
- 30. 3 goso 2 6 sg I. Ir O.Tf !
19./1 f f.33r
. I62. f
- 30. 3 So3o zG '3 fft l
- 30. 3 So3o tr8 7 I. 9o O. c/ o
/f.o3 f.-3 g 7 l
A l
B C
l D
l E
l F
INSTRUCTION' :
O s ( a s / HI loo
= A / (1-El. in Tx/UU test. A, = A, to&u sampi, A, = 4.so in 2).
oat O A/A : A = Initial aram of D& M semple.4.EO in 2. A as ettermined in @ Only neeeed f or TX/CU test and when testing samp6es c
Load Range is the rna simum canscaty of the load cencz. It is calibrated in g:f/% based on the innsat area of C&
t t
1 lD @ a Load Feetor: Loac Factor in ins. * (1% of Load Range a 4.601 / 1 4 bad Rangel /100 Loed Factor in psf
=
O core.ei.e oemator si,e.s ( e t e 1: f Tx/UU test - e, = @ in io.. i A, a p i OR IGI/,I 34-33 3
@ in est n (1-El = psf.
For TX/CU tett - C e = @ in ibs. / At = psi O R l
= @ in psi
' x ( A /A, ! = psi.
l 34-13 d
O d
3, n
Q 3
E
~
eo w
d r0 2
N 4
E 4
wo sw V
cs 9
=r ke
%)
+
w$
M W
I b
o t-O
?,
N N
O C
l Q
a
- g <
h.
n
>z 2
-:g C
N z
o O
o c
- E i w
c g
7 n
=
d WD 30 E
e Sw E
M n
/
w 25
/
e s
eg g
a
+
g C
5
- U
/
r_
E cr-t t
20 j
m e
Zw J
/
C r
co N
/
E D
l
/
Lo
%l3 4
II:
O i
- M l
Ce
'A r-lo l M
Y E
.=
l COMPRES31VE STRENGTH TEST DATA SL.AMARY I
PROJECT:
LOCXnON:
0.o
- 0. 2.
o.4
- c. 6 c.8 49 blU ~ O I j
JOB #
O % AXIAL STRAIN
- oppig3, o3 S DEFLECTION, INCH COMPUTC BYi M I_/ k /)'
/
TYPE OF PLOT:
/ 7/70
/
-e vs. Axial Strain)
- 1. Corrected s-Jeu-r: rain curve (Correced e i
s PLOTTED BY:
j
- 2. Uncorreced stress strain curve (% Rarge vs. Deflection).
NN C -2I 7 34-14 CHECK BY:
/
/ II
'\\S \\0
% rs t%
h D
N P'N 4
=.
=
. s w
o T
UQ W s
2 w ;-
(i V o
c gad D o
w
-o er) w O
=1
. N1 s
s
.m d
~
e 9
Skh M 7 3 D E
t-U W
N
=
3 N
C'O yy i
- ~
o =
6$0
$8
-x m,-<=w v
oO c o W O
J
-u n,r
., c
-.a s.
v v*
~.
1 u
6 1
C a
0%
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~.
o i
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o J
$ Q N
4 E
c~ V C'~
l
/
O 2
O C
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2 C
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'f s.O 0
1
=c 2
r :.-
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'em 2
3 hl 2
C E
1 C
~
i P
o d
D D
O N
o n
-=
c.:,
r-4 t-S.
Y DC n
's w
s a
=
c s
's a
%,s
[
0 c-O x
i m
(
-- E n
r --
h
', i~
u,
r o
n
~
=
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rs e
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e Ch t,
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o
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~
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s /
k k
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m l
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=
t E
6
~
ra ei t
/
's c-N o
A-1
=;
m +
w i
s s a l
p Li
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c I
w I
g l
g b
h H
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g m
+-
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gt x pd
- J.
SS3E.LS WV3HS o
i
$ bb 34-15
ENCLOSURE 3 O,
\\-.
SECTION VI DYNAMIC PROPERTY EVALUATION INTRODUCTION TO DYNAMIC TESTING OF SOILS The evaluation of soil behavior under dynamic or cyclic loadings is still a relatively new field and, while there has been some standardization of test procedures, there are ' aspects of both the actual testing and the interpretation of test results which are subject to constantly changing opinion. These notes sum =arize some of the background information required when ' requesting the types of dynamic tests presently performed by Dames & Moore.
They are reason-ably valid at the time of writing and will be updated from time to time.
If any points are not clear, the San Francisco or Cranford laboratories or the Professional Coordinator for Soil Dynamics and Earthquake Engineering can be consulted.
TYPES OF TESTS The three basic types of tests which can be perfomed are:
1.
The resonant column test (RC), in which samples are subjected to torsional oscillation _a order to~ measure shear modulus and damping values at relatively low strains.
(
2.
Strain-controlled cyclic triaxial tests (TX/ICU/CY or TI/ACU/CY), from which the shear modulus and damping values at larger strain levels can be obtained.
3.
Stress-controlled cyclic triaxial tests (TX/ICU/ LIQ or TX/ACU/ LIQ), which are used to evaluate the liquefaction potencial of sands or the loss of strength and the tendency to develop permanent strains of materials in general.
l SOME
GENERAL COMMENT
S ON DYNAMIC PROPERTIES I
l In the cyclic triaxial test, it is the axial load and defor-mation as well as pore pressure that are measured; values of the shear modulus and average shear strain are computed by the formula given below.
The co=puted stresses are based on the area of :he specimen after consolidation whereas the computer strains are based on the average, or platen-to platen deformations.
While the s tres s-s train relationships of soils under cyclic loading are nonlinear and take the form of hysteresis loops for uniform cycles, it is customary in present analyses to use an equiva-lent linear relationship in cyclic triaxial tests (defined in Figure VI-1).
While particular forms of analysis may call for either the shear modulus, G, or the Young's modulus, E, once linearity is assumed l'O VI-l
these are interchangeable via the relationship 0"
2(1 + u)
Since there is no method available for measuring the values of Poisson's ratio, p, values of Poisson's ratio may be assumed (for undrained conditions, p = 0.5).
The shear strain, y, is related to the axial strain, c, through the relationship y = c (1+ p ).
Damping values used in the analyses may be computed from the area of the hysteresis loop (Figure VI-1).
In the resonant column test, the shear modulus, calculated from the measured resonant frequency and the cyclic shear strain, for which results are quoted, is the value computed at two-thirds of the distance from the axis along the radius.
Damping values are obtained j
from the free vibration method (log decrement method) or steady state l
vibration method.
The ranges of cyclic shear strain over which various field and laboratory tests apply are shown in Figure VI-2.
The D&M RC equipment actually produces average cyclic shear strains in the range of 5x 10-4 percent to 10-3 percent, and cyclic triaxial test results-l are usually reliable over the range of 5x 10-2 percent to about 1 percent cyclic shear strain. With additional cara and at additional cost, it is possible to obtain results from the cyclic triaxial test
,)
at cyclic shear strains down'to about 10-3 percent.
SOME COMMENTS ON CYCLIC TRIAXIAL TESTS l
Although the triaxial test is easily performed, the axi-symmetric stress and deformation conditions are rarely encountered in the field.
Therefore, there is usually some degree of approximation in the application of the results of the test.
In the particular case of earthquake effects on soil deposits, it is generally believed that the cyclic simple shear test is a better representation of the field loading conditions.
.In the absence of sufficient data to indicate otherwise, the modulus and damping values obtained from strain-controlled cyclic triaxial tests are of ten in fact used directly in analyses, but the results of stress-controlled cyclic TX tests are of ten corrected in accordance with factors given by Seed & Peacock
[ Proc, ASCE, Vol. 97, No. SM8, 1971).
There are also particular features of cyclic triaxial. tests which arise from the extension portion of the load cycle.
In strain-controlled tests, there is a limiting cyclic strain beyond which the sample does not correspond, hence the axial stress drops to and remains at zero.
In stress-controlled tests, the axial stress may go into tension, hence the sample may fail by necking.
The actual 4
conditions governing the occurrence of necking are not well understood, however, and th,e results of stress-controlled tests must always a,
be examined closely to see if even a tendency for necking has
.z - -
4 VI-2
~
accentuated the developments of cyclic axial strains.
PREPARATION OF SAMPLES There is increasing evidence that the previous strain history and present fabric of a soil have a relatively greater effect on behavior under cyclic loading than under static loading.
Therefore, good quality undisturbed samples are decidely preferred.
If samples have to be compacted in the laboratory, as in the case of fill materials, test results may be sensitive to the method of compaction.
In D&M laboratories, the " wet-tamping" method of compaction is used unless otherwise requested.
This method involves compaction of moist i
soil in layers using a tamping rod with a diameter less than half the sample diameter.
Each layer is normally compacted to the specified i
density without undercompacting the bottom layers.
Similar to the case of static tests, the maximum particle size should not exceed one-tenth of the sample diameter.
SATURATION Most dynamic tests are conducted undrained because, for loadings such as those produced by earthquakes, there is insufficient time for drainage during the load application. For samples below the water table, great care is usually taken to ensure that they are fully saturated, either because there is evidence of full saturation in the field or because it is a conservative practice.
Full i{'-
saturation in the laboratory is accomplished by application of back j
pressure to force any air into solution.
The degree of saturation is indicated by the pore pressure parameter B, but the actual B value that corresponds to 100% saturation is a function of the stiffness of the soil.
For many soils, a B value of 0.95 is accepted as full saturation, but lower values are adequate for very stiff soils.
See Black and Lee (1973) for a fuller discussion.
The normal practice is to apply only a small effective confining pressure and then to saturate the sample using 10 psi increments in back pressure.
Some clayey soils tend to swell during saturation, however, and it should be specified whether or not the confining pressure should be increased to prevent or limit swelling.
This makes saturation more difficult and increases the length and cost of the test.
CONSOLIDATION 4
In the usual procedure, samples are consolidated af ter full saturation has been achieved.
For stress-controlled cyclic triaxial tests, samples are consolidated isotropically to represent conditions where there is zero initial shear stress in the direction of the maximum cyclic shear stress, or anisotropically where there are 4
initial shear stresses.
The consolidation stress ratio will not in general then correspond to the actual principal stress ratio in the VI-3
j field. Resonant column and strain-controlled cyclic triaxial tests are usually consolidated isotropically, irrespective of the in-situ princi-pal stress ratio.
Isotropic consolidation is normally carried out in a single step.
Unless otherwise requested, anisotropic consolidation will be carried out in two steps:.
the isotropic component will be applied first, followed by the deviatoric component.
Compacted samples are usually consolidated to an all-round stress or to a mean stress equal to the mean vertical effective stress in the field.
Undisturbed samples are usually re-consolidated to an all-round stress or to a mean stress equal to at least the vertical effective stress in the field.
Especially for overconsolidated soils, consideration should be given to use of the normalized soil parameter approach involving consolidation back to the virgin curve.,
The volume change during saturation is estimated from measure-ment of the axial strain, as the low friction piston bushings used for dynamic testing do not allow use of the cell-wster to measure volume changes.
The volume change during consolidation is indicated by the volume of water expelled from the sample.
This will include any mem-brane penetration.
).
ADDITIONAL TESTS Following cyclic loading, it may be possible to conduct certain static tests.
Because the undrained shear strength is of ten used to normalize the results of tests for dynamic properties of clays, this is routinely measured in the San Francisco laboratory.
The undrained shear strength may also be used as an indicator of the residual strength after stress-controlled loading.
Using the HTS equipment in the San Francisco laboratory, static strengths are measured under a quick (eight minutes to failure) strain-controlled loading.
(The MTS equipment at Cranford Laboratory makes possible a much slower rate of shearing).
If static strength tests are requested, it should be specified whether or not excess pore pressures should be dissipated before loading.
If excess pore pressures have built up during cyclic loading, it is also possible to measure the compressibility and permeability of the sampl* during dissipation of the pore pressure.
VI-4.
e
Shecr G
2 Stress J L g
Definitions (for larger hysteresis loop)
G' A
Locus of tips of I
hysteresis loops Sheer Modulus, G = G / I
/
2 Domping ratio, A s AL/47AT Ag s cree of hysteresis loop A s otee of triongle OA8 T
Shear f
IS Strain
~
1 Figure vt-1 Hysteretic stress-strain relationships at
(~.
different strain amplitudes i
i I
l g
p
+---- Geophysical l
h CycIlc Trioxlol 5'
4 M
+- Surf ac e Vibrotor d
+-- CycIlc Simple Shear
- l Vibratory
.I L
Torsional Sheer
- Plate Bearing
~3 F
7 44 esonant Frequencyq (hollow somples)
-[esonant Frequenge **
ITeolid samples) :
Strong
- Field
- -- Motion M M Laboratory l:
- l t
t I
f I
10-5 10' 4 10~3 10-2 go-l go b_
Shear strain-7, percent l
Figure vi-2 Field and laboratory tests showing approximate strain ranges of test procedures
CHAPTER 41 RESONANT COLUMN TEST (RC)
SCOPE This test determines shear modulus and damping values under low-amplitude cyclic strains.
SAMPLE This test can be performed on any type of soil sample, whether undisturbed or remolded.
Sample diameters between 1.4 inches and 2.8 inches can be accommodated. The maximum particle size to diameter ratio should preferably be less than 1 to 5 or 6, but can be increased to 1 to 3 or 4 if necessary. The length-to-diameter ratio should be between 2 and 3.
LABOR TIME Ten hours for a standard test.
EQUIPMENT TIME Normally on a per test basis, please consult the laboratory.
l TURN-AROUND TIME l
Five work days 1
TEST PROCEDURE The RC apparatus subjects solid cylindrical samples to tor-sional oscillations.
The sample base is fixed, and the top of the sample is excited by a Hardin oscillator which is driven by a variable frequency sine wave generator. The response of the sample. is measured by an accelerometer mounted in the oscillator, and the output is displayed,
oscilloscope.
The excitation frequency is varied on an until the maximum response, or resonant frequency is found.
The damping values may be computed from measurements of the logarithmic decrement, which are obtained by subjecting the sample to a steady-state oscillation and then shutting off their input voltage.
The decay curve is retained in a recording oscilloscope and may be photographed to make a permanent record.
Because the test does not subject the sample to high amplitude strains, it is_possible to use the same sample to gather data at several confining pressures.
Usually the test is run at three levels of current, which produces three levels of shear strain at resonance l
for each of three confining pressures.
l The test may be performed from natural water content or from a fully saturated (by back pressuring) condition.
41-1
' l.
DATA PRESENTATION l
The reduction of the test results has been programmed (EP 79
& Rescol 4H).
Normally only the computer printout (Figure 41-2) is provided.
The original data sheets are filed in the laboratory.
Upon special request, a plot of strain-versus-shear modulus and/or strain-versus-damping may be provided at additional cost.
ENGINEER'S INPUT A special form for requesting resonant column tests is used (Figure 41-la,b).
At the time of this writing, it is possible to fully saturate the sample, but not possible to anisotropically consolidate samples.
DISCUSSION The resonant column test was first developed in the 1950's and an early application is described by Wilson and Dietrich (1960).
At that time, longitudinal excitation was sometimes used instead of torsional excitation. The equipment used by Dames & Moore follows that described by Hardin and Music (1965).
The computation of the ' shear modulus from the resonant frequency obtained using this apparatus is rather complex, but it has been fully described by Hardin (1970), and 3
it has been programmed for routine use as noted above.
)
The shear modulus of soils varies with the shear strain amplitude and thus actually varies along the radius of the same.le.
However, in calculating the shear modulus, the average shear strain is taken to correspond to the cyclic shear strain developed at two-thirds of the distance along the radius.
POSSIBLE ERRORS The most common errors result from poor contact between the sample and the caps. The results are also sensitive to the presence of soft seam
- in the sample.
Such samples should be avoided unless seams are continuous in the field.
l REFERENCES
- Hardin, B.O., 1970, Suggested Methods of Test for Shear Modulus and Damping of Soils by the Resonant Column.
ASTM Special Tech-j nical Publication 979.
l i
41-2 1
,---,o-e v,.,n s
-,-,-n,
+-~r,,.-_,,,
,,n-
---n-~.---n-u,w,4-,,m-
,7,,
,,,w,n,,,-,
- Hardin, B.O.,
and Music, J.,
1965, Apparatus for Vibration of Soil Specimens During the Triaxial Test.
ASTM Special Technical Publication 392.
- Drnevich, V.P.,
- Hardin, B.O.,
and Shippy, D.J., 1977, Modulus and Dumping of Soils By the Resonant Column Method.
Proceedings of the ASTM Symposium on Dynamic Geotechnical Testing, ASTM STP654.
- Richart, F.E.,
- Hall, J. R., and Woods, R.D.,
1970, Vibrations of Soils and Foundations.
Prentice-Hall.
t
- Wilson, S.D.,
and Dietrich, R.J., 1960, Ef fects of Consolidation Pressure on Elastic and Strength Properties of Clay.
Proceedings of the American Society,of Civil Engineers Research Conference on Shear Strength of Cohesive Sc ils,
Boulder, Colorado.
C 9
L 41-3
m angjggWOOstm FIGURE 41-in i
REQUEST FOR RESONANT COLUMN TESTS CLIENT s. KW.O...........
roCATION:.H. A..L..I.L...E.. d..i R A N JOB !,0
- p. 5..f....c..'1. 2... 50 1
- 3. i J'
NUMBEROFTESTSCOVEfED)YTHISREQUEST.......I..........
]
SAMPLE DIAMETER. %/.07. >. inches
)
MAXIMUM PARTICLE SIZE.......... inches M UNDISTURBEQ,8.'DI.M.S.......
SAMPLES COMPACTED SAMPLES Sample type..F.
Sample or bag number.................
(list sample numbers on page 2)
Soil type.................
Target dry density.................
Allowable range.................
Target water content.................
Allowable range.................
O SATUnATE AND RUN UNDnAINED B value required...............
Should confining pressure be increased to prevent swelling during saturation......................
CONSOLIDATION: h Isotopic 0 Anisotropic Special instructicns.. 3. S. T.g. Ap.1...L.E..V. E..L.S.....P. o..A.
..E. b.c..M....C. O..N..EN.... W. 6... fM..(%.. 5..y.A..E..
Number of confining stress. levels......
(list values on page 2)
Damping values required FOR EACH TEST LIST ON PAGE 2 THE LATERAL CONSOLIDATION STRESS, 73e, CONSOLIDATION STRESS RATIO, Xe, AND STRESS RATIO f/6 e IF APPLICABLE. ALSO LIST ON PAGE 2 ANY STATIC TESTS THAT MAY BE 1
REQUIRED AFTER CYCLIC LOADING.
ECK HERE IF REQUIRED FOR ALL TEST AFTER CYCLIC LOADINC Mechanical analysis Sieve analysis
.Atterberg limits %
Static undrained strength ADDITIONAL INSTRUCTIONS... $...!.E...h. N N.T......................................................
ESTIMATED COMPLETION DATE: Testing
/ N.W ~
Final data./d/
."76 Obtained from.. b... on. N/. N/2.I Basic cost per test. 4.2 85. b Additional charges.............*.........g N...f.ld.3y. 3..o.. b.h.................
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3675504250 D A T.
102975 KWU-HALILEH BRG HL2 SAMPLE 3 AT 18.8 METERS RE*SONANT_ COLUMN TEST ON TAN BEDDED SAND AND CLAY
=
104.3 PCF DRY DENSITY
[0ISTURE CONTENT
=-
18.2 PERCENT
@0NFINING SINGLE AMRL.
@HESSuRE SHLAR MUQULUS SHEAR STRAIN SHEAR WAVE DAMPING K
(PSF)
(KSF)
(A8 SOLUTE)
VELOCITY (FT/SEC)
(PCT) 8090.9 2077.0 1 68432E-06 736.68 2.4 45.4 2090 9 2023.0 8.62090E-06 727.04 2.6 44.2 5090 4 1829.0 4.70786E-05 691.30 3.0 40.0
@l67.a 2680 0 1 25407L-06 867.47 2.8 51 3 3147 A 2o17 0 6 398086-06 857.93 2.9 50.2 3147 8 2714 0 3.30992E-05 842 10 30 48.4 6183 2 3159.0 1.15174E-06 908.52 3.4 48.8 6183 2 3115.0 5.83324E-06 902.17 3.4 48.2 6183.P 3050.0 2 97390t-05 892.71 3.6 47.2
@238.7 3847 0 9.58541E-07 1002.59 4.6 53.2 2238.7 3799.0 4.84926E-06 996.31 4.6 52.5 9238.7 3704.0 2.48270E-05 983.78 4.6 51.2 G274 1 4239 0 8.74776E-07 1052.43 5.5 53.5 M274 1 4189.0 4.42316E-06 1046.20 5.8 52.9 6274 1 4090 0 2.26213E-05 1033.77 6.1 51.6 SEAST SQUARES FIT TO STHESS - MODULUS EuuATIONS CODULUS = A * (STRESS)**B (BOTH IN P.S.F.
UNITS)
)[
UNERE A =
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.669 COEFF. OF CURRELATIuh =
.987 STANDARD DEVIATION =
.019 FORCE FIT TO 0 5 LAPONENTIAL MODULUS EuUATION BY LEAST SQUARES GODULUS = C * (STkESS)**0.5 (BOTH IN P.S.F. UNITS)
- HERE C =
49808.6
- PARAMETER K IN ACCONDANCE WITH AUMLEMEYER EuuATIONS
'uMERE 6 = (K/ POROSITY **2)* SIGMA **0.5 wITH K=
6800.3 VALUE OdTAINED FROM RICMART SAND TEST 5
=
-6600.0
'FOR SAND, K EVALUATED FHOM RELATIONSHIP G = 1000*K+(SIG3)**0.5 1
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CHAPTER 42 STRAIN-CONTROLLED CYCLIC TRIAXIAL TEST (TX/ICU/CY or TX/ACU/CY)
SCOPE
~
This test is the same as the cyclic triaxial test for dynamic
~
properties (D&M procedure 6-26) which appears in the Laboratory Manual of Technical Practices. This test determines and evaluates modulus and
-damping values at cyclic shear strain amplitudes which correspond to earthquakes' strong motions.
SAMPLE This test can be performed on undisturbed or reconstituted specimens having diameters between 1.4 and 4.0 inches.
The height of the specimen should be confined to the range of 2 to 3 times its diameter.
The maximum particle size to diameter ratio should prefer-
. ably be less than 1 to 5 or 6.
LABOR TIME Depending on the type of material being tested; on the average, sixteen hours for a standard test (the current fee list published by h
the Soil Dynamics Laboratory may be consulted).
EQUIPMENT TIME Normally on a per test basis.
Consult the laboratory for unit price.
TURN-AROUND TIME An average of five work days (the Soil Dynamics Laboratory has more precise listings)
TEST PROCEDURE f
The D&M cyclic triaxial test equipment is based on an MTS closed-loop electro-hydraulic test system which consists of a hydraulic power supply, a futetion generator, a controller, and a load frame with a 10-kip actuator.
In tests to deternine dynamic properties, strain-controlled sinusoidal loadings at a frequency of 0.5 to 1 hertz are l
usually employed.
The axial load and deformation are measured by a locd cell and linear variable deformation transformer (LVDT), respectively, and pore pressures are monitored by 'a transducer mounted in the base of the triaxial cell.
The outputs are recorded on a strip-chart recorder and an X-Y recorder (or oscilloscope).
42-1
Normally tests are run at several increasing values of cyclic strain.
For earthquake-type loadings, the modulus and damping values are usually computed for the fif th or the tenth cycle, and any excess pore pressures that are generated are allowed to be dissipated between each strain level. The D&M equipment is capable of routinely measuring moduli and damping values down to cyclic shear strains of about. 5 x 10-2 percent.
With additional care, which involves ensuring good scaling and calibrating the equipment deflection, it is possible to obtain results at cyclic shear strains as low as about 10-3 percent.
The upper limit of strnins for which useful values may be obtained is determined not by the equipment, but by limiting strain in extension, beyond which the sample is no longer confined in the axial direction.
This limit is usually reached at cyclic shear strains of about 0.5% to 1%.
The static shear strength of samples af t.er cyclic loading may be determined by application of a monotonically increasing axial com-pressive strain.
DATA PRESENTATION While it is not possible to directly apply a shear loading in the cyclic TX test, the equivalent linear shear modulus which is required for use in dynamic analyses may be obtained from the equiv-alent linear Young's modulus if Poisson's ratio is known or assumed.
The shear modulus, G, is given kr; O
2( + p )
and the average shear strain, Y, is given by:
Y=
c (1+U}
a where: E = Young's modulus U = Poisson's ratio Ea = average axial strain l
The equivalent hysteretic damping values may be computed from the hysteretic loops, which indicate the energy dissipated into the soil using the formula given in Figure VI-1.
The necessary computations have been programmed, and the results are printed as shown in Figure 42-2.
Plotting of data may be done'at extra cost if requested.
ENGINEER'S INPUT See request form--Figure 42-la,b.
42-2
ERARSM:38RSOORM FIGURE 42-la REQUEST FOR STRAIN-CONTROLLED CYCLIC TRIAXIAL TESTS CLIENTS.. M.Y..........
LOCATION:.
.f JOB NO:.
.~.
.. [.
NUMBER OF TESTS gOVERER BY THIS REQUEST..................
SAMPLE DI AMETER. 4M.%.. inches MAXIMUM PARTICLE SIZE..-"~...... inches k UNDISTURBEg gbMPLES COMPACTED SAMPLES Sample type. J. h.44W.&.......
Sample or bag number.................
(list sample numbers on page 2)
Soil type.................
Target dry density.................
Allowable range.................
Target water content.................
Allowable range.................
SATURATE AND RUN UN NED 3 value required.. C2 s.
Should confining pressure be increased to prevent swelling during saturation....N..............
[ Isotopic CONSOLIDATION:
J Anisotropic Special in s tructio ns h...
b.W.%3.. 7. j P...t..is..s.l.P.A. T.. i.o. 4... M... '.N... s..u...... s. 72...N. 4...
h MULTIPLE STRAIN LEVELS
,otherwisespecUyagroximateaxialstrainrequired:...T.....tpeaktopeak Frequency..O41.h e
Cycle number at which modulus and damping required... d.....
percent dissipation of pore pressure required between strain levels...N.4..t FOR EACH TEST LIST ON PAGE 2 THE LATERAL CONSOLIDATION STRESS, 73e, CONSOLIDATION STRESS RATIO, Kc, AND STRESS RATIO 7/C e IF APPLICABLE. ALSO LIST ON PAGE 2 ANY STATIC TESTS THAT MAY BE l
PIQUIRED AFTER CYCLIC LOADING.
ECK EERE IF REQUIRED FOR ALL TEST AFTER CYCLIC LOADING Mechanical analysis Sieve analysis Atterberg limits bF-c.tR(5%
Static undrained strength ADDITIONAL INSTRUCTIOMS...........................................................................
ESTIMATED COMPLETION DATE: Testing.I.Q./.2.
- 7. 3 Final data.40/. 7/.l5" obtained from.M.... on N./7.k/.I Basiccostpertest..$..h..$....
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OYNAMIC SOIL PROPERTY TEST 03/16/76 FIGURE 42-2 0675504250 JRW 102775 KtU-AEGI HALILEH BRG. HL-2 NO. 3 AT 19.0M.
OYNAMIC SOIL PROPERTIES OF TAN CLAYEY SAND INITIAL MOISTURE CONTENT
=
16 0 PERCENT INITIAL DRY DENSITY
=
107.00 PCF MolSTURE CUN(ENT AFTEH CONSUL.=
19.6 PERCENT DRY DENSITY AFTER CONSOL.
109.20 PCF
=
SAMPLE HEIGHT AFTER CONSOL.
=
6 23 IN SAMPLE DIAMETER AFTER CONSOL.
=
2 87 IN CONFINING PRESSURE
= 4176.0 PSF POISSON RATIO
=
.50 (ASSUMED)
VALUES MEASURED AT CYCLE NUMSER 5
EVIATOR CYLIC STRAIN YOUNGS SHEAR K
DAMPING STHESS AAIAL SHEAR MODULUS MODULUS HATIO (PSF)
(PERCENT)
(KSF)
(KSF)
(PERCENT) p 928 0
.0313
.0470 2965.
988.
15.3 8.7 e 1367.0
.0620
.0929 2206.
735.
11.4 11.3 P 1944.9
.1236
.1854 1574 525.
8.1 15.2 2356 2
.2496
.3744 944,.
315.
4.9 17.9 2934 1
.5024
.7536 584.-
195.
30 19 1 wHERE K IS GIVEN BY...K=G/(1000.*SIG3**1/2)
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DISCUSSION There are few, if any, written discussions of the details of using cyclic TX tests to evaluate dynamic properties. The laboratory can be consulted for current procedures on dynamic testing.
While existing publications tend to be out of date, Seed and Idriss (1971) and Hardin and Drnevich (1972) have published collected data which indicate the nature of the results obtained.
POSSIBLE ERRORS Poor sealing and alignment of
- sample, excessive piston
- friction, sample disturbance, incorrect drainage conditions, inappropriateness of the triaxial loading conditions, especially for samples exhibiting anisotropy.
REFERENCES Dames
& Moore Soil Mechanics Laboratory Manual of Technical Practice, 1977.
- Hardin, B.O.,
and Drnevich, V.P., 1972a, Shear Modulus and Damping in Soils.
Proceedings of the American Society of Civil Engineers, Vol. 98, No. SM6.
1972b, Shear Modulus and Damping on Soil:
Design Equations
]
and Curves.
Proceedings of the American Society of Civil s
Engineers, Vol. 98, No. SM7.
- Seed, H.B.,
and Idriss, I.M., 1970, Soil Moduli and Damping Factors for Dynamic Response Analysis.
Re port No. EERC 70-10, University of California, Berkeley.
- Silver, M.L.
and Park, T.K, 1975, Testing Procedure Effects on Dynamic Soil Behavior, Journal of Geotecnical Engineering Division, ASCE, Vol 101. No. GT10.
m 42-6
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CHAPTER 43 STRESS-CONTROLLED CYCLIC TRIAXIAL TEST (TX/ICU/ LIQ or TX/ACU/ LIQ)
SCOPE This test is the same as the cyclic triaxial test for lique-faction, which appears in the Laboratory Manual of Technical Practices
' *(D&M procedure 6-27).
It evaluates the liquefaction potential of sands or loss of strength and deformation characteristics of soils in general.
Samples may be consolidated isotropically to represent the initial stress conditions under horizontal ground surfaces, or aniso-tropically to represent the initial stress conditions in embankments or under sloping ground.
SAMPLE This test can be performed on undisturbed or reconstituted
- specimens.
Test specimens must be completely saturated to insure proper pcre pressure response.
Specimen sizes and constraints are the same as for strain-controlled cyclic triaxial tests (Chapter 42).
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