ML19289E211

To Reg Guide 1.132, Site Investigations for Foundations of Nuclear Power Plants

ML19289E211
Person / Time
Issue date:	03/31/1979
From:	NRC OFFICE OF STANDARDS DEVELOPMENT
To:
References
REGGD-01.132, REGGD-1.132, NUDOCS 7904050002
Download: ML19289E211 (25)

Text

.

Revision 1 U.S. NUCLEAR REGULATORY COMMISSION March 1979

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og), REGULATORY GUIDE OFFICE OF STANDARDS DEVELOPMENT

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REGULATORY GUIDE 1.132 SITE INVESTIGATIONS FOR FOUNDATIONS OF NUCLEAR POWER PLANTS i

A. INTRODUCTION This guide provides general guidance and recommendations for developing site-specific

• l Paragraph 100.10(c) and Appendix A, "Seis-investigation programs as well as specific guid-mic and Geologic Siting Criteria for Nuclear ance for conducting subsurface inicsugadons, Power Plants," to 10 CFR Part 100, " Reactor the spacing and depth of borings, and sam-Site Criteria," establish reqairements for con-pling. Because the details of the actual site in-ducting site investigations to permit evaluation vestigations program will be highly site of the site and to provide information needed dependent, the procedures described herein for seismic response analyses and engineering should be used only as guidance and should be design. Requirements include the development tempered with professional judgment. Alter-of geologic information relevant to the stratig-native and special investigative procedures raphy, lithology, geologic history, and struc-that have been derived in a professional tural geology of the site and the evaluation of manner will be considered equally applicable the engineering properties of subsurface for conducting foundation investigations.

materials.

Appendix A to this guide provides defini-Safety-related site characteristics are identi-tions for some of the terms used in this guide.

fied in detail in Regulatory Guide 1.70 These terms are identified in the text by an

" Standard Format and Content of Safety Analy-asterisk. Appendix B tabulates methods of sis Reports for Nuclear Power Plants." Regula-conducting subsurface investigations, and Ap-D teria for Nuclear Power Stations," discusses tory Guide 4.7, " General Site Suitability Cri-pendix C gives guidelines for the spacing and depth of borings for safety-related structures major site characteristics that affect site in regions of favorable or uniform conditions.

suitability.

References cited in the text and appendices are This guide describes programs of site inves-tigations that would normally meet the needs The Advisory Committee on Reactor Safe-for evaluating the safety of the site from the guards has been consulted concerning this standpoint of the performance of foundations guide and has concurred in the regulatory and earthworks under most anticipated loading position.

conditions, including earthquakes. It also describes site investigations required to evaluate geotechnical parameters needed for B.

DISCUSSION e eineering analysis and design. The site in-vestigations discussed in this guide are appli-

1. General cable to both land and offshore sites. This guide does not discuss detailed geologic fault Site investigations for nuclear power plants investigations required under Appendix A to are necessary to determine the geotechnical*

10 CFR Part 100, nor does it deal with hydro-characteristics of a site that affect the design, logic investigations, except for grounlwater performance, and safety of plants. The inves-measurements.

tigations produce the information needed to define the overall site geology to a degree that is necessary for an understanding of sub-

• Lines indicate substantive changes from previous issue.

surface Conditions and for identifying potential USNRC REGULATORY GUIDES Comments should be sent to the secretary of the Commason, U.s. Nuclear a*na,a"~'*" *"""5'"" " 2 56" ^"* ""'"5 R.guo,, r-des are -

descr e.nd r.e -e e to the -

ser methods acceptable to the NRC staff of implemennng specife parts of the Commesson's regulatons, to delineste techniques used by the staff in evolu-The gudos are usued in the follomng ten broad divisens:

stmg specific problems or postuisted accidents, or to provide guidance to appucent3L Reguistory Guides are not subsatutes for reguistons, and com-

1. Power Resetors

6. Products plance with them is not required. Methods and solutons ditterent from those

2. Research and Test Reactors

7. Transportaten set out in the guedes wiA be acceptable W they provide a base for the findangs

3. Fuels and Matenals Facdsties

8. occupatonal Health

'C M er Pr tion 1 G Requests for single copes of issued guides (whch may be reproduced) or for Comments and suggestions for ;.. _ _ _ in these guides are encouraged at piecement on an automate distribution list for aangle copes of future guides eR times and guidos wig be revised, as appropnate. to accommodate comments in specsfc divisions should be made in writmg to the U.s. Nuclear Regulatory and to reflect new information or exponence. This guide was rewmed as a result Commason. Washington, D.C. 20566. Attermon: Drector. Dnneson of of substanove comments receeved from the pubile and addmonal staff review.

Technscal Information and Document Control.

790405COM

geologic and earthquake hazards that may exist

2. Reconnaissance Investigations and Literature at the site. Investigations for hazards such as Reviews faulting, landslides, cavernous rocks, ground subsidence, and soil liquefaction are especially Planning of subsurface investigations an important.

the interpretation of data require thorough understanding of the general geology of the site. This understanding can be obtained by Site investigations also provide information field reconnaissance and a review, either pre-)

needed to define local foundation and ground-ceding or accompanying the subsurface investi-water conditions as well as the geotechnical gation, of available documentary materials and parameters needed for engineering analysis and results of previous investigations. In most design of foundations and earthworks. Geo-cases, a preliminary study of the site geology technical parameters needed for analysis and can be done by review of existing current and design include, but are not limited to, those historical documentary materials and by study used to evaluate the bearing capacity of foun-of aerial photographs and other remote-sensing dation materials, lateral earth pressures affect-imagery. Possible sources of current and his-ing walls, the stability of cuts and slopes in torical documentary information may include:

soil and rock, the effect of earthquake-induced motions transmitted through underlying de-posits on the response of soils and structures

a. Geology and engineering departments of (including the potential for inducing liquefac-State and local universities, tion in soils), and those needed to estimate the expected settlement of structures. Geotechnical

b. State government agencies such as the parameters are also needed for analysis and State Geological Survey, design of plant area fills, structural fills, backfills, and earth and rockfill dams, dikes,

c. U.S. Government agencies such as the and other water retention or flood protection U.S.

Geological Survey and the U.S.

Army structures.

Corps of Engineers,

d. Topographic maps, Site information needed to assess the func-tional integrity of foundations with respect to

e. Geologic and geophysical maps, geologic and geotechnical considerations includes:

f. Engineering geologic maps,

g. Soil survey maps,

a. The geologic origin, types, thicknesses, sequence, depth, location, and areal extent of

h. Geologic reports and other geological lit-soil and rock strata and the degree and extent eratu re,

of their weathering;

i. Geotechnical reports and other geotech-

b. 'Ihe history, type, and extent of geologic nical literature,

deformation;

j. Water well boring information and water

c. Orientation and characteristics of folia-supply reports, tions, bedding, jointing, and faulting in rock;

k. Oil and gas well records,

d. Groundwater conditions;

1. Hydrogeologic maps,

e. The static and dynamic engineering pro-perties of subsurface materials;

m. Hydrologic and tidal data and flood

records,

f. Information regarding the results of in-vestigations of adverse geological conditions

n. Climate and rainfall records, such as cavities, joints, faults, fissures, or unfavorable soil conditions;

o. Mining history, old mine plans, and sub-sidence records,

g. Information related to man's activities such as withdrawal of fluids from or addition of

p. Seismic data and historical earthquake fluids to the subsurface, extraction of miner-

records, als, or loading effects of dams or reservoirs; and

q. Newspaper records of landslides, floods, earthquakes, subsidence, and other events of

h. Information detailing any other geologic geologic or geotechnical significance, condition discovered at the site that may affect the design or performance of the plant or the

r. Records of performance of other struc location of structures.

tures in the vicinity, and 1.132-2

s. Personal communication with local inhabi-properly installed wells or piezometers* that tants and local professionals.

are read at regular intervals from the time of their installation at least through the construc-D soils Special or unusual problems such as swelling tion period. The U.S.

Army Corps of Engi-and shales (subject to large volume neers' manual on groundwater and pore pres-changes with changes in moisture), occur-sure observations in embankment dams and rences of gas, cavities in soluble rocks, sub-their foundations (Ref.1) provides guidance sider e caused by mining or pumping of water, on acceptable methods for the installation and gas, or oil from wells, and possible uplift due maintenance of piezometer and observation to pressurization from pumping of water, gas, well* instrumentation. Criteria for measuring or oil into the subsurface may require consul-groundwater conditions at a site and for tation with individuals, institutions, or firms assessing dewatering requirements during con-having experience in the area with such struction are given in regulatory position 3 of problems,

this guide. This guide does not cover ground-water monitoring needed during construction in The site investigation includes detailed plants that have permanent dewatering systems l surface studies and exploration of the incorporated in their design.

immediate site area and adjacent environs.

Further detailed surface exploration also may

4. Subsurface Investigations be required in areas remote to the immediate plant site to complete the geologic evaluation of

a. General the site or to conduct detailed investigations of surface faulting or other features. Surface ex-The appropriaic aepth, layout, spacing, and ploration needed for the assessment of the site sampling requirements for subsurface investi-geology is site dependent and may be carried gations are dictated by the foundation require-out with t e use of any appropriate combination ments and by the complexity of the anticipated of geological, geophysical, or engineering subsurface conditions. Methods of conducting techniques. Normally this includes the follow-subsurface investigations are tabu'ated in Ap-ing:

pendix B to this guide, and recommended guidelines for the spacing and depth of borings

a. Detailed mapping of topographic, hydro-for safety-related structures, where favorable logic, and surface geologic features, as appro-or uniform geologic conditions exist, are given priate for the particular site conditions, with in Appendix C.

scales and contour intervals suitable for analy-sis and engineering design. For offshore sites, Subsurface explorations for less critical D coastal sites,or sites located near lakes or foundations of pcwer plants should Fe carried rivers, this includes topography and detailed out with spacing and depth of penetration as hydrographic surveys to the extent that they necessary to define the general geologic and are needed for site evaluation and engineering foundation conditions of the site. Subsurface design.

investigations in areas remote from plant foun-dations may be needed to comp'ete the geologic

b. Detailed geologic interpretations of aerial description of the site and confirm geologic and photographs and other remote-sensing foundation conditions and should also be imagery, as appropriate for the particular site carefully planned.

conditions, to assist in identifying rock out-crops, soil conditions, evidence of past land-Subsurface conditions may be considered slides or soil liquefaction, faults, fracture favorable or uniform if the geologic and strati-l traces, geologic contacts, and lineaments.

graphic features to be defined can be cor-related from one boring or sounding

• location

c. Detailed onsite mapping of local engineer-to the next with relatively smooth variations in ing geology and soils, thicknesses or properties of the geologic units.

An occasional anomaly or a limited number of

d. Mapping of surface water features such as unexpected lateral variations may occur.

rivers, streams, or lakes and local surface Uniform conditions permit the maximum spacing drainage channels, ponds, springs, and sinks of borings for adequate definition of the sub-at the site, surface conditions at the site.

3. Groundwater Investigations Occasionally, soil or rock deposits may be encountered in which the deposition patterns Knowledge of groundwater conditions, their are so complex that only the major strati-relationship to surface waters, and variations graphic boundaries are correlatable, and mate-associated with seasons or tides is needed for rial types or properties may vary within major foundation analyses. Groundwater conditions geologic units in an apparently random manner l are normally observed in borings

• at the time from one boring to another. The number and they are made; however, for engineering appli-distribution of borings needed for these condi-cations, such data are supplemented by tions are determined by the degree of resolu-l groundwater observations made by means of tion needed in the definition of foundation 1.132-3

properties. The thicknesses of the various

b. Investigations Related to Specific Site Con-material types, their degree of variability, and ditions l defined.

ranges of the material properties should be Investigations for specific site conditions should include the following:

If there is evidence suggesting the presence of local adverse anomalies or discontinuities (1) Rock. The engineering characteristics such as cavities, sinkholes, fissures, faults, of rocks are re'ated primarily to their struc-brecciation, and lenses or pockets of unsuit-ture, bedding, jointing, fracturing, weather-able material, supplementary borings or sound-ing, and physical properties. Core samples are ings* at a spacing small enough to detect and needed to observe and define these features.

delineate these features are needed. It is Suitable coring methods should be employed in important that these to -ings penetrate all sampling, and rocks should be sampled to a suspect zones or extend to depths below which depth below which rock characteristics do not their presence would not influence the safety influence foundation performance.

Deeper of the structures. Geophysical investigations borings may be necded to investigate zones may be used to supplement the boring and critical to the evaluation of the site geology.

sounding program.

Within the depth intervals influencing founda-tion performance, zones of poor core recovery, In planning the exploration program for a low Rock Quality Designation (RQD),* zones site, consideration should also be given to the requiring casing, and other zones where possibility that the locations of structures may drilling difficulties, including loss of drilling be changed and that such changes may require fluid cii'culation and dropping of drill rods, are additional exploration to adequately define sub-encountered should be investigated by means surface conditions at the final locations.

of suitable logging or in situ observation methods to determine the nature, geometry,

The location and spacing of borings, sound-and spacing of any discontinuities or anomalous in gs, and exploratory excavations should bc zones. Where there is evidence of significant l chosen carefully to adequately define sub-residual stresses, they should be evaluated on surface conditions. A uniform grid may not the basis of in situ stress or strain measure-provide the most effective distribution of ex-ments.

pioration locations unless the site conditions are very uniform. The location of initial (2) Coarse-Grained Soils. Investigations of borings should be determined on the basis of coarse-grained soils should include borings conditions indicated by preliminary investiga-with split spoon sampling and Standard tion s. Locations for subsequent or supple-Penetration Tests with sufficient coverage to mental explorations should be chosen in a define the soil profile and variations of soil manner so as to result in the best definition of conditions. Soundings with cone penetration the foundation conditions on the basis of con-tests may also be used to provide useful sup-clusions derived from earlier exploratory work.

plemental data if the cone and test data are properly calibrated to site conditions.

Wherever feasible, subsurface explorations should be located to permit the construction of Suitable samples should be obtained for geological cross sections through foundations soil identification and classification, in situ of safety-related structures and other impor-density determinations where eppropriate,

tant locations at the site.

mechanical analyses, and anticipated laboratory testing. When obtaining samples for cyclic It is essential to verify during construction loading tests, it is important to obtain good-that in situ conditions have been realistically quality undisturbed samples

• for testing. The estimated during analysis and design. Excava-need for, number, and distribution of samples tions made during construction provide oppor-will depend on testing requirements and the tunities for obtaining additional geologic and variability of the soil conditions. In general, geotechnical data. All construction excavations however, samples should be included from at for safety-related structures and other excava-least one principal boring

• at the location of tions important to the verification of sub-each safety-related structure. Samples should surface conditions should be geologically be obtained at regular intervals in dep'h and mapped and logged in detail. Particular atten-when changes in materials occur. Criteria for tion should be given to the identification of the distribution of samples are given in regula-geologic features that may be important to tory position 6.

foundation behavior but were previously undetected in the investigations program. If Coarse-grained soils containing gravels l subsurface conditions substantially differ from and boulders are among the most difficult mate-those anticipated, casting doubt on the rials to sample. Obtaining good quality samples adequacy of the design or expected perform-in these coarser soils often requires the use of ance of the foundation, there may be a need trenches, pits, or other accessible excava-for additional exploration and redesign.

tions* into the zones of interest. Also, extreme e 1.132-4

care is necessary in interpreting results from surface voids will be fully revealed. Experience has shown that solution features may remain D the Standard Penetration Test in these mate-rials. Often such data are misleading and may undetected even where the area has been have to be disregarded. Whrn sampling of investigated by a large number of borings. The these coarse soils is difficult, information : hat fact that cavities are often filled or partially may be lost when the soil is later cletsified in filled with residual material and debris makes it the laboratary should be recorded in the field.

particularly difficult to detect cavities on the This information should inciude obcerved esti-basis of boring data and results of fluid mates of the percentage of cobbles, boulders, pressura and grout-take tests. Therefore, and coarse material and the hardness, shape, where a site is on solution-susceptible rock, it surface coating, and degree of weathering of may sometimes be necessary to inspect the rock coarse materials.

after stripping or excavation is complete and the rock is exposed.

l (3) Moderately Compressible or Normally Consolidated Clay or Clayey Soils. The prop-(5) Materials Unsuitable for Foundations.

erties of a fine-grained soil are related to the Borings and representative sampling and test-in situ structure of the soil,* and therefore the ing should be completed to delineate the recovery and testing of good undisturbed sam-boundaries of unsuitable materials. These ples are necessary. Criteria for obtaining boundaries should be used to define the undisturbed samples are discussed in regulato-required excavation limits.

ry position 6 of this guide.

(6) Borrow Materials. Exploration of borrow (4) Subsurface Cavities. Subsurface cav-sources requires the determination of the loca-ities may occur in water-soluble rocks, lavas, tion and amount of borrow fill materials avail-weakly indurated sedimentary rocks, or in able. Investigations in the borrow areas should other types of rocks as the r:sult of be at horizontal and vertical intervals suffi-subterranean solutioning and erosion. Cavities cient to determine the material variability and can also be found where mining has occurred should include adequate sampling of represen-or is in progress. Because of the wide tative materials for laboratory testing.

distribution of carbonate rocks in the United States, the occurrence of features such as Investigations of problem foundation cavities, sinkholes, and solution-widened joint conditions are discussed in Appendix A to openings is common. For this reason, it is best Reference 3 and in Reference 4.

D to thoroughly investigate any site on carbonate rock for solution features to determine their

c. Sampling influence on the performance of foundations.

Because of the possibility that incomplete or Representative samples

• of all soil and rock inaccurate records exist on mining activities, it should be obtained for testing. In many cases, is equally important N 21vestigate areas where to establish physical properties it is necessary mining has or may have occurred.

to obtain undisturbed samples that preserve the in situ structure of the soil. The recovery Investigations may be carried out with of undisturbed samples is discussed in Sec-borings alone or in conjunction with accessible tion B.6 of this guide.

excavations, soundings, pumping tests, pres-sure tests, geophysical surveys, or a combina-Sampling of soils should include, es a mini-tion of such methods. The investigation pro-mum, recovery of samples for all principal gram will depend on the details of the site borings at regular intervals and at changes in geology and the foundation design. Various strata. A number of samples suf'icient to geophysical techniques used for detecting sub-permit laboratory determination of average surfa:e cavities are discussed in Reference 2.

material properties and to indicate their varia-bility is necessary. Alternating split spoon and Indications of the presence of cavities undisturbe.1 samples with depth is cecom-(e.g., zones of lost drilling fluid circulation, mended. Where sampling is not continuous, the water flowing into or out of drillholes, mud elevations at which samples are taken should be fillings, poor core recovery, dropping or staggered from boring to boring so as to settling of drilling rods, anomalies in geo-provide continuous coverage of samples within physical surveys, or in situ tests

• that the soil column. In supplementary borings,

suggest voids) should be followed up with more sampling may be confined to the zone of detailed investigations. These investigations specific interest.

should include excavation to expose solution features or additional borings that define the Relatively thin zones of weak or unstable limits and extent of such features.

soils may be contained within more competent materials and may affect the engineering The occurrence, distribution, and characteristics or behavior of the soil or rock. l geometry of subsurface cavities are highly un-Continuous sampling in subsequent borings is needed through these suspect zones. Where it D predictable, and no preconstruction exploration program can ensure that all significant sub-is not possible to obtain continuous samples in 1.132-5

a single boring, samples may be obtained from discharge bits should be used only with low-to-adjacent closely spaced borings in the im-medium fluid pressure and with upward-mediate vicinity and may be used as deflected jets.

representative of the material in the omitted depth intervals. Such a set of borings should In addition to pertinent information normally be considered equivalent to one principal recorded for groundwater measurements and boring.

the results of field permeability tests, all depths and amounts of water or drilling mud

d. Determining the Engineering Properties of losses,

together with depths at which Subsurface Materials circulation is recovered, should be recorded and reported on boring logs and on geological A general discussion of the classifications of cross sections. Logs and sections should also soils and rocks and methods of determining reflect incidents of settling or dropping of drill their engineering properties is included in rodt, abnormally low resistance to drilling or Reference 5.

advance of samplers, core losses, instability or heave of the side and bottom of boreholes; The shear strengths of foundation materials influx of groundwater; and any other special l in all zones subjected to significant imposed feature or occurrence. Details of information stresses should be determined to establish that should be presented on logs of subsurface whether they are adequate to support the investigations are given in regulatory posi-iinposed loads with an appropriate margin of tion 2.

safety. Similarly, it is necessary both to determine the compressibilities and swelling po-Depths should be measured to the nearest tentials of all materials in zones subjected to tenth of a foot (3 cm) and should be significant changes of compressive stresses and correlatable to the elevation datum used for the to establish that the deformations will be site. Elevations of points in the borehole acceptable. In some cases, these determinations should also be determined with an accuracy of may be made by suitable in situ tests and 10.1 ft (13 cm). Surveys of vertical deviation classification tests.

Other situations may should be run in all boreholes that are used for require the laboratory testing of undisturbed crosshole seismic tests and in all boreholes samples. Determination of dynamic moduli and where vertical deviations are significant to the danping ratios over applicable strain ranges of use of data obtained. After use, f.t is advisable soil strata is needed for earthquake response to grout each borehole with cement to prevent analyses. Dynamic moduli and damping may be vertical movement of grvundwater through the evaluated in situ, but usual procedures pro-borehole.

vide information only for low shear strain amplitudes. Laboratory tests on undisturbed

6. Recovery of Undisturbed Soil Samples samples can provide additional modulus and damping values to cover the range of strains The best undisturbed samples are often anticipated under earthquake loading condi, obtamed by carefully performed hand trimming tions.

of block samples in accessible excavations.

However, it is normally not practical to obtain

5. Methods and Procedures for Exploratory Drilling nough block samples at the requisite spacings and depths by this method alone. It is customary, where possible, to use thin-wall in nearly every site investigation, the pri-tube samplers in borings for the major part of mary means of subsurface exploration are the undisturbed sampling. Criteria for obtain-borings and borehole sampling. Drilling ing undisturbed tube samples are given in reg-methods and procedures should be compatible ulatory position 6.

with sampling reqairements and the methods of sample recovery.

The recovery of undisturbed samples of good quality is dependent on rigorous attention to The top of the hole should be protected by a details of equipment and procedures. Proper suitable surface casing where needed. Below cleaning of the hole by methods that minimize l ground surface, the borehole should be pro-disturbance of the soil is necessary before tected by drilling mud or casing, as necessary, sampling. The sampler should be advanced in a to prevent caving and disturbance of materials manner that minimizes disturbance.

Forl to be sampled. The use of drilling mud is example, when using fixed-piston-type sam-preferred to prevent distyrbance when plers, the drilling rig should be firmly obtaining undisturbed samples of coarse-anchored or the piston should be fixed to an grained soils.

external anchor to prevent its moving upward during the push of the sampling tube. Care However, casing may be used if proper steps should be taken to ensure that the sample is are taken to prevent disturbance of the soil not disturbed during its removal from the being sampled and to prevent upward movement borehole or in disassembling the sampler.

of soil into the casing. Washing with open-References 6 and 7 provide descriptions of ended pipe for cleaning or advancing sample suitable procedures for obtaining undisturbed boreholes should not be pennitted. Bottom-samples.

1.132-6

With the conscientious use of proper field should be properly sealed and protected tech undisturbed samples in normally against moisture loss.

D con.niques, olidated clays and silts can usually be recovered by means of fixed-piston-type thin-Disturbed samples

• may be sealed in the same wall tuM samplers without serious difficulty.

way as undisturbed samples, if in tubes, or Recovery of good undisturbed samples in sands may be placed in noncorroding, airtight con-requires greatcr care than in clays, but, with tainers with identification tags, one on the in-proper care and attention to detail, they can terior and one on the exterior. Large repre-also be obtained with fixed-piston-type thin-sentative samples may be placed in plastic wall tube samplers in most sands that are free bags, in tightly woven cloth, or in noncorrod-of boulders and gravel-sized particles. Good-ing cans or othcr vessels that do not permit qur.lity undisturbed samples are sometimes loss of fine particles by sifting. Such samples difficult to obtain in dense and very loose may be transported by any convenient means.

sands. Therefore, it may be necessary to consider alternative sampling techniques for Rock cores need to be stored and trans-these materials. Appendix B to this guide lists ported in durable boxes provided with suitable a number of sampling methods that are often dividers to prevent shif ting of the cores in any used in these and other materials, direction. They should be clearly labeled to identify the site, the boring number, the core Undisturbed samples of boulders, gravels, or interval, the length of core lost or not sand-gravel mixtures generally are difficult to recovered in each core interval, and the top obtain, and often it is necessary to use hand-and bottom depths of the core interval. If the sampling methods in test pits, shafts, or other box has a removable lid, labeling should be accessible excavations to get good samples.

placed on both the outside and inside of the box, as well as on the lid. Special containers Dewatering by means of well points or other may be required to protect samples to be used suitable methods may sometimes be necessary to for fluid content determinations and shale obtain good-quality undisturbed samples of samples to be used for tests of mechanical pro-coarse-grained soils below the groundwater perties from changes in fluid content. Core table. Osterberg and Varaksin (Ref. 8) samples should be transported with the care describe a sampling program using deutering necessary to avoid breakage or disturbance.

of a shaft in sand with a frozen surrounding annulus. Samples suitable for density determi-C.

REGULATORY POSITION nation, though not for tests of mechanical pro-D perties, may sometimes be obtained from bore-The site investigations program needed to holes with the help of chemical stabilization or determine foundation conditions at a nuclear impregnation (Refs. 9 and 10). Special precau-power plant site is highly dependent on actual tions are required when toxic chemicals are c,ite conditions. The program should be flexible used. Also, where aquifers are involved, it and adjusted as the site investigation proceeds may not be advisable to inject chemicals or with the advice of experienced personnel famil-grouts into them.

Useful discussions of iar with the site. The staff will review the l methods of sampling coarse-grained soils are results of each site investigation program on a given by livorslev (Ref.11) and Barton (Ref.

case-by-case basis and make an independent 12).

evaluation of foundation conditions in order to judge the adequacy of the information

7. Ilandling. Field Storage, and Transporting of presented.

Samples

1. General Site Investigation Treatment of samples after their recovery from the ground is as critical to their quality Site investigations for nuclear power plants as the procedures used in obtaining them.

should be adequate, in terms of thoroughness, Samples of cohesionless soils are particularly suitability of the methods used, quality of sensitive to disturbance in handling and execution of the work, and documentation, to require extreme care during removal from the permit an accurate determination of the borehole, removal from the sampler, and sub-geologic and geotechnical conditions that affect sequent handling in order to prevent disturb-the design, performance, and safety of the ance from impact and vibration (Ref. 6).

plant. The investigations should provide infor-Special precautions are required in transport-mation needed to assess foundation conditions ling undisturbed samples of cohesionless soils at the site and to perform engineering analysis because of their sensitivity to vibration and and design with reasonable assurance that impact. They should be kept in a vertical posi-foundation conditions have been realistically tion at all times, should be well padded to estimated.

isolate them from vibration and impacts, and should be transported with extreme care.

Information to be developed should include, Transportation by commercial carriers is not as appropriate, (1) topographic, hydrologic,

advisable. Block samples should be handled by hydrographic, and geologic maps; (2) plot that give them equivalent protection plan s, showing locations of major structures 9 methods from disturbance. All undisturbed samples and explorations; (3) boring logs and logs of 1.132-7

exploratary trenches and excavations; (4) measurements, piezometers or wells should be gwlogic profiles showing excavation limits for installed in as many locations as needed to structures; and (5) geophysical data such as adequately define the groundwater environ-time-distance plots, profiles, and inhole mee t. Pumping tests are a preferable method surveys. Positions of all boreholes, piezom-for evaluating local permeability characteristics eters, observation wells, soundings, trenches, and assessing dewatering quirements for exploration pits, and geophysical investigations construction and operation of the plant. For should be surveyed in both plan and elevation major excavations where construction dewater-and should be shown on plot plans, geologic ing is required, piezometers or observation sections, and maps. All surveys should be wells should be used during construction to related to a fixed datum. The above information monitor the groundwater surface and pore should be in sufficient detail and be integrated pressures beneath the excavation and in the to develop an overall view of the project and adjacent ground.

the geologic and gentechnical conditions affecting it.

When the possibility of perched groundwater tables or artesian pressures is indicated by

2. Logs of Subsurface Investigations borings or other evidence, piezometer installa-tion should be made to measure each piezom-Boring logs should contain the date when the etric level independently. Care should be taken boring was made, the location of the boring in the design and installation of piezometers to with reference to the coordinate system used prevent hydraulic communication between for the site, the depths of borings, and the aquifers. The occurrence of artesian pressure elevations with respect to a permanent in borings should be noted on boring logs, and benchmark.

their heads should be measured and logged.

The logs should also include the elevations of

4. Procedures for Subsurface Investigations the top and bottom of borings and the level at which the water table and the boundaries of Some techniques widely used for subsurface soil or rock strata were encountered, the investigations are listed in Appendix B, which classification and description of the soil and also cites appropriate standards and references rock layers, blow count values obtained from procedures from published literature with gen-Standard Penetration Tests, percent recovery eral guiJelines on the applicability, limitations, of rock core, quantity of core lost or not and potential pitfalls in their use. The use of recovered for each core interval or drill run, investigations and sampling techniques other and Rock Quality Designation (RQD). Results than those indicated in this guide is acceptable of field permeability tests and borehole logging when it can be shown that the alternative should also be included on logs. The type of methods yield satisfactory results. The attain-tools used in making the boring should be ment of satisfactory results in drilling, sam-recorded. If the tools were changed, the depth plin g, and testing is dependent on the tech-at which the change was made and the reason niques used, on care in details of operations, for the change should be noted. Notes should and on timely recognition of and correction of be provided of everything significant to the potential sources of error.

interpretation of subsurface conditions, such as lost drilling fluid, rod drops, and changes Field operations should be supervised by in drilling rate. Incomplete or abandoned experienced professional perscnnel at the site borings should be described with the same care of operations, and systematic standards of as successfully completed borings. Logs of practice should be followed. Procedures and exploratory trenches and other excavation equipment used to carry out the field open a-features should be presented in a graphic tions should be documented, as should all con-format in which all important components of the ditions encountered in all phases of investiga-soil matrix and structural features in rock are tions. Experienced personnel thoroughly famil-shown in detail sufficient to permit independent iar with sampling and testing procedures evaluation. The location of all explorations should also inspect and document sampling should be shown on the geologic section results and transfer samples from the field to together with elevations and important data.

storage or laboratory facilities.

3. Groundwater Investigations

5. Spacing and Depth of Subsurface Investigations Groundwater conditions should be observed during the course of the site investigation, and General guidelines for the spacing and depth l measurements should be made of the water level of subsurface exploration at locations of in exploratory borings. The groundwater or safety-related structures for favorable or drilling mud level should be measured at the uniform geologic conditions are given in Ap-start of each workday for borings in progress, pendix C to this guide. The actual distribu-at the completion of drilling, and when the tion, number, and depth of borings needed for water levels in the borings have stabilized. In a site should be based on consideration of the addition to the normal boreho e groundwater complexity of geologic conditions and founda-1.132-8

tion requirements. The application of these

c. The Specific Recovery Ratio

• should be guidelines is discussed in Section B.4 of this between 90 and 100 percent; tubes with less D

guide. The investigative effort required for a recovery may be acceptable if it appears that nuclear power plant should be greatest at the the sample may have broken off and otherwise locations of safety-related structures and may appears essentially undisturbed; vary in density and scope in other areas according to their spatial and geological

d. The Inside Clearance Ratio

• should be the relations to the site, minimum required for complete sample recovery; and

6. Sampling

e. Samples recovered should contain no Sampling of soils should include, as a mini-visible distortion of strata or opening or mum, the recovery of samples at regular softening of materials brought about by the intervals and at changes in materials.

sampling procedure.

Alternating split spoon and undisturbed samples with depth is recommended.

7. Retention of Samg !es. Rock Core, and Records For coarse-grained soils, samples should be Samples and rock cores from principal taken at depth intervals no greater than 5 feet borings should be retained at least until the (1.5 meters). Beyond a depth of 50 feet power plant is licensed to operate and all (15 meters) below foundation level, the depth matters relating to the interpretation of sub-interval for sampling may be increased to 10 surface conditions at the site have been feet (3 meters). Also it is recommended that resolved. The need to retain samples and core one or more borings for each major structure beyond this time is a matter of judgment and be evntinuously sampled. The boring should be should be evaluated on a case-by-case basis.

reamed and cleaned between samples. Require-For example, soil samples in tubes will ments for undisturbed sampling of coarse-deteriorate with time and will not be suitable grained soils will depend on actual site condi-for any undisturbed testing. However, they tions and requirements for laboratory testing.

may be used as a visual record of what the Some general guidelines for recovering undis-foundation material is like. Similarly, cores of turbed samples are given in Sections B.4.b(2) rock subject to slaking and rapid weathering and B.6 of this guide. Experimentation with such as shale will also deteriorate. It is different sampling techniques may be necessary recommended that photographs of soil samples D conditions, to determine the method best suited to local soil and rock cores together with field and final logs of all borings and record samples with material descriptions be preserved for a For compressible or normally consolidated permanent record. Other important records of clays, undisturbed samples should be con-the subsurface investigations program should tinuous throughout the compressible strata in also be preserved.

one or more principal borings for each major structure. These samples should be obtained D.

IMPLEMENTATION by means of suitable fixed-piston-type thin-wall tube samplers or by methods that yield Except in those cases in which the applicant samples of equivalent quality.

proposes an acceptable alternative method for complying with specified portions of the Com-Borings used for undisturbed sampling of mission's regulations, this guide will be used sous should be at least 3 inches (7.6 cm) in by the staff to evaluate the results of founda-diameter. Criteria for obtaining undisturbed tion investigations submitted in connection with tube samples include the following:

construction permit applications docketed after March 30, 1979. The staff will also use this

a. Tubes should meet the specifications of guide to evaluate the results of foundation ASTM Standard D1587-67 (Ref.13);

investigations performed after March 30, 1979, for new construction or major changes in plant

b. The Area Ratio

• of the sampler should not layout or design by a person whose exceed 13 percent and preferably should not construction permit was issued on or before exceed 10 percent; March 30,1979.

D 1.132-9

APPENDIX A DEFINITIONS For the convenience of the user, the Observation well - an open boring that per-following terms are presented with their mits measuring the level of elevation of the definitions as used in this guide:

groundwater table.

Accessible excavation - an excavation made Piezometer - a device or instrument for mea-for the purpose of investigating and sampling suring pore pressure or hydraulic potential at materials or conditions below the ground a level or point below the ground surface.

surface, of such shape and dimensions as to permit the entry of personnel for direct Principal boring - an e>rloratory hole that is examination, testing, or sampling.

used as the primary source of subsurface information. It is used to explore and sample Area Ratio (C ) of a sampling device is all soil or rock strata within the interval pene-defined as:

trated to define the geology of the site and to determine the properties of the subsurface 2

2 D

- D materials. Not included are borings from which g

C* =

2 n

samples are taken, borings used to D

investigate specific or limited intervals, or borings so close to others that the information where D is the outside diameter of that part of yielded represents essentially a single location.

the sam;91ing device that is forced into the soil and D is the inside diameter, normally the Representative sample - a sample that (1) diamet8r of the cutting edge, contains approximately the same mineral con-stituents of the stratum from which it is taken, Boring - an exploratory hole in soil or rock, in the same proportions, and with the same or both, made by removal of materials in the grain-size distribution and (2) is uncon-form of samples or cuttings (cf. sounding).

taminated by foreign materials or chemical alteration.

Disturbed sample - a sample wnose internal structure has been damaged to su,ch a degree Rock Quality Designation (RQD) - an indirect that it does not reasonably approximate that of measurement of the degree of rock fracturing the material in situ. Such a sample may bear a and jointing and rock quality. It is calculated resemblance to an undisturbed sample in by summing the lengths of all hard and sound having preserved the gross shape given it by a pieces of recovered core longer than 4 inches sampling device.

(10 cm) and dividing the sum by the total Geotechnical - of or pertaining to the earth sciences (geology, soils, seismology, and Sounding - an exploratory penetration below groundwater hydrology) and that part of civil the ground surface by means of a device that engineering that deals with the interrelation-is used to measure or observe some in situ ship between the geologic environment and the property of the materials penetrated, usually works of man.

without recovery of samples or cuttings.

In situ soil structure - a complex physical-of a sample tube is defined asi) in the advance specific Recovery Ratio (R mechanical property, defined by the sizes,

shapes, and arrangements of the constituent grains and intergranular matter and thc R,_ALg bonding and capillary forces acting among the constituents,

where AL is the increment of length of sample In situ test - a test performed on in-place in the tube correspor. ding to an increment AH soil or rock for the purpose of determining of sampler advance.

some physical property. As used in this guide, it includes geophysicd measurements.

Supplementary boring or supplementary sounding - boring or sounding that is made in Inside Clearance Ratio (C ) of a sampling addition to principal borings for some specific g

device is defined as:

or limited purpose.

D

-D 3

e Ci=

D Undisturbed sample - a sample obtained and e

handled in such a way that disturbance of its where Ds.s the inside diameter of the sample original :tructure is minimal so that the sample tube or liner and D, is the diameter of the is suitable for laboratory tests of material pro-cutting edge.

perties that depend on in situ soil structure.

1.132-10

APPENDlX B I

METHODS OF SUBSURFACE EXPLORATION METIIOD PROCEDURE APPLICABILITY LIMITATIONS

1. Methods of Access for Sampling. Test, or Observation Pits, Trenches, Shafts, Excavation made by hand, Visual observation, photography, Depth of unprotected excavations Tunnels large auger, or digging disturbed and undisturt ed sampling, is hmited by groundwater or safe-machinery. (Ref.11) in situ testing of soil and rock.

ty considerations.

Auger Boring Boring advanced by hand Recovery of remolded samples and Will not penetrate boulders or most auger or power auger determining groundwater levels.

rock.

(Ref.11)

Access for undisturbed sampling of cohesive soils.

Hollow Stem Auger Boring advanced by means of Access for undisturbed or representa-Should not be used with plug in Boring continuous-flight helix auger tive sampling through hollow stem with coarse-grained soils. Not suitable with hollow center stem.

thin-wall tube sampler, core barrel, for undisturbed sampling in loose (Ref. 14) or split-barrel sampler.

sand or sil' (Ref. 15)

Wash Boring Boring advanced by chopping Cleaning out and advancing hole in Suitable for use with sampling with light bit and by jetting soil between sample intervals.

operations in soil only if done with g

with upward-deflected jet.

Iow water velocities and with up-a (Ref.11) ward-deflected jet.

Rotary Drilling Boring advanced by rocating Cleaning out and advancing hole Drilling mud should be used in drilling bit; cuttings removed in soil or rock between sample coarse-grained soils. Bottom dis-by circulating drilling fluid.

intervals.

charge bits are not suitable for (Ref. 11) use with undisturbed sampling in soils unless combined with protmd-ing core barrel, as in Denison sam-pler, or with upward-deflected jets.

Percussion Drilling Boring advanced by air-Detection of voids and zones of Not suitable for use in soils, operated impact hammer.

weakness in rock by changes in drill rate or resistance. Access for in suu testing or logging.

Cable Drilling Boring advanced by repeated Advancing hole in soil or rock.

Causes severe disturbance in soils; dropping of heavy bit; removal Access for sampling, in situ not suitable for use with undis-of cuttings by bailing.

testing, or logging in rock, turbed sampling methods.

( Ref. 11 )

Penetration of hard layers, gravel, or boulders in auger borings.

iSee also Reference 5.

APPENDIX B (Continued)

METHODS OF SUBSURFACE EXPLORATION METilOD PROCEDURE APPLICAllILITY LI\\tITATIONS

1. Methods of Access for Sampling. Test, or Observation (Continued)

Continuous Sampling or Boring advanced by repeated Recovery of representative samples Effects rf advance and withdrawal Displacement Boring pushing of sampler or closed of cohesive soils and undisturbed of sampler result in aisturbed sec-sampler is pushed to desired samples in some cohesive soils, tions at top and bottom of sample.

depth and sample is taken.

In some soils, entire sample may be

( Ref. 11) disturbed. Best suited for use in cohesive soils. Continuous sampling in cohesionless soils may be made by successive reaming and cleaning of hole between sampling.

2. Methods of Sampling Soil and Rock liand-Cut Block Sample is cut by hand from liighest quality undisturbed samples Requires accessible excavation and or Cylindrical Sample soil exposed in excavation.

in all soils and in soft rock.

dewatering if below water table.

(Refs.16 and 17)

Extreme care is required in sam-

-y pling cohesionless soils.

Fixed-Piston Sampler Thin-walled tube is pushed Undisturbed samples in cohesive Some types do not have a positive into soil, with fixed piston soils, silts, and sands above or means to prevent piston movement.

in contact with top of sample below the water table.

during push. (Refs. 6 and 11) llydraulic Piston Sampler Thin-walled tube is pushed Undisturbed samples in cohesive Not possible to detennine amount (Osterberg Sampler) into soil by hydraulic pres-soils, silts, and sands above or of sampler penetration during push.

sure. Fixed piston in contact below the water table.

Does not have vacuum-breaker in with top of sample during pis ton.

push. (Refs. 6,18, and 19)

Free-Piston

.pler Thin-walled tube is pushed Undisturbed samples in stiff co-May not be suitable for sampling into soil. Piston rests on hesive soils. Representative in cohesionless soils. Free piston top of soil sample during samples in soft-to-medium cohesive provides no control of specific push. (Ref. 6) sons and sHts.

recovery ratio.

Open Drive Sampler Thin-walled, open tube is Undisturbed samples in stiff cohe-Small diameter of tubes may not be pushed into soil. (Refs. 11 sive soils. Representative samples suitable for sampling in cohesion-and 16) in soft-to-medium cohesive soils less soils or for undisturbed sampling and silts.

in uncased boreholes. No control of specific recovery ratio.

9 9

W APPENDlX B (Continued)

METHODS OF SUBSURFACE EXPLORATION METilOll PROCEDURE APPL.ICABILIW LIMITATIONS

2. Methods of Sampling Soil and Rock (Continued)

Swedish Foil Sampler Sample tube is pushed into Continuous undisturbed samples up Not suitable for use in soils con-soil while stainless steel to 66 feet (20 m) long in very taining gravel, sand layers, or strips unrolling from spools soft to soft clays.

shells, which may rupture foils and envelop sample. Piston, fixed damage samples. Difficulty may be by chain from surface, main-encountered in a"ernating hard and tains contact with top of sam-soft layers with squeezing of soft ple. (Refs. 17 and 20) layers and reduction in thickness.

R.. quires expc.-fenced operator.

Pitcher Sampler Thin-walled tube is pushed Undisturbed samples in stiff, hard, Frequently ineffec'.ive in cohesion-into soil by spring above brittle, cohesive soils and sands less soils.

sampler while outer core bit with cementation and in soft rock.

reams hole. Cuttings removed Effective in sampling alternating by circulating drilling fluid.

hard and soft layers. Representa-g (Ref. 17) tive samples in soft-to~ mediura cohesive eg soils and silts. Disturbed samples may be obtained in cohesionless materials with variable success.

Denison Sampler IIole is advanced and reamed Ur. disturbed samples in stiff-to-hard Not suitable for undisturbed sam-by core drill while sample is cohesive soil, sands with cementation',

pling in loose cchesionless soils retained in nonrotating inner and soft rocks. 1;isturbed sample may or soft cohesive soils. Difficulties core barrel with corecatcher.

be obtained in cohesionless materials may be experienced in sampling Cuttings removed by circulating with variable success.

alternating hard and soft layers.

drilhng fluid. (Refs. 16 and 17)

Split-Barrel or Split Split-barrel tube is driven into Representative samples in soils Samples are disturbed and not suit-Spoon Sampler soil by Llows of falling ram.

other than coarse-grained soils.

able for tests of physical properties.

Sampling is carried out in conjunction with Standard Penetrr.uon T(st.

( Ref. 13)

Auger Sampling Auger drill used to advance Detemine boundaries of soil layers Samples not suitable for physical hole is withdrawn at intervals and obtain samples for soil classifica-properties or density tests. Large for recovery of seil < aples tion.

errors in locating strata boundaries from auger flights.

( Ref. 13) may occur without close attention to details of procedure. (Ref. 17) In some soils, particle breakdown by auger or sorting effects may result in errors in detemining gradation.

APPENDIX B (Continued)

METHODS OF SUBSURFACE EXPLCRATION

\\lETHOD PROCEDURE APPLICABILITY LIMITATIONS

2. Methods of Sampling Soil and Rock (Continued)

Rotary Core Barrel Hole is advanced by core bit Core samples in competent rock and Because recovery is poorest in zones while core sample is retained hard soils with single-tube core of weakness, samples generally fail within core barrel or within barrel. Core samples in poor or to yield positive information on soft stationary inner tube. Cut-broken rock may be obtainable with seams, joints, or other defects in tings removed by circulating double-tube core barrel with bottom-

rock, drilling fluid. (Ref.13) discharge bit.

Shot Core Boring Boring advanced by rotating Large-diameter cores and accessible Cannot be used in drilling at large (Calyx) single core barrel, which cuts boreholes in rock, angles to the vertical. Often inef-by grinding with chilled steel fective in securing small-diamete.r shot fed with circulating wash cores.

water. Used shot and coarser cuttings are deposited in an annular cup, or calyx, above

~

the core barrel. (Ref.11)

U wa Oriented Integral Reinforcing rod is grouted Core samples in rock with preserva-Samples are not well suited to tests A

Samphng into small-diameter hole, then tion of joints and other zones of of physical properties.

overcored to obtain an annular weakness.

core sample. (Ref. 21).

Wash Sampling or Cuttings are recovered from Samples useful in conjunction with Sample quality is not adequate for Cuttings Sampling wash water or drilling fluid.

other data for identification of major site investigations for nuclear strata.

facilities.

Submersible Vibratory Core tube is driven into soil Continuous representative samples Because of high area ratio and (Vibracore) Sampler by vibrator. (Ref. 22) in unconsolidated marine sediments.

effects of vibration, samples may be disturbed.

Underwater Piston Corer Core tube attached to drop Representative samples in uncon-Samples may be seriously disturbed weight is driven into soil by solidated marine sediments.

(Ref. 24) gravity after a free fall of con-trolled height. Cable-supported piston remains in contact with soil surface during drive.

(Ref. 23)

Gravity Corer Open core tube attached to Representative samples at shallow No centrol of specific recovery drop weight is driven into soil depth in unconsolidated marine ratio. Samples are disturbed.

by gravity after free fall.

sediments.

(Ref. 23)

W W

W APPENDIX B (Continued)

METHODS OF SUBSURFACE EXPLORATION METi!0D PROCEDURE AFPLICABILITY LIMITATIONS

,3. Methods of In Situ Testing of Soil and Rock 2 Standard Penetration Split-barrel sampler is driven Blow count may be used as an index Extremely unreliable in silts, silty Test into soil by blows of free of consistency or density of soil.

sands, er soils containing gravel.

falling weight. Blow count for May be used fcr detection of changes In sands below water table, posi-each 6 in. (15 cm) of penetra-in consistency or density in clay or tive head must be maintained in tion is recorded. (Ref. 13) sands. May be used with empirical borehole. Determination of relative relationships to estimate relative density in sands requires site-density of clean sand.

specific correlation or highly con-servative use of published correla-tions. Results are sensitive to details of apparatus and procedure.

Dutch Cone Penetrometer Steel cone is pusned into soil Detection of changes in consistency Strength estimates require onsite and followed by subsequent or relative density in clays or sands.

verification by other methods of advance of friction sleeve.

Used to estimate static undrained testing.

Resistance is measured during shear strength of clay. Used with M

both phases of advance.

empirical relationships to obtain

.L (Ref. 26) estimate of static compressibility of sand.

Field Vane Shear Test Four-bladed vane is pushed Used to estimate in situ undrained Not suitable for use in silt, sand, into undisturbed soil, then shear strength and sensitivity of or soils containing appreciable rotated to cause shear failure clays.

amounts of gravel or shells. May on cylindrical surface. Tor-yield unconservative estimates of sional resistance versus shear strength in fissured clay angular deflection is recorded, soils or where strength is strain-(Ref. 13) rate dependent.

Drive-Point Penetrometer Expendable steel cone is Detection of gross changes in con-Provides no quantitative informa-driven into soil by blows of sistency or relative density. May tion on soil properties.

falling weight. Blow count be used in some coarse-grained versus penetration is soils.

recorded. (Ref.17)

Plate Bearing Test (Soil) Steel loading plate is p; aced on Estimation of strength and rrodui.

Results can be extrapolated to horizontal surface and is stati-of soil. May be used at ground loaded areas larger than hearing cally loaded, usually by hy-surface, in er avations, or in platt only if properties of soil are draulic jack. Settlement versus boreholes,

uniform laterally and with depth.

time is recorded for each load increment. (Ref. 17) zSee also Reference 25.

APPENDIX B (Continued)

METHODS OF SUBSURFACE EXPLORATION M ETilOD PROCEDURE APPLICAHILITY LIMITATIONS

3. Methods of in Situ Testing of Soil and Rock (Continued)

Plate Bearing Test or Bearing pad on rock surface is Estimation of elastic moduli of rock Results can be extrapolated to Plate Jacking Test statically loaded by hydraulic masses. May be used at ground sur-baded areas larger than bearing (Rock) jack. Deflection versus load is face, in excavations, in tunnels, or pad only if rock properties are recorded. (Ref. 27) in boreholes, unifom over volume of interest and if diameter of bearing pad is larger than average spacing of joints or other discontinuities.

Pressure Meter Test Unifom radial pressure is Estimation of elastic moduli of Test results represent properties (Dilatometer Test) applied hydraulically over a rocks and estimation of shear only of materials in near vicinity length of borehole several strengths and compressibility of borehole. Results may be mis-times its diameter. Change of soils by empirical relationships.

leading in testing materials whose in diameter versus pressure properties may be anisotropic.

is recorded. (Refs. 27 and 28) g w

Field Pumping Test Water is pumped from or into Estimation of in situ permeability Apparent pemeability may be aquifer at constant rate of soils and rock mass.

greatly influenced by local fea-tures. Effective nermeability of through penetrating well.

Change in piezometric level rock is dependent primarily on is measured at well and at one frequency and distribution of joints.

or more obrervation wells.

Test result in rock is representative Pumping pressures and flow only to extent that the borehole rates are recceded. Packers intersects a sufficient number of may be used for pump-in pres-joints to be representative of the sure tests. (Refs. 29 and 30) joint system of the rock mass.

Borehole Field Permea-Water is added to an open-Rough approximation of in situ Pipe casing must be carefully bility Test ended pipe casing sunk to permeability of soils and rock cleaned out just to the bottom desired depth. With constant

mass, of the casing. Clear water head tests, constant rate of must be used or tests may be gravity flow into hole and size grossly misleading. Measure-of casing of pipe are measured.

ment of local pemeability Variations include applied pres-only.

sure tests and falling head testr.. (Ref. 16)

APPENDIX B (Continued)

METHODS OF SUBSURFACE EXPLORATION NILTiiOD PROCEDURE APPLICABILITY LIMITATIONS

3. Slethods of In Situ Testing of Soil and Rock (Continued)

Direct Shear Test Block of in situ rock is iso-Measurement of shearing re-Tests are costly. Usually variabil-lated to permit shearing along sistance of rock mass in situ.

ity of rock mass requires a suffi-a preselected surface. Normal cient number of tests to provide and shearing loads are applied statistical control.

by jacking. Loads and dis-placements are recorded.

(Ref. 31)

Pressure Tunnel Test flydraulic pressure is applied Determination of elastic constants Volume of mck tested is dependent to sealed-off length of circular of the rock mass in situ.

on tunnel diameter. Cracking due tunnel, and diametral deforma-to tensile hoop stresses may affect tions are measured. (Ref. 27) apparent stiffness of rock.

Radial Jacking Test Radial pressure is applied to a Same as pressure tunnel test.

Same as pressure tunnel test.

~

23 length of circular tunnel by flat 7

jacks. Diametral deformations G

are measured. (Refs. 32 and 33)

Borehole Jack Test Load is applied to wall of bore-Determination of elastic modulus of Apparent stiffness may be affected hole by two diametrically op-rock in situ. Capable of apply-by development of tension cracks.

posed jacks. Deformations and ing greater pressures than pressures are recorded.

duatometers.

(Ref. 34)

Borehole Deformation Device for measurement of Measurement of absolute stresses Stress field is affected by bore-Meter diameters (deformation meter) in situ.

hole. Analysis subject to limita-is placed in borehole, and hole tions of elastic theory. Two bore-is overcored to relieve stresses holes at different orientations are on annular rock core containing required for determination of com-deformation meter. Diameters plete stress field. Questionable (usually 3) are measured before results in rocks with strongly and after overcoring. Modulus time-dependent properties.

of rock is measured by labora-tory tests on core; stresses are computed by elastic theory.

(Ref. 35)

APPENDlX B (Continued)

METHODS OF SUBSURFACE EXPLORATION METilOD Pf0CEDURE APPLICABILID' fl\\flTATIONS

3. Methods of In Situ Testing of Soil and Rock (Continued)

Inclusion Stressmeter Rigid stress indicating device Measurement of absolute stresses Same as above.

(stressmeter) is placed in bore-in situ. Does not require accurate hole, and hole is overcored to knowledge of rock modulus, relieve stresses on annular core containing stressmeter. In situ stresses are computed by elastic theory. (Ref. 3" Borehole Strain Gauge Strain gauge is v,

.-d to Measurement of absolute stresses in Same as above.

bottom (end) of borea.

• ,and situ. Requires only one core driu gauge is overcored to re ieve size.

stresses on core-containin c strain gauge. Stresses ars computed from resulting strains and from modulus

_g obtained by laboratory a

tests on core. (Ref. 35) m Flat Jack Test Slot is drilled in rock surface Measurement of one component Stress field is affected by excava-producing stress relief in of normal stress in situ. Does tion or tunnel. Interpretation of adjacent rock. Flat jack is not require knowledge of rock test results subject to assumption grouted into slot and hydrau-modulus.

that loading and unloading moduli lically pressurized. Pressure are equal. Questionable results in required to reverse deforma-

k with strongly time-dependent tions produced by stress pro, erties.

rehef is observed. (Refs. 35 and 36)

Hydraulic Fracturing Fluid is pumped into sealed-off Estimation of minor principal Affected by anisotropy of tensile Test portion of borehole with pres-stress.

strength of rock.

sure increasing until fracture occurs. (Ref. 35)

Crosshold Seismic Test Seismic signal is transmitted In situ measurement of com-Requires deviation survey of bore-from source in one borehole pression wave velocity and shear holes to eliminate errors due to to receiver (s) in other bore-wave velocity in soils and rocks.

deviation of holes from vertical.

hole (s), and transit time is Refraction of signal through recorded. (Ref. 37) adjacent high-velocity beds must be considered in interpretation.

APPENDIX B (Continued)

METHODS OF SUBSURFACE EXPLORATION METIIOD PROCEDURE APPLICABILITY LIMITATIONS

3. Methods of In Situ Testing of Soil and Rock (Continued)

Uphole/ Downhole Seismic Seismic signal transmitted In situ measurement of compression Apparent velocity obtained is time-Test between borehole and ground wave velocity and shear wave velo-average for all strata between surface, and transit time is city in soils and rocks.

source and receiver.

recorded. (Ref. 37)

Acoustic Velocity Log Logging tool contains trans-Measurement of compression wave Results represent only the mate-mitting transducer and two velocity. Used primarily in rocks rial immediately adjacent to the receiving transducers sepa-to obtain estimate of porosity.

barehole. Can be obtained only rated by fixed gage length.

in uncased, fluid-filled borehole.

Signal is transmitted through Use is limited to materials with rock adjacent to borehole, P-wave eelocity greater than that and transit time over the gage of borehole fluid.

length is recorded as differ-ence in arrival times at the receivers. (Refs. 38 and 39)

OO 3-D Velocity Log Logging tool contains transmit-Measurement of compression wave Results represent only the material ting transducer and receiving and shear wave velocity ties in immediately adjacent to the borehole-transducer separated by fixed rock. Detection of void spaces.

Can be obtained only in uncased, gage length. Signal is trans-open fractures, and zones of fluid-filled borehole. Correction mitted through rock adjacent weakness.

required for variation in hole size.

to borehole, and wave train Use is Umited to materials with P-at receiver is recorded.

wave velocity greater than that of (Ref. 40) borehole fluid.

Electrical Resistivity Log Apparent electrical resistivity Appropriate combinations of Can be obtained only in uncased of soil or rock in neighborhood resistivity logs can be used to boreholes. IIole must be fluid of borehole is measured by estimate porosity and degree of filled, or electrodes must be in-hole logging tool containing water saturation in rocks In soils.

pressed against wall of hok.

one of a wide variety of elec-may be used as qualitative indica-Apparant resistivity values are trode configurations.

tion of changes in void ratio or strongly affected by changes in (Refs. 38 and 39) water content, for correlation of hole diameter, strata thickness, strata between boreholes, and for resistivity contrast between location of strata boundaries, adjacent strata, resistivity of driPJng fluid, etc.

APPENDIX B (Continued)

METHODS OF SUBSURFACE EXPLORATION NtETilOD PROCEDURE APPLICABILITY LI%tITATIONS

3. Stethods of In Situ Testing of Soil and Rock (Continued)

Neutron Log Neutrons are emitted into rock Correlation of strata between bore-Because of very arong borehole or soil around borehole by a holes and location of strata bound-effects, results are generally not neutron source in the logging aries. Provides an approximation to of sufficient accuracy for quantita-tool, and a detector isolated water content and can be run in tive engineering uses.

from the source responds to cased or uncased, fluid-filled or either slow neutrons or second-empty boreholes.

ary gamma rays. Response of detector is recorded.

(Refs. 36 nd 39)

Gamma-Gamma Log Gamma rays are emitted into Estimation of bulk density in rocks, Effects of borehole size and density

(" Density Log")

rock around the borehole by a qualitative incication of changes in of drilling fluid must be accounted source in the logging tool, and density of soils. May be run in for. Presently not suitable for a detector isolated from the empty or fluid-filled holas.

qualitative estimate of density in source responds to back-soils other than those of " rock-O scattered gamma rays.

IAe" character. Cannot be used A

Response of detector is ir cased boreholes.

recorded. (Ref. 38)

Borehole Cameras Film-type or television camera Detection and mapping of joints, Results are affected by any condi-in a suitable protective con-seams, cavities, or other visually tion that affects visibility.

tainer is used for observation observable features in rock. Can of walls of borehole.

be used in empty, uncased hcles or (Ref. 41) in holes filled with clear water.

APPENDIX C SPACING AND DEPTH OF SUBSURFACE EXPLORATIOh'3 FOR SAFETY-RELATEDI FOUNDATIONS 2

TYPE OF STRUCfURE SPAC { OF BORINGS OR SOUNDINGS MINIMUM DEI'Til OF PENETRATION General For favorab), uniform geologic conditions, where con-The depth of borings should be determined on the tinuity of a ibsurface strata is found, the recowended basis of the type of structure and geologic conditions.

spacing is us indicated for the type of structure. At All borings should be extended to a depth sufficient least one boring should be at the location of every safe-to define J ' site geology and to sample all materials ty-related structure. Where variable conditions are that may swe..e during excavation, may consolidate found, spacing should be smaller, as needed, to obtain subsequent to construction, tuay be unstable under a clear picture of soil or rock properties and their earthquake loading, or whose physical properties variability. Where cavities or other discontinuities of would affect foundation behavior or stability. Where engineering significance may occur, the normal soils are very thick, the maximum required depth for exploratory work should be supplemented by borings engineering purposes, denoted dmax, may be taken as or soundings at a spacing small enough to detect such the depth at which the change in the vertical stress featu res.

during or after construction for the combined founda-tion loading is less than 10% of the in situ effective overburden stress. It may be necessary to include in l the investigation program several borings to establish the soil model for soil-structure interaction studies.

These borings may be required to penetrate depths M

greater than those depths required for general engi-4 neering purposes. Borings should be deep enough to

~

define and evaluate the potential for deep stability problems at the site. Generally, all borings should extend at least 30 feet (9 meters) below the lowest part of the foundation. If competent rock is encoun-tered :it lesser depths than those given, borings should penetrate to the greatest depth where discon-tinuities or zones of weakness or alteration can affect foundations and should penetrate at least 20 feet (6 meters) into sound rock. For weathered shale or soft rock, depths should be as for soils.

1As determined by the final locations of safety-related structures and facilities.

2 Includes shafts or other accessible excavations that meet depth requirements.

APPENDIX C (Continued)

I FOUNDATIONS SPACING AND DEPTH OF SUBSURFACE EXPLORATIONS FOR SAFETY-RELATED TYPE OF STRUCTURE SPACING OF BORINGS 2 OR SOUNDINGS MINIMUM DEPTH OF PENETRATION Structures including Principal borings: at least one boring beneath every At least one-fourth of the principal borings and a buildings, retaining safety-related structure. For larger, heavier struc-minimum of one boring per structure to penetrate walls, concrete dams, tures, such as the containment and auxiliary bu21dinge, into sound rock or to a depth equal to dmax. Others 2

2 at least one boring per 10,000 ft (900 m ) (approxi-to s depth below foundation elevation equal to the mately 100-foot (30-meter) spacing). In addition, a wiath of structure or to i depth equal to the fcunda-number of borings along the periphery, at corners, tion depth below the original ground surface, whichever and other selected locations. One boring per 100 linear is greater.8 feet (30 linear meters) for essentially linear structures.3 Earth dams, dikes, Principal borings: one per 100 linear feet (30 linear Principal borings: one per 200 linear feet (60 linear levees, and embank-meters) along axis of structure and at critical locations meters) to dmax. Others should penetrate all strata ments perpendicular to the axis t establish geological sec-whose properties would affect the performance of the tions with groundwater ccnditions for analysis.8 foundation. For water-impounding structures, to sufficient depth to define all aquifers and zones of underseepage that could affect the performance of

~

g stmetu res.

Yy Deep cuts,*

Principal borings: one per 200 linear feet (60 linear Principal borings: one per 200 linear feet (60 linear canals meters) along the alignment and at critical locations meters) to penetrate into sound rock or to dmax-perpendicular to the alignment to establish geologic Others to a depth below the bottom elevation of exca-sections with groundwater conditions for analysis.8 vation equal to the depth of cut or to below the 8

lowest potential failure zone of the slope Borings should penetrate previous strata below which ground-waar may influence stability.2 Pipelines Principal borings: This may vary depending on how Principal borings: For buried pipelines, one of every well site conditions are understood from other plant three to penetrate into sound rock or to dmax. Others site borings. For variable conditions, one per 100 to 5 times the pipe diameters below the invert elevation.

linear feet (30 linear meters) for buried pipelines; at For pipelines above ground, depths as for foundation least one boring for each footing for pipelines above structu res. 3, s groun d. 5 Tunnels Principal borings: one per 100 linear feet (30 linear Principal borings: one per 200 linear feet (60 linear meters),8 may vary for rock tunnels, depending on meters) M r>enetrate into sound rock or to dmax. Others rock type and characteristics, and planned exploratory to 5 times the tunnel diameter below the invert shafts or adits.

elevation. 4, s 3Also supplementary borings or soundings that are design dependent or necessary to define anomalies, critical conditions, etc.

4 Includes temporary cuts that would affect ultimate site safety.

5Supplementary boringc or soundings as necessary to define anomalies.

APPENDIX C (Continued)

SPACING AND DEPTH OF SUBSURFACE EXPLORATIONS FOR SAFETY.RELATEDI FOUNDATIONS TYPE OF STRUCTURE SPACING OF BORINGS 2 OR SOUNDINGS MINIMUM DEI'Til OF PENETRATION Reservoirs, Principal borings: In addition to borings at the loca-Principal borings: at least one-fourth to penetrate impoundments tions of dams or dikes, a number of borings should that portion of the saturation zone that may influence be used to investigate geologic conditions of the seepage conditions or stability. Others to a depth of reservoir basin. The number and spacing of borings 25 feet (7.6 meters) below reservoir bottom should vary with the largest concentration being near.

elevation. 5 control structures and the coverage decreasing with distance upstream.

Y U

APPENDlX D REFERENCES

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Barton, " Borehole Sampling of tation of Earth and Rock-Fill Dams (Ground-Saturated Uncemented Sands and G routs,"

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neer MadiiaTT.M 1110-2-1908,1972.

~~

13. American Society for Testing and Mate-

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Testing Soil and Rocx for Engmeering Pur-J. Soil Mech. Found. Div., American Society of poses, AmTiican Society for Testing and 14ile-Ulvillngineers,1972 T. 98(SM5): pp. 481-nals, Philadelphia, STP 479,1969, pp. 69-70.

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20. W.

Kjellman,

T.

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Groundwater Table," Evaluation of Relative Wager, Soil Sampler with Metal Foils, Royal Density and Its Role in Geotechnical Projects Swedish 7eotechnical Institute, Proce c. ling Involvmg Cohesionless boils, Amencan Society No.1, Stockholm, Sweden,1950.

for Testmg and Materials, Philadelphia, STP 523,1973, pp. 364-376.

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.n and M. Soulie, " Technique Sampling, Testing, and Construction Contr51-for Study of Gt sular Materials," J. Soil Mech.

American Society for Testing and Materials,

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2",

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and Saopling of Soils Tor Civil Engineenng Unduwater Soil Sampling, Testing, and Con-

Purposes, U.S' Army Wilerways Experunent stri etion Coni 61, Amencan Society for Testmg Btation, Vicksburg, Mississippi,1949, pp. 51-and 1'Hienals, Philadelphia, STP 501, 1972, 71,83-139, 156-157.

pp. 3-41.

1.132-24

24. F.W. McCoy, Jr., "An Analysis of Piston

33. G.B. Wallace, E.J.

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Ccring Through Corehead Camera Photo-Anderson, " Radial Jacking Test for Arch D

and Construction ControT, Amencan So'cTety for graphy," Underwater Soil Sampling, Tesjtin Dams," Proceedings of the Tenth ySnposium on Rock Mechanics, Austm Texas,19G8, pp. 633-Testing and bfaterials, Philadelphia STP 501, F6E 1972, pp.90-105.

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T.K.

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~ ~

Response Analyiii', U.S. AEC Report-~ 972.

1

35. A. Roberts, "The Measurement of Strain and Stress in Rock Masses," Rock Mechanics in

26. J.H Schmertmann, " Suggested Method for Dee; -atatic-Core Penetration Test," Special Engineering Practice,

K.G.

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Engineenng Erposes, AmVican Society f6r New York,1968, pp.166-191,194.

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~

ability Testing of In Situ Rock Masses," Deter-mination of the In Situ Modulus of Deformation

27. K.G. Stagg, "In Situ Tests on the Rock

, Society for Testing and f Rock, Amencan Mas s," Rock Mechanics in Engineering Prac-tice, K.G. Stagg and O.C. Zienkiewicz, edi,

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and F.G. McLean,

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and Flow Wets, John Wiley Tanons, Tnc., New Y5rk' 19sF*

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40. R.L. Geyer and J.I. Myung "The 3-D

31. R.K. Dodds, " Suggested Method Special Velocity Log; A Tool for In Situ De' termination Procedures for Testing Soil and Rock for Engmeenng Erposes, Amen,can, Society f5r of the Elastic Moduli of Rocks," Proceedings of the Twelfth Symposium on Rock Mechanics'-

estmg and aterials, Philadelphia, STP 479' Rolla, Missouri,1971, pp.71-107.

o

41. R. Lundgren, F.C. Sturges, and L.S.

32. D.L. Misterek, " Analysis of Data from Cluff, " General Guide for Use of Borehole Radial Jacking Tests," Determination of the In Cameras-- A Guide," Special Procedures for Situ Modulus of Deformation of Rock, Tm Fican Testing Soil and Rock for Engmeermg Pur--

35ciety for Testmg and Materiali, Miiladelphia, poses, AmEcan-Society f5r Testmg and Mate-t STP 477,1970, pp. 27-38.

rials, Philadelphia, STP 479,1970, pp. 56-61.

I 1.132-25

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