ML20050A920

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Soil Dynamic Modulus Study
ML20050A920
Person / Time
Site: Midland
Issue date: 03/05/1982
From:
DAMES & MOORE
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Shared Package
ML20050A919 List:
References
NUDOCS 8204020395
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{{#Wiki_filter:.. -. -i ' f~ i l l 1 I I l i I 1 i I 1 i l l l l <l; i i i t REPORT S0Il DYNAMIC MODULUS STUDY l MIDLAND UNITS 1 AND 2 CONSUMERS POWER COMPANY i BECHTEL TECHNICAL SERVICES AGREEMENT 7220-C-1(Q) ,;i

i Dames & Moore EXTRA 00 I

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r g, i 1550 Lrthwest Highway Dames & Moore u ame2-s % (312) 297-6120 TWX. 910-253-4097 Ciole address: DANIEMORE I i March 5, 1982 a i l Bechtel Associates Professional Corporation P. O. Box 1000 I 777 East Eisenhower Parkway 1 Ann Arbor, Michigan 48106 Attention: Mr. L. H. Curtis DMO-17 Project Engineer Gentlemen; Re: Report i t Soil Dynamic Modulus Study f Consumers Power Company, Midland Units 1 and 2 Bechtel Technical Services Agreement 7220-C-1(0) This letter transmits 15 copies of our Report - Soil Dynamic Modulus Study for M1dland Units 1 and 2. The scope of the services was presented in Bechtel's Technical Services Agreement 7220-C-1(Q). It is our opinion that the modulus of elasticity values recommended in 1970 are still appropriate for use in seismic analyses for acceleration levels of.up to 0.12g. This opinion is based on our reevaluations of the existing data using current state-of-the-art techniques. If you have any questions or require any additional information, please feel free to contact us. Respectfully submitted, i DAMES & MOORE b Michael L. Kiefer Partner e MLK:id Enclosure n

= 3 TABLE OF CONTENTS i PAGE INTRODUCTION. 1 SCOPE OF WORK. 1 'l EVALUATION OF' DYNAMIC Sull PROPERTIES.................. 2 i INTRODUCTION.... 2 { TECHNICAL APPROACH. 3 EVALUATION OF Gmax... 4 STRAIN DEGRADATION.............. 11 RECOMMENDED STRAIN-RELATED MUDULUS. 12 EARTHQUAKE-INDUCEV STRAINS........................ 12 CONCLUSIONS............................... 14 REFERENCES................................ 16 0 5 o 9 7 0 3 i 9 0 7 C P L s O I 1 i 4 u,,-. s ; .. w-

y s REPORT S0ll DYNAMIC MODULUS STUDY MIDLAND UNITS 1 AND 2 i-CONSUMERS POWER COMPANY I INTRODUCTION i l This report presents the results of the geotechnical services provided with respect to the soil dynamic modulus et ablished for the soils at t Consumers Power Company's Midland Units 1 and 2, .acated near Midland, 4 l Micnigan. The geotecnnical services consisted of a review and reevaluation of the soil dynamic modulus that was recommended by Dames & Moore in 1970 and y i subsequently used by others in. the seismic analyses of structures founded on i glacial till. The review was based on soil data collected by Dames & Moore in 6 i 1968 and 1969 (Dames & Moore,1968 and 1969) at the Midland site, as well as j data collected at the site by others and at geologically similar sites. i 0 The purpose of this investigation is to review and confinn or modify 5 the recommended dynamic elastic moduli for the subsurface soils (Dames & e 6 9 Moore, 1970), and to connent on the applicability of the value for various 'l } structures and levels of earthquake motion. The recommended dynamic modulus of elasticity was 22 x 106 psf, with a ' range of plus or minus 50 percent. } This modulus was recommended for shear strain levels of 0.001 to 0.01 percent. 7 i i C SCOPE OF WORK !s P C The scope of the geotechnical services is presented below: I 1. Confirm that the nominal value (22 x 106 i 4 psf) and range (+50*.) of the' soil dynamic modulus of elasticity (presented in I tiie 1970 Dames & Moore letter) are accurate and appropriate for use in the seismic analysis of structures founded on the glacial till at the Midland site. t l$ fo Y 68

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6 2. Clarify that the dynamic modulus is appiicable for seismic analyses performed for both the operating basis earthquake (OBE) - 0.06 g, and the safe snutdown earthquake (SSE) - 0.12 g. f; j 3. Confirm that the dynamic modulus is applicable to all major Seismic Category I structures which are founded on till. The major Seismic Category I structures include the reactor I l building, the auxiliary building, and the service water pump structure. 4. Submit a report to Bechtel containing at least: i a. Recommendations for the soil dynamic modulus and its range. t i b. A statement regarding the applicability of this value of i soil dynamic modulus for OBE and SSE. c. A correlation between this recommendation and the 19/0 recommendation, i f required. d. Recommendations for appropriate dynamic moduli for SSE i levels of 0.14 g, 0.16 g, and 0.18 g if the recommendation I in Item a.above is not applicable to the higher acceler-q, ation levels. . 1 i O i 5 EVALUATION OF DYNAMIC S0Il PROPERTIES I 6 INTRODUCTION l 0 The soil dynamic moduli recommended for design in 1970 (Dames & 3 I 9 Moore, 1970) were based on the state-of-the-art at that time, dynamic i 0 7 1 boratory tests performed by Dames & Moore, and geophysical measurements made C by Weston Geophysical Engineers, Inc. (Consumers Power Company,1981). As the P C original evaluation was performed o/er 10 years ago and the state-of-the-art 0 has changed substantially, the recommendations have been reevaluated in light i 1 of the current state-of-the-art, recent data collected at the site by others, 4 and published data, c The results of the investigation performed at Midland indicate that the soil profile beneath the power block can De simplified into three i L2] ,o m us s. u.mn,c

= y a 1 i i i' ) layers as shown on Figure 1. The layers were delineated based on index i properties, moisture content, density, and strength (Dames & Moore, 1968, 1969). The locat' ion of the reactor foundation is presented on Figure 1 to ? illustrate the relationship between the foundation and the: supporting soils. i The width of the foundation and thicknesses of the upper and middle layers dictate that the seismic response of the structure will be controlled by these two layers. Therefore, the dynamic modulus of elasticity was evaluated. for only the upper two layers and a weighted modulus was developed for use in design. TEChitICAL APPROACH The purposes of the study are to review and evaluate: (1) the reasonableness of the laboratory and geophysical data; and (2) the appropri-4 0 ateness of the value considering the anticipated strain range resulting from 5 ..!6 various levels of earthquake motion. The work was performed as follows: 9 7 1. Laboratory data and results presented in the Dames.& Moore 1970 4 letter were reevaluated. U 3 2. Published data on other glacial soils, including geophysical I +b9 measurements, were evaluated, and recent work performed at Midland was reviewed (Woodward-Clyde, 1981; Woods, 1980; O Bechtel,1979). 7 3. The shear moduli at small strains (Gmax defined at shear j C strain of 10-4 percent) were determined using Hardin and P Drnevich (1972) based on overconsolidation ratios obtained l C from static testing, effective stress conditions under the O structures based on loading conditions presented in the Final Safety Analysis Report (Consumers Power, 1981), soil

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plasticity, and void ratio. j 1 !i 4 4. A weighted modulus representing the combined upper and middle i layers was estimated. i. 5. Strain degradation curves were formulated utilizing the Midland dynamic soil test data and other published data. 4,bdh h ( e b N e - ~~ --n ---,--.-,m

= -j, 6. Strain-related modulus curves were prepared based on the l. weighted G value and the strain degradation curves. max 7. The shear strain levels resulting from various earthquake motions (0.06 ' to 0.18 g) were estimated based on simpli fied i rigid body analyses, the recommended weighted G and the 1{ strain degradation curves.

max, 8.

' The modulus values at the estimated shear strains were compared with the 1970 recommendations and an opinion is presented on the appropriateness of the original recommendations. EVALUATION OF Gmax Gmax, defined as the shear modulus at 10-4 percent shear strain, was estimated using site-speci fi c information from the Midland site in concert with published empirical relationships and data from other sites. The !{ rationale for each of these methods is described separately below. ? Midland Dynamic Test Data - The dynamic laboratory tests performed O by Dames & Moore in 1968 and 1969 were reviewed to determine the appropri-ateness of the test procedures and to evaluate the reasonableness of the test 7 results. The dynamic test results from the 1968 laboratory program (Dames & O Moore, 1968) do not appear to be representative since the modulus values are 9 relatively constant at shear strain levels ranging from 10-1 to 10-3 percent 0 (Figure 2). Publisned strain degradation relationships for similar soils also 7 support this conclusion. P The results of the two tests performed in 1969 (Boring 14 at L 0 Elevation 587.5* and Boring 15 at Elevation 546.6) are also presented on ) 1 Figure 2. A curve was fit to the laboratory data for shear strain values i

  • Elevations refer to USG1 Datum.

1 1 'E43 i< uwamm , - - -. - ~ e-n r-3 ,c w* e,-- e e-- -s. y ---r-,.w-

l i q l l I! 'i greater than 10-3 percent and extrapolated to obtain Gmax utilizing the t upper and lower limits of the recommendeo band for strain degradation discussed in detail later and shown on Figure 3. This extrapolation yields a range of Gmax of 4.3 to 4.9 x 106 I psf and an average of 4.6 x 106 psf. The tests were performed at a mean effective confining stress of 6,000 psf. t Although the two test results were utilized to arrive at an average laboratory curve, the two test specimens have a large difference in density and appear to represent soils from the upper and middle soil layers. As a result, the laboratory test data can only be used for comparative purposes and i-cannot be used directly in the evaluation of Gmax-Empirical Relationships It has been shown (Hardin and Drnevich, 1972) that the shear modulus at small strain (Gmax) of cl'ay may be expressed {l as: max = 1230 x (2.973 - e)2 x OCRX x (3 )0 5 G m 6 9 l 7 r wnere-Gmax = shear modulus (psi) 9 e = the void ratio; O OCR = the overconsolidation ratio of the soil; 7 i, K = a dimensionless coef ficient that is a function of soil C plasticity. For these glacial tills, this coef ficient is P estimated to be 0.14 and 0.21; and ,i C i 0 c = the mean ef fective stress = 1/3 (i + 2? ) (psi). m y h I The soil properties for the upper two soil layers were evaluated l 1 based on laboratory test data presented in Dames & Moore reports (1968 and i' 1969). A summary of the test data is presented on Figure 4. The estimated i i OCR and void ratio values are presented on Table 1. t LS] a.nos.. m m e -... _, _,. ~ - -.

e, 4-TABLE 1 } PRECONSTRUCTION VOID RATIO AND OVERCuriSOLIDATION RATIO DATA APPROXIMATE VOID RATIO 50ll LAYER ELEVATION RAfiGE AVERAGE ESTIMATED OCR Upper 600 to 550 0.44 to 0.62 0.53 4 to 8 0 to 50 ft i Middle 550 to 410 0.33 to 0.47 0.40 4 to 8 l 50 to 190 ft i 4 The vertical stress conditions under the power block were calculated using the Boussinesq stress distribution and adding the resulting incremental stresses caused by structural loads ranging from 2000 to 10,000 psf to the i e free field stresses. The structural loads considered in the analysis included i' the reactor load and the overlapping effects of the adjacent reactor, turbine, .radwaste, and auxiliary buildings plus the fill to Elevation 634 (Consumers O Power, 1981). It is understood that local permanent dewatering systems will 6 be installed and that the design water level will generally be Elevation 595. 7 The exceptions to this condition are the auxiliary building and the service ,l, O water pumphouse, wnere the design water levels will be Elevations 585 and 610, !9 respectively (Bechtel,1982). The mean effective stress was calculated based-I- 0 on the stresses below the reactor foundation and an average ground water level !h at Elevation 595. The stress conditions under the other Category I structures l including the service water pumphouse were evaluated, and it was concluded t t 'O that the modulus for the materials underlying the reactor would provide a I .easonable estimate of the modulus under the other structures within the 4 limits of the analyses. l ( Using the calculated mean effective stress parametes s and a post-I' loading OCR of 2.5 and 4 for the upper and middle soil layers, respectively, i Darnes C. Moore l' .-r- ___--m. - r

1, l t I G is computed to be on the order of 7 x 106 max psf for the upper soil layer and 10 x 106 psf for the middle soil layer. i The post-loading OCR value of 2.5 is considered a reasonable value i i for the upper layer; however, since it is difficult to accurately define the maximum past pressure for heavily preloaded soils sucn as the middle layer, a range of OCR values was considered in order to evaluate the effects of a variati on in the OCR on the calculated G This parametric evaluation max. i indicates that an increase in the OCR from 4 to 8 corresponds to a difference in modulus of about 25 percent. The calcufated bounds of G for the max middle layer, based on the above discussion, are 10 x 106 to 12 x 106 psf. Midland Geophysical Investigation - A geophysical investigation was performed at Midland by Weston Geophysical Engineers, Inc. in 1968 (Consumers j Power Company, 1981). This investigation presented data (Table 2) for three i layers (0 to 50 feet, 50 to 140 feet, and 140 to 340 feet below Elevation g l{ f 600). It should be noted that the middle layer should extend from about 50 to 9 190 feet (approximately Elevation 550 to 410) (Figure 1) basea on boring data 1 (Dames & Moore, 1968). 1 0 3 { 9 i TABLE 2 O MIDLAND GEOPHYSICAL DATA BY WESTON C COMPRESSIONAL SHEAR lt E DEPTH ELEVATION VELOCITY VELOCITY POISSON'S SHEAR MODULUS l C (ft) ' (ft) (ft/sec) ( f t/sec-) RATIO (psf) O 0-50 600 - 550 5,200 850 0.49 2.5 x 106 i 4 50 - 140 550 - 460 6,100 2,300 0.42 22.1.x 106 4 j 140 - 340 460 - 260 6,100 3,000 0.34 37.7 x 106 Dames & Moore

. _ = +,. I i At the location of the survey, the upper soil layer reportedly l consisted primarily of sand. As a resul t, the calculated shear modulus '( is not considered to be representative of the upper glacial till layer, l which underlies the reactor. Based on our experience, the results reported for the middle layer appear to be high. This opinion is supported by results presented for soils having similar densities and undrained strength (Detroit Edison Company, 1978). The Poisson's ratio, as calculated from the i geophysical data, appears to be low. Based on our evaluation of geophysical data recorded at other sites with soils of similar composition to those at the Midland site, it is our opinion that Poisson's ratios for glacial soils i generally range from 0.45 to 0.48. + j A comparison of the measured compressional wave velocity of 6100 feet per second with values measured at other sites having similar soil conditions 1 j indicates that the compressional wave velocity is reasonable for the Midland O middle layer. Therefore, this value has been utilized as the basis to I estimate the shea r wave velocity used in the shear modulus calculations. 7 ) Direct measurements of shear and compressional wave velocities s U have been made in glacial till soils at a number of sites. The measurements I9 at each site, which include recent closely spaced crosshole tests, were 0 evaluated, and mean values were established for each till deposit at each I. site. Data from six sites that included 15 till deposits are plotted on C l Figure 5. A linear regression analysis was performed on the data, resulting 0 in the mean relationship between shear and compressional wave velocities. f The mean plus and minus one standard deviation are presented on Figure 5. This data set indicates that there is a good correlation between compressional and shear wave velocities for glacial tills. Based on Figure 5 and the [8] anmes a r.1oore

.o t 4 i measured compressional wave velocity of 6100 feet per second, the mean shear wave velocity for the middle layer is on the order of 1400 feet per 4 second. The shear wave velocity at the mean plus one standard deviation { is estimated to be 1600 feet per second. On this basis, the shear wave velocity for the middle layer is expected to be within the range of 1400 to 1600 feet per second. The mean minus one standard deviation velocity is not considered representative for the soils present at Midland. The free field G values calculated from these velocities are 8.2 x 106 max and 10.7 x 106 psf, respectively. The G values based on geopnysical observations are representative max of the free field stress conditions. Since the shear modulus is dependent l on the mean effective stress and also the overconsolidation ratio (OCR), the shear moduli in these cases must be corrected for stress concitions corresponding to those under the reactor building. O The Hardin and Drnevich expression presented above can be simplified by replacing 1230 by C and (2.973 - e)2 (1+e) by f(e): / 7 Gmax = C x f(e) x OCRK x (c )0.5 0 m 3 9 Using this equation, the shear modulus presented above can be converted to 0 a shear modulus for the stress conditions beneath the reactor building as f 1 ws: C P O f(e)r OCR IK 15 0 I 5 l 9 Gmax " G***o X x } { f(e( lg* ( r 4 i j where the subscript "r" represents the conditions under the reactor building and "o" denotes.the original data. j-E93 cames a Moore.

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!f The ef fect of tne void ratio factor was neglected since parametric evaluation indicated that the slight variation in void ratio resulting from ( consolidation under the net structural loads will have an insignificant i j impa c t, on the shear modulus calculation and the equation may be further i simplified, as follows: ! I 'OCR IK m,3 5 0 r r

  • *r
  • *o DCR

&m ) n o i The range of shear modulus (Gmax ) fr the middle layer under the reactor r i l building, based on the Midland geophysics, is calculated to be 10 x 106 to i j 12 x 106 psf, using the above relationship. Summary - Table 3 presents the results of our evaluation of Gmax 1 and the recomended value for each layer. i TABLE 3 O 5 ESTIMATED SHEAR MODULI UNDER REACTOR i 6-9 G - 106 p.; f max r UPPER LAYER MIDDLE LAYER i 0 0-50 feet 50-190 feet i 3 UATA BASE (El. 600-550) (El. 550-410) i i 9 ,j _ Midland Site 0 Hardin & Drnevich 7 10 to 12 i 7 Midland Geophysics 10 to 12 C p Recomended Value 7 12 I! C il 0 ' Weighted Value for Two layers 10 j 1 jL The weighted shear modulus was estimated based on the thicknesses j of the two soil layers and the recommended modulus for each layer. Using a Poisson's ratio of 0.47, this recommended value (Gnax = 10 x 106 psf) converts

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[10] , 3 ;,7.y l

4 l f I jt to a maximum modulus of elasticity at low strains, Emax, of approximately { 30 x 106 psf. This value will be used as the anchor point for the recommended strain-related modulus curve. 1 8 The extrapolated laboratory Gmax value was 4.6 x 106 psf (Figure '2). Comparing this value to the recommended value indicates that the 4 i 4 disturbance factor for the laboratory tested samples is on the order of 2. This fa'ctor falls within a reasonable range based on our experience on otner projects. I t i STRAIN DEGRADATION 3 Strain degradation of the shear modulus was evaluated based on s i published information and the site-specific relationship obtained from the j dynamic triaxial tests performed in 1969. Figure 3 presents a summary of 4 1 6 0 the relationships that were utilized. Extensive laboratory testing and 5 II 6 geophysical programs were performed under a U.S. Nuclear Regulatory Grant and 9 ,i 7 were published by Arango, et al. (1978). The data points f'or clays and \\ o silts are presented on Figure 3 for comparison purposes. Arango, et all 3 ij 9 concluded that the Seed and Idriss (1970) " clay curve" seemed too low i O throughout the entire strain range. The Greenwood degradation curves and-y n data for similar soils support this conclusion. The recommended band for r C p degradation is presented on Figure 3. 1 C s l* g A degradation curve was calculated from the laboratory test results '[ 5 based on the extrapolated average curve from the 1969 dynamic laboratory tests i 1-4 presented on Figure 2. .This curve, shown on Figure 3, is generally enveloped within the recommended band at strains of less than 10-2 percent; however, at strains in excess of 10-2 percent, the Midland curve falls slightly below [11] - aames a m c,e t

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t -\\ .s s i i y\\ b a ?, 1-l s ~ 1 3 s the recomcended' band. 7 It was concluded that the recommended band should not i be widened to envelope tye Midland curve since the syntnesized curve was based

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N - on only two tests and V.s 'snape<may have been influenced more by testing y ~s s t s s j procedures than soil proper les,' \\ RECOMMENDED STRAIN-RELATED MODULb5 s g (.y t I .i...K Strain-related moduli

ticity were developed based on the

, z[ s,} '. recommended weighted G 1 6 max value (10 x'10 psf) ara the recommended degradation p. q; d curves (Figure 3). Figure 6 presents the recommended design curve for i s im e i I I the modulus of: elasticity, as well as the 1970 recommended values. The N - N i s s m recomme5ded design curves fall 91thic the previous modulus recommendations for l s g-t ~~ shear" strdins less than 2 x 10-2 percent. y r d I i A . EMTHQUAKE-INDUCED STRAINS 0 5 v, t l e. 6 The maximum.snea stressds inc;ced by earthquake accelerations were 9 7 p. .compbted ' assuming the scil column above a soil element as a rigid body.. The

J N.

S weighted shear modulus' (Gmax) presented above is 10 x 106 psf. Starting 3 i 9 j with this shear modulus, value at a low strain level (10-4 percent) and using I i ,s ) O the recognded strain degradation curves (Figure 3), the anticipated maximum f ,l t -shear st rai n"leve h generated by various earthquake accelerations and the ( C P corresponding shear modulus values were determined by the iterative procedure I i i .C i 0 I described below: j 'l I 4 1. 4 ' The maximum snear stress on the soil element (T max) is calcu-i lated assuming tne soil column above a soil element is a rigid l body. r Yh Tmax * ( g ) a max i> .5 [12] jp \\ m 'k. Aw N' w, _m. m.

m

+<--r

- -. ~ _. -. - 1 il.- 4 where: Y = the average bulk density (136.5 pcf); I' h = depth; 1< max = design acceleration; and o g = acceleration of gravity. 2. Using the' above calculated maximum shear stress for a given ground acceleration and the G chear modulus value of ria x 10 x 106 psf, a shear strain, y, is calculated (y = r/G). i 3. The shear modulus value corresponding to the shear strain I calculated in Step 2 is determined from strain related modulus ] (Gmax and Figure 3). l 1 4. A new strain is determined using the shear modulus obtained in i Step 3 and the maximum shear stress calculated in Step 1. I Compare this new shear strain with the previous shear strain obtained in Step 2. If they are within a tolerable limit (say i 1 5 percent), the shear strain and shear modulus values obtained in Steps 4 and 3, respectively, are the final values. If they are not close enough, continue to Step 5. i I j 5. Determine the shear modulus value at the strain level obtained in the previous step, using Figure 3 and G ax-m l 6. Determine a new strain using the latest shear modulus value

4 obtained in the previous step and the maximum shear stress in l

0 Step 1. ? 5 [ c 7. Repeat Steps 5 and 6 until the latest strain obtained in Step 6 9 is close to tnat obtained from the previous step. 7

1 0

The calculations were performed for ground accelerations ranging !{ 3 9 from 0.06g to 0.189 for a soil element at the base of the Peactor (a depth of i 2 0 50 feet below the present ground surface). The results are summarized in 'l 7 j, Table 4 and shown on Figure 6. g ll, P C 4l i 0 !L 1 1 4 4 - p r. w

  • r,_

5 -m,_

TABLE 4 EARTHQUME It4DUCED SHEAR STRAltiS CALCULATED CORRESP0fiDING MAXIMUM CORRESP0f4 DING DYNAMIC MODULUS GROUl4D SHEAR STRAIN SHEAR MODULUS OF ELASTICITY ACCELERATION (percent) (psf) (psf) 0.069 7.6x10 5.2x10-3 5.5x106-8.0x106 16.2x106 - 23.5x106 0.129 2.2x10-2 _ 1,3xio-2 3.6x106-6.5x106 10.6x106 - 19.1x106 0.149 3.1x10 1.6x10-2 3.1x106-6.0x106 9,1x196 - 17.6x106 0.169 3.9x10 2.0x10-2 2.8x106-5.5x106 8.2x106 - 16.2x106 { 0.189 4.9x10 2.5r.10-2 2.5x106-5.0x106 7.4x106 _ 14,7xio6 CONCLUSIONS It is our opinion that the modulus of elasticity values recommended 0 in 1970 are still appropriate for use in the seismic analysis for ecceleration 5 6 l e ve l s up t o 0.129.. This opinion is based on o'ur reeval ua t ion of the 9 7 existing data using current state-of-the-art techniques. O The calculated maximum snear strains resulting from various design 3 ') earthquake accelerations and corresponding moduli of elasticity are plotted 0 on Figure 6. The maximum shear strains are somewhat higher than those 7 assumed in 1970, however, the strain-related moduli of elasticity for the C P earthquake accelerations of 0.06g and 0.129 are in agreement witn the C 0-previously re' commended range of 22 x 106 ps f + 50 percent. Although the 0.129 1 acceleration associated with the lower bound modalus is slightly lower than 4 the previously recommended band, the amount is not considered to be of consequence. Therefore, the 1970 recommendations are still considerea appropriate for use in seismic structural analyses for acceleration levels of [14]

I up to 0.12. In addition, it i, our opinion tnat the recc: mended val ues are 9 1 applicable to all major seismic Category I structures founded in glacial till, including the service water pumphouse. The recommended strain-related, dynamic modulus of elasticity for I gr ound acceleration levels of 0.14, 0.169, and 0.189 are presented on Table 4 9 1 and F1gure 6. --00000-- t The references and following figures are attached and ccaplete this report: Figure 1 - Idealized Subsurface Profile Jeneath Power Block Figure 2 - Dynamic Test Results - Midland i Figure 3 - Strain Degradation Curves 0 Figure 4 - Shear and Compressional Wave Velocity Correlation S 6 Figure 5 - Summary of Test Data - Midland l 9 7 Figure 6 - Recommended Strain Related Podulus of Elasticity O 3 9 Respectfully submitted, O DAMES & MOORE s 7 / (NYk . p Michael L. Kiefer C Partner s U /g/ '.. f( l l 4 t William J. Babcock Project Manager ML A/ WJ ti: l hk [15] .y,,,,

_ _ = _ i. e j'- REFERENCES sl l-

Arango, I., Mortwaki, Y., and Brown, F., 1978, In-situ and laboratory shear velocity and modulus:

Proceedings of Earthquake Engineering and Soil Dynamics Conference, ASCE, p. 198-212(June). Bechtel Associates Professional Corporation, 1979, Boring logs, CH-1 through i 21 series, Midland plant units 1 and 2: Prepared for Consumers Power Company.

,s 1982, Personal connunication, S. Rao, Geotechnical Engineer, (February j

18 and March 3). 9 } Connonwealth Edison Company, 1980, Final safety analysis report, LaSalle i county station: Response to Nuclear Regulatory Commission questions, ),, Amendment 49 (May). 4 i Consumers Power CompJny, 1981, Final safety analysis report, Midland plant o, units 1 and 2: Appendices 2A, 28, and 2C ( April) and Figure 2.5-47 from j Section 2.5. ~ Oames & Moore,1968, Report, Foundation investigation and preliminary explor-ations for borrow materi a l s, Proposed nuclear power plant, Midland, Michigan: Prepared for Consumers Power Company, Project No. 05697-001-07 1 (June 28). i 1909' SUPP ement to report, Foundation investigation and preliminary l U l1' 5 explorations for borrow materials, Proposed nuclear power plant, Midland, Micnigan: Prepared for Consumers Power Company, Project No. 05697-001-07 (Marcn 15). 7 1970, Short-term static moduli of elasticity, Proposed nuclear power ,} plant, Midland, Michigan, for Consumers Power Company: Letter from G. D. 4 3 Leal to J. H. Blasingame, Bechtel Corporation ( April 3). 9 Detroit Edison Company, 1978, Preliminary safety analysis report, Greenwood '-} energy center units 2 and 3: Section 2.5.4 and appendices (Amendment j 14). 7 C Hardin, B.0., and Drnevich, V.P., 1972, Shear modulus and damping in soils: p Design equations and curves: Jour. of the Soil Mechanics and Foundations C Divisions, Proceedings of the ASCE, vol. 98, no. SM7, p. 667-692 (July). O Seed. H.B., and Idriss, I.M.,1970, Soil moduli and damping factors of dynamic { response analyses: Earthquake Engineering Research Center, Univ. of i California, Berkeley, Report no. EERC70-10. _4 Woods, R.D.,1979, Pile stif fness for supplemental piles at service water pump structure: Prepared for Bechtel Ascociates Professional Corporation (August 10). [16] - a r.2; a 9.x.;.s .~~.. . - - = -

i 7' i 1980, Seismic crosshole tests at Midland power plant: Prepared for Cechtel Associates Professional Corporation (January 8). i d Woodward-Clyde Consultants,1981a, Test results, service water structure, soil boring and testing program, Midland plant - units 1 and 2: Prepared for j' Consumers Power Company (October 1). t 1981b, Test results, auxiliary building (Part 2), soil boring and testing program, Midland plant - units 1 and 2: Prepared for Consumers Power Company (Octooer 26). 1981c, Test results, retaining walls, soil coring and testing program, Midland plant - units 1 and 2: Prepared for Consumers Power Company (November 6). 9 l 1 i = l I O 5 i 0 9 7 O 3 9 0 7 'C P C -0 e 1 4 I 9 ,8 ~

e;... ea ~ 650 o-i ). FILL REACTCR FlLL s e,y t.- uu 'a C RIGIN AL "" GRADE s-i 4 UPPER L AYER (GLACI AL TILL) d. (VERY STIFF TO H ARD) 50 - - 550 ai L i: 100 - m500 MIDDLE L AYER (GLACI AL TILL) j.. (HARD) -e I [* k n J Lu /50- - 450 1 ke {W

t wE k

4 w h. W t 4 200-

1..

- 400 250 - ~ J50 t. LOWER LAYER (GRANULAR SOILS) (VERY DENSE) 3C0- - 300 a M e. o l N l 1 o , //,, ,,/,/,,,,//,,,,,,si,,,, 350 - ~ 250 BEDROCK 1~ 1. o so ico rEET "NE FIG U R E 1 9 I lDEALIZED SUBSURF ACE PROFILE BENE ATH POWER BLOCK Dames & Moore .1

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e, O r,. e, i, e-1. 10 O, ' No f 8_g g[.9 6 l l l o.g dI A d-O \\O O GREENWOOD PS AR fs (0 70 FEET) g ) i og h \\ 1 O i CLAY O ll (SEED a IDRISS) \\ 1 j o \\ O f -. - _ _g 04 i l\\ .) MIDL A ND s DYN AMIC i l TRIAXIAL b N (h s fg I 02 N w O 4 2 4 6 8 3 2 4 6 8 2 2 4 6 8 1 2 4 6 8 SHE AR STR AIN, % E XPL AN ATION: O LOW PL ASTICITY SILTS AND CL AYS ( ARANGO et al) 6 HIGH PL ASTICITY SILTS AND CLAYS ( AR ANGO et ol) [ RECOMMENDED BAr D ~ ? S 8 FIGURE 3 STR AIN DEGR AD ATION acrterset: RELATIONSHIPS ADAPTtD FROM ARANGO et al.(1973) Dames & Moore

n MOISTURE CONTENT ORY DENSITY ? HEARING STRENGTH (%) (LBS /FT ) {xIO]LBS/f7 ) 3 E

  • ~

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SUMMARY

OF TEST DATA at rtatnct ' - MIDLAND 1 D4'tS f. MCORE, (1968. 1969). Dames & Moore

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