settlement_of_shallow_foundations_on_granular_soils (Lutenegger ang DeGroot)

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1.01:-.00<>0.80;/c0.6g_q ult<>0'fo~:-.1For constant B0.4IDr(%)1:-. 590 471:-.0.2<> 310 21I,<>028 10p8%Figure 7.11 Normalized Load-Displacement Behavior of Shalow Foundations on Sand(after Vesic 1973).187
The bearing capacity factors are a function of the soil friction angle only. The cohesion term isusually taken as zero which is a conservative approach and generally assumes that the soil is cleanand free of any fine material, cementation, or apparent cohesion from moisture which would providesome component of strength at zero normal stress. For saturated clean sands this assumption isprobably valid, however for partially saturated sands, especially with an appreciable amount offmes, this assumption provides a conservative estimate of Qu.Results of load tests may be evaluated to determine the failure load and displacementcharacteristics. A number of methods may be used to interpret the failure load, however, Trautmannand Kulhawy (1988) found that the "slope tangent" method worked reasonably well to determinethe ultimate load of shallow foundations subjected to uplift load. As shown in Figure 7.12 in thismethod the failure load is taken as the intersection of the tangents to the initial and final portion ofthe load-displacement curve and the failure displacement is taken as that corresponding to the failureload. Clearly, this method is somewhat dependent on the range of displacements achieved in thetest since the shape of the curve never really approaches an asymptotic valve even at largedisplacements. In general, provided that a total displacement is in excess of 5% of the footingwidth, this method should provide reasonable estimates for granular soils. The value given by thismethod may not be the actual "ultimate" load representing complete plastic failure, but it can beconsidered a "failure" load.In the case of a shallow foundation in uplift, the displacement may be normalized by thedepth of burial which represents the entire zone of soil participating in the foundation movement.However in the case of a footing under an applied compressive load, the zone of influencecontributing to deformation is not actually known and hence, another length term must be chosen.It is reasonable to expect that the width of the footing may be used to reflect in some fashion thezone of influence and therefore the settlements may be normalized by footing width.Using results of laboratory model footing tests, prototype footing tests and a few testsperformed on full-scale footings available in the literature, the load-displacement curves of shallowfoundations under axial compression loading may be reevaluated.188
Page 1 and 2:
SETTLEMENT OF SHALLOW FOUNDATIONSON
Page 3 and 4:
ACKNOWLEDGEMENTSThis study was fund
Page 5 and 6:
5.2.6 Alpan (1964) ................
Page 7 and 8:
LIST OF TABLESTable 2.1 Previous In
Page 9 and 10:
Figure 5.9 Schultze and Sherif(l973
Page 11 and 12:
Figure B.8 Updated Douglas Chart (O
Page 13 and 14:
2.0 BACKGROUND - SETTLEMENT OF SHAL
Page 15 and 16:
HORIZONTAL DISPLACEMENT, mm10. 0Not
Page 17 and 18:
3.1 Introduction3.0 DESIGN APPROACH
Page 19 and 20:
4.0 ELASTIC SOLUTIONS FOR ESTIMATIN
Page 21 and 22:
"o2.8-2.4t2.01.61.2(a)iII-~10520.80
Page 23 and 24:
- 0 2:::::>0a::- (!)-Q.1.5 H.......
Page 25 and 26:
2.52.0fl-1 1.5Figure 4.5 Janbu et a
Page 27 and 28:
thus underestimate settlement. A co
Page 29 and 30:
1.00.9 ~--~~~ ~t::$:::"--+-----+---
Page 31 and 32:
1.0~'-o0.90.80.70.60.5~~~-BURLAND\~
Page 33 and 34:
settlement of each layer. The layer
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ifa.=JO" S=Q867xplbxC 80 02 .Cs04 0
Page 37 and 38:
0. I 00. 150.20m'-.NJ:>-~w0w>....<-
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I2IIfvEDG~- ~,..=.33~vc/-""CENTERJL
Page 41 and 42:
" ~...,I...,"~~....."'w 0-~'z z1.0~
Page 43 and 44:
2 - Compute the settlement of one c
Page 45 and 46:
s = settlementq = foundation stress
Page 47 and 48:
4.8 Wahls and Gupta (1994)A method
Page 49 and 50:
Corrections to the SPT blowcount sh
Page 51 and 52:
4.9.1 Standard Penetration TestNume
Page 53 and 54:
there are several techniques that h
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Overconsolidation ratio, OCRFigure
Page 57 and 58:
Table 4.3 Soil Modulus from Standar
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Table 4.5 Soil Modulus from Cone Pe
Page 61 and 62:
Table 4.5 Cont'dReference Relations
Page 63 and 64:
Table 4.6 Other Expressions for Soi
Page 65 and 66:
Table 5.1 Methods to Evaluate Settl
Page 67 and 68:
19. Stroud (1989)20. Berardi eta!.
Page 69 and 70:
-100.-----~-----------------,~-----
Page 71 and 72:
the compression of the layer is cal
Page 73 and 74:
20 40 60 dO 100Std. Penetration Res
Page 75 and 76:
40 60 80 100RELATIVE DENSITY, PER C
Page 77 and 78:
VIa..LLI0::JVIS P T- NUMBERS OF BLO
Page 79 and 80:
Alp an suggested that the correctio
Page 81 and 82:
y = soil total unit weightCw = wate
Page 83 and 84:
1000~-------r----~~--------~-------
Page 85 and 86:
00 0·5 1·0 1·5·Ye2•0Figure 5,
Page 87 and 88:
s M~87 !1•D.U/B)p~<=::!::':'"'e11
Page 89 and 90:
N = uncorrected blowcountC, = embed
Page 91 and 92:
I 2 3UNCONFINED COMPRESSIVE STRENGT
Page 93 and 94:
~-~LU-LU~ eJ:.:t::\:!W~~k-----4----
Page 95 and 96:
5.2.19 Stroud (1989)Stroud (1989) s
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'E-z~161412 J-100WIZI.D8 J-4 J- 1jz
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N)'Nq140 IIIN'YINcIIII20 80 I/N'Y 1
Page 101 and 102:
The soil stiffness is evaluated usi
Page 103 and 104:
1 •••. ... .,1-: •. .......
Page 105 and 106:
5.2.21 Anagnostopoulos eta!. (1991)
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Ll.p' = (2P cos 6 8)/rcz 2 [5.91]Ad
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0~·Illso ·~100 II~\~ 0••100 "
Page 111 and 112:
5.3.5 Schmertmann (1970)In what may
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4.- Use Equation 5.95 to calculate
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Soil Type.QJNsandy silt 2.5sand & g
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IOr---.----,,---,---,,,---,---,----
Page 119 and 120:
Table 5.5 Influence Factors for Ber
Page 121 and 122:
Table 5.6 Reported Use ofPressureme
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q' =net footing pressureB = footing
Page 125 and 126:
In order to recognize the strain ar
Page 127 and 128:
For different soils Menard suggeste
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5.5 Dilatometer TestMarchetti (1980
Page 131 and 132:
Method B - Special MethodThis metho
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OCR= [K(OC)/(1-sin ~ )](1 10·' sin
Page 135 and 136:
Figure 5.29 Settlement Ratio as a f
Page 137 and 138:
5.6.2 Barata (1973)B arata also poi
Page 139 and 140:
6"';_;51 v = o , 1~ c~ 4 o/:;0-~ "'
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and circular foundation; 4B for str
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~N~~~~~~"' ~0.~100 1.0ii..., c. 10
Page 145 and 146:
Table 5.9 Comparison of Settlement
Page 147 and 148: 6.0 ALLOWABLE BEARING CAPACITY CHAR
Page 149 and 150: 5lr)lr.tl\)J~2~'§ I~t--·/_'f()()/
Page 151 and 152: 7\~' "'--O&nseVery Dense..___ N=5o-
Page 153 and 154: also noted that "If the pressure co
Page 155 and 156: 6;:.:5~4~~ 3'~~ 2~~tl. I~~',I) 0(c!
Page 157 and 158: capacity is reduced, the allowable
Page 159 and 160: 6.6 Sowers (1962)Sowers (1962) in L
Page 161 and 162: 301-E~. (2-1 1 9)251-201-l\1050~1-"
Page 163 and 164: 800700~- N'qo- 0.05 qo OOB 8~0_!:!.
Page 165 and 166: It was stated by Mohan et al. (1971
Page 167 and 168: 1 4f--u.-(")1 2C IIVl'->- 1 0z!;;au
Page 169 and 170: 600(a) D/B = 1 (b) D/B = 0.5 (c) D/
Page 171 and 172: 6050z~- 40c:~0u~ 30/v----/0~ 20 ".0
Page 173 and 174: 250----200 ,........15010050•/...
Page 175 and 176: q. = NJO.Ol2B (kN/m 2 ) [6.27)Equat
Page 177 and 178: fl(m)6 600~N.:::~~"2 ~~M"5 500-~~4
Page 179 and 180: 0 2 4B,FT10 12Qo =ALLOWABLE BEARING
Page 181 and 182: 0 0 010c"' E~-V> "' 8.£~0-V>drr!'?
Page 183 and 184: Table 6.2 (continuted)Method lxlm 1
Page 185 and 186: 7.0 LOAD-SETTLEMENT BEHAVIOR OF SPR
Page 187 and 188: The value of Q/Q, 1 , is essentiall
Page 189 and 190: Figure 7.3 Nondimensional Load-Sett
Page 191 and 192: 120~-------------------------------
Page 193 and 194: z00 0.7:5w 0.6f- <t~ 0.5~:::J 0.4--
Page 195 and 196: qb(s/0=5%)0.5 1.0 150~6-....2"~zUJ
Page 197: tDr= 59%q'YB0 20 40 6040 t,-Dr= 47%
Page 201 and 202: 7.3 Review of Load TestsInitially,
Page 203 and 204: Table 7.2 Normalized Load-Settlemen
Page 205 and 206: Table 7.3 Normalized Load - Settlem
Page 207 and 208: Table 7.4 Normalized Load- Settleme
Page 209 and 210: 0.9* •+.•t * ' '........... ,
Page 211 and 212: 1.0'I' i 'I' i0.9~"' i "'v :'I' "'
Page 213 and 214: 8.0 SETTLEMENTS FROM CYCLIC LOADING
Page 215 and 216: 9.0 RECOMMENDATIONSBased on the res
Page 217 and 218: 4- Martin (1987) Method (PMT)5- Par
Page 219 and 220: Berardi, R., Jamiolkowski, M., and
Page 221 and 222: Engineering." Proceedings of the 2n
Page 223 and 224: Garga, V.K., and Quin, J.T., 1974.
Page 225 and 226: Kovacs, W.D., Evans, J.C. and Griff
Page 227 and 228: Meigh, A.C., 1963. "Discussion on S
Page 229 and 230: Parry, R.H.G., 1978. "Estimating Fo
Page 231 and 232: Schultze, E. and Sherif, G., 1973.
Page 233: Tucker, K.D., 1987. "Uplift Behavio
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settlement_of_shallow_foundations_on_granular_soils (Lutenegger ang DeGroot)

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