settlement_of_shallow_foundations_on_granular_soils (Lutenegger ang DeGroot)

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1-'iL' length "'0.5DHp' averagesettlementq BP, 1-'01-'1 E00.110H/8L/B'Q)100LIB' 101000Figure 4.6 Improved Influence Factor Chart Proposed byChristian and Carrier (1978).15
thus underestimate settlement. A comparison between the Fox (1948) and Burland (1970) charts fora circular area is shown in Figure 4.10. Christian and Carrier (1978) suggested that Burland's (1970)embedment correction factors be used with Giraud's (1972) depth factors as shown in Figure 4.11but also noted that "ignoring embedment all together is nearly as good a procedure and may be thebest approach when other effects .... are to be considered". Christian and Carrier (1989) restatedtheir position in a discussion to Bowles (1987).Other factors have been suggested to account for embedment of the foundation, e.g.,Yamaguchi (1984), however, the factors presented by Fox, Janbu or Burland appear to be moreoften used in practice.4.2 Tschebotarioff (1953, 1971)Tschebotarioff (1953, 1971) suggested a simplified method of settlement analysis useful forfootings resting on sands and other cohesionless soils. The method, as applied to square footings,assumes that the surface load is carried within the soil mass by a truncated pyramid of soil. Thesurface settlement is equal to the compression of the entire pyramid of height H. The totalcompression is the sum of the compressive strains of all of the successive horizontal layers dH ofthe pyramid. Each of the successive layers occupies a horizontal area A= (b + 2H tano:) 2 , where o:is defined as shown in Figure 4.12. For an assumed value of o: = 30', the settlement is given as:s = (0.867 qbC,)IE[4.4]where:q = applied footing stressb = footing widthC, = layer thickness correction factorE = Young's ModulusThe correction factor C, is to account for values of H less than infinity. Values of c; for variousvalues ofH/b are shown in Figure 4.13. For an infinity long strip footing of width b, the settlementmay be obtained in a similar manner foro:= 30" as:s = [(2.0qb)/ E]log [1 + (1.154H)/b] [4.5]4.3 Canadian Foundation Manual (1975, 1985, 1992)The Canadian Foundation Manual (CFM) suggests that settlement estimates of footings maybe made by dividing the soil into layers, calculating the value of the applied stress at the midpointof each layer and using an apparent modulus of elasticity of the soil layer to determine the16
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: 2.52.0fl-1 1.5Figure 4.5 Janbu et a
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
Page 35 and 36: ifa.=JO" S=Q867xplbxC 80 02 .Cs04 0
Page 37 and 38: 0. I 00. 150.20m'-.NJ:>-~w0w>....<-
Page 39 and 40: 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
Page 55 and 56: Overconsolidation ratio, OCRFigure
Page 57 and 58: Table 4.3 Soil Modulus from Standar
Page 59 and 60: 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
Page 97 and 98:
'E-z~161412 J-100WIZI.D8 J-4 J- 1jz
Page 99 and 100:
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)
Page 107 and 108:
Ll.p' = (2P cos 6 8)/rcz 2 [5.91]Ad
Page 109 and 110:
0~·Illso ·~100 II~\~ 0••100 "
Page 111 and 112:
5.3.5 Schmertmann (1970)In what may
Page 113 and 114:
4.- Use Equation 5.95 to calculate
Page 115 and 116:
Soil Type.QJNsandy silt 2.5sand & g
Page 117 and 118:
IOr---.----,,---,---,,,---,---,----
Page 119 and 120:
Table 5.5 Influence Factors for Ber
Page 121 and 122:
Table 5.6 Reported Use ofPressureme
Page 123 and 124:
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
Page 129 and 130:
5.5 Dilatometer TestMarchetti (1980
Page 131 and 132:
Method B - Special MethodThis metho
Page 133 and 134:
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-~ "'
Page 141 and 142:
and circular foundation; 4B for str
Page 143 and 144:
~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 and 198:
tDr= 59%q'YB0 20 40 6040 t,-Dr= 47%
Page 199 and 200:
The bearing capacity factors are a
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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