settlement_of_shallow_foundations_on_granular_soils (Lutenegger ang DeGroot)

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s = settlement (in inches)q = net footing stress (in tsf)N =uncorrected (field) blowcountsB =footing width (in ft.)Cw = water correction= 2- (W/2B) ~ 2.0 for surface footings= 2- 0.5 (D/B) ~ 2.0 for fully submerged,embedded footing; W ~DCd =embedment correction= 1 - 0.25 (D/B)[5.5][5.6][5.7]where:W = depth of water table (in ft.)D = footing depth (in ft.)The uncorrected SPT blowcount data are used in calculating settlement, however, if the sand isdense, saturated and very fine or silty (e.g., abundant fines content), it was recommended that theblowcount should be corrected according to:N,= 15 +0.5 (N -15)forN> 15 [5.8]The correction for water table applies to cases where ground water is at or above the baseof the footing (complete submerged case). For partial submergence (water located between D andD+B) a correction factor is given for surface footings (no embedment) only. In common practice,the water correction is often omitted from the settlement estimates using this method since themethod is generally considered to be overly conservative.5.2.2 Meyerhof (1956, 1965)Meyerhof (1956) suggested that the allowable bearing pressures for a footing on granularsoils could be estimated based on the results of SPT blowcounts. The allowable pressure includesa minimum factor of safety of 3 against bearing capacity failure and may be less than the safebearing pressure ( q, 1 /3) if the settlement resulting from the safe bearing pressure is excessive.Assuming that the allowable bearing pressure cause 25 mm (1 in.) of total settlement, Meyerhof(1956) proposed the following expression for dry and moist sands:q, = N/8q, = N(1 + 1/B) 2 /12q, = N/10where:(forB ,; 4ft.)(forB> 4ft.)(approximately, for any B)[5.9][5.10][5.11]57
-100.-----~-----------------,~----------~-.......~ Results for air-dry and partially~ ! wetted cohesionless sand and ·~·.a cons1dered conservatively reliable Cf.80 in all sands ------+--':'0\ 0 1-f------1------ Laboratory tank data for ~C1J(J~ 60.'(!V)~c::.<;2.._tJ..... .._C1Jc::C1JQ.4020. j saturated coarse sand--- Laboratory lank data forf----- saturated fine sand '------+--+~~-+-------i0 20 40 60 80 100Relative density "!.0 15 35 65 85 100I Very I Loose I Medium I DenS!! I I Very /oosl!'denseFigure 5.1 Gibbs and Holtz (1957) SPT Correction.58
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
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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
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: 19. Stroud (1989)20. Berardi eta!.
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
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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
Page 129 and 130:
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
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5.6.2 Barata (1973)B arata also poi
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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()()/
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7\~' "'--O&nseVery Dense..___ N=5o-
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also noted that "If the pressure co
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6;:.:5~4~~ 3'~~ 2~~tl. I~~',I) 0(c!
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capacity is reduced, the allowable
Page 159 and 160:
6.6 Sowers (1962)Sowers (1962) in L
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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
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250----200 ,........15010050•/...
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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%
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The bearing capacity factors are a
Page 201 and 202:
7.3 Review of Load TestsInitially,
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Table 7.2 Normalized Load-Settlemen
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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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