Chapter 32 - Deep Foundations - Index of - Free

TABLE 32.13Relative toWater TableFriction Angle and ConsistencyFriction Angle and Consistency29°–30° 30°–36° 36°–40°(Loose) (Medium Dense) (Dense)Above 20 pci 60 pci 125 pciBelow 25 pci 90 pci 225 pci1 pci = 272 kPa/m.Segment 2 is parabolic and starts from end of Segment 1 atykpmym= ⎡ n⎣ ⎢ / ⎤( kx)⎥⎦1 ( n−1)andpk= ( kx)yk, the power of the parabolicn =ypmm⎛ p⎜⎝ yuu− p ⎞m− y⎟⎠mSegments 3 and 4 are straight lines. y m, y u, p m, and p uare expressed asby = m60by = 3 u80pp= B pm s s= A pu s s(32.37)(32.38)(32.39)(32.40)where b is the diameter of a pile; A sand B sare coefficients that can be determined fromFigures 32.12 and 32.13, depending on either static or cyclic loading conditions; p sis equal to theminimum of and , asp stp sdpst⎡ Kxotanϕsinβtanβ⎤⎢+( b+xtanβtan α)= x −−⎥γ tan( β ϕ)cosαtan( β ϕ) ⎢⎥⎢⎥⎣+ Kxotan β(tan φtanϕ−tan α)−Kba⎦81p sd = K a bxγ[ tan β–] + K o bγxtanφtanβp= min( p , p )stsd4(32.41)(32.42)(32.43)in which ϕ is the friction angle of soil; α is taken as ϕ /2; β is equal to 45 o +ϕ/ 2 ; K ois thecoefficient of the earth pressure at rest and is usually assumed to be 0.4; and K ais the coefficientof the active earth pressure and equals to tan 2 ( 45 o −ϕ / 2).© 2000 by CRC Press LLC