Chapter 32 - Deep Foundations - Index of - Free

p–y Curves for Soft ClayMatlock [35] proposed a method to calculate p–y curves for soft clays as shown on Figure 32.10.The lateral soil resistance p is expressed asFIGURE 32.10 Characteristic shape of p–y curve for soft clay. [After Matlock, (1970) 35 ]p=⎧ y0.5⎛-----⎪ ⎝y 50 ⎠⎨⎪ p u⎩1⁄3⎞p uy< y p = 8y 50y≥y p(32.34)in whichp u= ultimate lateral soil resistance corresponding to ultimate shear stress of soily 50= lateral movement of soil corresponding to 50% of ultimate lateral soil resistancey = lateral movement of soilThe ultimate lateral soil resistancep uis calculated as⎧⎛γ′x --x3 + ------ + J ⎞⎪B cBp⎝ c ⎠u = ⎨⎪9cB⎩γ′Bx < x r = ( 6B)⁄ ⎛------- + J⎞⎝ c ⎠x ≥x r(32.35)where γ′is the effective unit weight, x is the depth from ground surface, c is the undrainedshear strength of the clay, and J is a constant frequently taken as 0.5.The lateral movement of soil corresponding to 50% of ultimate lateral soil resistance y 50iscalculated asy= 25 . ε50 50B(32.36)where ε 50is the strain of soil corresponding to half of the maximum deviator stress. Table 32.12shows the representative values of ε 50.p–y Curves for SandsReese et al. [53] proposed a method for developing p–y curves for sandy materials. As shown onFigure 32.11, a typical p–y curve usually consists of the following four segments:© 2000 by CRC Press LLC