2.4 Allowable bearing capacity of shallow foundations Assume the coefficient of earth pressure at-rest(K)is 1, the increments in principal stresses can be superimposed to the principal stresses.The final principal stresses at depth z are(假设静止土压力系数K=l,这样自重应力 与附加应力可以在任意方向叠加，地基中任意点M的大 小主应力可从以下公式找出) o-9p+sn2p++d c;-9-Y-d(2B-sin2p)+y(z+d)2.4 Allowable bearing capacity of shallow foundations ▪ Assume the coefficient of earth pressure at-rest (Ko ) is 1, the increments in principal stresses can be superimposed to the principal stresses. The final principal stresses at depth z are (假设静止土压力系数Ko =1,这样自重应力 与附加应力可以在任意方向叠加,地基中任意点M的大 小主应力可从以下公式找出 ) (2 sin 2 ) (z d) q d 1 b + b +  +  −    = (2 sin 2 ) (z d) q d 3 b − b +  +  −    =