粘性土被动土压力系数计算方法探讨

Study on the Calculation Methods for Coefficient of Passive Earth Pressure of Clayey Soil

粘性土的被动土压力系数是基坑支护设计中倍受岩土工程师关注的问题。作者先后总结出三种计算被动土压力系数的方法。为讨论不同计算方法对四类土的适用性 ,选用计算土层厚度为 8m来计算每种土的被动土压力强度 ,其结果是对于软土而言三种方法计算的结果较相近 ,因而用任意一种方法都可以 ;对湿陷性黄土用等值内摩角法更有利于发挥土的强度 ;而对于超固结土趋于用库仑法 ;对于正常固结土来说用朗肯法更恰当。

The coefficient of passive earth pressure of clay is important for retaining and protection of foundation pit. The authors put forward three calculation methods for the coefficient. In order to discuss applicability of different methods to the four sorts of clay, the authors use eight--meter soil depth to calculate the intensity of passive earth pressure. Its conclusion is that for a soft soil, the results computed by three kinds of methods are close by, so every method can be used; for collapsible loess, the method of equivalent internal friction angle is more beneficial to develop the soil's strength. But for the overconsolidation, Coulomb's earth pressure is more fitting, the Rankine's method is more appropriate to normally consolidated soil.