有限填土静止土压力系数计算方法研究

基于已激发内摩擦角概念，通过莫尔圆分析得到粗粒有限填土静止土压力系数Κ₀ 的计算方法，并与Jaky半无限土体静止土压力系数Κ_0J 和有限填土主动土压力系数Κ_a 进行了对比。结果表明，当填土与基岩之间的摩擦角δ_r等于填土内摩擦角Ф 时，Κ₀ 接近或小于Κ_0J。当δ_r小于φ 时，Κ₀ 不仅与Κ₀ 和基岩坡面倾角有关，而且与δ_r 的大小有关，Κ₀ 可能大于也可能小于Κ_0J 。Κ₀ 和Κ_a均随基岩坡面倾角的增加而减小，且保持基岩坡面粗糙或分台阶开挖是减小有限填土静止土压力的有效措施。给出了有限填土静止土压力计算图。

Coefficient of at-rest earth pressure from limited backfill

Based on the concept of mobilized angle of internal friction,the coefficient of at-rest earth pressure from limited coarse backfill Ko is obtained after the analysis of the Mohr’s cycle.A comparison is made with Jaky’s formula for half infinite soil mass Koj and active earth pressure from limited backfill Ka.It is found that Ko is close to or smaller than Koj,when the internal friction angle between the rock face and backfill δr is equal to that of backfill φ.Ko is not only influenced by φ and inclination of the rock face,but also by δr;Ko may be larger or smaller than Koj,when δr is smaller than φ;Ko and Ka decrease with the increase of the inclination of the rock slop;and Ko is larger than Ka.To make the rock face rough and to adopt bench excavation are both effective methods to reduce the at-rest earth pressure from the limited backfill.A design graph is given at the end of the paper.