土岩组合地质条件下适宜嵌岩深度分析

Appropriate rock-socketed depth under geological conditions of soil and rock combination

基于土岩组合基坑支护结构安全的重要性,探讨了保证岩体稳定性的适宜嵌岩深度的精确算法,提出了利用积分形式推导3种临界深度支护桩的嵌岩深度,并配合MATLAB编程与理正设计软件使用,研究了一套可以同时满足支护桩内力变形和岩体稳定的相对智能而高效的计算适宜嵌岩深度的方法,并用实际算例进行验证.结果表明:探寻出的计算流程通过不断的修正计算,给出了适宜嵌岩深度,与传统方法的计算结果相比大于5%,说明仅考虑内力变形要求,嵌岩桩存在失稳的可能;增加考虑岩体的稳定性,可以更科学的确定嵌岩深度,保证支护桩和岩体的稳定性,为土岩组合基坑支护重要设计参数提供参考依据,确保工程的安全性和经济性.

Based on the importance of the safety in the supporting structure of soil-rock composite foundation pit,an accurate algorithm of the appropriate depth of embedded rock from the perspective of rock mass stability was investigated.The rock-socketed depth of support pile with three critical depth values was deducted by integral form.Combining MATLAB and LIZHENG software,an intelligent and efficient method to calculate the appropriate depth of embedded rock was presented,which can meet the internal force deformation of supporting piles and stability of rock mass at the same time.The results show that the appropriate depth of embedded rock given by repeatedly modified calculation process is 5%larger than that derived from the traditional method,which shows that the rock-socketed pile may be unstable by only considering the internal force deformation.Taking the stability of rock mass into account,the rock-socketed depth can be determined more accurately to ensure the stability of supporting pile and rock mass,and provide reference for the design parameters of rock-soil combined foundation pit support.