关键词: 基坑, Morgenstern-Price法, 可靠度指标, 响应面, 遗传算法, 禁忌搜索

Abstract:

Aiming at the uncertainty and variation of geo-material parameters in foundation pit engineering, the reliability analysis method of soil-nailing wall is discussed based on the response surface method, genetic algorithm and taboo search techniques. A modified Morgenstern-Price limit equilibrium method for analysis of the interior stability of soil-nailing wall is presented by considering the reinforcement effect of soil nails. An approximate reliability calculation method of soil-nailing wall, in which the response surface function is constructed by these sample points that are obtained from the modified Morgenstern-Price method instead of traditional FEM numerical simulation method, is established based on the response surface principle. Taking soil shearing strength parameters and as the random variables? a global optimal algorithm?adaptive taboo search genetic algorithm (ATSGA) is presented for soil-nailing wall reliability, which can effectively locate the critical slip surface associated with the minimum reliability index. An example is given; and the calculation results computed by proposed method show that if taking the minimum reliability index and the minimum safety factor as the target function respectively, the two critical slip surfaces are significantly different.

Key words: foundation pit, Morgenstern-Price method, reliability index, response surface, genetic algorithm, taboo search