确定深基坑隆起破坏面的优化方法

采用有限元程序求得深基坑支护结构和土体开挖前后的应力状态以及土体任一点处的极限状态函数值；运用人工参与的优化方法选择坑底最大可能隆起破坏的起点与终点以及潜在隆起破裂面的形状和位置，并计算相应的安全系数。计算表明，潜在破裂面终点的位置对围护桩插入比不敏感．而潜在破裂面起点位置随围护桩入土深度的增加而逐渐靠近围护桩。工程实例证实了组合优化算法对潜在破裂面确定的有效性和实用性。

Optimization of bulge fracture plane searching in foundation pit

Stress status of supporting structure and the retained soil was analyzed with FEM in foundation pit, and the value of limiting status function of retained soil was calculated. With "artificial participation" optimization, the shape and position of potential bulge fracture plane in foundation pit were calculated with the dijkstra algorithm and the relative safety coefficient was proposed. Large scale numeric calculation and in situ measurements show that the end point of potential fracture plane is insensitive to the insertion ratio of supporting pile, that the start point of potential fracture plane is near the supporting pile when the insertion of pile is increasing. The in situ measurements show the availability and utilization of method of the potential bulge fracture plane searching based on the optimization algorithm in composite optimization.