软土地区综合管廊基坑工程中的两墙合一地下连续墙长度优化分析

Length Optimization Analysis of Dual-Purpose Underground Diaphragm Wall in Foundation Pit Engineering of Integrated Pipe Gallery in Soft Soil Area

综合管廊基坑多为狭长型基坑,在实际工程中具有很好的稳定性且受基坑宽度影响明显,但现行规范无法体现。结合实际工程,通过有限元软件建立数值模型,分析围护墙插入深度对基坑稳定性及围护墙受力影响,并采用强度折减法计算各工况下的安全系数。结果表明:当插入比达到一定值后,围护墙水平位移、周边最大沉降量及围护墙最大弯矩随插入比增加而小幅变化;利用强度折减法分析时的基坑安全系数与插入比呈近线性关系,随着插入比的增大而增高。

The foundation pits of integrated pipe gallery are mostly narrow and long foundation pits.They have better stability and are obviously affected by the width of foundation pits in the actual engineering,a numerical model is established by finite element software,to analyze the impact of insertion depth of the retaining wall on foundation pit stability and load-bearing capability of retaining wall itself,and to calculate the under various working conditions by using the strength reduction method.The results indicate that,when the insertion ratio reaches a certain value,the horizontal displacement,the maximum settlement,and the maximum bending moment of the retaining wall will vary slightly with the increase of insertion ratio;the relation between the safety factor of foundation pit and the insert ratio of retaining wall is almost linear when analyzed by using the strength reduction method,which means the safety factor increases with the increase of insertion ratio.