基坑支护结构设计参数的敏感性分析

Sensitivity Analysis of Design Parameters of Excavation Support

基坑设计各参数的取值与施工方法、土体降水的情况、施工进度的安排等都密切相关。利用目前基坑设计中常用的软件进行计算,对土参数(容重γ、粘聚力c、内摩擦角φ)、地基土水平抗力系数的比例系数m值和支撑刚度k对围护结构最大位移和弯矩的影响的敏感性做了比较与分析。结果表明围护结构最大位移和最大弯矩对容重γ和地基土水平抗力系数的比例系数m值敏感程度较大。特别当m值较小时,取值要慎重考虑。支撑刚度k和摩擦角φ的敏感程度次之,且支撑刚度k随着其值的增大影响程度会明显减小。

Design parameters of foundation excavation are highly associated with the method of construction,the water in the soil,the schedule of construction and so on.This paper makes a sensitivity analysis of design parameters of excavation support,which includes soil parameters,such as unit weight γ、cohesion c、angle of internal friction φ,the proportional coefficient m of the horizontal resistance coefficient of ground soil and strut rigidity k by using software.The result shows that the maximum displacement and bending moment of braced structure are more sensitive to the unit weight γ and the proportional coefficient m,especially when the numerical value of m is small.Strut rigidity k and angle of internal friction φ are less sensitive,and the sensitivity of k will obviously decrease when its value increased.