某综合管廊基坑支护安全数值分析

Numerical Analysis of Support Safety of A Comprehensive Tube Gallery Foundation Pit

以某基坑支护结构为例,计算基坑施工过程的受力形为及安全的其他影响因素。结果表明:当基坑开挖过程中,受力与变形随非线性增加;同时受汽车、起重机、堆土等偏荷载影响,施工过程基坑左右受力与变形差异较大;其中堆土方式影响最大,当一边堆土时桩体产生的最大正应力大于桩体屈服强度,而且位移量比较大,基坑可能发生失稳;考虑两边堆土时,桩体产生的最大正应力位移量明显减小;最后考虑地下水后除土体最大横向位移外,其他的应力、位移变化相差不大,说明基坑安全所受地下水位的影响有限。

In this paper,a foundation pit supporting structure is used as an example to calculate the stress shape of foundation pit construction process and other factors of safety. The results show that the force and deformation of the foundation pit are non-linear.Meanwhile,due to the influence of partial loads such as automobile,crane and heap soil,the force and deformation of the foundation pit are different. The maximum positive stress of pile is greater than the yield strength of pile,and the displacement quantity is large,and the foundation pit can be unstable. When considering the soil,the maximum positive displacement of pile is obviously reduced. At last,considering the maximum lateral displacement of soil after ground water,the difference of stress and displacement is not large,and the influence of foundation pit is limited by the underground water level.