临海湖地铁深基坑支护体系稳定性影响参数分析

Analysis of Influence Parameters on Stability of Deep Foundation Pit Support System in Coastal Lake Metro

为研究沿海地区基坑被动区加固参数对围护结构内力和位移的影响,以厦门地铁2号线育秀东路站为工程背景,利用三维弹塑性有限元数值模拟方法,分析了基坑围护结构的变形与支撑结构的内力变化规律,并通过设置不同基坑被动区加固参数对支护结构的内力变化和变形效果进行比对.研究结果表明:增加连续墙的厚度,能够有效地降低围护结构的水平位移和基坑底部土体的隆起,减小支撑结构的内力;连续墙的嵌固深度对围护结构变形以及支撑结构的内力基本没有影响,但从经济方面考虑,在满足稳定性要求情况下,应尽量减小连续墙嵌固深度;随着被动区水泥掺量的增加,围护结构的水平位移和坑底隆起明显减小,而增加被动区加固深度仅能减小基坑底部的隆起,对围护结构的水平变形和内支撑的轴力几乎没有影响.

In order to study the influence of the reinforcement parameters in the passive zone of excavations in the coastal area on the internal forces and displacement of the retaining structure,the Yuxiu East Road Station of Xiamen Metro 2 Line was used as the engineering background.By using three-dimensional elastoplastie finite element numerical simulation method,this paper analyzed the deformation law of the retaining structure of excavations and the internal force change law of support structure,and compared the internal force change and deformation effect of support structure by setting different passive excavations reinforcement parameters.The results show that increasing the thickness of the continuous wall can effectively reduce the horizontal displacement of the retaining structure and the bulge of the soil at the bottom of the excavations,and decrease the internal force of the supporting structure.The embedded depth of the continuous wall has no effects on the defonnation of structure and internal force of supporting structure.However,considering the economy,the embedded depth of continuous wall should be reduced aftar as possible when the stability requirement is satisfied.With the increase of cement in the passive zone,the horizontal displacement of the retaining structure and the bottom of the bulge significantly decrease,ami increasing the depth of reinforcement in the passive zone can only reduce the bulge at the bottom of the excavations,which has little effect on the horizontal deformation of the retaining structure and the axial force of the inner support.