基坑被动区软土层加固宽度的数值分析

Numerical Analysis on Reinforcement Width of Soft Soil in Passive Zone of Foundation Pit

结合深圳市一实际工程,采用数值模拟方法,研究基坑被动区软土层加固宽度对基坑桩锚(撑)支护结构的影响规律。结果表明:坑底被动区加固对减小围护桩变形、受力及坑外地表沉降有效;同时坑底被动区软土层加固存在最优加固宽度,在加固宽度大于最优加固宽度时,围护桩变形、受力及坑外地表沉降基本处于稳定状态;考虑安全、经济等多方面的因素,在以减小围护结构变形、内力和地面沉降为主要目标时,建议基坑被动区软土层最优加固宽度取坑底软土层厚度的3~4倍。

Based on the actual project in Shenzhen,the influence of the reinforcement width of soft soil layer on the pile-anchor retaining structure in foundation pit was studied by numerical simulation method.The results show that the passive zone reinforcement of the pit bottom is effective in reducing the deformation and stress of retaining piles,and the settlement of ground surface;There is an optimal reinforcement width of the soft soil layer in the passive zone of the pit bottom,and when the reinforcement width is larger than the optimal reinforcement width,the deformation and stress of retaining pile,and ground surface settlement are basically in stable state;Considering safety,economic and other aspects,aiming at reducing the stress and deformation of retaining wall,and decreasing the ground settlement pptimal reinforcement width is suggested 3~4 times the thickness of the soft soil layer of the pit bottom.