泥质粉砂岩地层基坑桩锚支护数值模拟分析  

Numerical Simulation Analysis of Pile-anchor Supporting Structure of Foundation Pit in Argillaceous Siltstone Formation

作　　者：曾东旭 查小君 周晓宇 谢昭晖 ZENG Dongxu;ZHA Xiaojun;ZHOU Xiaoyu;XIE Zhaohui(Jinhua Rail Transit Group Co.,Ltd.,Jinhua 321000,Zhejiang,China;China Railway Fifth Survey and Design Institute Group Co.,Ltd.,Beijing 102600,China)

机构地区：[1]金华市轨道交通集团有限公司,浙江金华321000 [2]中铁第五勘察设计院集团有限公司,北京102600

出　　处：《路基工程》2021年第3期134-138,共5页Subgrade Engineering

摘　　要：针对特定的泥质粉砂岩地层,以某地下二层双岛四线换乘地铁车站为依托,运用mIdas GTS软件对支护体系进行模拟分析,并将模拟结果与实测结果进行对比。结果表明:基坑开挖后,表层土体以拉应力为主,深层岩土体以压应力为主,在坑脚位置出现应力集中现象,其应力是周围岩土体应力的3倍;围护桩+预应力锚索复合式支护体系中,变形最大的位置是围护结构顶部,与实测结果吻合度较高,第二层锚索比第一层锚索锚固效果好,实测锚索受力与模拟锚索受力一致。模拟结果显示,围护桩自身内力较小,因此,在复合式支护体系中,围护桩骨架作用较为明显,受力机理主要通过锚索拉力提供力矩保持边坡稳定。Based on a four lines transfer subway station projects with underground two double islands,midas GTS software was used to simulate and analyze the support system for specific argillaceous siltstone formation,the simulation results were compared with the measured results.The results show that after the excavation of the foundation pit,the surface soil is dominated by tensile stress and the deep rock and soil is dominated by compressive stress.Stress concentration occurs at the foot of the pit,where it is three times of that of the surrounding rock mass.In the composite supporting system of retaining pile and prestressed anchor cable,the position with the largest deformation is the top of the retaining structure.The simulation results are in good agreement with the measured results.The second layer of anchor cable has better anchoring effect than the first layer.The measured anchor cable stress is consistent with the simulated anchor cable stress.The simulation results show that the internal force of retaining piles is small.Therefore,in the composite supporting system,the framework of retaining piles plays an obvious role,and the stress mechanism mainly provides torque to maintain the slope stability through anchor cable tension.

关 键 词：泥质粉砂岩 围护桩 预应力锚索 支护结构 数值模拟 

分 类 号：TU470.3[建筑科学—结构工程]