考虑土体应力路径及非线性影响的基坑支护结构受力与变形分析  

Stress and Deformation Analysis of Foundation Pit Supporting Structure Considering Soil Stress Path and Nonlinear Influence

作　　者：高洪滨 陈聪 罗家易 徐鹏 GAO Hongbin;CHEN Cong;LUO Jiayi;XU Peng(Urban Communications Engineering Co.,Ltd.of CCCC First Harbor Engineering Co.,Ltd.,Tianjin 300461,China;State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures,Shijiazhuang Tiedao University,Shijiazhuang 050043,China;School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China)

机构地区：[1]中交一航局城市交通工程有限公司,天津300461 [2]石家庄铁道大学省部共建交通工程结构力学行为与系统安全国家重点实验室,石家庄050043 [3]西南交通大学土木工程学院,成都610031

出　　处：《路基工程》2023年第4期119-123,共5页Subgrade Engineering

基　　金：国家自然科学基金项目(52108331)。

摘　　要：基坑开挖将导致周边土体应力状态发生变化,忽略开挖过程中土体应力路径及应力-应变关系非线性影响的仿真计算将影响预测精度。通过与实际监测值进行对比,验证了考虑土体应力路径与非线性影响的数值仿真模型合理性,并且分析了桩长、锚索预应力、土钉长度对支护桩受力与变形的影响。结果表明:忽略土体应力路径与非线性的影响将低估地表沉降、高估支护桩底部变形;与桩长、锚索预应力相比,土钉长度对支护桩受力与变形的影响较小;支护桩反弯点出现在距离桩端约(0.4~0.6)H处;锚索预应力超过110kN后对降低工点基坑支护桩变形的效果减弱。Excavation of foundation pit results in change on the stress state of surrounding soil.The prediction accuracy of simulation calculation ignoring the soil stress path and the nonlinear influence of stress-strain relationship during excavation will be affected.In contrast with the actual monitoring data,it was verified that the numerical simulation model considering the soil stress path and the nonlinear influence was reasonable;furthermore,the effects of pile length,anchor cable pre-stress and soil nail length on the stress and deformation of supporting piles were analyzed.The result shows that,the neglection of soil stress path and nonlinear influence will underestimate ground surface subsidence and overestimate bottom deformation of supporting pile;compared with the pile length and cable pre-stress,the soil nail length has less effect on the stress and deformation of supporting piles;the reverse bending point of support pile appears in the place away from the pile end by approximately(0.4-0.6)H;the cable pre-stress,when exceeding 110 kN,will have weakened effect on reducing the deformation of foundation pit supporting pile at the working point.

关 键 词：基坑 土钉 桩 应力路径 位移 

分 类 号：TU473.2[建筑科学—结构工程]