考虑超挖深大基坑地表沉降机理及基坑稳定性分析  

Analysis of Surface Settlement Mechanism and Stability of Considering Over-excavation of Deep and Large Foundation Pits

作　　者：张艳玲 王新宇[2] 刘淑红[3] ZHANG Yanling;WANG Xinyu;LIU Shuhong(Hebei Construction Engineering Quality Testing Center Co.,Ltd.,Shijiazhuang 050227,China;Henan Polytechnic University,Jiaozuo 454003,China;Shijiazhuang Tiedao University,Shijiazhuang 050043,China)

机构地区：[1]河北省建筑工程质量检测中心有限公司,河北石家庄050227 [2]河南理工大学,河南焦作454003 [3]石家庄铁道大学,河北石家庄050043

出　　处：《粉煤灰综合利用》2021年第6期41-45,63,共6页Fly Ash Comprehensive Utilization

摘　　要：本文研究了深大基坑地表沉降机理和超挖后架设支撑对基坑稳定性分析。基于三维FLAC 3D有限元软件,建立了架设第3道内支撑前,考虑超挖的三维数值模型。结果表明:超挖对地表沉降和坑底隆起影响较大,较于正常开挖而言,随超挖深度的增加,地表沉降和坑底隆起整体呈增加趋势;超挖深度对地连墙侧移的影响主要集中在12 m深度以下;超挖深度对地连墙墙顶侧移和墙顶沉降影响较小,基本可以忽略。结合地层损失法,对地表沉降最大值进行计算可知,计算结果和数值结果相差不大,验证了模型的合理性。研究结果对相关理论和实践具有指导意义。This paper studies the ground settlement mechanism of deep and large foundation pits and the stability analysis of foundation pit by erection of support after over-excavation.Based on FLAC 3D finite element software,a 3D numerical model was established to consider over excavation before erecting the 3rd inner support.The numerical results show that over excavation has a greater impact on the ground settlement and basal heaves.Compared with normal excavation,the ground settlement and basal heaves tend to increase with the increase of over excavation depth.The influence of over excavation depth on lateral movement of wall is mainly depth in the below 12 m.The lateral movement and the settlement of the top of the wall is negligible with the influence of the over excavation depth.Combined with the formation loss method,the calculation of the maximum ground settlement shows that the calculated result is almost the same as the numerical result,which verifies the rationality of the model.The research results have guiding significance to relevant theories and practices.

关 键 词：基坑稳定 超挖 内支撑 地表沉降 

分 类 号：TU91[建筑科学—建筑理论]