基于离心模型试验的软土基坑被动区加固  

Passive zone reinforcement of soft soil foundation pit based on centrifugal model tests

作　　者：蔡雪峰 崔泽恒 冯晓腊[2] 阎波 冯钰淞 CAI Xuefeng;CUI Zeheng;FENG Xiaola;YAN Bo;FENG Yusong(CITIC Construction Co.,Ltd.,Beijing 100027,China;School of Engineering,China University of Geosciences(Wuhan),Wuhan 430074,China;Central&Southern China Municipal Engineering Design and Research Institute Co.,Ltd.,Wuhan 430010,China)

机构地区：[1]中信建设有限责任公司,北京100027 [2]中国地质大学(武汉)工程学院,湖北武汉430074 [3]中国市政工程中南设计研究总院有限公司,湖北武汉430010

出　　处：《安全与环境工程》2024年第4期84-98,108,共16页Safety and Environmental Engineering

基　　金：国家自然科学基金项目(51708526);武汉市城乡建设局科技计划项目(202045、202009);校企科研攻关项目(2020056378)。

摘　　要：深厚软土地区深基坑内侧被动区土体抗力明显不足,开挖容易诱发较大的围护结构变形和基坑整体失稳,被动区软土加固能有效改善软土力学性能,约束基坑围护结构变形。为探究软土深基坑被动区加固的作用效果,结合离心模型试验和数值模拟技术,对被动区软土加固基坑的变形与受力特性进行了分析。结果表明:深基坑被动区软土加固能够抑制基坑围护结构出现较大的变形,且提升了被动区土体的抗力;随着被动区加固体加固宽度或加固深度的增加,基坑支护桩水平位移、主动区地表沉降值、被动区基底隆起值均呈减小的趋势;被动区加固宽度和加固深度存在合理的区间范围,当加固深度为0.5~0.6倍开挖深度、加固宽度为0.6倍开挖深度时,基坑变形控制程度较好,加固体加固深度变化对基坑变形响应更敏感,因此在软土地区深基坑被动区加固时,应优先考虑加固体加固深度对基坑变形控制的影响。The passive zone reinforcement can effectively improve the mechanical properties of the soft soil and restrain the deformation of the foundation pit enclosure.In order to investigate the effect of passive zone reinforcement in soft soil deep foundation pits,the deformation and force characteristics of soft soil reinforced foundation pits in the passive zone were investigated through a combination of centrifugal model tests and numerical simulation techniques.The results are as follows:the passive zone reinforcement of deep soft soil foundation pits can inhibit large deformation of the foundation pit enclosure structure and improve the resistance of the passive zone soil body;with the increase of the width or depth of the passive zone reinforcement,the horizontal displacement of the foundation pit support piles,the value of the surface settlement of the active zone,and the value of the passive zone footing elevation are all in a decreasing trend;there is a reasonable interval range of the width and depth of the passive zone reinforcement,and the degree of control of the foundation pit deformation is better when the depth of the reinforcement is 0.5-0.6 times the excavation depth,and the change of the depth of reinforcement is 0.6 times the excavation depth,and the change of reinforcement depth is more sensitive to the response of foundation deformation.Therefore,for the passive zone reinforcement of deep foundation pits in soft soil areas,priority should be given to the influence of reinforcement depth on the deformation control of the foundation pits.

关 键 词：软土基坑 被动区软土加固 离心模型试验 数值模拟 

分 类 号：X948[环境科学与工程—安全科学] TU47[建筑科学—结构工程]