富水粉土基坑装配式可回收支护开挖响应分析  

Excavation response analysis of prefabricated recyclable support structure for water-rich silt foundation pit

作　　者：王锐松 郭成超 林沛元 王复明 WANG Rui-song;GUO Cheng-chao;LIN Pei-yuan;WANG Fu-ming(School of Civil Engineering,Sun Yat-Sen University,Guangzhou,Guangdong 510275,China;Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai),Zhuhai,Guangdong 510275,China;Guangdong research center for underground space exploitation technology,Guangzhou,Guangdong 510275,China;Southern Institute of Infrastructure Testing and Rehabilitation Technology,Huizhou,Guangdong 516000,China)

机构地区：[1]中山大学土木工程学院,广东广州510275 [2]南方海洋科学与工程广东省实验室(珠海),广东珠海519080 [3]广东省地下空间开发工程技术研究中心,广东广州510275 [4]南方工程检测修复技术研究院,广东惠州516000

出　　处：《岩土力学》2023年第3期843-853,共11页Rock and Soil Mechanics

基　　金：国家自然科学基金青年基金资助项目(No.52008408);国家重点研发计划(No.2021YFC3100800,No.2021YFC3100803)。

摘　　要：装配式可回收支护结构为地下空间开发提供了一种经济安全、功能协同、可持续发展的新型绿色支护体系。以郑州市某顶管工作井基坑为背景,基于相似比理论开展了缩尺基坑模型试验,并采用ABAQUS建立能够区分支护系统中刚性构件与柔性构件变形差异的三维流固耦合模型,研究降水开挖过程中支护结构受力和变形特性,分析了降水和开挖对基坑变形发展的影响规律。研究表明:降水开挖过程中,支护结构受力及变形整体均小于设计值,但是钢面板在与支撑连接的位置易出现局部屈服现象;支护结构水平位移增量模式随降水施工和开挖施工的情况不同而差异较大,随着基坑降水开挖的进行,影响支护结构变形的主要因素由基坑降水逐渐向基坑开挖转变;基坑降水对地表沉降的影响较基坑开挖更大,第1级降水期间地表沉降快速增长,沉降增量占比最大达44.6%。The prefabricated recyclable support structure provides a new green support system with economic security,functional coordination and sustainable development for the development of underground space.The physical model test of the foundation pit of a pipe-jacking working well in Zhengzhou city is carried out based on the similarity theory.A three-dimensional fluid-solid coupling model that can differentiate the deformation difference between rigid and flexible members in the support system is established by using the ABAQUS software.The stress and deformation characteristics of supporting structure in the process of dewatering and excavation are analyzed.The influences of dewatering and excavation on the deformation characteristics of foundation pit are also studied.Results show that in the processes of dewatering and excavation,both the stress and deformation of the main supporting structural members are all less than those of the design values,but the steel panels are prone to local yield at the position connected with the waist beams.The increment mode of horizontal displacement of retaining pile varies greatly with the processes of dewatering and excavation.With the progress of the dewatering and excavation of the foundation pit,the deformation of the supporting structure is less affected by dewatering,and the main factor affecting the deformation of the supporting structure is gradually changing from foundation pit dewatering to foundation pit excavation.The influence of foundation pit dewatering on the surface settlement is greater than that of foundation pit excavation.The surface settlement increases rapidly during the first level of dewatering,with the maximum settlement increment accounting for 44.6%.

关 键 词：装配式可回收支护 基坑开挖 基坑降水 模型试验 有限元分析 

分 类 号：TU476.9[建筑科学—结构工程]