超大地面荷载下盾构工作井叠合结构的力学响应  

Mechanical Response of Composite Structure in Shield Working Shafts Under Very Heavy Ground Loads

作　　者：宋博 刘俊岩[1] 刘燕[1] 宋享桦 扈萍[1] 李春林 张亮亮[3] 孙文昊[3] SONG Bo;LIU Junyan;LIU Yan;SONG Xianghua;HU Ping;LI Chunlin;ZHANG Liangliang;SUN Wenhao(School of Civil Engineering and Architecture,University of Jinan,Jinan 250022,Shandong,China;Jinan City Construction Group Co.,Ltd.,Jinan 250014,Shandong,China;China Railway Siyuan Survey and Design Group Co.,Ltd.,Wuhan 430063,Hubei,China)

机构地区：[1]济南大学土木建筑学院,山东济南250022 [2]济南城市建设集团有限公司,山东济南250014 [3]中铁第四勘察设计院集团有限公司,湖北武汉430063

出　　处：《济南大学学报（自然科学版）》2024年第1期29-36,47,共9页Journal of University of Jinan(Science and Technology)

基　　金：国家自然科学基金项目(51979122);山东省自然科学基金项目(ZR202111100198)。

摘　　要：为了解决现行盾构工作井的设计缺乏对超大地面荷载作用的验算问题,通过开展室内缩尺模型试验,研究盾构工作井从施工期到服役期在超大地面荷载下地下连续墙与主体结构侧墙所构成叠合结构的力学响应,并考虑盾构工作井周围土体中地下水的作用,探讨土体抗剪强度减小对超大地面荷载最大值的影响。结果表明:在超大地面荷载作用下,盾构工作井中隔墙的抗压刚度较大,以受压的形式承担了大量的荷载效应,导致叠合结构上部容易发生低应力水平下的整体水平位移,进而在围护结构底部发生失稳,导致整体破坏;主体结构侧墙在施工期的初始挠度及叠合结构整体水平位移使得叠合结构中地下连续墙承担了大部分内力;通过观测室内缩尺模型中叠合结构的变形量,由模型数据换算得到盾构工作井顶部极限超载为445.5 kPa,远大于盾构工作井周围土体地基承载力特征值130 kPa,验证了采用地基承载力对超大地面荷载下地面硬化进行设计的安全、可靠性。To solve the problem of lack of verification for effects of very heavy ground loads in current design of shield working shafts,an indoor scale model test was carried out to research mechanical response of composite structure in shield working shafts composed of underground diaphragm walls and main structure inner walls under very heavy ground loads from constructing period to service period.Considering effects of ground water in soil around shield working shafts,impacts of soil shear strength loss on the maximum very heavy ground load was discussed.The results show that under the very heavy ground loads,the middle wall in the shield working shaft has a large compressive stiffness and bears a large amount of load effect in the form of compression.An integral horizontal displacement at a low stress level is therefore prone to occur at upper composite structure,and an integral collapse due to instability occurs at lower supporting structure.The underground diaphragm wall in the composite structure bears most of the internal force due to the initial deflection of main structure inner walls during constructing period and the integral horizontal displacement of composite structure.By observing the deformation of composite structure in the indoor scale model, the ultimate overload at the top of the shield working shaft conversed from model data is 445.5 kPa, which is much greater than the subsoil bearing capacity characteristic value of 130 kPa of soil around the shield working shaft. Safety and reliability of ground hardening design under very heavy ground loads according to subsoil bearing capacity are therefore verified.

关 键 词：盾构工作井 叠合结构 超大地面荷载 模型试验 地基承载力 

分 类 号：TU921[建筑科学—建筑设计及理论]