摘要
针对淤泥质土中综合管廊基坑在施工过程中变形超限现象,结合具体工程实例,采用Midas GTS有限元软件模拟了综合管廊基坑的开挖及回填过程,验证了数值模拟结果与现场数据的一致性,分析了综合管廊基坑变形及围护结构受力情况,并提出了一种框架双排钢板桩+钢支撑绿色支护优化方式。研究结果表明:综合管廊基坑开挖阶段的位移与位移速率均超出预警值,且位移速率对于综合管廊基坑位移超限更具有预警前兆性;淤泥质土中综合管廊基坑坑底隆起更能反映基坑变形状态;开挖到综合管廊基坑坑底所产生的位移增量可达总增量的55%,此时为综合管廊基坑施工最危险阶段;钢板桩全阶段变形呈弓字形,在综合管廊基坑开挖结束时的钢板桩变形最大,位置约在0.5H(H为钢板桩长度)处;采用支护优化的框架双排钢板桩+钢支撑结构有效控制了综合管廊基坑及围护结构变形,支护优化后的钢板桩变形呈悬臂式,综合管廊基坑位移控制在20 mm内;提出的框架双排钢板桩+钢支撑支护结构可以回收重复利用,实现了绿色施工。相关研究结论可为类似工程提供参考。
Aiming at the deformation overlimit of foundation pit in silt soil utility tunnel during the construction,combined with the actual engineering,Midas GTS finite element software was used to simulate the excavation and backfilling process of the foundation pit,and the consistency between numerical simulation results and field data was verified.Then,the deformation and the stress information of the pit were extracted and analyzed to propose a green support optimization method of frame double-row steel sheet pile+steel support.The results show that both the displacement and displacement rate exceed the warning value,and the displacement rate has more warning precursor for the displacement overlimit;The uplift at the bottom of the foundation pit can better reflect the deformation state of the foundation pit;When the displacement reach 55%of the total increment,it is the most dangerous stage.The full-stage deformation of the steel sheet pile presents a‘bow’shape.When the excavation completes,the deformation of the steel sheet pile is the largest at the position about 0.5H(H is the length of the steel sheet pile);The supporting structure of frame double row steel sheet pile+steel support is adopted to effectively controls the deformation of the foundation pit and the retaining structure.The deformation of the steel sheet pile is cantilevered after the support optimization.The displacement is controlled within 20 mm.The proposed frame double-row steel sheet pile+steel support structure can be recycled and reused to achieve green construction.The relevant research conclusions can provide reference for similar projects.
作者
王勇轩
袁长丰
李振
刘辛波
张顺哲
仲臣
Wang Yongxuan;Yuan Changfeng;Li Zhen;Liu Xinbo;Zhang Shunzhe;Zhong Chen(College of Civil Engineering,Qingdao Technology University,Qingdao 266525,China;Qingdao First Municipal Engineering Co.,Ltd.,Qingdao 266000,China)
出处
《市政技术》
2024年第6期52-59,67,共9页
Journal of Municipal Technology
基金
山东省重点研发计划(公益类专项)项目资助(2018GSF120005)。
关键词
综合管廊基坑
淤泥质土
变形超限
支护优化
钢支撑
钢板桩
foundation pit of the utility tunnel
silt soil
deformation overlimit
support optimization
steel supports
steel sheet piles
