船行二站基坑开挖支护设计及有限元数值模拟研究

Design and finite element numerical simulation study of foundation pit excavation support of Shipyard No.2 Station

基坑的开挖和支护是当前水利工程安全施工中的重要问题。该研究以江苏省宿迁市船行二站拆建工程深基坑开挖工程为研究对象,采用每2m一层的开挖步长,南北侧设置钻孔灌注桩加一道锚索张拉,同时采用施打钢板桩的支护方案,利用有限元软件对其开挖和支护进行模拟。模拟结果表明,在基坑的开挖过程中,基坑开挖面由于上部荷载的释放会产生地面反弹,基坑中心反弹量最大;基坑坡面整体向基坑内侧方向变形,混凝土灌注桩顶部向基坑外侧方向变形,底部向基坑内侧方向变形,但变形量较小,从而证明采用的加固措施方法是有效的。

The excavation and support of foundation pits are important problems in safe construction of current water conservancy projects.The deep foundation pit excavation project of demolition and construcfion project of the ship No.2 station in Suqian of Jiangsu is adopted as the object in the study.The excavation step length of one floor for every 2 meters is adopted.A bored cast-in-place pile and an anchor cable support are set on the north-south side.A support scheme of applying steel sheet piles is adopted at the same time.Excavation and support are simulated by the finite element software.The simulation results show that the ground rebound will occur on the excavation surface of the foundation pit due to the release of the upper load in the process of foundation pit excavation,and the amount of rebound is the largest in the center of the foundation pit;the whole slope of the foundation pit is deformed to the inside of the foundation pit;the top of the concrete cast-in-place pile deforms to the outside of the foundation pit,and the bottom deforms to the inside of the foundation pit,but the deformation is small.It is proved that the adopted reinforcement methods and measures are effective.