承压水砂层地基通道下抗浮桩拔桩施工技术

Pile Pulling Technique of Anti-floating Pile of Underground Passage on Silty Sand Ground with Confined Water

针对承压水作用下粉砂地基上通道底板抗拔桩拔除作业中的承压水水位控制和低净空拔桩作业的关键问题,结合现场实践,研究了粉砂地基下承压水的降水方案,实现了对通道沉降和地表位移的有效控制,保证了通道结构和周边建筑物的安全。结合通道特点,研究了通道内低净空拔桩的施工工艺,针对拔桩底板破坏后底板修复中的防水处理和结构安全等关键问题,采取有效措施对拔桩引起的底板破坏进行了修复。

Combined with field engineering practice, the dewatering scheme of confined water under silty sand ground is studied, which is directed against the key problems of controlling the confined water level and pile pulling under the low clearance in the pulling out the piles of the channel bottom on the silty sand foundation under the influence of confined water. It realizes the effective control of channel settlement and surface displacement, and ensures the safety of the channel structure and surrounding buildings. According to the channel characteristics, this paper proposes channel low headroom pile construction method. At the same time, in view of the key problems such as waterproof treatment and structural safety in the repair of the floor after the wreck of the pull out of the pile bottom, effective measures are adopted to repair the floor failure caused by the pulling out of the pile.