低净空环境下顶管桩施工技术研究

Study on Pipe-jacking Pile Construction Technology in Low-clearance Environment

介绍了某工程顶管桩系统概况及其成套施工工艺。顶管桩将土压反力自平衡顶管技术和钻孔灌注桩技术结合,可解决既有建筑低净空环境下围护结构打设施工困难以及承压水地层成桩困难问题。顶管机头顶进至设计深度后可被回收并灌注混凝土成桩,监测数据反映整个施工过程对桩周环境扰动较小。最后,从机头优化、反力系统设计、混凝土同步灌注、承压水地层加固和洞口止水等5个方面提出后续施工优化方案。

The article introduces the general situation and integral construction technology of pipe-jacking pile system. The pipe-jacking pile combining the earth pressure counter-force self-balance pipe jacking technology and the cast-in-situ pile technology can solve the difficulties of enclosure structure construction of the existing buildings in the low-clearance environment and the difficulties of pile construction in the stratum of confined water. The pipe-jacking machine head can be recycled after jacking to the design depth,and pour the concrete to complete the pile. The monitor data show that the whole construction process has a little disturbance on the surrounding environment of pile. The optimized scheme of follow-up construction is proposed from the optimization of machine head, design of counter-force system, synchronizing pouring of concrete, reinforcement of confined water stratum and water stop of portal.