超大直径钢顶管近距离侧穿高架桩基施工关键技术

Key Technologies for Construction of SuperLarge Diameter Steel Pipe Jacking by Side Crossing Viaduct Pile Foundation at Close Distance

以虹桥商务区核心区(二期)管沟工程为例,结合目前国内超大直径DN4200钢顶管近距离侧穿高架桥桩基和地表沉降监测数据,分析顶管顶进引起土体损失、顶管机正面推力及摩擦力等因素对周边土体的扰动是地表及周边构筑物变形的主要原因。通过对顶管近距离穿越桩基的顶进控制研究,制订合理的施工技术方案,采取必要的保障措施。施工中地表和临近桥梁沉降因顶管机正面推力、注浆压力等因素发生波动,沉降和变形均符合变形控制标准,确保工程顺利实施。这为类似工程提供良好的借鉴经验;也为今后城市复杂环境、复杂施工工况下,城市综合管廊开发应用奠定基础。

Taking the pipe ditch project of the core area of Hongqiao Business District(Phase II) as an example, combined with the current domestic super-large diameter DN4200 steel pipe jacking close distance lateral crossing viaduct pile foundation and ground settlement monitoring data, it is analyzed that the disturbance of the surrounding soil caused by the jacking of pipe jacking, the front thrust & friction of pipe jacking machine are the main causes to the deformation of the surface & surrounding structures. Through the study on jacking control of pipe jacking passing through pile foundation in close distance, reasonable construction technology scheme is worked out and necessary safeguard measures are taken. The settlement of the surface & adjacent bridges during construction fluctuates due to factors such as the front thrust of pipe jacking machine and grouting pressure. The settlement & deformation meet the deformation control standard and ensure the smooth implementation of the project. This provides a good reference for similar projects, and also lays a foundation for the development & application of urban utility tunnel in complex urban environment & construction conditions in the future.