富水砂层超深地下连续墙施工塌方机制与处置技术研究

Research on the Collapse Mechanism and Disposal Technology during Construction of Ultra-deep Diaphragm Wall in Water-rich Sand Strata

摘要:

针对近长江口区域的厚层粉砂土地层中超深地下连续墙施工中槽壁塌方的问题，以上海市长江口某工程圆工作井100 m超深地下连续墙为案例，通过现场勘查、事故复盘与实践验证，系统分析了塌方产生的原因并研究相关的防范技术。研究结果表明，塌方主要由地质、荷载和泥浆等多因素耦合导致，由此提出以“回填控险—分层加固—降水稳土—荷载优化”为核心的综合处置方案，包括分级回填、差异化加固、降水稳土等措施。应用验证表明，该技术方案能够有效控制塌方风险，保障施工安全。研究成果可为类似工程提供参考。

Abstract:

Aiming at the challenge of trench wall collapse during the construction of ultra-deep diaphragm walls in thick silty sand strata near the Yangtze River Estuary, taking the 100-m ultra-deep diaphragm wall of a circular working shaft in the Shanghai Yangtze River Estuary as a case study, the causes of the collapse are systematically analyzed and the relevant prevention technologies are studied through on-site investigation, accident review and practical verification. The research result identifies that collapses are mainly caused by the coupling of multiple factors such as geology, load and mud. Consequently, an integrated disposal scheme centered on “backfilling for risk control - layered reinforcement - dewatering for soil stabilization - load optimization” is proposed, including the measures such as graded backfilling, differentiated reinforcement and dewatering for soil stabilization. Application results demonstrate that the proposed technical scheme can effectively control the collapse risks and ensure the construction safety. The research results can provide references for similar projects.