大断面矩形顶管近距离下穿河道开挖方案比选研究

Comparison and Analysis on Excavation Schemes for Large Cross-section Rectangular Pipe Jacking to Cross River Channels at Short Range

摘要:

大断面矩形顶管近距离下穿河道具有一定的风险性，需要在设计和施工中采用合适的方案来降低隧道开挖风险。依托陆翔路—祁连山路大断面矩形顶管地道工程，采用数值分析的方法分别对先顶进后抗浮工法和先抗浮后顶进工法进行分析，并基于施工流程、数值模拟结果等进行方案比选，确立了先顶进后抗浮工法的开挖方案。施工监测结果表明，贯通后一段时间内，顶管结构整体略有沉降，约2.5 mm，管节最大上浮量约30 mm。

Abstract:

The large cross-section rectangular pipe jacking to cross the rivers at short range has a certain risks. It is necessary to use the suitable scheme to reduce the excavation risk of tunnel in the design and construction. Relying on the large cross-section rectangular pipe jacking tunnel project of Luxiang Road - Qilianshan Road, the numerical analysis methods are used to analyze the method of first-jacking and then anti-floating construction, and the method of first anti-floating and then jacking construction. Based on the construction process and numerical simulation results, the schemes are compared and selected. The excavation scheme of first-jacking and then anti-floating construction is established. The construction monitoring results show that the overall settlement of the pipe jacking structure is slightly, about 2.5 mm, and the maximum floating of the pipe segment is about 30 mm for some time after the connection.