砂质黄土区管涵上穿城际隧道施工影响分析

Analysis on Impact of Pipe Culvert Construction Passing through Intercity Tunnels in Sandy Loess Areas

摘要:

为探究砂质黄土地层条件下，上穿城际铁路隧道管涵施工对隧道的不利影响，依托我国西北地区排水管涵上穿某城际铁路隧道项目，针对典型砂质黄土增湿变形特性，采用有限元差分软件FLAC 3D开展数值模拟，分析管涵施工时土体沉降和隧道结构变形。结果表明：不考虑水害情况下，管涵施工对既有隧道结构的影响较小。当砂质黄土遇水劣化后，管涵施工造成的土体沉降范围和程度均明显增大，既有隧道结构的受力与变形均超过预警值。通过加强施工区域内的防水设计、排水系统设计、确保填土质量等措施可降低水对砂质黄土力学性能劣化的影响，提高既有隧道的运营安全。

Abstract:

In order to explore the adverse impact of the construction of pipe culvert passing through an intercity railway tunnel under the condition of sandy loess stratum, relying on a drainage pipe culvert passing through an intercity railway tunnel project in the northwest China and aiming at the humidification and deformation characteristics of typical sandy loess, the numerical simulation is carried out by using the finite element difference software FLAC 3D to analyze the soil settlement and tunnel structure deformation during the construction of the pipe culvert. The results show that without considering water damage, the impact of pipe culvert construction on the existing tunnel structure is relatively small. When the sandy loess is deteriorated by water, the range and degree of soil settlement caused by pipe culvert construction increase significantly, and the force and deformation of the existing tunnel structure all exceed the warning values. By strengthening the waterproof design, drainage system design, and ensuring the filling quality in the construction area, the adverse effects of water on the mechanical properties of sandy loess can be reduced, and the operational safety of the existing tunnel can be improved.