地铁施工影响邻近管线的研究现状与展望

Current Situation and Prospect of Studies on Tunneling-Induced Effect of Adjacent Pipelines

从地下管线初始应力、接口模拟、失效模式、管土相互作用、控制标准、评估简化算法、离心模型试验以及有限元数值分析等方面,综述了国内外隧道施工对地下管线影响的已有研究成果。开挖引起周围地层的差异沉降是导致管线功能丧失的主要原因,主要表现形式为纵向弯矩引起的横向断裂和非刚性连接的管线接头张开等。影响管线变形的主要因素包括管线与隧道的相对位置、管线的弯曲刚度和土体的强度。管线的控制标准可以从地层移动、管线接头转角与脱开以及管线应变等方面考虑制定。对此类问题的分析,常用的弹性地基梁法与工程类比法都是基于经验的预测方法,没有考虑管道腐蚀引起的安全性下降,仅是采用较严格的变形控制标准。应在腐蚀管道评定的基础上合理制定变形控制标准,结合开挖引起地层移动与管土相互作用以及管材强度与变形特性的研究,建立一套完整实用的管线安全性评估体系。

This paper summarizes the existing home and abroad research results of the effects induced by tunneling engineering constructions on underground pipelines in terms of the initial stress of underground pipelines, simulation of the joints, failure mode, pipe-soil interaction, control criterion, simplified algorithm for evaluation, centrifugal model test, and finite element numerical analysis. Study results show that the pipeline failure is caused by differential ground movement associated with adjacent excavation. The patterns of pipeline failure include transverse fracture caused by longitudinal bending moment and joint leakage of flexible pipes. The relative positions of tunnel and pipeline, the bending rigidity of pipeline, and the strength of soil are the main influential factors of pipeline deformation. The pipeline deformation control criteria can be worked out by taking account of the strata movement, joint rotation and pullout of pipes, and the additional strain of pipes, etc. in common forecasting methods, beam on elastic foundation Winkler foundation model and empirical analogy method, are difficult to achieve precise results, because they neglect the pipe corrosion and adopt conservative deformation control criteria. Reasonable and safety evaluation standards should be established, and the pipeline safety evaluation system can be made based on the knowledge of ground movement at pipeline level, pipe-soil interaction and deformation properties and strength of pipes.