地铁盾构施工对地下管线影响的模型试验研究

Model test study of underground pipelines affected by metro shield tunneling

文章以合肥地区典型黏土和砂土为试验材料进行室内模型试验,探究在盾构开挖条件下,地下管线在黏土和砂土不同地层中受力和变形的规律。研究结果表明,由于管-土相互作用程度和相对刚度不同,导致盾构开挖管线在砂土中变形曲线呈沉降槽型,在黏土中呈小双峰型;管线在砂土中最大沉降值大于黏土,而黏土中管线底部最大拉应力大于砂土;相邻管线部位变形具有上拱和下拉效应,且上拱和下拉效应对相邻管线部位的影响范围和程度不同;管线的最大变形量与地层损失量、沉降槽宽度有线性关系。

Taking the typical clay and sand of Hefei City as test materials,indoor model test was conducted to analyze the strain and deformation of underground pipelines in clay stratum and sand stratum under the condition of shield tunneling.The results show that the deformation curve of the pipeline exhibits settlement trough pattern in sand and small bimodal pattern in clay due to the different degrees of soil-pipe interaction and relative stiffness.The maximum settlement of the pipeline in sand is greater than that in clay,and the maximum tensile stress at the bottom of the pipeline in clay is larger than that in sand.The upper-arching and pull-down effect influences the deformation of the adjacent pipeline parts greatly.The influence scope and extent of the upper-arching and pull-down effect are different between the adjacent pipeline parts.The maximum deformation of the pipeline has a linear relationship with the ground loss and settlement trough width.