注浆压力不均匀分布影响下过江盾构隧道变形分析

Study of the Deformation of Cross-River Shield Tunnel on the Effect of Uneven Distribution of Grouting Pressure

摘要: 为研究盾构隧道同步注浆施工过程对隧道变形的影响，本文依托长沙地铁4号线跨湘江段盾构工程，通过设置四种不同的注浆压力分布方案进行数值模拟分析，研究注浆压力不均匀分布对盾构隧道变形的影响。模拟结果表明：相同注浆量下，注浆压力不均匀分布对隧道围岩所受径向压力有较大影响，不利于衬砌管片的受力，使隧道底部受力大于顶部受力，并引起隧道上浮；而且注浆压力不均匀分布会使沿隧道的纵向和横向地表沉降值减小，地表隆起量增大。所以盾构隧道施工过程中需严格控制注浆压力分布和大小，研究结果可为今后盾构施工技术提供参考。

Abstract: In order to study the influence of synchronous grouting construction of shield tunnel on the de-formation of tunnel, based on the Changsha Metro Line 4 Project, the numerical simulation analysis was conducted in this paper to explore the influence of disintegration of grouting pressure caused by uneven distribution of slurry pressure on the deformation of shield tunnel. The results show that: when the grouting volumes were same, the uneven distribution of grouting pressure had a significant impact on the radial pressure of the surrounding rocks, harmful to the stress of lining segments; and it caused tunnel stress of the bottom more than the top, resulting in the float of tunnel, increasing the ground surface upheave. Moreover, the uneven distribution of grouting pressure will reduce the settlement and increase the upheave of the vertical and horizontal ground surface along the tunnel. So the pressure distribution and value of grouting pressure should be strictly controlled in the construction of shield tunnel. And the conclusions can provide some reference for the later shield construction.