盾构隧道下穿上软下硬地层对地表沉降的影响
Study on the Effect of Shield Tunneling through Upper Soft and Lower Hard Strata on Surface Settlement

地下交通建设在城市建设中的地位越来越重要，盾构法作为一种新型的地铁隧道施工工法，以其较高的施工效率、较小扰动、较强的地层适应性、较高的安全性等优势，得到了越来越多的应用。上软下硬复合地层是盾构施工过程中经常遇到的不良地层，在此地层中盾构施工时更容易引发地表沉降，对周围环境产生较大影响。以此地层为工程背景，通过Midas软件对盾构掘进参数对地表的沉降影响进行了分析，发现在不同开挖参数下，地表沉降和变形是不同的，最终确定了盾构掘进参数的安全取值范围。
Underground transportation construction plays an increasingly important role in urban construction. As a new type of subway tunnel construction method, shield tunneling method is characterized by its higher construction efficiency, less disturbance, stronger stratum adaptability, and higher safety and other advantages, and has been more and more applications. The upper-soft lower-hard composite stratum is an unfavorable stratum often encountered in the shield construction process. In this stratum, the shield construction is more likely to cause surface subsidence, which has a greater impact on the surrounding environment. Taking this stratum as the engineering background, the Midas software was used to analyze the influence of the shield tunneling parameters on the surface settlement. It is found that the surface settlement and deformation are different under different excavation parameters, and the safe value range of shield tunneling parameters is finally determined.