高速公路下穿既有线路对周围环境的沉降影响分析

Analysis of the Settlement Impact of Expressway Undercrossing Existing Lines on the Surrounding Environment

为提升高速公路下穿既有线路的施工安全性,文中分析了高速公路下穿既有线路对周围环境产生的沉降影响,提出高速公路下穿既有线路对周围环境的沉降影响分析方法,首先,分析了高速公路下穿既有线路导致地层变化的主要原因;其次,建立了高速公路下穿既有线路的数值模拟模型;最后,在数值模拟模型的基础上,分析了高速公路下穿既有线路施工过程中,不同开挖方法、开挖进尺和交通荷载条件下产生的沉降特征。结果表明,高速公路下穿既有线路施工时,双侧壁导坑法施工过程中产生的地表沉降量最小;随着循环进尺的持续增大,失稳越来越严重;随着交通荷载的增大,隧道变形量和路面沉降量均有所增大。

In order to improve the construction safety of underpass existing lines on highways,analyze the settlement impact of underpass existing lines on the surrounding environment.Propose an analysis method for the settlement impact of highways crossing existing lines on the surrounding environment.Firstly,analyze the main reasons for geological changes caused by highways crossing existing lines;Secondly,a numerical simulation model was established for the underpass of existing lines on highways;Finally,based on the numerical simulation model,the settlement characteristics caused by different excavation methods,excavation footage,and traffic load conditions during the construction process of underpass existing lines on highways were analyzed.The results indicate that the surface settlement generated during the construction process of the double-sided wall heading method is the smallest when the expressway crosses the existing line;As the cyclic footage continues to increase,instability becomes increasingly severe;As the traffic load increases,both the deformation of the tunnel and the settlement of the road surface increase.