Ground Subsidence Control And Engineering Application Of Construction Of Shallow Tunnel In Loess

With the development of the national economy and the increasing urban population, urban traffic has become increasingly crowded.So the construction of the underground transport and the formation of three-dimensional traffic network of space has become an inevitable requirement of urban modernization.Construction of the highway tunnel must meet the traffic and pedestrian requirements,so the form of shallow,subsurface excavation and large section is often used.Because a number of tunnels pass through the city traffic artery,the safety of support construction of tunnels must be ensured.At the same time,there are a variety of stringent conditions for the construction of urban roads tunnels.This paper is aimed to make an analysis of ground subsidence control and engineering application of construction of shallow tunnel in loess,with the engineering background of pedestrian tunnel in Jinshui Road-Jingsi Road of Zhengzhou City.The main findings are as follows.Firstly,main factors effecting surface settlement in the process of constructing during the construction of underground works are analyzed.Secondly,settlement mechanism of work wells is analyzed with the application of finite difference software FLAC^3D.Work well's settlement is under the conditions of whether or not grouting.Based on the field investigation and the results of numerical simulation,the main reasons of work well's settlement are found out,and control measures are put forward in the similar incident under similar geological conditions.Thirdly,by the application of large-scale general-purpose finite element analysis software ANSYS using load - structural model,the subsidence value of the support of roof and the convergence value between two groups caused by different excavation forms under various loads methods are calculated,and the differences are analyzed. Relevant research results can provide a theoretical basis for engineering design and the choice of construction method under similar engineering geological conditions.