Highway Loess Tunnel Construction Technology Simulation And Field Monitoring Analysis Of Yang Qu No.1in Shanxi Province

NO.1tunnel of Yang Qu, in Shan Xi province, located in loess buried shallow section ofthe Ling Jing small basin. The moisture content of surrounding rock in NO.1loess tunnel isabout23%, which is much higher in tunnel engineering. There are many problems in the loessconstruction of high moisture content, and analyses for loess tunnel construction technologyof high moisture content are much valuable.In order to analyze loess tunnel construction technology of high moisture content, thispaper has taken two different methods. One researches different loess tunnel construction bymeans of the MIDAS/GTS finite element method (FEM), the calculation parameters of whichwere got from high-moisture content loess indoor collapsibility test, based on the NO.1tunnel engineering of Yang Qu. The other is site monitoring measurement, which weremainly for tunnel deformation tests, vault crown settlement, level convergence andsurrounding rock pressure, by measuring point buried in surrounding rock duringconstruction.The main work of paper as follows:(1) Parameters used in number simulation got from loess, NO.1tunnel of Yang Qu,physical and mechanical experiments under different moisture content.(2) Based on one moisture content but different construction technology, subsectionexcavated length, support form and excavation progress, this paper builds different finiteelement modes and calculates separately. These modes calculated results reveals thesurrounding rock displacement and stress change rule during the tunnel excavation causeprocess, then putted forward the more reasonable construction method, division and properlength excavation in high moisture content loess tunnel construction. (3) Through the tunnel surrounding rock deformation monitoring, vault convergencesettlement deformation monitoring and surrounding rock pressure monitoring, this paperresearches loess tunnel deformation characteristics of the development and provides themeasured basis for finite element calculation.(4) Compared to the finite element results with field test results, this paper verifies thereliability of finite element results.