Rock Underground Subway Station Construction Mechanical Behavior Of Large Dip Angle

At present,large and medium-sized cities in our country generally exist in road congestion,vehicles,traffic chaos phenomenon,It has become the major problems which restrict the development of the city.Along with our country urbanization trend of widening and rapid growth of national economy,People gradually by the past country gradually transferred to the city,theurban population in the constantly expanding.Ground transportation has been unable to adapt to economic activity and the increasing traffic demand of the lives of people.Development of rail transit as the backbone,therefore,as the main body of publicrelies on transfer with conventional public traffic system,for the cityresidents to provide safe,fast and comfortable traffic environment,guide urban residents to use public transport system is the successful experience of foreign cities to solve urban traffic problem,is also an effective way to solve the traffic problemsof big cities in China.From all over the world the development of rail transit,the development of rail transit without and with the development of corresponding technology closely related to economic policy.In the process of rail transit construction,the need to consider several aspects of content:(1)the overbreak excavation of metro station and owes digging problem;(2)in the excavation effect on the stability of the adjacent buildings;(3)the surface subsidence and environmental pollution problems.This paper in view of the large cross section underground subway station under different strata dip angle excavation construction mechanical behavior analysis,relying on rail loop TuShan station engineering,through the finite element numerical simulation method for three kinds of tunnel excavation on the mechanical behavior under different strata dip Angle of two-dimensional analysis;And through the three-dimensional numerical model to simulate the track loop TuShan station actual excavation construction process,the station in the process of double wall method of pilot tunnel excavation of tunnel surrounding rock and lining structure to study the change rule of stress and displacement,comparing with the field monitoring measurement data analysis;to verify the accuracy of the numerical simulation,and analyze the risk in the process of station tunnel during excavation.After the final result for the design and construction of similar projects in the construction to provide certain reference.By chongqing municipal rail loop TuShan station numerical simulation of excavation process,combined with the actual monitoring data,as well as to the different Angle of rock tunnel with double side pilot tunnel excavation construction mechanical behavior research,the following conclusions:(1)the station tunnel after excavation,the maximum horizontal displacement and maximum vertical displacement performance after the first decreases with the increase of strata dip Angle increases;The maximum horizontal stress and vertical stress performance after the first increase with the increase of strata dip Angle decreases.(2)Whatever the obliquity of rock,the tunnel after excavation of the inverted arch of the vertical uplift displacement is greater than the vertical displacement of arch,inverted arch space produced by horizontal stress and vertical stress should be greater than the vault displacement;And the vault is inverted arch after excavation safety,often inverted arch before vault damage occurs,should be taken into consideration seriously.(3)Whatever the dip Angle of the rock,often a few key points of the after excavation,vaultthe displacement ratio of inverted arch arch waist and sidewall displacement.Therefore,from the Angle of the control of displacement of surrounding rock,should focus on considering the adverse effects of inverted arch and vault deformation,strengthen vault and inverted arch supporting measures,to ensure the stability of surrounding rock.(4)TuShan station excavation process using three-dimensional finite element numerical simulation of the mechanical behavior and the actual monitoring data,this paper compares and analyzes the simple analysis of the causes of errors between the two,but also fully validated the reliability of finite element numerical simulation analysis.