The Study Of The Soft Ground Treatment Of The Highway Tunnel In The Loess

With the rapid development of national economy and the implementation of the strategy of western development,the construction of the highwaygradually transfer from the eastern developed areastothe Midwest,so it is inevitably encountering the loesstunnel.Tunnel,the indispensable important part of road engineering,is playing an increasingly important role,however,due to the special engineering mechanics properties of the loess strata,in the construction of the tunnel often encountered the soft ground,and it is easy to cause collapses,roof falling;in the operating leading to the tunnel wall uneven subsidence,lining structure crack and the tunnel pavement endanger the driving safety,so it is necessary for us to research a set of feasible,effective and durablesoft foundation reinforcement technology,and it is a urgent subject to solve in the design and construction.This paper takes the four typical loess tunnels in the Pingliang to Dingxi highway as the engineering background and mainly studying the following issues:1.First making a simple introduction to the soft ground treatment measures,and making an analysis of their difference and comparing the advantages and disadvantages of the different measures.2.Introducing the methods of evaluating the surrounding rock stability and the stability of lining structures under the load.3.Introducing the basic principle of the tunnel structure calculation,using the FEM software ANSYS as a tool,based on the Jingning tunnel as an engineering background,building a 2D model simulating the whole process of the tunnel construction,making a analysis of the surrounding rock stability and the stability of lining structures on the surrounding rock load and the vehicle load.4.In order to guarantee the tunnel construction is smooth,safe,fast,and verify the soft foundation reinforcement effect,in the constructions of the Pingliang to Dingxi highway,through the clearance change value and the displacement of deep surrounding rock to reflect the dynamic information of surrounding rock.This paper are analyzing the results of the monitoring result,and coming to the conclusion that using the treatment measures introduced in the thesis,can effectively control the deformation of the surrounding rock and ensure construction safety.5.Taking Jingning tunnel as an engineering background,making a static load test.Simply introducing the test method and analyzing the test results.Through the treatment the tunnel basal bearing capacity satisfy the design requirements,reaching the expected effect;the design of soft ground treatment scheme is reasonable and feasible.