Study On The Impact Of The Construction Method Of Tunnel Surrounding Rock With Variable Spacing

With the rapid development of China’s highway tunnel, in-line tunnel gradually failed to meet the rapidly expanding needs of today’s traffic, In order to meet the needs of rapid development of highway tunnel,therefore, tunnel experts and scholars began to pay more attention to the relevant theoretical research of the constraction of two-lane tunnel. As the two-lane tunnel increases every year, two-hole spacing lane tunnel will inevitably lead to a variety of situations, besides, different spacing tunnels require different construction methods and influence tunnel in surrounding rock entirely different. However, on tunnel construction method with respect to the degree of influence of surrounding rock of double tunnel with variable spacing research lags behind double tunnel in engineering practice.In the ((highway tunnel design specifications JTGD 70-2014》 clearly put forward that when the V surrounding rock is at less than 3.5 times the cross-holes, it need to consider the interaction between the two-hole. But the specification the details about the degree double hole within 3.5 times across the hole influence each other and choise requirement of constraction methods, the general rule design of the tunnel was all checking depending on the experience value in the design, and then in order to provide tunnel design with relevent reference date, it is necessary to research the incidence the constraction method contributed to surrounding rock of double tunnel with variable spacing. These findings will provide the design of the V surrounding rock and construction with important value refrence data.By looking up the actual construction status of V surrounding rock in our country and combined with computer software to calculate the two-dimensional model of the construction method of tunnel surrounding rock study the impact of the variable pitch, And it has been verified in Xi shi po tunnel project,the main research work and the research results are as follows:1) The article essay chooses the frequently-used constraction method of V surrounding rock including method step,CRD method by means of surveying the common constraction method of Vsurrounding rock,and then researching the degree of influence the two constraction methods contributed to the surrounding rock of double tunnel with variable spacing.2) Through the use of numerical simulation software ABAQUS V surrounding rock using the CRD method, the plastic surrounding rock, vault settlement displacement, horizontal convergence and intermediate rock pillar stress analyzed to obtain the CRD construction method, the spacing of the tunnel tunnel Rock affect the degree of sensitivity.3) Through the use of numerical simulation software ABAQUS V surrounding rock using the step method of plastic surrounding rock, vault settlement displacement, stress level convergence and intermediate rock pillar for analysis were obtained when the step method of construction, the tunnel to the pitch tunnel Rock affect the degree of sensitivity.4) By comparing two construction methods impact on the surrounding rock tunnel, Proposed changing the spacing tunnel construction methods and how to choose the method of determining the reasonable construction5) Variable pitch tunnel numerical simulation for the calculation of the relevant conclusions proposed tunnel spacing of 3.0D, the time to consider the Tunnel in interaction.6) Variable pitch tunnel numerical simulation for the calculation of the relevant conclusions, has been applied in beauty slope tunnel and verify the reliability of conclusions.