Study On Support Design And Construction Control Of Small Interval Tunnel

At present,the research on the calculation theory of the surrounding rock pressure of small interval tunnel is not much,and does not consider the influence of the tunnel construction process.In this paper,with the Da chang mountain tunnel in Zhong-Kai highway as a support project.According to the monitoring data of Da chang mountain tunnel,request of present highway tunnel design standard and the design project description,mainly carries on the calculation of the tunnel supporting parameters.First,take the engineering geological conditions into consideration,all levels of surrounding rock pressure are calculated.In the calculation of lining structure,the composite lining is mainly used in the archstructure.The initial support adopts the elastic-plastic theory(stratigraphic structure method)to calculate anchor and shotcrete support which can fully develop and mobilize the self-bearing capacity of the surrounding rock,then a new secondary equilibrium of the surrounding rock with the minimum support will be done.Secondary lining structure internal force is analysised with finite element software,in terms to getthe shear force,axial force and bending moment distribution state.Then add reinforcement and checking,using the factor of safety to force analysis,And adjust the value of tunnel support parameter design to make it more reasonable.Due to the uncertainty of its geological condition and the complexity of the construction,so it is very important to do the construction process control,this article mainly from the construction methods and construction excavation method,carries on the preliminary construction organization design for the tunnel construction.the preliminary construction organization design is carried out from the construction methods of tunnel in this article.