Research On The Construction Technology Of Debris Flow In The Liuhuanggou Incline Of Qilianshan Tunnel

With the construction of railway tunnels in the west, the tunnel geological hazards is also increasirg,as a result of western rock located in alpine、complex rock structure、broad moutains and abundant water. Research about rock deformation of tunnel is the hotspot in the engineering field.The resolution of rock deformation determines the smooth construction of the tunnels.Debris Flow is a kind of special geological disasters,which reduce the self-stability of the rock、influence the surrounding rock,lead to the collapse of the tunnel and pose a direct threat to the safety of equipment,also affect the entire progress of tunnel construction. Debris Flow is first encountered in the construction of our residential railway tunnels.we don’t have theoretical basis and relevant successful experience,so we must use the monitoring data analysis and unstand the deformation characteristics through researching in order to reduce the cost、ensure the safe construction and the smooth construction of the tunnels.Based on the engineering case of the Liuhuanggou incline in Qilianshan Tunnel, the paper studied on the deformation of the tunnel by using the theory combined with practice. The research work and results are shown as follows:· We must find out the reason of Debris Flow by using the existing survey information which based on the engineering geological investigation of the Liuhuanggou incline in Qilianshan tunnel and engineering construction.· To judge the engineering geological condition of the front surrounding rock by using advanced geological prediction which consist of TSP detection technology on the geological forecast,Infrared Acquisition Technology applied to detecte the water distribution and water bearing structure of the front surrounding rock,the addition of Horizontal Drilling which applied to get the rock samples.· The debris flow was defined.Based on the theory of rock mechanics and engineering geology,the addition of field investigation and monitoring data, a number of measures aiming at runnel construction face、water inrush and excavation supports were advanced to ensure the safety tunneling construction.· In order to direct tunnel construction across Debris Flow area,we need relevant theory about deformation characteristics and mechanical behavior in the process of tunneling construction by using the FLAC3d numerical simulation to build three-dimensional finte difference element model of stratum structure and the Drucker-Prager plastic theory to simulate the excavation process of the incline.· To carry out the surrounding rock convergence monitoring.according to the monitoring data we can draw convergence and regression line in order to get the actual changes in the construction site and validate the rationality of treatment project.