Study On Mechanism Of Mud Inrush In Karst Tunneland Its Influence On Stability Of Tunnel Excavation

Karst is one of the most common geology in tunnel construction.Complex geological conditions and karsts have caused great damage to the safety of tunnel construction personnel and production operation.In engineering practice,due to the limitations of advanced geological prediction technology.It can not be completely accurate in Predicting the situation of the front tunnel and the lack of a certain understanding of the mechanism of karst Mud-bursting,leading to the frequent occurrence of a series of karst disasters,so the analysis and study of karst tunneling mechanism and the tunnel before the different holes,different spacing of the cave on the different The influence of excavation section has certain engineering value.This paper is based on the actual situation of YonGji Expressway WuXiZuo tunnel and LiuYueTian tunnel.Then analyzes the mechanism of tunneling and the application of numerical simulation to study the stability of karst tunnel excavation.The main works are as follows:(1)Collecting some typical karst tunnels in China,and summarizing the treatment technology of karst according to the geological disasters of karst tunnels in China,and then according to the actual Techinical data collected from the actual collection based on WuXiZuo tunnel and LiuYueTian tunnel,then according to the characteristics of the tunnel cave to sort out statistics,analyzing the current karst tunnel of the main engineering problems and disposal measures.(2)Studying on the mechanism of rock formation in karst tunnel.Study combined with the physical and mechanical properties of karst fillers,groundwater,karst development characteristics and construction methods.(3)Analyzing and summarizing the deformation behavior of the tunnel during the construction of the karst tunnel according to the measured data.(4)Making the conclusions by establishing a three-dimensional model with midasGTS software,and simulating the influence of different sizes of the top and the left arch waist on the stability of the surrounding rock of different excavation section.