Studies On The Stability Of Surrounding Rock And Seepage Characteristics Of Karst Hydraulic Tunnel Based On Monte-Carlo Stochastic Fracture Network

Carbonate rocks are widely distributed in southwest China. It is easy to form caves, springs of rock-salt cavity and other geological flaws after scour and erosion. The existence of the karst influence on tunnel mainly have two aspects: ①Change the distribution of in-situ stress which degenerate the stabilty of surrounding rock, even cause collapse happen. ②Watery karst drainages, burst mud and water gushing may happen when the water is too lager. As a consequence, in order to keep tunnels safe in karst area, it is necessary to study the stability of surrounding rock and seepage characteristics.(1)Consult the correlative documents about karst tunnel. Summarize the types of karst, the disasters of karst tunnel and related treatment method.(2)This paper conducts a thorough research on Monte-Carlo method. The process of two-dimensional stochastic fracture network are summarized which including①Collect rock fracture geometry parameters;②Analysis of statistical data about rock fracture;③The realization of the stochastic fracture network. Finally, built the karat tunnel of two-dimensional random fracture network model on this basis.(3)Based on the discrete element software UDEC, analyses the effect on karst tunnel of irregular watery karst in different locations. Thereinto, through convergence of tunnel displacement, shear stress and the plastic zone distribution, internal force of tunnel lining and so on, this paper analysis the stability of karst tunnel features; Through each monitoring point water inflow and distribution around the tunnel, the total yield around tunnel, fissure water pressure distribution, fissure water seepage path and scope, also analysis the seepage characteristics of karst tunnel.