Research On Water Burst Mechanism And Structure Mechanical Behavior Of Karst Tunnel

(?) distributes most widely in China, and covering and exposed carbonate (?) about one fifth of territory area. Accompanying the implementation of (?) Development Strategy, tunnel as an important part of transport (?) plays an increasingly important role.However, geological disasters of tunnel (?)ring still universally exist, especially in poor geological conditions of the (?)opment area. The geological disasters create great difficulties for tunnel construction, and a huge loss to the national economy.(?) high-risk karst tunnel of new Guiguang high speed railway Railway as the (?)ject, using orthogonal experiment analysis, multiple linear means of regr(?)sion and simulation analysis of the finite difference method, study on water inrush mechanism, against-inrush thickness and structure mechanical behavior of karst tunnel is carried out, the main work and results are as follows:1.The principle of the coupling between the seepage field and stress field is summarized and analyzed, on the basis, combined with the finite difference fluid-structure interaction, a fluid-solid interaction mechanics analysis model and boundary conditions for karst tunnel with high water pressure cave nearby are put forward.2. The minimum against-inrush thickness of water pressure tunnel is studied, using orthogonal design for the cave in the upper part of the tunnel, the influence laws of minimum against-inrush thickness corresponding to change of the surrounding rock level, the pressure coefficient, the cave span, the depth of the tunnel and the hydraulic inside cave are achieved, using multiple regression methods, mathematical prediction model on the minimum against-inrush thickness is established.3Take high water pressure water-filled cave located in the tunnel the upper for example, considering the tunnel drainage, such as the hole block method and eplugging limit drainage, using finite difference method, fluid-structure interaction of lining seepage field and stress field is analyzed, laws of structural changes corresponding to construction and support tunnel of high water pressure water-filled karst tunnel are achieved.4.Summaring existing experience and research results of karst tunnels, combined with project examples, measures and techniques on water inrush control of karst tunnels with water-filled cave are summarized.