| ABSTRACT:With the rapid development of domestic transport, it requires us to build large number of deep and long mountain tunnels. Build tunnel through the karst area of water-rich segment is still the focus and difficulty of the international research in the field of tunnel construction, especially for urban subway tunnel in which process of construction it will make influence on domestic water of residents living nearby.When build tunnel through water-rich area, it is not allowed to drain ground water at random, but rather as the principle of "integrate the techniques of preventing, intercept, discharge and stifled, varies according to the local conditions".The major disasters easily occurred in construction of karst tunnel can be divided into two types, one is water inrush or burst mud, the other is the landslide. This paper which is based on the project of Zhongliangshan tunnel has studied the mayor technical means used in Zhongliangshan tunnel when safely through the karst area to avoid the two kind of disasters furthest. In the paper, it is also introduced some patterns employed in the research process, such as theoretical analysis and field monitoring. The main research contents and results are as follows:1. Through analysis of domestic and foreign research status about water-rich karst tunnel and the stress mechanism and laws of surrounding rock of karst tunnel, having combined with the specific geological conditions in Zhongliangshan tunnel and the construction methods comparison, the paper analyses advantages and disadvantages of various methods of construction by means of numerical simulation and comparative methods, and determines the construction methods of Zhongliangshan tunnel.2. Using the information in" advanced geological forecast", come to the conclusion that Zhongliangshan tunnel has four large cross-sections of gushing water. Analysing a cross-section of gushing water which is V grade level rock, determine the optimal construction scheme, and optimize the support parameters, through the numerical simulation.3.We tested the sedimentation effect of vault and constringency of walls after this construction, then explained in mechanical theory at the assistance of track monitoring system.4. Here we investigated the force characteristic of the deformation of rich water karst tunnel, then bring forward the applicable demand, detailed construction outlines and technological advantages of "seven excavate work", at last work out the accordingly monitoring project, content and monitoring effect analysis, which ensured the favorably accomplishment of constructions. This work ravel out many technological difficulties, and provided valuable references to future similar constructions. |
