Research On Mechanical Characters And Drainage Of Karst Tunnel With High Water Pressure

:With the expansion of road net to mountainous regions, especially with the large-scaled construction of high-speed railways, it is unavoidable to meet with Karst in tunnel construction. The long-term security of the liner is a major problem in high water pressure region. Due to the high water pressure, the problem of liner crack and invert crack is growing in the recent years. Therefore, it is important to carry out the research on mechanical characters and drainage technology of Karst tunnel in high water pressure region.Field measured data statistics, numerical analysis and other research means are mainly adopted to analyze mechanical characters of the lining in Karst tunnels. Meanwhile, the design of drainage is discussed. On the basis of predecessors’research, it has carried out detailed research work, the main work is as follows:(l)Based on the statistical analysis of water pressure load on tunnel lining, main influencing factors of water pressure are analyzed. The population distribution characteristics of water pressure on liner are also studied.(2)A fuzzy synthetic evaluation system of water pressure is established. According to the evaluation results of water pressure, reasonable choice of different drainage patterns can be acquired.(3)On the background of the Yingshanyan Tunnel of Chenggui High-speed Railways, the research on mechanical characters of liner is carried out according to the fluid-mechanical interaction by numerical analysis. Then, the effect of drainage is evaluated.(4)In view of the high pressure on invert, the central deep buried ditch below the arch is recommended. Research on mechanical characters of liner and drainage is carried out by numerical analysis.(5)On the basis of numerical analysis and similar projects, the appropriate discharge, the proper grouting range and the proper permeability coefficient of grouting circle is studied.In this paper, it is a total of80images,43tables,96references.