Research On Fluid-Mechanical Interaction Of Drainaged Segment Lining In High Water Pressure Railway Tunnel

At present, China has become the country with the largest number, the largest scope, the most complicated technical difficulty and the fastest-growing railway tunnel projects in the world. Because of the development of tunnel projects to mountainous terrain, the deeply, long and high wate pressure tunnels grow more and more. Mountain tunnel construction with high water pressure will apply the tunnel boring machine method (TBM) more and more. When the project schedule requires tightly and the support demands to be constructed very timely, we need to use a lot of fabricated segment lining. And we must apply the concept of the drainaged segment lining to respond the high wate pressure. But now, there is still a lack of relevant theoretical and technical support which is about load characteristics and mechanical properties of the drainaged segment lining structure.This paper is based on National Natural Science Foundation of China project—Research on the Load and Mechanics Characteristics of Drainaged Segment Lining with High Water Pressure Railway Tunnel, and the object project is based on Daiyunshan high water pressure railway tunnel on XiangPu railway. The author uses the finite difference method simulation analysis and similar model test as research means, then studies systematically on the load and mechanics characteristics of drainaged segment lining with high water pressure railway tunnel. The main works and results are as follows:(1) Basis on analysis of the three means about dealing with water pressure, just as: grouting the whole block method; completely drainage method; plugging limit drainage, the author gets to research the activity mechanism of drainaged segment lining in high water pressure mountain railway tunnel. Combining the features of high water pressure mountain railway tunnel, the author carries out the comparative study of the specific response means.(2) Basis on analysis of the fluid-mechanical interaction theories of seepage field and stress field interaction at home and abroad, and combining the calculation theories of the finite difference method, the author presents the calculation analysis model and suitable border conditions of fluid-mechanical interaction to adapt the features of high water pressure mountain railway.(3)The author uses FDM to calculate fluid-mechanical interaction about high water pressure drainaged segment lining. In order to make sure the relationship between rational drainage amount of segment lining and water pressure distribution shape behind the lining wall and the rule of internal force changement about drainaged segment lining, the author carries out the numerical simulation analysis on different structure types of lining drainage hole, different water pressure and different grouting washer and so on.(4) Taking geometric similarity ratio 1:20 and bulk density similarity ratio 1:1 as basic similarity ratio, the author carries out the drainaged segment lining indoor model test in order to check the security of structure. Then the author studies on the effect rule of structure internal force with different structure types of lining drainage hole or different water pressure, and carries out the comparative analysis of the results between the numerical simulation and model test.