Development Of New Model Test System Of Undersea Tunnel And Research Of Fault Water Inflow Test

In recent years, with the rapid development of the basic infrastructure of China, the cross-sea transport has raised more and more public attention. the Cross-Harbour Tunnel makes great progress because of its advantages in shipping, hydrogeology, and many other aspects.Compared with ordinary mountain tunnel, Cross-Harbour Tunnel is difficult to research and has greater risk due to its particularity and complexity. Recently, the study still remains in the theoretical analysis and numerical simulation, and exploration of the model test is still in its infancy. For this research gap, the emphasis is developing the model test system of the undersea tunnel, simulating the project conditions of the Cross-Harbour Tunnel with fault and applying it in Qingdao Kiaochow Bay Subsea Tunnel, which make a series of research results.(1) Based on traditional geomechanical model test and similarity theory of fluid-solid coupling, the research in this dissertation developed the new fluid-solid coupling similar materials of surrounding rock and fault, through large numbers of comparative test. The rock similar material uses cement and vaseline as cementing agent, sand, barite powder and talcum powder as the aggregate, silicone oil as modifier. While the fault similar material selects gypsum and vaseline as cementing agent, quartz sand and talcum powder as the aggregate. Considering the similar conditions of deformation and permeability, combined with the analysis of damage characteristics of brittle materials, the problem that the material disintegration in water has been solved.(2) The research develops a new scalable model test bench, with the steel structure and toughened glass as the main framework. Overall dimensions:length*width*height=3000mm*1200mm*2700mm, suit with the independent design seepage flow acquisition device, can simulate the different sizes and types water inrush test. This test has also developed a software system which collects and analyzes the data.(3) Based on the new fluid-solid coupling similar materials and the Subsea tunnel model test system, The Qingdao Kiaochow Bay Subsea Tunnel fault water inrush test has been done, which captured the information of the seepage field, displacement field, stress field of the surrounding rock and fault, reproducing the influence of tunnel excavation on the stability of the tunnel. The similar material meets the test requirements and the test system is stable and reliable. The test revealed that the excavation of the tunnel has a profound effect on displacement field, stress field and seepage field of the surrounding rock and fault, and the monitoring data have experienced three stages, which are steady stage, mutation stage and steady stage.