Proto-Type Test Of Linging Structure Of Segment Rings With Staggered Joints For Shiziyang Underwater Shield Tunnel

With the background of Shiziyang high-speed railway underwater shield tunnel project and Science and Technology Program of Ministry of Railway of China, this paper takes the lining structure's mechanical behavior of large-scale underwater shield tunnel segment ring as research object. By prototype loading test and numerical simulation analysis, it researches the lining structure's mechanical behavior of segment ring including structure's internal force, deformation, bearing capacity and failure characteristic in the circumstances of different earth pressures and water pressures, different load models and different assembling method. Also it makes out structure's key parameters of segment ring's effective ratio of bending rigidity and increasing rate of moment. The series of study achievements can offer the important reference for the lining structure design of segment ring of Shiziyang high-speed railway underwater shield tunnel. The main contents can be listed as follows.1, "Multi-function Shield Tunnel Structure Test System" device, which is devised by Southwest Jiaotong University, is used in prototype loading test of lining structure of segment rings with staggered joints, which reflect the mechanical effect of water pressure by the hoop beam and bent moment by opposite-drawing beam. That realizes the real loading of earth and water pressures to the segment lining structure of shield tunnel and correctly reflects the characteristic of the segment lining structure when earth and water pressures singly changes.2, The 1:1 prototype loading test of lining structure of segment rings with staggered joints researches the rule of change of segment ring structure's internal force in the circumstances of different loading models and the loading effect of different water pressures and earth pressures, as well as the internal force condition of calculated sections. This test also detects structure's internal force, deformation, longitudinal joint's splaying amount and bearing capacity, which offer the full basis to optimize some key structure's parameter, such as segment reinforcement, joint morphology and lining and so on. Finally, the destruction test of lining structure of segment rings in the high water pressures condition researches structure crack's growth and failure characteristic and verifies segment lining structure's reliability. 3, The comparative analysis to the results of finite element method and prototype test shows that numerical calculate to structure's internal force by using beam-spring model is logical and available, as well as indicates that the method has safety stock. And segment lining structure's internal force and deformation of shield tunnel in various kinds of assembly conditions, and the comparative analysis of straight joint and staggered joint have be studied, which make clear the reason of the most unfavorable assembling method to straight joint and staggered joint. Based on the calculation results of beam-spring model, the logical value range of segment ring's effective ratio of bending rigidity and increasing rate of moment have be made out.