Analysis And Experimental Study On Lateral Deformation Reinforcement Of Shield Tunnel Lining Structure

With the development of social economy, the running mileage of urban subway traffic increase rapidly in our country. Because of the influence of various unfavorable factors in the process of serving, shield tunnel lining structure may generate large lateral deformation, which is a threat to tunnel. Against those adverse factors, the current common practice is to use a steel ring in the reinforcement, but this reinforcement method is to use a large amount of steel and high cost. Therefore, for the lateral deformation of shield tunnel lining structure, this paper puts forward two new kinds of reinforcement methods, which are the reinforcement of concrete-filled GFRP(glass fiber reinforced polymer) tube and channel steel. Through numerical analysis and model tests, the feasibility of the proposed methods has carried on the preliminary discussion, the main work includes:(1) Through using the finite element analysis software ABQAUS, the changing rule of the lateral deformation and reinforcement efficiency of tunnel lining structure are discussed, which reinforced with concrete-filled GFRP tube. And this article introduces the reinforcement effect of the GFRP tube wall thickness, section height and concrete strength. Then studies show that the method can effectively reduce the lateral deformation of lining structure, and under the situation that could satisfy the requirement of tunnel clearance, GFRP tube section height should be first increase in order to enhance reinforcement effect.(2) Through using finite element analysis software ABQAUS, the changing rule and reinforcement efficiency of the lateral deformation of shield tunnel lining structure by reinforced with channel steel are analyzed. And this article demonstrates the reinforcement effect of local strengthening region, partial filling concrete strength and local strengthening steel plate thickness. Steel saving rate are proposed in which channel steel parts strengthen relatively traditional steel ring. At last, studies show that the proposed method can effectively enhance the ultimate bearing capacity of lining structure, but the influence on reinforcement effect of the channel model(14a~18b) is limited.(3) By means of the locally strengthen improvement for the reinforcement method of the channel steel parts, and numerical analysis for lateral deformation of local enhanced channel steel parts strengthening backing structure tunnel lining structure, this article introduce steel saving rate of local enhanced channel steel parts strengthening relatively traditional steel ring. At last, research show that the reinforcement effect increases with the expansion of local strengthening region, but more than 30 ° corresponds to the region of central angle, then the increase slows down.(4) Two groups of shield tunnel lining segment joint reinforcement tests by using channel steel parts were carried out, in order to verify the validity and feasibility of the method. Research shows that it is less meaning to excessively pursuit of structural adhesive strength, but the reinforcement effect may be further improved when enhancing anchorage measures of channel steel.