| With the rapid development of the national economy of our country, the scale of highway construction is increasingly extended. It has promoted the development of highway tunnel construction. Multiple-arch tunnel and separated tunnel are two kinds of the superhighway tunnels. Multiple-arch tunnel, especially double-arch tunnel, is adopted widely in the condition that geology conditions are permitted, circuitry is short, the cost of land is high, and route's separation is difficult.However, because the ratio of height and span of double-arch tunnel is very small, its structure, design and construction are more complicated. Particularly during the complicated geology conditions, the unreasonableness of structure analysis or construction method will result in the serious geology disaster of tunnel. Therefore, it is important to analyze the structure of superhighway tunnel, and find out reasonable construction methods combining with the practical engineering project in order to control and optimize the construction of double-arch tunnel.This thesis depends on the research item "Construction Technique Research and Application of Double-Arch Tunnel of Superhighway in Complicated Geology Conditions", focusing on three tunnels in XiangWu section of XiangShi superhighway, including Qinjiagou Tunnel, Xujiawan Tunnel and Meizigou Tunnel. The research objective of the thesis is the double-arch tunnel in mountains constructed by drilling and blasting. Thought the combination of design, construction, simulation and measurement, the application of advanced construction technics at home and abroad, and introduction of computer means such as finite element method, the thesis gets some related conditions and suggestions.The first, the thesis introduces the general engineering hydrological general situation of the double-arch tunnels in XiangShi superhighway. This is the premise of the tunnel's design methods and construction technics, as well as the base of simulating the parameter with finite element method. The thesis also evaluated the stability of the tunnels.The second, the thesis explained the design of the tunnel's cross section, entrance to cave, timbering structure, waterproof ways and so on, on the base of analysis on structure's mechanical character and stability of double-arch tunnel in complicated geology conditions.The third, the thesis studied the logical construction scheme of double-arch tunnel, it discussed and simulated construction scheme of double-arch tunnels in XiangShi superhighway, analyzed transfiguration and stress state in every step of rock excavation and timbering and also compared the characterististics and rationality of some other construction schemes. What's more, it discussed and optimized the working procedure, introduced more logical construction scheme and working procedure in this geology conditions.The fourth, the thesis investigated the construction technics of double-arch tunnel at homeand abroad, summarized much experiences from the success and failure, and analyzed rationality of construction technics, according to the project of double-arch tunnels in XiangShi superhighway. It also proposed some assistant design methods, such as bolt, shotcrete, steel arch, leading bolt, grouting pipe, pipe shed, and so on, introduced their working mechanism and main points of construction, and also evaluated the parameters standards and rationality and feasibility. Because of the middle wall in the structure, the compound reinforcement has been changed, the top part of the wall became the water habitat, in the view of its "M" shape, the wall rock around is also perturbed since the working procedures. Thus, the treatment of the stress of the design and construction details had great influences on the stress of the middle wall, security of reinforcement, the stability of the tunnels, and its appearance. So, the structure of the wall, the effective of the design and construction become the key point for the double-arch tunnels. The thesis analyzed the construction control technics...
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