Long-span Stone Arch Bridge Strengthening Technology Research Based On Composite Main Circle With Variable Cross-section Rib Arch

Based on the conventional composite arch ring reinforcing arch the deficiency of technology as a starting point, in the paper, found in the actual engineering application and puts forward problems, in order to solve practical engineering problems, for the purpose of optimized improvement measures are put forward, and analysis of theoretical research, and is verified in the context of an engineering example, finally formed a "derived from the actual return in actual research trajectory line.First discusses the general situation of the historical experience of our country stone arch Bridges, by the ancient stone bridge to the modern stone bridge glorious achievements; The practical significance of the general maintenance of the bridge reinforcement, and summarized the current research status of the stone bridge reinforcement are introduced including conventional reinforced concrete composite strengthening technology with the main arch ring, and points out its defects and problems existing in the application in the engineering practice, and brings up the main content and purpose of this study.Then aiming at is more widely used in long-span arch of catenary arch, analyzed the related mechanical characteristics, this paper briefly describes the arch bridge arch ring under the permanent load and variable load and the mode of bearing force and internal force calculation problem. For reinforced concrete composite arch ring form to illustrate the construction technological process and technical characteristics, analysis summarized the reinforcement of composite arch ring after three phase stress problem.After the concrete definition of variable cross-section rib arch composite strengthening bridge technology, the concept of the main arch ring, according to the variable cross-section catenary arch bridge, the design formula of thickness of arch ring transformation is deduced from the variable cross-section rib arch reinforcement layer thickness calculation formula, and discusses and analyzes the compression member strength calculation problem.The last of this chapter to longshan county of hunan province doll pond bridge as the research background, using the finite element software midas Civil calculation model for the bridge is established as a whole, and extract the carrying capacity under the limit state of arch ring cross section internal force, the bearing capacity of strength calculation, got the original arch ring section bearing capacity factor of safety; Isobtained under different conditions according to the calculation formula of the variable cross-section of rib arch reinforcement layer thickness values, respectively for the doll pond bridge main arch ring to carry on the corresponding reinforcement effect trial, through comparative analysis have the best variable cross-section is suitable for the bridge reinforcement layer thickness values. Through the actual engineering application, examine the practical effects of the formula for computing and finally proves the feasibility and its rationality, at the same time, provides reference to the same kind of bridge reinforcement design.