Research On Reasonable Construction And The Optimization Of Arch Axis In Reinforced Concrete Box Arch With Cantilever Method

Has its unique reasonable finished dead state into different forms of arch bridge, different construction method, construction of arch bridge, the reasonable construction state is not invariant.The determination of reasonable finished dead state and reasonable construction state contains many optimization of design and construction parameters, and the key point of the two is the main content of this paper, the optimization of reasonable construction stage cable force and reasonable arch axis. This paper based on the national natural science fund project?Theory and method of configuration and safety of concrete arch bridges with cantilever casting construction on multi-obiective?,also the domestic water conservancy industry first span arch aqueduct, Guizhou Longchang aqueduct(main arch ring width, net-span of 200 m), as the engineering background. Specific research work mainly include the following aspects:(1) On the development of reinforced concrete arch bridge at home and abroad are introduced, this paper expounds the main construction method, and the existing cable hoisting suspension hanging method, the problems existing in the construction of arch bridge is briefly analyzed, and finally put forward in this paper, we study the main content.(2) When determining the reasonable construction state, from the construction parameters, the actual stress state, the construction phase buckle cable force determined, etc to clarify. When determining reasonable finished dead state, mainly from the main arch ring of reasonable arch axis, the reasonable finished dead state of main arch ring, the reasonable finished dead state buckle cable force to determine these aspects has carried on the induction.(3) Put forward "first tensioning cable force determined by static equilibrium, second cable force is given priority to with adjusting internal force" of the cable forces many times tension control thought.The bridge adopts the method of current segmental hoisting tensioning many times to control the cable force, after the completion of the segmental hoisting for cable force adjustment no longer.(4) Reasonable construction in the process of the cable force calculation and optimization, based on the unknown load coefficient of influence matrix method is used in finite element software Midas Civil the reasonable construction of cable force optimization. By the observed data of the cable force from frequency method and the main arch ring control section by comparing the measured stress and the theory of data, verified by means of optimization of cable force is reasonable and easy to implement in the construction.(5) Numerical method is discussed in the variable cross-section of the main arch ring internal force calculation of application, mainly solves the two problems in the process of computing: variable cross-section arm of main arch ring corresponding weight heart-shaped correction, avoids the general numerical method the micro unit period of midpoint internal force caused by the deviation. Variable width the area of the main arch ring function is determined.(6) Provides a use of MATLAB programming tools for variable cross-section optimization method, the arch axis coefficient and the MATLAB simulation program is given. According to arch ring variable width, the cables in engineering design and construction characteristics of cable-stayed buckle to hang, implements the cubic spline difference as this bridge widened section arch axis shape approximating function optimization.