| As a long-span bridge,the construction method of cable-stayed bridge is divided into several stages.In order to make the bridge meet the design requirements in the stress state and displacement state after the construction.on the one hand to select a suitable structure calculation method to determine the intermediate state of construction,and strictly according to the determination of intermediate construction to organizate construction,which is the premise to ensure bridge after the construction satisfy design requirements in the internal force and displacement state.On the other hand,there is existing deviation between the internal force and the displacement state of the bridge after the construction and the design state,and the effective corrective action should be taken to adjust the structure.The research which calculation method of the control parameters and cable force of cable-stayed bridge optimization adjustment during the construction has been achieved fruitful results.But for the cable internal force and displacement of the girder and the design of the target state deviation adjusting and optimizing of mature research is relatively small.But for adjustment of bridge cable internal force and the displacement of girder and design target state deviation is optimized with respect to the mature relatively little research.Therefore,the establishment of a clear in theory,convenient in calculation and engineering application of deviation adjustment optimization method,is one of the cable-stayed bridge into the bridge after optimization for control field.(1)Providing an overview of the non stress state law theory,the basic point of view,as well as in the construction control of cable-stayed bridge structure without the stress state of two important;This paper expounds the concept and optimization theory of cable force optimization,and introduces the calculation process of the optimization mathematical model by using the least square method.(2)With Fengdu Yangtze River Bridge as an example,based on the theory of stress free state,on the ideal construction of the main bridge of intermediate process determined were analyzed and explained.In ensuring the phased into bridge structure,external loads,boundary conditions and a into bridge state consistent with the premise,in accordance with no state law theory and to ensure the continuous girder elastic curve,you can ensure the same two inner force and displacement state.(3)First in-depth analysis of the cable force adjustment influence matrix method for the nonlinear factors caused by the inherent contradictions,traditional influence matrix method is also a constraint algorithm pointed out that and this method has very strong constraint conditions and requirements of each control point displacement must be adjusted according to the proportion.Therefore,this paper puts forward a kind of optimization algorithm of relaxation,and establishes the mathematical formula.The optimization algorithm to analysis of the cable-stayed bridge linear control process from the two path.First,from the constraints of optimization the physical meaning of optimization,however,due to the existence of nonlinear problems such as the cable sag,practicality is low;second,the cable stress free cable length in the linear range to the greatest degree,the highest efficiency goal solving linear.(4)According to the calculation method of the objective function derived,we analyses the example of Fengdu Yangtze river bridge.First,with the analysis of the traditional influence matrix in Fengdu Yangtze River Bridge,the convergence speed is slow.Second,object function and solving process derived in this paper was applied to linear calculation in Fengdu Yangtze River Bridge,and good results have been obtained,significantly improves the convergence speed,verified the feasibility and correctness of this method.The method has the potential to further promote the application of linear control optimization of various types of cable stayed bridge,which can greatly improve the work efficiency. |
