A Study On Design Of Self-anchorde Suspension Bridge With Simply Supported Truss Based On Optimal Reliability Distribution

The goal, constructing a economical,safe and reliable bridge,pursuit by the bridge designer,surly the way of bridge optimized design is the more effective method.But,the optimized design method for now can not be promoted used in engineering because of no thinking about the objective existence of the uncertainty.However,the optimized design method based on reliability theory can make up the traditional shortcomings. Unfortunately, the update method is used in the component design stage,and without the study of structural system.On this paper,the self-anchored suspension bridge with simple supported truss will be used for a example and try to make a design about the static and dynamic reliability analysis of the whole construction system and the component with the optimized design theory base on optimal allocation reliability.With all above work, can obtain the more economical and reasonable bridge construction and promote important reference for other bridge that also optimized designed with this same method.The mainly study of this paper as follow:1. We have developed the calculation program of JC method based on MATLAB platform, and the efficiency of soving the reliability index will be greatly improved.2. The mathematical model based on optimal distribution of reliability is establisted, and it is applied to truss structure. Optimize he design for statically determinate truss and indeterminate truss. It was verified that the optimum design theory which based on optimal reliability distribution was applicable and effective.3. Using the software ANSYS, the finite element model is established for the selfanchored suspension bridge with simply supported truss. The failure path of bridge was searched by appling the modified beta bound method. The system reliability of the bridge was obtained finally.4. Based on optimal reliability distribution, the optimization design of static reliability is carried out for self-anchored suspension bridge with simply supported truss.Optimizing the reliability and section size of each component, and obtaining the more economical and reasonable design scheme, and it is proved that the optimization design theory based on optimal reliability allocation is feasible to large bridge structure optimization design.5. Based on optimal reliability distribution, the optimization design of dynamic reliability is carried out for self-anchored suspension bridge with simply supported truss. The model of optimization design of dynamic reliability is established. The reliability and design variable for each component of the whole structure system are optimized allocation by using the response spectrum method. The potential of optimization design theory of optimal reliability allocation in the bridge structure seismic design is preliminarily showed.