Dynamic Optimization Of Continuous Rigid Frame Bridge

Prestressed concrete continuous rigid frame bridge is a kind of structural form of pier-girder consolidation, up from the structural mechanics is a kind of statically indeterminate structure. There are many advantages:good-integrity, large-span; continuou structure jointless, driving-comfort; The related material used in the province; construction is convenient; the negative bending moment at the pier top cut positive moment at the mid span; able to better adapt the prestressing force, shrinkage, creep and the displacement produced by temperature change; in the long span bridge the structure is relatively low cost a lot; structure of delicate, beautiful appearance etc.. Based on so many advantages, is widely used in high pier and long-span continuous rigid frame structure form, such as navigation requirements of high river, mountains in the V channel and other complex terrain, the application of continuous rigid frame bridge is the existence with a large number. Due to the large number of applications of this kind of bridge, the design of related aspects is fairly high requirements, however, this type of design work, the design parameters of structure comes from most experience,this is not reasonable. High pier and long span continuous rigid frame bridge is widely used in the complex terrain where Southwest Yunnan Guizhou Plateau, and the earthquakes that frequent, large earthquake recurrence period is short, and the seismic performance of continuous rigid frame bridge parameters optimization and less and less based on experience value, the design is not the economy of the continuous rigid frame bridge, and no the theory basis, the structure safety degree is unknown. Therefore, the long span PC continuous rigid frame bridge with high piers parameters optimization based on seismic performance has great significance.The Ma Guo He bridge in Jiao Zi Mountain Tourist Highway 3 contract section of Kunming City as the research background, the seismic performance of continuous rigid frame bridge parametes optimization based on the research work, the main work and conclusions as follows:(1) the cause of the different kinds of seismic damage to bridges and seismic damage of the enlightenment and lessons, and introduces the process of development and continuous rigid frame bridge’s seismic. The analysis method of the structural seismic response are described in detail, the seismic research methods used in this paperstatic elasto-plastic analysis method (Pushover method), and introduces the theoretical basis and methods for using the method.(2) the parameters of continuous rigid frame bridge has been built by summarizing the corresponding theuse scope. According to the seismic fortification level, setting goal function. First of all, using the orthogonal table was used to optimize the parameters, the initial parameter combination was obtained:the side span ratio is 0.6, the double thin-wall pier spacing is 10m, thickness of one pier is 4m, the pier wall thickness is 0.7m. By using orthogonal table in the premise of saving optimization time, and ensure the accuracy of the optimization results.(3) orthogonal table can only have a good combination of parameters, select theoptimal combination of the parameters, and can not escape the scope, there are some limitations. In the orthogonal table 36 parameters unchanged, for solving the optimal value by using neural network and genetic algorithm, the neural network has a strong nonlinear mapping ability, the training results of optimization by genetic algorithm, for solving the optimal value. The optimal combination of the conclusion is drawn that theside span ratio is 0.53, pier and pier spacing is 9.56m, the thickness is 3.99m, the pier wall thickness is 0.654m.