| The application of section prefabricated assembly technology on continuous rigid bridges is a model for the development of modern bridges,which is in line with the ecological concepts of "carbon neutrality" and "carbon peaking" put forward by our country,and conforms to the development strategy of national green buildings.In recent years,section prefabricated assembled continuous rigid bridges have been widely used by virtue of their own high efficiency,energy saving,fast construction speed and beautiful appearance.However,due to the complexity of the dynamic characteristics of the continuous rigid bridge and the particularity of the connection with the pier,the seismic performance of the continuous rigid bridge is very critical.Combined with a bridge project under construction in Guangdong Province,this thesis performs three-dimensional finite element calculation on the model according to the construction drawings and geological environment of the project,introduces the construction process of the section prefabricated continuous rigid bridge,and analyzes the seismic calculation results under the action of different seismic waves.The main work content is as follows:(1)From the background of the study,the current development status of continuous rigid bridges at home and abroad is introduced,the prospect of the development of segmental prefabricated assembling technology is studied,and the need for research on the seismic work of this type of bridge is clarified.The basic methods used in the seismic process of continuous rigid bridges are listed,from which the reaction spectrum method and transient time course analysis are selected as the methods for seismic analysis in this thesis.(2)Through the analysis of the actual engineering project problems,the BIM technology is used to simulate the assembly process of the section prefabricated assembly technology in the construction,and the advantages and disadvantages of the long-term method and the short-term method are compared,and the short-term method is selected as the prefabricated construction method of the bridge.The finite element calculation software ANSYS parametrically modeled the actual bridge,which can simplify the bridge appropriately.(3)Since the pile foundation of the continuous rigid bridge is generally long,the interaction force between the underground soil and the pile foundation should be fully considered under the action of seismic vibration.Using the ANSYS APDL program,the bridge structure is used to model the pier bottom consolidation and the two models considering the interaction between pile and soil,and the self-vibration characteristics of the structure are analyzed separately,and it can be seen that the basic mode of the two models is the whole bridge longitudinal drift.(4)Through the modal analysis of the two models,the self-vibration characteristics of the structure are obtained,and a reasonable acceleration response spectrum is designed according to the seismic design specifications,and the seismic inputs of the cross-bridge and the downstream bridge are performed on the two models,and the internal forces and displacement results generated by the seismic response of the two models of the bridge are compared.(5)The seismic waves that fit the site were selected from the ground shaking database for three-way seismic input,and the adjusted seismic response of El-Centro,Taft and artificial waves were analyzed and compared.The El-Centro wave with the largest seismic response value was selected,and the displacement and acceleration results generated by the two models under the action of the El-Centro wave were plotted in time and analyzed.With regard to the seismic design content of segmental precast continuous rigid bridges,it is concluded that the pier and girder consolidation of continuous rigid bridges are prone to peak displacements and internal forces,which should be paid special attention in the design,and the results of the study can provide reference for the design of similar bridges. |
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