The Seismic Response And Pushover Study Analysis Of Cable-stayed Bridges With Double-diamond Tower

The width of bridge is wider and wider with the increased traffic in China. This prompted a new tower—double diamond to emerge. The common forms of cable-stayed bridge tower including column type, gate type, A-shaped , inverted Y-shaped and diamond, etc. However,the cable-stayed bridge with double–diamond tower which is connected transversely by two compound diamond tower is very rare in China. Permanent load, vehicle load and pedestrian load are all transferred to the tower by stay cables. Therefore, the tower is the core component which bears and transfer natural forces, such as temperature, wind, water, ice and earthquake, etc. The tower form has direct influence on dynamic characteristics of the cable-stayed bridge. In recent years, earthquakes occur frequently in China and the other place of the earth, and endanger people's lives and property security seriously. Under seismic action, the destruction of the bridge structure which is one of the lifeline projects, will increase the secondary disasters, and it also will lead to more serious life and property and economic losses. Therefore, it is necessary to analyze the seismic response of this new type of long-span cable-stayed bridge in-depth.Based on the related research achievements at home and abroad and the construction of the Li Jia-sha cable-stayed bridge,This article studied the seismic responses of cable-stayed bridge with double-diamond tower in the following aspects:(1)For the construction of the Li Jia-sha cable-stayed bridge with double-diamond tower, using Midas establish three-dimensional finite element models of the cable-stayed bridge with double-diamond tower and the cable-stayed bridge with diamond tower, and analysis the dynamic characteristics of cable-stayed bridge analysis of the two different tower cable-stayed bridges.(2)According to the seismic intensity area and field types of Li Jia-sha cable-stayed bridge, this article analyzes the response spectrum of the cable-stayed bridge with double-diamond tower and the cable-stayed bridge with diamond tower respectively. Comparative analysis shows that the vibration mode of the cable-stayed bridge with double-diamond tower is more complicated than the cable-stayed bridge with diamond tower; seismic response spectrum load response shows that cable-stayed bridge structure with double-diamond tower has great influence on the horizontal seismic response. (3)Time history analysis of cable-stayed bridge with double-diamond tower in consistent excitation was analyzed. The bridge structure seismic response was studied when earthquake wave were input in one-dimensional and two-dimensional, contrasting the response spectrum analysis results.(4)Three different wave speed were input along the longitudinal. Study to consider traveling wave in the cable-stayed bridge with double-diamond tower under the effect of the earthquake response.Study the impact of displacement and internal force by different wave speed. The response of the same structure in the non-uniform excitation and in the uniform excitation were compared. Discuss seismic response variation of long-span cable-stayed bridges with double-diamond tower in different seismic excitation.(5) MPA method and modified MPA method (MMPA) are applied to the Pushover analysis of a double-diamond tower respectively. Test and verify the feasibility of MMPA on the seismic performance analysis of tower. Provide a reference for the engineering design.