Study on Seismic Evaluation of Curve Bridges

• Main Authors: Ke-Xin Wang, 王科欣
• Other Authors: Yu-Chi Sung
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/afxfm3

碩士 === 國立臺北科技大學 === 土木工程系土木與防災碩士班 === 106 === The seismic capacity of domestic bridges evaluation mostly use pushover analysis or nonlinear timehistory analysis.Both of the two methods are closely linked with the vibration characteristics of bridges. Generally, the seismic capacity evaluation of straight bridges is based on the distribution of seismic forces to the vibration characteristics of the vehicle and the vertical direction. The nonlinear behavior pattern of the beam-column members is calculated by the auxiliary program as the plastic hinge setting of the beam-column members, and the capacity spectrum is utilized. The method of checking determines whether the seismic resistance of the bridge is sufficient. However, the vibration characteristics of curved bridges are not the same as straight bridges. Because the plane of the main beam is curved, the support points of the lower structure piers are not on the same straight line, and the upper and lower structures of the curved bridge are subjected to bending moment and torque. In the form of structure, when the curved bridge is subjected to seismic force, the column member is subjected to the axial force, the torque and the biaxial bending moment. Therefore, the mechanical characteristics of the curved bridge must be discussed. Currently, a complete set of curved bridges has not been developed in domestic.Through analysis to understand the basic characteristics of the curved bridge, and according to the mechanical behavior of the beam and column members plastic hinge setting and inspection, in order to achieve the purpose of accurate analysis. This study provides a complete set of analysis and analysis process for seismic performance of curved bridges. Considering the mechanical properties of curved bridges subjected to axial force and biaxial bending moment, the fiber element method is used to cut the section of the column section into non-surrounded areas. The fiber element, considering the nonlinear of the material of steel and concrete, incorporating with equilibrium and compatibility condition, the constitutive law of concrete proposed by Kawashima et. al. as well as the elastoplastic model of reinforcement was taken into account mechanically, analyzes the axial force and biaxial bending moment interaction curve (PMM interaction curve), and considers the curve bridge to be subjected to torque. The reaction and define its nonlinear behavior. In this study, the SAP2000 structural analysis software was used to establish a curved bridge analysis model, and the plastic hinges of each bridge column were established by the above theoretical analysis. The effects of earthquakes on different directions and different grade of input on curved bridges were considered, and the responses of each bridge column were analyzed. At the same time, a biaxial bending moment check program was developed to check the failure order and failure pattern of column members under different earthquake conditions. Finally, the analysis results summary table was compiled as the overall reaction of the case study. The results of the research can provide engineers with reference for seismic analysis and design of curved bridges.