Study On Adaptive Pushover Analysis Of Long Span Tridimensional Steel Truss Arch

Pushover Analysis, which is widely applied at home and abroad, is essentially a combination of response spectra and nonlinear static analysis method. As an important tool to implement the anti-seismic design, Pushover Analysis has been widely recognized in the design of high-rise buildings, but the application to the anti-seismic study of long-span structures was at an early stage. This article based on relevant theories and methods at home and abroad, the long-span structures under many rare earthquakes are studied by using two kinds of Pushover Analysis, and the results were compared with nonlinear time history analysis to verify the applicability and advantages and disadvantages of two kinds of Pushover Analysis on anti-seismic study of long-span structures.Adaptive capacity spectrum method (referred to ACSM) is a kind of displacement-based adaptive pushed technology, is a performance-based engineering theory. This theory considers the degradation of stiffness, with the actual deformation response characteristics of structural changes.In this paper, one of the long-span tridimensional arched steel truss is taken as a case study. With the three kinds of wave amplitude under the Elcentro as seismic input, the methods of THA, CSM and ACSM were employed to evaluate the performance of the structures. The results of the displacement and plastic hinges distribution from the three methods were compared to verify the feasibility and accuracy of Adaptive Pushover Analysis, and compared the advantages and disadvantages of ACSM and CSM at higher amplitude.Obtained through research and analysis, compared with the nonlinear time history analysis, under the ground motion of Elcentro with peak acceleration 4m/s2, CSM and ACSM evaluate the dynamic displacements and week locations of the long span structure accurately enough to meet the practical application, but when the amplitude increase, two methods of prediction accuracy was decline. However, the distribution of the plastic hinges still needs some improvement.