CAPACITY SPECTRUM METHOD FOR ECCENTRIC BUILDINGS BASED ON BIAXIAL CONSTANT STRENGTH SPECTRA
The conventional inelastic response spectra constructed by single-degree-of-freedom (SDOF) system is short of the capability to accurately estimate the seismic performance of eccentric buildings. For solving the structure performance evaluation issues including lateral-rotational coupled effect in performance estimation and designation of eccentric structures,the capacity-spectrum method is improved by introducing the equivalent two-degree-of-freedom (E2DOF) systems and biaxial constant strength spectra. The E2DOF system,which is a good tool for performance estimation of eccentric buildings,is established based on the modal information and multidimensional modal pushover analysis (MPA) method. The lateral-rotational coupled capacity spectrum is deduced with MPA procedure and the yielding strength of structure is assumed at the same strength level for lateral and rotational deformations. Thus,there are two different strength reduction coefficients for lateral and rotational deformation capability for inelastic deformation. It is illustrated that the two capacity spectra are not identical in modal capacity spectrum normally. The biaxial constant strength nonlinear response spectra is proposed based-on the two strength reduction coefficients for lateral and rotational deformation. The biaxial constant strength spectrum is adopted in capacity spectrum method to determine the target displacement for eccentric buildings. Furthermore,the influence of E2DOF parameters on the biaxial constant strength response spectra is demonstrated. The parameters include the first lateral vibration period,vibration frequency ratio and eccentric distance. The proposed capacity spectrum method is verified through a numerical example. Nonlinear time history analysis is performed on the eccentric building in order to obtain the exact structural performance. Then the structure performance deduced by the capacity spectrum method is compared with the result of nonlinear time history analysis. The results show that the capacity-spectrum method proposed in this paper is reliable for evaluating the seismic performance of eccentric building with favorable precision. The proposed procedure has good computational efficiency for computing the seismic demand considering lateral and rotational coupled effect.
Rotational response Capacity-spectrum method Seismic performance estimation Eccentric building Modal pushover analysis
Ning Li Zhong-Xian Li Li-Li Xie
School of Civil Engineering,Tianjin University/Key Laboratory of Coast Civil Structure Safety (Tianj School of Civil Engineering,Tianjin University/Key Laboratory of Coast Civil Structure Safety (Tianj School of Civil Engineering,Harbin Institute of Technology,Harbin 150090,P. R. China Institute of En
国际会议
The Eleventh International Symposium on Structural Engineering(第十一届结构工程国际研讨会)
广州
英文
1070-1076
2010-12-01（万方平台首次上网日期，不代表论文的发表时间）