一种考虑局部场地收敛性的多点地震动合成方法

提出一种符合实际地震动传播特点的多点地震动合成方法。目前的非平稳空间相关多点地震动合成方法在局部场地上不具备收敛性，与实际的地震波传播机制相矛盾。通过修正随机相位角，使生成的多点地震动在局部场地上具备收敛性，给出了未知和已知相位差谱统计规律两种情况下非平稳多点地震动的合成方法，进一步提出了基于实际地震记录的空间相关多点地震动合成方法。采用本文方法进行了基于美国Northridge地震和我国集集地震的多点地震动模拟研究，结果表明方法具有良好的局部收敛性，可用于大尺度结构的多点输入分析。

A LOCAL CONVERGENT METHOD FOR SIMULATIONG MULTI-POINT EARTHOUAKE GROUND MOTION

A novel method to simulate non-stationary spatial correlative time histories of multi-point earthquake ground motion is presented.The currently used method is non-convergent in local fields,which contradicts the propagating mechanism of the real earthquake wave.By modifying random phase angle,a local convergent approach is proposed to simulate non-stationary multi-point earthquake ground motion.Two cases of the known phase-difference spectrum and the unknown phase-difference spectrum are studied herein.A new method to simulate time histories of multi-point ground motion using actual earthquake records is then developed.The proposed method is applied to the real ground motion records of the American Northridge earthquake and the Chinese ChiChi earthquake.The results indicate that the proposed method has the local convergence of the simulated ground motions,it can be used for multi-support excitation analysis of large scale structures.