本文首次采用虚实分离法来进行功率谱矩阵的分解,并将该分解法生成的地震动相关特性与传统的cholesky分解法进行对比分析,结果显示该方法不仅计算快速、准确可行,而且在多方面具有明显的优越性。另外,本文在使用虚实分离法分解矩阵的同时,具体推导了该方法的可行性,并给出了详细的证明过程。通过文中的合成实例可以看出,该方法生成的人工地震动时程空间相关性良好,且具有频域、时域范围内的双重非平稳特性。
A new method was proposed in this paper for the first time to decompose the power spectrum,which separated the imaginary part from the power spectrum matrix,then just a real matrix had been left,and only needed to decompose the real matrix. Compared with the traditional Cholesky decomposition,this method is simple in calculation and become more accurate,so it has an obvious advantage over the traditional method. In addition,the feasibility of this matrix separation method is derived,and the detailed proof process was given at the same time.Through a synthetic examples in this paper,it can be seen that the ground motion has a good spatial correlation which generated by this method. At last,the analysis results confirmed that this ground motion showed double nonstationary characteristic not only in time domain but also in frequency domain.