2014-11-22康定MS6.3地震加速度记录的时频分析与震害特征

采用一种基于聚类经验模态分解（EEMD）的HHT方法提取康定M_S6.3地震强震记录的时频特性，通过对各台站获取的强震动加速度记录进行EEMD和Hilbert变换及谱分析，并与Fourier变换进行对比研究。结果表明，对于非线性的强震记录，采用EEMD能有效抑制EMD中存在的模态混叠问题。康定震区震害调查结果发现，“崩科”藏式建筑房屋表现出的震害特征较严重。通过Hilbert边际谱分析可以看出，震区台站主频集中在10 Hz左右，瞬时能量谱高频段信息较为丰富，而藏式建筑较差的抗震性也是造成震区“崩科”藏式结构房屋表现出震害偏重的重要原因。

Time-Frequency Analysis and Earthquake Damage Characteristics of Acceleration Records from Kangding MS6.3 Earthquake on Nov 22,2014

The HHT method based on clustering empirical mode decomposition(EEMD) is used to extract the time-frequency characteristics of the strong earthquake record of Kangding M_S6.3 earthquake. The EEMD and Hilbert transform and spectrum analysis are performed on the strong vibration acceleration records acquired by each station. We compare with the Fourier transform. The results show that for nonlinear strong earthquake recording, EEMD can effectively suppress the modal aliasing problem existing in EMD. The results of the earthquake damage investigation in Kangding earthquake area show that the seismic damage characteristics of the collapsed building houses are more serious. It can be seen from the Hilbert marginal spectrum analysis that the main frequency of the stations in the earthquake zone is concentrated at around 10 Hz, and the instantaneous energy spectrum is high. The information is richer, and the poor seismic resistance of Tibetan buildings is also an important reason for the earthquake-damaged Tibetan-style structural houses.