汶川地震前宽频带信号的疲劳损伤分析
Fatigue Damage Analysis of Broadband Signals Prior to the 2008 Wenchuan MS8.0 Earthquake

近年来的地震观测发现，在许多大地震发生前数天的宽频带地震仪信号，都明显存在不同程度的异常信号叠加，进一步的频谱分析可以对这些信号在频域上进行区分，这些发现表明宽频带数字信号包含了丰富的地壳运动和损伤等变化信息。基于疲劳损伤理论，对汶川大地震前三天恩思台（ENH）、昆明台（KMI）、拉萨台（LSA）的宽频带数字信号，进行相对等效应力的计算分析和跟踪。结果显示：在大地震前三天，这些台站宽频带数字信号所包含的相对等效应力都有显著增加的过程。
In recent years, broadband seismographs have shown the obvious superposition of abnormal seismic observation signals a few days prior to large earthquakes. These signals can be distinguished in the frequency domain by frequency spectrum analysis. Study results show that broadband digital signals contain rich information related to crustal movement and damage. In this study, based on the fatigue damage theory, we computed and analyzed the broadband digital signals from the ENH, KMI, and LSA stations three days prior to the 2008 Wenchuan MS8.0 earthquake. The results show that the relative equivalent stress indicated by the signals increased significantly in the three days prior to the earthquake.