中文摘要：

本文以芦山地震为例,收集了70个该地震的强震波形记录,分析了峰值加速度随震中距的变化特征,讨论了空间加速度变化过程及相关波形传播特征,并运用计算获得的峰值加速度数据,根据经验加速度及烈度关系确定了芦山地震空间烈度分布,得出的最大烈度为Ⅸ度,地震灾害的重灾区位于芦山、宝兴区域,Ⅷ度以上烈度区主要分布在以芦山为中心及以宝兴、天全、雅安、名山等地的交汇区域,Ⅴ度以上烈度分布主要沿龙门山断裂带的灌县—安县断裂两侧呈NE向为长轴的分布特征,所得到的烈度结果与中国地震局给出的较相似.另外,研究结果认为本次地震的时段峰值记录表明其初始破裂是以近乎纯逆断层性质的地震,与哈佛大学给出的此次地震震源机制解较为一致;峰值加速度的高值分布特征显示出了断裂构造对峰值加速度有一定的影响.实践表明本方法具有一定的实用性和可靠性,可为快速抗震救灾提供参考.

英文摘要：

In order to acquire the disaster loss assessment data accurately and quickly when a strong earthquake occurs,we need both the detailed information about the structural features of the earthquake occurring region and reliable seismic observation data.After the huge earthquake of Wenchan MS8.0 on May 12th,2008,many observation stations have been deployed and some important research results have been obtained in the Longmenshan fault zone by the China Earthquake Administration （CEA）,which also provided valuable data for investigating the Lushan MS7.0 earthquake of April 20th,2013.By analyzing the seismic waveform data recorded by 70 strong-motion seismographs,we reveal the variation characteristics of the peak ground acceleration （PGA） for different epicentral distances,discuss the spatial acceleration dynamic change and the related waveform propagation features,and calculate the seismic intensity distribution of the Lushan MS7.0 earthquake based on the obtained PGA in this study and empirical formulae.Our results indicate that the highest seismic intensity is about Ⅸ degree and both the Lushan and Baoxing regions are among the severely afflicted areas.Areas in which the seismic intensities are above Ⅷ are mainly located in the center of Lushan and jointly in the regions of Baoxing,Tianquan,Ya＇an,Minshan,etc.Furthermore,seismic intensities above Ⅴ have a NE long axis distribution along both sides of the Guanxian-Anxian fault in the Longmenshan fault zone.The characteristics of the seismic intensity shown in this study are consistent with the results reported by the CEA.In addition,the PGA shows that the initial rupture of the Lushan earthquake has a thrust fault,which agrees well with the focal mechanism solution of Harvard University.It is also noted that the large fault probably has an effect on the PGA distribution.As a result,our method of analysis is feasible and stable,and it can offer important references for earthquake relief work to the government.