Newmark方法在芦山地震诱发滑坡分布预测研究中的应用

APPLYING THE NEWMARK'S MODEL TO THE ASSESSMENT OF EARTHQUAKE-TRIGGERED LANDSLIDES DURING THE LUSHAN EARTHQUAKE

对于地震滑坡灾害而言,进行地震滑坡危险区划是降低损失的有效手段之一。因此,地震滑坡危险性预测方法的研究成为这一领域的热点。2013年4月20日芦山地震诱发了大量的滑坡崩塌,造成了严重的人员伤亡和社会经济财产损失。文中通过对地震灾区震后航片、遥感影像等的解译,初步获得此次地震诱发滑坡的分布概况。在芦山地震灾区的地形和岩性分析的基础上,基于Newmark物理平衡模型,对该区的潜在地震滑坡危险区进行了分析预测,通过对比本研究获得的潜在滑坡区域预测结果与解译的滑坡分布情况,表明Newmark模型是一种有效的地震诱发滑坡预测分析方法。进一步探讨了不同滑坡影响范围估算方法的差异,认为震级与产生滑坡最远距离之间的关系是一种较好的估算方法。

As a kind of secondary disasters caused by strong earthquakes,earthquake-triggered landslide has drawn much attention in the world because of severe hazards it causes. The 2013 Lushan, China, earthquake triggered lots of landslides and provided an opportunity to test various kinds of methods which have been used in earthquake triggered landslides assessment. Based on the high-resolution sat- ellite images and aerial photos,we preliminarily interpret landslides in the damaged region. It is found that almost all of the landslides took place in the area with seismic intensity above VII. Spatially, the triggered landslides are controlled by the causative faults in their distribution and mainly concentrate around the epicenter. Based on the Newmark＇s method model, critical acceleration ac is used to predict potential landslides. Comparing with the landslides occurrences in the study area,the result of our cal- culation proves that Newmark＇s model is effective in seismic hazards analysis. Also,the landslide af- fected area is estimated by several methods and the difference between them is discussed.