基于Newmark方法的四川芦山6.1级地震公路滑坡快速评估

Rapid Estimation of Road Landslides Based on Newmark Method for The 6.1 Magnitude Earthquake in Lushan, Sichuan

2022年6月1日四川省雅安市芦山县6.1级地震发生后,基于地震震级与历次地震中震区交通状况综合考虑,对震区公路滑坡风险等级开展快速评估工作,使用Newmark模型计算得到研究区内岩土体永久累积位移并划定地震滑坡风险等级。结果显示,在芦山6.1级地震的影响下,研究区内滑坡风险等级由震中区域向四周逐渐降低,与地震动强度的衰减具有相似的规律;区内北西侧的滑坡风险等级要明显高于南东侧,该分布规律与研究区地形地貌特征相吻合;依据划定的危险性等级,在研究区圈定7个公路滑坡高风险区域,收集到的实际7处受灾路段有6处落在公路滑坡高风险区内。验证表明,基于Newmark模型与路网数据划定的公路滑坡高风险区具有较高的可信度,该地震公路滑坡快速评估方法可以为灾后应急救援力量部署及减轻地质灾害造成的损失提供一定帮助。

On 1 June 2022,a 6.1 magnitude earthquake occurred in Lushan County,Ya'an City,Sichuan Province,with a depth of 17 km.Based on the comprehensive consideration of the earthquake magnitude and the traffic condition of the earthquake area in previous earthquakes,this paper carries out a rapid assessment of the risk level of road landslides in the earthquake affected.The Newmark model was used to calculate the permanent cumulative displacement of rock mass in the study area and to classify the earthquake landslide risk level.The assessment results show that under the influence of the Lushan 6.1 magnitude earthquake,the landslide risk level in the study area gradually decreases from the epicenter to the surrounding area with a similar pattern to the attenuation of ground shaking intensity;the landslide risk level on the north-west side of the study area is significantly higher than that on the south-east side,and this distribution pattern is consistent with the topographic and geomorphological characteristics of the study area;based on the classified risk level,seven high risk areas for road landslides were identified in the study area.Five of the six affected road sections collected fell within the high-risk area of road landslides.The verification showed that the high-risk area of road landslides delineated based on the Newmark model and road network data had a high degree of confidence,and the rapid assessment method of earthquake road landslides could support the deployment of emergency rescue forces and mitigation of losses caused by geological disasters after the earthquake.