Newmark模型中同震滑坡饱和比率计算方法分析

周　宇

摘 要：地震发生后，为确定同震滑坡带来的危害，科学有效指导灾后重建工作，必须第一时间预测同震滑坡的易发性，其间，Newmark模型被国内外学者广泛应用。作为该模型的重要参数，同震滑坡饱和比率是指同震滑坡中饱和部分占总滑体厚度的比例，但目前尚无精确的计算公式。经过遥感解译及调查统计，本文建立中国九寨沟地震、芦山地震及日本北海道地震三场地震的同震滑坡数据库，结合地形、地质及地面运动峰值加速度等参数，统计并分析三场地震同震滑坡厚度与饱和部分占总滑体厚度的比例关系，探讨Newmark模型中同震滑坡饱和比率的计算方法。

关键词：Newmark模型;同震滑坡;饱和比率;地面运动峰值加速度

中图分类号：P315.9文献标识码：A文章编号：1003-5168（2021）17-0021-05

Analysis of Calculation Method of Co-seismic Landslide Saturation

Ratio in Newmark Model

ZHOU Yu

（Chengdu University of Technology，Chengdu Sichuan 610059）

Abstract： After the earthquake， in order to determine the harm caused by co-seismic landslides and scientifically and effectively guide post-disaster reconstruction work， it is necessary to predict the susceptibility of co-seismic landslides in the first time， in the meantime， the Newmark model has been widely used by scholars at home and abroad. As an important parameter of the model， the saturation ratio of coseismic landslides refers to the ratio of the saturated part of the coseismic landslide to the total thickness of the landslide， but there is no precise calculation formula yet. After remote sensing interpretation and survey statistics， this paper established a coseismic landslide database for three earthquakes， such as the Jiuzhaigou earthquake and the Lushan earthquake in China， and the Hokkaido earthquake in Japan， combines parameters such as topography， geology and seismic peak ground acceleration （PGA）， counts and analyzes the relationship between the thickness of the coseismic landslide and the proportion of the saturated part to the total thickness of the landslide in the three earthquakes， and discusses the calculation method of the saturation ratio of the coseismic landslide in the Newmark model.

Keywords： Newmark model;coseismic landslide;saturation ratio;PGA

Newmark模型是國内外研究地震诱发同震滑坡易发性的常用预测模型，指当地震强度大于边坡的抗震强度时，坡面滑体将会克服滑动摩擦力，开始滑动并产生同震滑坡[1]。国内外学者利用Newmark模型开展同震滑坡易发性分析，但模型中滑坡饱和比率参数的取值一般默认为0或1，滑坡厚度默认为5 m[2-5]。现阶段，虽然Newmark模型广泛运用在同震滑坡易发性评价中，但是针对该模型中同震滑坡饱和比率这个重要参数的取值一直不明确，多数情况下默认地震发生时同震滑坡易发区域的土体干燥，饱和比率为0。本文以中国九寨沟地震、芦山地震及日本北海道地震三场地震区域为研究区，通过调查发现这三场地震前震区都发生了降雨事件[6-8]。……