滑坡是一种破坏性非常强的地质灾害,其中地震与降雨均为诱导滑坡发生的关键因素.从降雨期间发生地震的角度考虑,基于 GreenGAmpt降雨入渗模型对 Newmark模型进行改进,推导两因素耦合作用下的边坡安全系数FS.以云南省鲁甸县某一区域为例,分别开展无降雨、降雨无积水与降雨积水三种情况下的地震滑坡危险性预测及坡度与入渗深度因子对位移影响分析.通过比较上述三种情况,得到研究区域内的 Newmark累积位移分布及危险性区划.结果表明:与未降雨情况相比,后两种情况下地震滑坡高危险程度区域面积占比计算区域随着降雨时间的增加从1% 分别提高至9%、12%,滑坡低危险程度区域面积从51%分别降低至35%、33%;坡度值与入渗深度值越大,滑坡位移越大,危险性越高.Newmark改进模型充分考虑了降雨对地震滑坡产生的促进作用,能更好地反映出研究区每个场点相对的滑坡危险性,对滑坡危险性预测具有一定指导意义.
As a kind of destructive geological disaster, earthquake and rainfall are two key factors to induce landslide. From the perspective of earthquakes occurred during rainfall, this paper improved the Newmark model based on the Green-Ampt rainfall infiltration model, and derived the slope safety factor FS under the coupled action of two factors. The seismic landslide risk prediction and the influence of slope and infiltration depth factor on the displacement in an area of Ludian County, Yunnan Province were carried out under three conditions, i.e., no rainfall, rainfall with ponding, and rainfall without ponding. Then the Newmark cumulative displacement distribution and risk zoning in the study area were obtained through a comparison between the three cases. The results show that: compared with the case without rainfall, the area proportions of high-risk area of earthquake landslide in the latter two cases increase from 1% to 9% and 12% with the increase of rainfall time, respectively, and the area proportions of low-risk landslides reduce from 51% to 35% and 33%, respectively. With the increase of slope and infiltration depth, the displacement and the risk of landslide also increase. The improved Newmark model fully considers the promotion effect of rainfall on the occurrence of earthquake landslide and can better reflect the relative landslide risk of each site in the study area, thus having certain guiding significance for the landslide risk prediction.
雷真,李林锐,隆交凤,陈敬男,杨洋.基于降雨入渗的Newmark模型改进及地震滑坡危险性预测研究[J].地震工程学报,2022,44(3):527-534. LEI Zhen, LI Linrui, LONG Jiaofeng, CHEN Jingnan, YANG Yang. Improvement of Newmark model and prediction of seismiclandslide risk based on rainfall infiltration[J]. China Earthquake Engineering Journal,2022,44(3):527-534.复制