降雨引起的两类不同浅层滑坡稳定性的计算模型——与“浅层黄土滑坡易发性评价:以晋西黄土区蔡家川农地小流域为例”一文商榷  

Two Different Types of Models for Stability Assessment of Rainfall Triggered Shallow Landslides——Discuss with the paper Risk Assessment of Shallow Loess Landslides

作　　者：李同录[1,2] 袁思凡 徐家隆 胡向阳[4] 李萍[1,2] LI Tonglu;YUAN Sifan;XU Jialong;HU Xiangyang;LI Ping(School of Geological Engineering and Geomatics,Ministry of Education,Xi’an,710054;Observation and Research Station of Water Cycle and Geological Environment for the Chinese Loess Plateau,Ministry of Education,Zhengning,Gansu 745399,Chang’an University,China;Monitoring Center of Shaanxi Province for Water-Soil Conservation and Ecological Environment,Xi’an,710199,China;PowerChina Northwest Engineering Corporation Limited,Xi’an,710065,China)

机构地区：[1]长安大学地质工程与测绘学院,西安710054 [2]长安大学黄土高原水循环与地质环境教育部野外科学观测研究站,甘肃正宁745300 [3]陕西省水土保持生态环境监测中心,西安710199 [4]中国电建集团西北勘测设计研究院有限公司,西安710065

出　　处：《山地学报》2023年第6期916-925,共10页Mountain Research

基　　金：国家重点研发计划(2021YFE0111900);陕西省水土保持生态环境监测中心(2023SBJC-01);中国电建集团西北勘测设计研究院有限公司资助项目(XBY-PTKJ-2022-8)。

摘　　要：在“浅层黄土滑坡易发性评价:以晋西黄土区蔡家川农地小流域为例”一文中,采用SHALSTAB模型评价降雨引起的黄土斜坡浅层滑移稳定性。该模型是将降雨引起的斜坡水文模型和无限边坡稳定性评价模型结合,便于在MAPGIS中提取地形要素,进行区域性斜坡稳定性评价。模型假定基岩与松散层界面是滑动面,降雨在松散层中形成地下水,并平行基岩面向坡下流动,且为稳定流,排泄量与其上游汇水区的降雨量均衡。可以看出,SHALSTAB模型不适用于黄土斜坡。黄土为厚层非饱和土,斜坡中不存在类似于基岩面的隔水界面,也不会形成平行坡面的地下水流。降雨主要是向下入渗在黄土中形成一个湿润带,湿润带中的水不是潜水,而是毛细悬挂水,其中的孔隙水压力为接近0的一个负值,不存在SHALSTAB模型中的正孔隙水压力,因此在选用模型时,必须仔细甄别其适用条件。In the article Risk Assessment of Shallow Loess Landslides:Taking a Small Watershed of Caijiachuan Farmland in the Loess Region of Western Shanxi of China as an Example,a SHALSTAB model was used to evaluate the stability of shallow loess landslides triggered by rainfalls.This model combines a rainfall-induced slope hydrological model with an infinite slope stability model,which facilitates the extraction of terrain features in MAPGIS for regional slope stability assessment.In the model it theoretically assumes that the interface between underlying bedrock and loose detritus is a sliding surface;rainfall turns into groundwater in loose material,flowing downslope parallel to the bedrock as an assumed steady flow,with discharge equalized to the rainfall in its upstream.It can be seen that the SHALSTAB model is not suitable for loess slopes.Loess is a thick,unsaturated soil and there is no impermeable interface similar to a bedrock surface in a slope,nor does it drain underground water parallel to a slope surface.Actually,in a loess slope,rainfall mainly infiltrates downward and forms a wet zone in the profile.In the wet zone,the water is capillary suspended rather than phreatic water,and the pore water pressure is a negative value close to zero.There is no positive pore water pressure on the failure surface in loess slope as it is supposed in SHALSTAB model.Therefore,when selecting a model,it is necessary to carefully consider its applicable conditions.

关 键 词：黄土 降雨 浅层滑坡 SHALSTAB模型 SINMAP模型 GREEN-AMPT模型 

分 类 号：P642[天文地球—工程地质学]