陇东陕甘边界降雨水毁灾情调查与启示

Investigation of water induced damages triggered by rainfall in east Gansu and the implications

黄土地区降雨导致的水毁灾害常有发生,造成严重的工程灾害和人员伤亡。对已有水毁灾害的调查和成因分析,可为防治区灾害提供经验。2021年8月中旬至10月初,在陇东陕甘边界黄土地区持续了50多天降雨,引发了大量水毁灾害,导致G211国道中断两周。文中介绍了这次降雨在G211沿线及其附近的村镇引起水毁灾害的现场调查情况,发生在村镇的水毁灾害有黄土窑洞塌陷、土质房屋和夯土围墙倒塌;发生在道路上的水毁灾害有路基外缘沉陷开裂,路基内侧边坡崩塌、斜坡浅层滑移及滑坡泥流等地质灾害。这些灾害规模小、影响范围不大;但数量多、致灾性较为普遍。文章还调查了植被对黄土斜坡稳定性的有利和不利影响。针对水毁灾害,分析其原因并提出了村镇和道路建设中针对此类水毁灾害的预防措施。

Flood-induced disaster caused by rainfall in loess area often occurs,causing serious engineering disasters and casualties.The investigation and cause analysis of existing flood-induced disaster can provide experience for disaster prevention and control areas.From mid-August to early October,2021,more than 50 days of rainfall triggered a large number of Flood-induced disaster in the loess area of east Gansu Province.The damages made G211 national highway close for two weeks.This paper introduces the on-the-spot investigation of the flood disaster caused by this rainfall in villages and towns along route 211 and its vicinity,it happened in the villages and towns are mainly the collapse of loess living caves,collapse of earth-houses and fall of earth-walls.Geo-disasters on the road are subsidence and cracking of the soil filling subgrade,collapse of the cutting slope at inner side of the road,shallow flow-slide of the main slope.These disasters are small in scale and weak in influence,but it is large in number and serious in disastrous.We also investigated the positive and passive effects of vegetation on the loess slope.Based on investigation of the flood-induced disaster,this paper analyzes its causes,and puts forward some preventive measures in the construction of villages,towns and roads.