持续强降雨影响下黄梅县袁山村三组滑坡破坏特征与成因分析

2020 年7 月8 日凌晨4 点5 分，湖北省黄梅县大河镇袁山村三组在强降雨作用下突发一起体积为40000 m3的小型岩土混合型滑坡，造成8 人遇难，1 人受伤，以及大量农田、房屋、管道、输电线路损毁，直接经济损失约1760 万元。为查明滑坡破坏特征和成因机制，采用现场工程地质调查和流固耦合数值模拟方法，对滑坡体的形态、规模、变形破坏特征与成因机制进行分析总结，认为袁山村三组滑坡为持续性强降雨诱发的小型高位远程岩土混合型滑坡-碎屑流，强降雨作用3.5 h 之后，雨水渗至滑面，导致坡体地下水位迅速抬升，滑坡岩土体基质吸力和有效应力急剧降低，破坏模式为牵引式破坏。本文研究成果可为鄂东北地区类似滑坡的机理分析与监测预警工作提供有益的借鉴。

Analysis of Characteristics and Causes of Landslide Damage in Group 3 of Yuanshan Village,Huangmei County Under the Influence of Continuous Heavy Rainfall

At 4:05 a.m. on July 8, 2020, a small rock-soil mixed landslide with a volume of 40,000 m3suddenly occurred in the third group of Yuanshan Village, Dahe Town, Huangmei County. The landslide killed 8 people, injured 1 person, and destroyed a lot of farmland, houses, pipelines, transmission lines, and caused a direct economic loss of about 17.6 million yuan. In order to identify the characteristics and cause of landslide, on-site engineering geological survey and fluid-structure coupling numerical simulation were used to analyze and summarize the form, scale, deformation and damage characteristics and cause of the landslide. It is concluded that the landslides in Yuanshancun Group are small and high long-range mixed landslide-debris flow induced by sustained heavy rainfall. After 3.5 hours of heavy rainfall, the rainwater seeps into the sliding surface, causing the rapid rise of the groundwater level of the slope, the sharp decrease of the suction and effective stress of the landslide mass. The landslide failure mode is retrogressive. This paper can provide a useful reference for mechanical analysis, monitoring, and previous warning of similar landslides in northeast of Hubei province.