汶川地震公路边坡灾害分析及震后边坡灾害发育特点

Analysis of Highway Slope Disaster in Wenchuan Earthquake and its Development Characteristics after Earthquake

汶川地震使得震后长时期公路边坡地质灾害频发,其中岩体震裂失稳是引起震后公路边坡地质灾害的主要原因。文章在震后公路沿线地质灾害调查的基础上,以地震重灾公路G213汶川~茂县段为例,介绍公路边坡震害发育特征,探讨其破坏力学机制,分析震后公路沿线边坡破坏的发育特点,结果表明:(1)公路沿线边坡失稳主要发生在坡度35°~65°范围内,属于碎石土或强风化层岩体的失稳;(2)震裂岩体的结构面破坏特征主要表现为地震力作用下结构面的延长、贯通、张开程度,以及岩块的错动、塌陷等;(3)边坡表现为以拉裂破坏为主的特征,破坏力学机制有"拉裂~倾倒型"和"拉裂~滑移型";(4)震后边坡地质灾害主要发生在雨季。

The Wenchuan earthquake has caused frequent geological disasters on highway slopes after the earthquake and the main cause of geological disasters on highway slopes after the earthquake is the rock mass loss.Based on the investigation of geological disasters along the highway after the earthquake,in this paper,the earthquake-stricken highway G213 Wenchuan-Maoxian section is taken as an example to introduce the seismic damage development characteristics of the highway slope,and its failure mechanics mechanism is explored,and the developmental characteristics of the slope along the highway after the earthquake are analyzed.The results show:①the instability of the slope along the highway mainly occurs in the range of 35°~ 65°,which is the instability of the gravel or strong weathered rock mass;② the structural surface failure characteristics of the shattered rock mass are mainly characterized by the extension,penetration and openness of the structural plane under the action of seismic force,as well as the displacement and collapse of the rock mass;③ the slope is characterized by tensile failure,and the mechanism of failure mechanics is"pull-dump-type"and"pull-slip type";and④the geological disasters of the slope after earthquake mainly occur in the rainy season.