摘要
Abstract
Mountainous expressways are frequently subjected to threats from geological disasters such as collapses,landslides and debris flows,which severely disrupt the normal operation of transportation and pose a grave hazard to the lives and property of passing vehicles and personnel.Taking the debris flow disaster triggered by typhoon at Section K263 of Chaohui Expressway in May 2017 as a typical case,this study analyzes the formation and evolutionary process of the typhoon-induced disaster chain,and explores its fundamental characteristics and disaster-causing mechanism on the basis of systematic field investigations into the hazard-prone environment,disaster-inducing factors and disaster-forming characteristics.The research demonstrates that heavy rainfall is the primary triggering factor of this typhoon-induced disaster,and the key to the occurrence of the disaster hinges on whether precipitation can initiate the landslide-debris flow disaster chain.The underlying disaster-causing mechanism is elaborated as follows:due to the perennial water discharge from the canal of the upstream power station,the surrounding rock and soil masses remain in a state of high saturation.When continuous rainfall infiltrates into the already highly saturated rock and soil matrix,the sliding force of the potential landslide mass increases;concurrently,rainfall infiltration forms a saturated aquifer at a specific depth,which reduces the effective stress of the soil and thereby triggers the initiation of landslides.Rainfall exceeding the soil's infiltration capacity generates surface runoff,which acts as a continuous water supply to replenish the interior of the landslide mass during its movement.Under the persistent scouring effect of heavy rainfall,the runoff carries the loose solid materials derived from the landslide mass and flows along the gullies,ultimately evolving into debris flow.Finally,this paper puts forward targeted disaster chain-breaking and mitigation measures from the perspectives of hazard-prone environment,disaster-inducing factors and disaster-bearing bodies.These measures are anticipated to provide a reliable technical basis for the prevention,mitigation and relief of highway disasters,as well as for supporting government administrative decision-making in relevant fields.关键词
灾害链/泥石流/台风/致灾机理/防治/公路Key words
disaster chain/debris flow/typhoon/disaster-causing mechanism/prevention and control measures/highway分类
天文与地球科学
