Analysis of Highway Damage Caused by Mountain Torrents and Debris Flows After Extremely Heavy Rainstorm in Western Sichuan
The objective is to analyze the damage characteristics of highways due to mountain torrents and debris flows.Based on the investigation of National Highway 351 after the extraordinary torrential rain in Ya'an in August 2019,Combining the regional engineering geological conditions,the damage characteristics of 63 damaged sections of the highway were studied from four aspects:debris flow deposits,damage to retaining structures,roadbed dam-age,and total loss,and emergency treatment measures were proposed.The results show that:Work sites with debris flow deposits exceeding 2×104 m3 accounted for 81.28%,with the deposits mostly fan-shaped and the particle sizes of the debris flow ejecta varying greatly,and their compositions vary due to the formation of the sediment source;Work sites with more than 1 500 m3 of damage to retaining structures accounted for 56.82%,mainly caused by riv-erbank side erosion and boulder impacts;Work sites with more than 300 m of roadbed damage accounted for 26.67%,mainly due to river erosion hollowing out the roadbed,mountainside collapses,and landslides burying the roadbed;Work sites with total losses exceeding 7 million CNY account for 26.55%.Mountain highway surveys and designs should fully assess the vulnerable sections along the highway and the disaster prone sections.Implementing temporary passage roads built with different particle sizes of fill materials in stages is an effective emergency repair measure.
HighwayMountain torrents and debris flowRainstorm flood damageSubgrade damageEmergency treatment
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万方数据
