川藏公路四川段泥石流灾害研究与治理

大量现场调查和观测发现，川藏公路四川段的泥石流灾害集中分布在4个区域，即龙胆溪泥石流区、雅江泥石流区、波戈溪泥石流区和巴塘—金沙江泥石流区。波戈溪泥石流区和巴塘—金沙江泥石流区是境内泥石流灾害最严重的地区，流域面积超过20km^2的特大型泥石流有24条。自东向西，川藏公路四川段泥石流由水石流逐渐演变为稀性泥石流；复杂的地质构造环境、高山深谷地貌特征、强烈的地震活动、高强度的降雨和冰雪融水，构成泥石流灾害显著发育的环境条件。将公路沿线泥石流形成机理概括为4种，即降雨冲击机理、强度衰减机理、冲刷切割机理和沟床拖拽机理；2003年以来采用护岸结构、速流结构、抗冲击结构、拦渣坝、消能坎等技术实施了30余个大型泥石流灾害治理工程，治理效果显著。

Studies and Harnessing for Debris Flow Disaster along the Sichuan-Tibet Highway in Sichuan Province

Large numbers of field investigation and observation have revealed the distribution regularity of debris flow disaster along the Sichuan-Tibet highway in Sichuan province, which consists of four zones respectively in Longdanxi catchment, in Yajiang catchment, in Bogexi catchment and in Batang-Jinshajiang catchment. Specially, debris flow disasers are deeply serious in both Bogexi and Batang-Jinshajiang catchments, there are 24 giant debris flows with their basin areas over 20 km^2. From east to west along the highway, debris flows evolve gradually from torrents with various rocks to dilute debris flows. The environment to develop debris flow disasters along the highway is characterized of complex geological tectonic actions, landforms with deep valleys and high mountains, active earthquakes, intense precipitation, and abundant thawing water from snow and ice. Four types of mechanisms to trigger debris flows can be classi- fied generally, i.e. , rainfall impact, strength attenuation, erosion cutting and drawing. More than 30 giant debris flow disasters have been harnessed with the technical measures of bank protection works, high-speed drainage structures, anti-impact structures, guiding-flow dams, energy releasing ridges etc. since 2003, which have ensured significantly the communication service of the Sichuan-Tibet highway.