摘要
西藏冰缘雪线附近寒冻风化十分严重,其风化形成的大量碎屑颗粒极易导致碎屑流、泥石流、滑坡以及落石等地质灾害,严重威胁西藏主要交通干线的安全营运、矿山的安全生产以及当地群众的生命财产安全。文章分析了西藏雪线斜坡碎屑颗粒的形成原因,讨论了稳定状态的受力平衡,并运用信息熵计算了碎屑颗粒失稳下滑的主要因素。结果表明,构造及气象共同作用是碎屑颗粒形成的主要原因;坡度、震动、粘聚力和内摩擦角是控制碎屑颗粒稳定的主要参数;使碎屑颗粒失稳的主要因素从大到小依次为降雨融雪、人为工程、斜坡坡度、植被覆盖率、地震活动、碎屑颗粒物。
The cold and frost weathering is very serious near the snow lines in Tibet, and the large amount of clastic particles formed by weathering are very easy to result in geological hazards such as debris flow, mud-rock flow, landslide, and falling stone etc., which seriously threatens the safe operation of main transportation lines in Tibet, the safe production of mines, and the safety of the lives and property of local people. In this paper, reasons for formation of clastic particles on the slope of the snow lines was analyzed and the equilibrium condition for forces of the stability state was discussed. Moreover, using information entropy, the main factors of decline of clastic particles was calculated. The results showed that the joint interaction of structure and meteorology is the main reason for the formation of clastic particles. The slope, vibration, cohesion, and internal friction angle are the main parameters to control the stability of granular particles, and the main factors that make the clastic particles unstable are precipitation, snowmelt, artificial engineering, slope, vegetation coverage, seismic activity, and debris particles in turn.
基金
2016年度国家自然科学基金项目"G318西藏境内溜砂坡流水作用下失稳与运动机理"(项目号:41662020)
2016年度西藏自治区自然科学基金项目"基于西藏高原大温差环境下不同岩石类型石质文物(岩画)的风化速率及风化机理研究"(项目号:2016ZR-15-7)
2015年度西藏自治区高校青年教师创新支持计划项目"甲玛融雪型碎屑流的启动机理及运动特征研究"(项目号:QC2015-23)阶段性成果
关键词
碎屑斜坡
稳定性
雪线
Debris slope
Stability
Snow line
