成昆铁路泸沽至西昌段泥石流基本特征研究

成昆铁路泸沽至西昌段位于安宁河大断裂带影响范围内,是地震的源地,也是泥石流集中暴发段。调查了影响研究段泥石流发育的6个因素;其中,地形地貌、降雨、不良地质是对泥石流的发育特征起决定性作用。通过大量调查获取了沿线泥石流暴发的最大雨强值;着重分析了不良地质的4种类型;流域面积与纵坡比、沟谷长度的关系。孕灾环境致使泥石流的类型和发育特征呈现串联形态分布、沟谷形态差异大、冲淤大、漫流能力强等特点。甄选了沿线9条典型泥石流沟进行重度和动力学参数计算,分析了形成机理以及发展趋势,对铁路的安全运行以及灾害的治理具有重要意义。

Study on the Basic Features for Debris Flows along Lugu to Xichang Section of Chengdu-Kunming Railway

The Lugu to Xichang section of Chengdu-Kunming railway is located within the scope of influence of Anning river-fault zone, however,this zone is the source of earthquake and section of debris flow outbreak.Six factors affecting the debris flow development of the studied location were investigated, where the topography, rainfall and bad geology play decisive role for the development characteristics of debris flow.Mainly analyzed were the relationships of the drainage area with the valleys ratio,valleys length and four types of bad geological.The data about the biggest rain which could lead to the debris were collected in investigation. The disaster-forming environment rendered the type and development characteristics of the debris showing some special characters including distribution in series, morphological differences of the valleys, vast sediment deposition and strong flow ability. Nine typical debris flows along the ditch were selected to calculate the severe movement and dynamics parameters and analyze the debris flow formation mechanism and development trend in studied section, that was of great significance to the safety of railway operation and the management of disasters.