川藏铁路起于成都，经蒲江、雅安、康定、理塘、左贡、波密、林芝到拉萨，全长1 629 km。川 藏铁路穿越的高寒山区，具有地形高差悬殊、地质构造活跃、气候空间分异明显的特点，该区域是地震、泥石流、滑坡等灾害的高发、易发区。本文针对目前泥石流工程防治研究中的不足，提出一种适用于高寒山区高容重、低粘性泥石流排导的阶梯式排导槽。通过试验研究，对比分析了传统的混凝土衬砌矩形槽和阶梯式排导槽在泥石流排导过程中流态、沿程流速、消能率等方面的变化规律，进一步分析了阶梯式排导槽的排导-消能机理，提出了阶梯长度的计算方法。实验结果表明：（1）传统的混凝土衬砌排导槽排导泥石流时，泥石流流态平顺，而采用阶梯式排导槽排导泥石流时，泥石流周期性波动现象明显，沿程阻力增加，使得泥石流通过阶梯式排导槽的流速减小；（2）阶梯式排导槽增强了泥石流体间的相互摩擦、碰撞，从而提高了排导槽的消能率，最大消能率达到61%；（3）基于质点抛射体理论，建立了排导槽单级阶梯长度计算公式。本研究可为泥石流工程防治提供参考。

Sichuan-Tibet railway started from Chengdu, via Pujiang, Ya’an, Kangding, Litang,
Zuogong, Bomi, nyingchi, and lhasa, which covers a distance of 1,629 km. The Sichuan-Tibet railway cuts through the alpine region that has the feature of large elevation difference, active tectonics, and obvious space differentiation. Debris flows with high density, low viscosity, and high speed are one of the most common geo-hazards in these regions. A new type of drainage channel with stepped dissipater was proposed to apply to mitigate the debris flow disaster in the alpine region. The main hydraulic characteristics such as the debris flow patterns, debris flow velocity, energy dissipation along the drainage channel was analyzed under different structures of the drainage channels based on the experiments. The results indicated that compared with the
traditional rectangular drainage channel, the channel with stepped dissipater has more efficiency to decrease the flow velocity, Reduce the abrasion along drainage channel, and improve the energy dissipation rate due to the Intense collision, friction between debris flows and the solid boundary. The maximum energy dissipation rate reaches approximately 61%. Based on the theory of particle projectile, the relation between the step length and the debris flow velocity, step height was proposed. The investigation on the hydraulic characteristics of debris flows in the new type of the drainage channel can give some reference for debris flow engineering mitigation in the future.