泥石流排导槽研究进展及发展方向

A Review:Design of debris flow drainage canal

泥石流是我国最常见的地质灾害之一,在5.12汶川地震后表现得尤为突出。排导槽作为一种结构简单、经济适用的防护措施在泥石流的防治工程中发挥了重要作用。本文简要阐述了泥石流排导槽的发展历程,重点分析比较全衬砌槽和软基消能型槽的结构特点、排导原理、优缺点及适用范围,其中全衬砌槽束水冲砂的特点增加泥石流的排泄,减少淤积,适于下游有广阔停淤区域或主河有足够输移能力的泥石流;而软基消能槽设置贯穿型横向潜槛,增大摩擦,降低流速,适于下游有城镇、铁路、工厂等重要基础设施的泥石流;分别从横纵断面优化、材料选择等角度总结了排导槽的研究进展:初步界定排导槽合理纵比降为3°～10°;横断面上对矩/梯形、圆形、V形等几种主要槽型水力条件进行分析比较,得出圆形断面最优;尝试运用高强混凝土等新型材料或结构增加排导槽的抗磨强度,延长其使用年限;综合考虑泥石流地质地貌背景、水文条件、施工难易程度、经济与否等多方面因素,选择最合适的排导工程;指出随着各项土木工程中生态需求的日益增长,今后研究工作中应加强模型试验,尤其是交错齿槛等生态型泥石流排导槽的研究,进一步完善泥石流排导槽的优化设计体系。

Debris flow is one of the most common geo-hazards in China,which occurred more actively after 5.12 Wenchuan Earthquake.Debris flow drainage canal——a simple and applicable countermeasure acts a significant role in the mitigation and prevention of debris flow.This paper briefly presents the development history of drainage canal,as well as the difference between two common types of drainage canal from such aspects as structural characteristic,drainage principle,advantages or disadvantages and applicable scope,and due to the special characteristic of clearing sands with converging flow,V type drainage canal is more appropriate for the areas where there are more open spaces or the main stream has adequate ability of transport;on the contrary,with the help of submerged sil,l＂Dongchuan type＂drainage canal can be used in the areas in which there are many infrastructures,like railways,factories,etc. Also,some research achievements on debris flow drainage canal are introduced from the optimization of transverse and vertical section,selection of materials：1）the rational longitudinal slope is 3-10°;2）hydraulic conditions of such types of drainage canal as rectangle/trapezoid,circle,V type are discussed;3）high strength concrete is tried to be used in the construction of drainage canal to enlarge service life;4）a variety of factors in the construction of drainage canal are synthetically considered,such as geological background,hydrologic conditions,ease of construction,etc. In view of deficiency of present researches,it is suggested that more model tests should be conducted in the future to prefect optimization designation of debris flow drainage canal,especially including the study of ecotype drainage canal with indented-sill.