鱼脊型水石分离系统对漂木减灾效果的实验研究
文献类型：学位论文
| 作者 | 谢湘平
|
| 学位类别 | 硕士 |
| 答辩日期 | 2014 |
| 授予单位 | 中国科学院研究生院 |
| 授予地点 | 北京 |
| 导师 | 韦方强 |
| 关键词 | 山地灾害 漂木 鱼脊型水石分离系统 优化设计 |
| 其他题名 | Experimental study on the mitigation effect of the herringbone water-sediment separation system for driftwood disaster |
| 学位专业 | 建筑与土木工程 |
| 中文摘要 | 在植被覆盖良好的山区，由于滑坡、沟岸侵蚀、风力、火灾等各种原因产生的枯、倒树木进入沟道、河流形成丰富的漂木，漂木是山地生态系统的重要组成。漂木既有重要的生态环境效应，也会产生严重的灾害效应，当山洪、泥石流携带漂木向下游运动时，会造成沟道桥涵堵塞，造成洪水泛滥；堵塞坝体，造成泥沙堆积；冲击建构筑物，造成严重破坏等。因此，对漂木灾害进行防治是山地灾害减灾的重要内容之一。 鱼脊型水石分离系统作为一种新型泥石流减灾结构，利用重力作用将泥石流中的较大砾石分离出来，同时也可将漂木分离出来，用于漂木灾害减灾。本文首先根据该系统的特点及漂木的危害性，确定了针对漂木的减灾策略，即“防堵增排、水木分离”；通过实验验证了该系统在合理的优化设计条件下能对漂木起到良好的减灾效果；并从结构本身及减灾对象两方面考虑，探讨了影响减灾效果的主要因素；最后提出了基于漂木减灾效果的结构参数优化设计原则。通过以上研究，取得了如下研究成果： 1、漂木易在引流坝前堆积，堵塞引流口，影响减灾效果。通过模型实验和现场考察，确定了漂木在引流坝前的堵塞堆积形态，主要呈三种：引流口搭桥型、交错咬合型、坝前停积型，其中，以引流口搭桥型堵塞最为普遍。 2、通过模型实验，确定了漂木在坝前堆积堵塞与漂木长度L和引流口宽度b之间的关系。漂木拦截率Pt随L/b的增大呈线性增大，而漂木堵塞率Pc在L/b<1时，变化不大，整体不超过5%，在坝口基本不堵塞；1 |
| 英文摘要 | In mountain areas with forest coverage, there are full of fallen and dead woods due to landslide, bank erosion, windthrow, fire and disease or human activity. When these fallen woods are brought into streams and channels, they will become driftwoods. Driftwood is benefit to aquatic creatures and has positive effects on river morphology and hydrology from ecological perspective. When they go to the passive effects, they could cause severe damage to bridges, culverts and artificial channels, etc. due to their clog and accumulation in piers, aggravating erosion around piers, blocking freeboard, rising back water pressure. Driftwoods transported by debris flow or flood could form temporary dams which will amplify the peak discharge when they break out. Driftwoods often deposit and capture extra sediments in dams of debris flow defense. These sediments will reduce the service life of dams. Hence, it is of great importance and necessity to develop effective measures to reduce driftwood disasters in mountain disaster mitigation. Herringbonewater-sediment separationsystem, a new measure against debris flow disaster, invented very recently, is still in developing and testing stage. Its water-sediment separation function has been verified to be effective for debris flow by a series of model experiments. Can it also be used in driftwood defense? In order to answer this question, firstly, a series experiments were carried out to test the driftwood mitigation effects, which should a positive results. Secondly, efforts were taken to find out factors which significantly influence the mitigation effect,both from the structure characteristics and driftwood properties. At last, an optimal design method of the main structural parameters were proposed based on the driftwood mitigation effect. According to these researchs, following results are taken out. 1.As driftwood transported to the check dam, it accumulated and clogged in front of the dam and open spaces such as spillway. There are three main regimes of accumulation and clogging in or next to spillway, which are spillway bridging, muti-debris interacting and dead-water area depositing respectively. Among the three, spillway bridging is the most comman type found in nature. 2. Model tests results show that driftwood accumulation in front of drain dyke or clog in spillway have great relation with the relative log length(L/b). Driftwood accumulation rate increase linearly with the increase of L/b,while driftwood clogging rate keeps lower than 5% when L/b<1 and presents a parabola trend with L/b increase when 1 |
| 语种 | 中文 |
| 公开日期 | 2015-02-26 |
| 源URL | [http://ir.imde.ac.cn/handle/131551/7829]  |
| 专题 | 成都山地灾害与环境研究所_山地灾害与地表过程重点实验室 |
| 推荐引用方式 GB/T 7714 | 谢湘平. 鱼脊型水石分离系统对漂木减灾效果的实验研究[D]. 北京. 中国科学院研究生院. 2014. |
入库方式： OAI收割
来源：成都山地灾害与环境研究所
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