【作者】 沈娜；

【导师】 唐川； 许强；

【作者基本信息】 成都理工大学 ， 地质工程， 2008， 硕士

【摘要】 泥石流是一种暴发突然、危害严重的地质灾害。随着人类社会经济活动的不断增强,人们对自然资源的过度索取和对环境的持续破坏,使得泥石流灾害更趋严重。因此必须加强对泥石流灾害的调查、研究和防治,组织实施经济有效的减灾措施,从而尽可能地防范泥石流灾害的发生,尽量减轻灾害损失。本文的研究对象石头沟位于四川省九龙县,在2007年5月24日以前未曾暴发过泥石流,5月24日暴发的泥石流造成直接经济损失达300多万元,目前仍有600余人受到泥石流不同程度的威胁。本文从石头沟的流域背景和沟谷特征入手,分析了石头沟泥石流的三个形成条件,并按照地形与物源特征把石头沟流域划分为四个区域:清水区、形成区、流通区和堆积区。在此基础上,计算分析石头沟泥石流的容重、流速、流量、冲击力等运动特征。我们得出石头沟是一个典型的低频稀性沟谷型泥石流沟,2007年5月24日暴发的泥石流频率为50年一遇,重度为1.65g/cm~3,最大流量为143.42m~3/s,整体冲压力为93.05kP,最大单体石块冲击力达48.79×10~4N,破坏力大,严重威胁下游居民和建筑物的安全,采取治理措施是非常必要的。本文在分析计算石头沟泥石流运动特征的基础上,结合其形成条件和危害对象的特点,综合了预防措施、防治工程措施和农田措施,按照“综合分析,合理划分,安全经济”原则,针对石头沟这类低频稀性泥石流提出了乡镇泥石流防治模式,并对石头沟泥石流防治工程措施进行了进一步研究,即:在物源相对较多较集中的支沟牛场小沟内修建一座重力拦挡坝、在石头沟主沟修建一座格栅坝和一座重力拦挡坝,拦蓄泥砂,调节规模;从石头沟出山口处修建排导槽,顺畅排出泥石流;再配合适当谷坊群和潜坝,稳沟固床,减小冲刷,抑制泥石流发育,从而达到保护石头沟堆积区上的居民、建筑物和农田的减灾目的。更多还原

【Abstract】 Debris flow is a geo-hazard which outbreaks abruptly and causes a severe consequence. Along with development of human society, the debris flow disasters become more severe because of peope’s over obtainment of natural resource and constante destruction of the environment. Thus, in order to diminish the occurrence probability of disasters and weaken the loss of it, the investigation and assessment should be strengthen and prevention meansures should be taken.The study area of the Shitou gully is situated in the southwestern part of Jiulong country, Sichuan Province. The disaster occurred on 24^th May in 2007 and caused a directly economic loss of three million Yuan. In this thesis, we investagte the geological and geomorphologic settings and formation conditions of the debris flow by field investigation, study on the properties and dynamic characters of the debris flow, then propose the prevention measures. Firstly, analyze the various factors of Shitou Galley by studying the drainage background and its characteristics, divide the drainage area into four zones: the watering zone, the forming zone, the flowing zone and the deposition zone according to its loose material origin and terrain. Secondly, calculate the density, velocity, discharge and impulsive force of the debris flow, the result is that: Shitou gully is a very typical turbulent, site-specific debris flow at a low frequency. The dencity of the debris flow occurring on 24 May, 2007 is 1.65g/cm³, its frequency is about 50years once, its peak discharge is 143.42m³ /s, the whole impulsive force is 93.05kP, the peak individual rock impulsive force is 48.79×10⁴N. All the parameters show that the destructive power of the debris flow is very large, the people and buildings on the alluvial fan are seriously threatened. It’s necessary to take prevention meansures.Based on the formation conditions, dynamic characteristics, debris flow scale at different frequency and the damaged objects, aiming at the type of turbulent and low frequency debris flow such as Shitou gully, considering preventive measures, civil control measures and farmland measures, this thesis propose a mode of township debris flow control in accordence with the principle of "comprehensive analysis, rational classification, safety and economic". A further study on civil control measures was taken: construct a gravity dam in Niuchangxiao Gully; construct a railing dam and a gravity dam in Shitou gully to barrier the debris flow and regulate its scale; build a drainage channel from the top of the alluvial fan to the Jiulong River to excretion the debris flow; construct check dams and phreatic dams to improve the stability of gully bed, reduce erosion and control the debris flow, therefore the people and structures on the alluvial fan can be protected.更多还原