题名泥石流起动中孔隙压力机理
作者杨志全
学位类别博士
答辩日期2013
授予单位中国科学院研究生院
授予地点北京
导师D.H.Steve Zo(邹代华) ; 孔纪名
关键词孔隙气压力 孔隙压力 土体初始含水量 泥石流孔隙压力起动机理 泥石流起动时间模型
其他题名The pore pressure mechanism of motivating debris flow
学位专业岩土工程
中文摘要国内外学者对泥石流起动机理方面开展了大量的研究,并取得了丰富的研究成果,但也存在一些重要的问题有待进一步研究与探讨,如,土体孔隙中的气体对泥石流起动的作用效果、土体初始含水量对泥石流起动影响等等。 本文通过文献评阅(300多篇国内外文献)、野外考察(10次都汶公路及2次中巴公路沿线泥石流灾害考查)、气象观测(野外实测泥石流起动降雨数据)、三维测量(野外测定泥石流特征参数)、水槽模型试验(34组)、原位试验(2组)、室内测试(测定土体物理力学性质)、统计计算与理论分析等研究方法,以汶川地震震中牛圈沟泥石流为研究对象,系统地探索了震后松散砾石土在人工降雨入渗条件下的失稳破坏并激发泥石流现象。 本文取得了以下创新性成果: (1)实施了降雨强度、坡度,土体初始含水量、颗粒级配、土体干密度5个单因素和多变量降雨入渗泥石流水槽模型试验和原位实验,证实了泥石流起动过程中孔隙压力由孔隙气压和孔隙水压构成,二者综合作用诱发泥石流; (2)试验分析了不同条件下泥石流起动过程中土体含水量及孔隙压力间的关系变化特征,提出了泥石流起动中孔隙水压与孔隙气压转化机制,探讨了泥石流起动中孔隙压力机理,在此基础上完善了震后砾石土泥石流起动机理; (3)建立了包括坡度、降雨强度、土体干密度、初始含水量及土体级配等因素的泥石流起动时间模型的数学表达式,结果符合统计意义。
英文摘要Although for past years great achievements have been made in close connection with mechanism of debris flow, there hitherto exist unknown fields which are giving rise to scientist’s attentions.These ongoing investigations in question are critical to debris flow science, ranging over a variety of topics, from the effects of air pressure in soil voidage on motivating debris flow, to the action of initial soil moisture on triggering debris flow. Author with his team have conducted a series of elaborate researches on the aforesaid issues. Research activities got thorough literature review (more than 300 documents), field trip to designated research sites (10 at Douwen Highway and 2 for KKH), meteorological observation (rainfall and wind strength, etc.), topography survey (debris flow property), flute model experiments (34 sets), situ experiments (2 sets), indoor soil testing (gravel soil physical property), statistical analysis and theoretical analysis and so on. All of these works is designed to examine the failure process of gravel soil slope under rainfall at post-shock places and the phenomenon of ensuing debris flow. The prevailing debris flow at Liujuan gulley, the epicenter of 2008 Wenchuan Earthquake, is regarded as representative case of this research. The following innovative achievements were obtained: (1) Situ experiments and flume model experiments including 5 sets of single factors, such as,rainfall intensity, slope, initial soil moisture, soil particle size distribution and soil dry density and multiple factors were carried out under rainfall infiltration conditions, therefore confirmed that pore pressure consists of pore air pressure and pore water pressure in the process of triggering debris flow; (2) Relationship variation characteristics of initial soil moisture and pore pressure under different conditions and conversion mechanisms between pore water pressure and pore air pressure in the process of initiating debris flow were analyzed respectively, and the pore pressure mechanism of motivating debris flow was proposed, thence the initiation mechanism of debris flow to gravel soil in the post-earthquake areas was perfected; (3) The start time model of debris flow was established ,which comprises rainfall intensity,slope, initial soil moisture, soil particle size distribution and soil dry density and conforms to the statistical significance.
语种中文
公开日期2014-08-25
内容类型学位论文
源URL[http://ir.imde.ac.cn/handle/131551/7132]  
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
杨志全. 泥石流起动中孔隙压力机理[D]. 北京. 中国科学院研究生院. 2013.
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