极端降雨条件下红壤土滑坡的灾变规律及机理研究

发布时间：2018-11-24 21:27

【摘要】：鄱阳湖生态经济区位于中国南方红壤区,广泛分布着以网纹红土为主的红壤土层,降雨时间长、强度大、降雨诱发的滑坡、崩塌等地质灾害频发于红壤土分布区,严重影响生态建设进程。本文以鄱阳湖生态经济区内红壤土为研究对象,通过对研究区地质灾害及相关资料的分析,得到了研究区的地质环境,气象水文及地质灾害特征,并通过野外地质调查、理论研究和试验,掌握红壤土坡体的工程力学性质、水理性质等基本物理性质;在此基础上通过讨论分析了极端降雨条件下滑坡灾变的规律特征。结合室内试验及相关数据资料统计分析,探讨了极端降雨引发滑坡的破坏机理。(1)对研究区的区域地质构造环境进行论述,并重点对研究区降雨特征、研究区滑坡发生特征及红壤土特性进行阐述。(2)揭示了鄱阳湖生态经济区极端降雨时间分布特征。年际分布上平均1.29次/年,单次持续多为3~12天,最多持续29天;月份上主要发生于每年4~8月,主要是由于梅雨准静止锋导致的长时间持续降雨及台风导致的短时强降雨,前者在时间上集中于6月中下旬和7月上旬,后者主要发生于8月份。(3)揭示了鄱阳湖生态经济区极端降雨空间分布特征。在空间分布上,江西省的4个多雨中心分布于研究区边缘,直接影响研究区内的极端降雨分布,总体为东南部极端降水偏多、西北部偏少;鄱阳湖盆地区偏少,周边丘陵区和庐山山区偏多的形式。研究区极端降雨中心主要有鹰潭—乐平、庐山山区2个区域。(4)对极端降雨与滑坡的时空分布相关性进行分析研究。从研究区的极端降雨时空规律出发,将极端降雨的年、月、日时间分布规律和滑坡发生规律进行对比分析;将研究区年降雨总量、极端降雨日均雨量、暴雨和大暴雨天数、持续暴雨、大暴雨天数空间分布及其他相关因子与研究区滑坡空间位置分布进行对比分析。得出研究区极端降雨条件下红壤土斜坡灾变的规律特征。(5)对极端降雨情况下红壤土滑坡的发生机理进行分析。分别从红壤土滑坡发生的基本条件、降雨对滑坡的力学机制、孔隙水压力的作用机制和降雨对坡面冲刷机制这几个方面进行理论分析。
[Abstract]:The Poyang Lake Ecological Economic Zone is located in the red soil region of southern China. It is widely distributed in the red soil layer dominated by reticulated red soil. The rainfall time is long, the intensity is high, the landslide induced by rainfall, the collapse and other geological disasters frequently occur in the distribution area of Yu Hong loam. Seriously affect the progress of ecological construction. Taking red loam soil in Poyang Lake Ecological Economic Zone as the research object, the geological environment, meteorology, hydrology and geological hazard characteristics of the study area are obtained through the analysis of geological hazards and related data in the study area, and the field geological survey is carried out. The basic physical properties of the red soil slope body, such as engineering mechanics, hydrological properties and so on, are studied and tested in theory. On this basis, the characteristics of landslide catastrophe under extreme rainfall are discussed and analyzed. Combined with indoor test and statistical analysis of relevant data, the failure mechanism of landslide caused by extreme rainfall is discussed. (1) the regional geological tectonic environment of the study area is discussed, and the rainfall characteristics of the study area are emphasized. The characteristics of landslide occurrence and red loam were discussed. (2) the characteristics of extreme rainfall time distribution in Poyang Lake Ecological Economic Zone were revealed. The average annual distribution was 1.29 times / year, and the duration of the single time was 3 ~ 12 days, and the maximum duration was 29 days. Months mainly occur in April to August of each year, mainly due to the long and sustained rainfall caused by the Meiyu quasi stationary front and the short time strong rainfall caused by typhoon. The former is concentrated in the middle and late June and the first ten days of July. The latter occurred mainly in August. (3) the spatial distribution of extreme rainfall in Poyang Lake Ecological Economic Zone was revealed. In spatial distribution, the four rainy centers in Jiangxi Province are located at the edge of the study area, which directly affect the distribution of extreme rainfall in the study area, generally speaking, the extreme precipitation is more in the southeast and less in the northwest. Poyang Lake basin area is less, the surrounding hilly area and Lushan mountain area more form. There are two regions in the study area: Yingtan Leping and Lushan Mountain. (4) the correlation between extreme rainfall and landslide distribution is analyzed. Based on the spatio-temporal law of extreme rainfall in the study area, the distribution of the year, month and day of extreme rainfall and the law of landslide occurrence are compared and analyzed. The total annual rainfall, the daily average rainfall of extreme rainfall, the days of heavy rain and heavy rain, the spatial distribution of continuous rainstorm, the days of heavy rain and other related factors were compared with the spatial distribution of landslide in the study area. The characteristics of slope cataclysm of red loam under extreme rainfall in the study area were obtained. (5) the occurrence mechanism of red soil landslide under extreme rainfall was analyzed. The basic conditions for the occurrence of red loam landslide, the mechanics mechanism of rainfall on landslide, the action mechanism of pore water pressure and the mechanism of rainfall erosion on slope are analyzed theoretically.
【学位授予单位】：东华理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P642.22

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