三峡库区宝塔滑坡泥化夹层泥化过程的水岩作用  

Water-rock interaction of clay gouged intercalation sludging process of baota landslides in Three Gorges reservoir area

作　　者：李守定[1] 李晓[1] 张年学[1] 刘艳辉[1] 

机构地区：[1]中国科学院工程地质力学重点实验室,北京100029

出　　处：《岩土力学》2006年第10期1841-1846,共6页Rock and Soil Mechanics

基　　金：国家973项目(No.2002CB412702);中科院知识创新重点方向项目(No.KJCX2-SW-L1-1);中科院工程地质力学重点实验室资助项目(04-6)。

摘　　要：宝塔滑坡群是三峡库区4个体积大于1亿m3的特大型滑坡之一,滑坡发育在侏罗系蓬莱镇组砂泥岩互层的地层中,其中泥化夹层比较发育,是致使滑坡发生的最重要的原因之一。基于地质分析,进行X射线衍射(XRD)试验、扫描电子显微镜和X射线能谱(SEM-EDX)试验、物理化学试验和地下水水质分析,对宝塔滑坡区泥化夹层及其原岩的组分和结构进行了对比分析,认为宝塔滑坡区泥化夹层形成的原因为:上硬下软的地层结构是物质基础;构造应力或重力是泥化夹层形成的必要条件;地下水的长期作用是泥岩泥化的主导因素。在此基础上,研究了宝塔滑坡泥岩泥化过程中的水岩相互作用。研究表明,地下水与泥岩的水化作用、离子交换作用、溶蚀作用相互促进,改变了泥岩的组构和性质,使泥岩泥化,转变为泥化夹层,从而解释了泥岩泥化的机理。Baota landslides are one of the four landslides whose volume is more than 1× 10^8 m^3 in Three Gorges reservoir area. Baota landslides are in the sandstone and mudstone alternate layers of Jurassic Penglaizhen formation. The clay gouged intercalation, existing much in Baota landslides, is one of the most important reasons of Baota landslides happened. On the basis of geology analysis, using X-ray diffraction （XRD） test, scanning electron microscopy and energy dispersive X-ray test（SEM-EDX）, physical chemistry test and underground water quality analysis test, the composition, the structure, the characters of clay gouged intercalation and its original rock are analyzed contrastively. The reasons of clay gouged intercalation establishment are concluded： the layer structure of sandstone and mudstone alternate layer is the basic reason; the tectonic stress or gravity is the necessary condition; and the long action of underground water is the main reason. The water-rock interaction of clay gouged intercalation establishment is studied on the basis of above conclusion. The study results indicate that hydration, ion exchange, corrosion between underground water and mudstone are promoting each other. These water-rock interactions change the structure, composition and characters of mudstone; then induce the mudstone sludging thoroughly. At last, mudstone is changed into the clay gouged intercalation. Thereby, the establishment mechanism of clay gouged intercalation in Baota landslides is interpreted.

关 键 词：宝塔滑坡群 泥化夹层 水岩作用 

分 类 号：TU443[建筑科学—岩土工程]