PHENOMENOLOGY RESEARCH ON DEFORMATION AND FAILURE MODES OF SLOPES COMPOSED OF ARGILLACEOUS LIMESTONE OF THE THIRD NUMBER OF BADONG GROUP (T2b3) IN NEW SITE OF FENGJIE COUNTY OF THREE GORGES RESERVOIR AREA
Abstract：Slopes in the new site of Fengjie County，Three Gorges Reservoir area，are the most concerned problems among prevention of geological hazards and protection of slopes，because of their occurrence mechanism of deformation and failure and special property of their deposits. The stratum of the argillaceous limestone of the third number of Badong Group (T2b3)，is one of the argumentative focuses among scientific and engineering domain. The following viewpoints on the occurrence mechanism of deformation and failure of argillaceous limestone are obtained with phenomenology research：(1) Property of argillaceous limestone is fragile and rock mass strength decreases and crisp structure are formed by infiltrative weathering；(2) Slope rock mass，by compression cracking and sliding along the steep and moderate steep plane，produces the gravitational bend phenomena of loose structure，one by one cascade，resulting in remarkable decrease of rock structural strength；(3) The deposit composed of argillaceous limestone is almost homogeneous，irregular arrangement，without uniform sliding belt. It is not deposit of landslide or rock mass falling，but the product of slope structural decomposition in certain range；(4) Deformation and failure process of argillaceous limestone are resulted from weakness of rock mechanical property caused by weathering and from loose structure caused by gravitational bend；and finally，the whole structure of rock mass is entirely collapsed.
