Main Mechanism And Fatalness Evaluation Of Rockfall In Juma River Region, The North Of Taihang Mountain

Based on the separate research on collapses in Bailixia, Junma river region and the basis of the theory of collapses hazard evaluation, according to joints observing, layout, identifying and measure in our field work, analyzing of the remote sensing image (1:150000) of zone of tectonic fracture and fixed amount evaluating by stereographic, the conclusions are following:1) We summarized four types of the Engineering Geology Mode, three types of them are found in this area, such as dumpage landslide, slippage landslide, ripping landslide. Moreover, based on high frequency of joints, gravitation and rock-fall are separated into three types, such as dumpage rock-fall and falling rock-fall. The qualitative and quantitative study conduces to quantitative arbitrate dangerous degree of the geological hazard and put forward prevent the geological hazard and evade the substance of hazard.2) The author first finds that four episodes conjugated shear joints cut Mesoproterozoic Wumishan Formation and cover layer of Cambrian strata. The author distinguish and confirm that the conjugated shear joints show four tectonic cycles, such as: Indosinia, Early Yanshan, Late Yanshan and Himalaya by stereographic.3) The author summed Himalaya in NW, NEE trending and Early Yanshan in NE, EW trending by the control joints development and collapses. The tectonic belt of Early Yanshan NE, EW trending, in the two valleys of Haitangyu and Shiquanxia, Bailixia area, controlled the fracture distribution, trending and joints development. However, the joints of Himalaya in NW, NEE trending, only controlled the Xiezigou, Bailixia valley.4) We provide the evaluation value table of the collapses hazard and the hazard evaluation graphic. However, the result mentioned above makes a rationalization prevention and pertinence cure of collapses. Meanwhile, the result need put into practice.