On The Deformation Mechanism And Support Measurement Of Suguping Fracturing Rock Mass

The rock and soil engineering are always confronted with the important research topics such as deformation phenomenon, mechanism of deformation, evolvement course, analysis of stability, evaluation of calamity of instability and rational surpport of slope. The Suguping fracturing crag is located on the left bank of Da-du river' narrow reach in Shen Xi-gou hydropower station reservoir area in Si Chuan province. If the crag is destroyed and loses stability, it will block the Da-du river and cause great trouble to the Cheng-Kun railway and upriver Zipinpu hydropower station as well as Shen Xi-gou hydropower station. The results, which are acquired from the research of Suguping crag deformation characteristics, are listed as follows:(1) Based on investigation and the geologic mechanics analysis principle of rock-soil engeering, the mode of destruction are established from the analysis of the characteristics and mechanism of deformation and the stability of Suguping crag are estimated. It is illuminated that the reason of deformation and destruction lies in the unloading-ripping going with creeping. It is demonstrated that the deformation is initiated by unloading along with down-cutting of the Da-du river, which leads to amostly vertically ripping of the upper bank rock layer and sheering of the ratherish inclining-outside terrane because of the gravity and exterior casual loads.(2) A rheological mechanics model has been set up based on the mode of destruction of the crag and rheology analysis principle, which can be used to predict instability time for the crag body. Finally, the instability time, which is calculated by the rear crack width and the depth of down-cutting of the Da-du river as well as the prophase creeping velocity, is 6.70×10~5 years.(3) Through comparing the numeric results worked out by GEO-SLOPE software simulating the crag with the theoretical analysis results, it is indicated that the theoretical fracturing area is almost accordant to the actual region and the deformation and fracture of the slope are dominated by the inside structure faces.(4) Based on the scale and mechanism of deformation and the result of the support-scheme argumentation, it is a technically dependable and economically reasonable treatment scheme to adopt prestressed anchors.(5) Finally, according to the previous research fruits and the elasticity theory, the author brings up calculating formulae of the length of anchor segment, optimizing anchor-angle, anchor-space between and the length of freedom segment, by which the problems of Suguping crag were solved successfully.