Structural Characteristics Of Foundation Rock And Rock Mass Quality Evaluation Of Rumei Hydropower Station On The Left Bank Abutment

Proposed Rumei hydropower station dam is as high as 315 m,is one of our country and even the world's highest earth-rock dams.Rumei hydropower station is located in the upper reaches of lancang river in Tibet mangkang county,river valley as the high and steep valley "V" shape.Reservoir structural plane is very development,rock mass structure is very complicated.So you need to find out the abutment rock mass structure characteristic,to build the dam rock mass structural plane grading system,the structure of rock mass classification system,find out different types of rock structure face orientation,the morphological characteristics,reasonable division of rock mass quality classification,extraction and structure of the physical and mechanical parameters of rock mass,the right to choose for the dam foundation surface and provide geological basis for high slope stability evaluation.In this paper,on the basis of engineering geological conditions,Rumei hydropower station set up such as the dam rock mass weathering quantitative indicators of classification of unloading zones.In the quantitative analysis of the characteristic of rock mass weathering,puts forward the structure surface weathering index rebound RHI this new indicators to zoning characteristics of rock mass weathering.Based on field investigation,this paper puts forward that the left dam abutment rock mass unloading mode in five categories: pour the fault type and steep slow crack sliding,cracking,long slow slip crack control cracking,steep dip crack control dumping,cracking,flat fracture control of slip,cracking and pressure to cracking.According to the characteristics of the weathering of the rock mass unloading rock mass is mainly divided into strong unloading,the weak unloading,weak,weak under weathering,micro five points such as the new rock belt.According to field investigation and collected information on the left bank ?and ? structure the development characteristics are analyzed,found on the left bank more yokogawa grew up to the fault or fracture development,one of the largest L72,? level of structural plane,on the left bank of the dam,is the controlling fault.Based on the results of adit for dam site zone ? level has carried on the detailed analysis of structural plane developmental characteristics;Using the RBI(index of rock mass)and RSI(index of rock mass structure),and other indicators of tunnel rock mass structure characteristic has carried on the quantitative analysis and comparison,found the RSI indicators can better reflect Rumei of the rock mass structure characteristics.In a large number of indoor and field in-situ shear test,on the basis of the different characteristics of structural plane and the weathering unloading rock mass shear strength parameters for the research value,set up with all kinds of structural plane and rock mass mechanics parameters.Combined with the field of the test section of rock mass structure and springback test results,establish corresponding relations between characteristic parameters and mechanical parameters of rock mass structure.Using the qualitative grading,BQ classification and grade of RMR and Q classifying method to evaluate rock mass quality,and according to the site as the working condition,the method of classification is improved,found after comprehensive classification rock mass quality classification in dam foundation is given priority to with ?,? rock mass,the BQ classification result result the most optimistic,RMRclassification result next and Q classification result most conservative;? level,mainly in strong unloading zones,the weak rock mass unloading zone,fracture zones for the development of intensive and extrusion disturbed belt,? level,mainly in weak rock mass weathering,not on the unloading zones,the weak,not new in the rock mass unloading and micro,and combined with indoor and field test results recommendations and mechanical parameters of rock mass at all levels.As a scientific research project "Lancang river such as hydropower complex geological environment of rock mass engineering properties and the application research on corpus four-dam foundation rock mass engineering characteristics and application research on" part of this thesis at the completion of the work,on the basis of the combination of high rockfill dam requirement for dam foundation rock mass of dam foundation rock mass availability evaluation of foundation surface for the left side of the selection Suggestions are put forward.