| Perilous rock formation process of gradualness, instability with sudden onset of.Perilous rock instability with powerful impact and damage, which serious threat toconstruction workers in the engineering construction and buildings. Effectively tocombat the Perilous rock, based on a reasonable evaluation of its stability. Butdeficiencies in a variety of dangerous rock mass stability analysis method: qualitativeanalysis method that empirically strong and quantitative calculation of the requiredboundary surface parameters such as the size and structure is more difficult toaccurately obtain, which Lead between evaluation findings and reality have somedeviation. Therefore need to seek an evaluation method to make evaluation easier toobtain, evaluation results more reasonable methods.In this paper, the following Southwest proposed hydropower selected for thestudy: Dagu and Jiexu hydropower of the Yarlung Zangbo River, Danba hydropowerof the Dadu River, Kala and Yang fang-gou hydropower of the Yalong River. Througha more comprehensive geological survey and detailed interpret with hree-dimensionallaser scanning, Summarize the main factors controlling the development of the studyarea perilous rock is topography, lithology, structural features and rock weatheringand unloading, base on fully mastered the development environment,distribution,structural characteristics and morphology, and other basic information of perilous rockin study area. The statistics and analysis show: different factors and theircombinations, ease of perilous rocks are quite different and perilous rock formationdevelopment density, size, type, and so on. Meanwhile, in the collection and analysisof data on the basis of previous studies, for the study area characterized by perilousrock. Respectively, from the dangerous rock size, and developmental characteristics ofinstability way to start, Established unstable rock classification system which can easyto analyze deformation and failure mechanisms in the scene. And in-depth analysis ofthe different types of dangerous rock deformation mechanism of instability: in Slidingunstable rock, adherent type and form of wedge are slip crack-compression and shearslip, Block type is mainly slip–cut. In Dumping unstable rock, Cantilever is crack–dumping, Hung upside down type of compression-crack–dumping,. Unstable rock fall mainly to the fall cavity, which mechanical mechanism to crack–cut.On this basis. first, analyzes the factors affecting the stability of unstable rock.The results showed that terrain features, structural features rock, rock strength,weathering and unloading as well as rain and vibration control of the key factors inthe development of dangerous rock deformation and failure, which played a crucialrole in the stability. Different factors and combinations influence the stability ofdifferent types (buckling mode) of unstable rock, which lead differences in thestability of unstable rock. Accordingly, Starting from the instability of the way, takinginto account the of main factors unstable rock stability, making unstable rock intopoor, more poor and worst three levels. Establishing qualitative evaluation criteria f aperilous rock stability. Secondly, the use of Interaction Matrix analysis of the stabilityof the interaction between the factors and the degree of influence on the stability ofunstable rock. The degree of influence were F5(weathered rock), F6(rock unloading),F1(structural surface features), F4(rock strength), F3(rock strength), F2(topographic features). And calculate the activity index K（F1,F2,F3,F4,F5,F6）=（16.67,12.50,14.17,15.83,20.83,20.00）. Finally, depending on the characteristics ofunstable rock instability ways, evaluation indicators status classification and establishthe value of the standard. According to the formula calculated dangerous rockinstability index to distinguish dangerous rock level. And evaluation methods used inunstable rock dam on the left bank of Yang Fang-gou Hydropower Station: hroughqualitative evaluation57dangerous rock stability, and comparative with the instabilityindex based on the calculated level of classification stable. The results show that，Thecalculated result of unstable rock instability index for the degree of classification ofdangerous rock steady which coincide with the result of qualitative analysis.Description using the calculated index value divided by dangerous rocks unstableunstable rock stability level approach is reasonable, the evaluation method has strongapplicability. |
