Stability Analysis And Risk Assessment Of Dangerous Rock Mass In Danxia Mountain Scenic Area

Danxia Mountain is the world's geological park and the world's Danxia landform.At the 34 th World Heritage Conference in 2010,Danxia Mountain was officially listed as one of the Danxia landforms in the World Natural Heritage List,filling the blank of natural heritage types.Danxia Mountain is a representative area in the evolution of modern Danxia landforms,with extraordinary geology,teaching and research,aesthetics,ecology and cultural value.However,due to the influence of tectonic movement,stratum lithology,hydrological conditions and man-made transformation,the scenic area has more development of dangerous rock masses,which poses a great threat to tourists' safety and landscape.It is urgent to stabilize the dangerous rock in the scenic area.Risk analysis.Based on this,this paper takes the dangerous rock mass in Danxia Mountain Scenic Area as the research object,studies the development characteristics of dangerous rock mass in Danxia Mountain Scenic Area,and selects the appropriate mechanical parameters and calculation methods to analyze the stability of dangerous rock mass and establish it for Danxia Mountain.The risk assessment system of the scenic spot evaluates the risk of dangerous rock in the scenic spot,and studies the characteristics of the risk zoning.Based on the results of stability and risk assessment,the recommendations for the management of dangerous rock mass in Danxia Mountain Scenic Spot are formulated.The conclusions are as follows:(1)In the dangerous rocks of Danxia Mountain Scenic Area,the massive rock mass and thin slab rock mass are the main types of dangerous rock development;the development scale of dangerous rock is mainly large and medium-sized dangerous rock;the dangerous rock joint is in the middle of the trend,and the strike is at 330°~ The joints of 339° are the most developed,which play an important role in the formation of dangerous rock masses.The failure modes of the three groups of dangerous rocks in the study area are all developed.The most important forms of failure are falling and dumping;the dangerous rock mass is mainly affected by steep and inclined joints.Cutting,differential weathering,unloading,and gravity effects,individual dangerous rock masses are affected by running water.(2)The basic quality grade of rock mass in the study area belongs to Class III,the internal friction angle is 39°,the cohesion is 0.7MPa;the structural surface is 4,the internal friction angle is 13°,and the cohesion is 0.05 MPa.(3)Through the stability calculation and analysis,the stability state obtained is basically consistent with the state of the dangerous rock mass on site.Under heavy rain and earthquake conditions,the stability of dangerous rock mass is obviously deteriorated,and the heavy rain conditions have a great impact on the stability of dangerous rock mass.(4)Through the dangerous rock calculation,in the dangerous rock of Danxia Mountain Scenic Area,the risk is 30 grade I,accounting for 73.2%.There are 11 grade II dangerous rocks,accounting for 26.8%,and there is no dangerous dangerous rock of grade III;the risk of Danxia Mountain Scenic Area is relatively high.It is the risk of the Changlao Peak Scenic Area,the Bazhai Scenic Area,the Yangyuan Mountain Scenic Area,the Niu Nao Village Area and the Wollongong District.Larger,less overall risk,Xianglong Lake scenic area is the least dangerous.