Kinematics Simulation And Optimal Design Of Prevention And Control Of Dangerous Rock Mass On High And Steep Slope

Coal mining activities in northern Shaanxi are frequent and continuous,which can easily cause a series of geological disasters.The high and steep excavation slopes created during the construction of the coal mine industry site are likely to cause hidden dangers of the collapse of dangerous rock masses,which pose a great threat to the buildings,equipment,personnel and vehicles on the site.Information such as geometric dimensions,structural planes,and fracture planes of dangerous rock masses is critical to the stability evaluation of dangerous rock masses.The traditional way of obtaining the above-mentioned information is mainly relying on on-site human climbing measurement,which has limitations such as lower efficiency,more dangerous,and larger errors.With the popularity of consumer drones and the simplification of oblique aerial photogrammetry and digital image processing technology,their combination has the advantages of higher efficiency,higher accuracy,simpler operation,and easier data processing,so it has greater advantages in the investigation of dangerous rock masses and the acquisition of important information.This paper is based on drone oblique aerial photogrammetry and image processing technology,combined with on-site investigation,the main tasks completed are as follows:(1)Using drone oblique aerial photogrammetry technology and digital image processing technology,the point cloud,digital elevation model,and digital orthophoto of the study area were obtained,and data such as the geometric size of the target dangerous rock mass and the length and width of the crack were extracted.On the basis of verifying the reliability of the structural plane data of the dangerous rock mass extracted from the point cloud,the main control structural plane parameters of the dangerous rock mass are obtained.(2)The field survey combined with the digital elevation model determined and summarized the distribution characteristics and laws of 66 dangerous rock masses in the study area,and analyzed the factors affecting the stability of the dangerous rock masses from both internal and external factors.(3)According to the different stages of stress and deformation and displacement characteristics of dangerous rocks when they are affected by the environment,the dangerous rock masses are divided into three main evolution stages,and they are divided into three categories according to different instability models.(4)The stability of 66 dangerous rock masses in the study area was evaluated based on the cutting relationship of rock mass discontinuities.Based on the rigid body limit equilibrium calculation,the stability quantitative evaluation of natural,heavy rain,and earthquake conditions is carried out.(5)RocPro3 D and ROCFALL are used to simulate the kinematics of dangerous rock masses from three-dimensional and two-dimensional levels,respectively.The data of movement trajectory,bounce height,movement kinetic energy,movement speed and falling point can provide data basis for the prevention and control design of dangerous rock mass in the study area.(6)Using ROCFALL,a single-stage slope is taken as an example to discuss the influence of different parameters on the law of rockfall movement.The influence of step setting,slope parameters,and protection setting on the law of rockfall movement is studied.The slope optimization design of "no steps on the slope body + re-greening of the surface of the slope +passive protection net at the foot of the slope" is given.