Three-dimensional Network Simulation And Application Of Rock Mass Discontinuities Supported By Point Cloud Data

The structural plane of rock mass plays a major controlling role in the rock mass,and the acquisition of structural plane information is the basis for studying engineering geological problems.In the traditional field survey of structural surfaces,when encountering high and steep slopes that cannot be reached by the surveyor,they can only abandon the measurement,or choose the structural surface at the bottom of the slope for measurement,but this will cause structural problems.The problem of incomplete surface information,which cannot fully reflect the overall distribution of the structural surface in the study area with the development of science and the continuous advancement of science and technology,the method of obtaining structural surface information is no longer limited to compasses and measuring tapes.Non-contact measurement methods such as threedimensional laser scanning(T.L.S),and drone tilt photography have a wide range of applications.The advantages of good safety and high efficiency are widely used in today's geological surveys.Non-contact measurement can also effectively overcome the measurement difficulties caused by the harsh natural conditions of the project area.Because only a small part of the structural planes developed in the rock mass can be directly observed,it is difficult for people to correctly understand the overall threedimensional distribution of the structural planes in the rock mass.Using statistical principles to perform statistical analysis on various geometric feature parameters of structural planes,combined with Monte Carlo stochastic simulation method to generate a three-dimensional network model of structural planes on a computer,it can help people intuitively understand the distribution law of internal structural planes of rock masses,and make a reasonable evaluation of the stability and integrity of the rock mass.This paper uses a variety of measurement methods to obtain structural plane information,establishes a three-dimensional network model of the structural plane,and optimizes the model.The main research work is as follows:1.Process and transform the 3D laser scanning point cloud data and UAV tilt photogrammetry data and generate high-precision models.2.Use a variety of measurement methods to obtain various geometric characteristic parameters of rock mass structural planes.Through indoor data collection and on-site surveys,it was decided to use a combination of manual and non-contact measurements to investigate the slopes of the study area.First,the measurement method is used to manually obtain the structural surface information at the bottom of the slope;secondly,the highprecision DEM model is used to solve the structural surface occurrence at the height of the slope through a geometric algorithm;Finally,Split-FX used to automatically identify structural planes in the slope point cloud model and calculate their occurrence information.3.The statistical analysis obtains the probability distribution function of the geometric characteristic parameters of the structural plane,and builds a three-dimensional network model of the random structural plane based on this.In view of the poor reduction of joint distribution in the purely random structural plane network model,the deterministic structural plane obtained from the point cloud data is combined with the random structural plane to improve the rationality of the structural plane network model.4.Use the vector method in the block theory to determine the key blocks and stability of the slope rock mass,search for the key blocks that may be instability and damage on the free surface of the slope,and calculate the safety factors one by one to determine the stability of the key blocks.The method in this paper effectively improves the safety and work efficiency in the structural plane information survey,optimizes the random structural plane threedimensional network model,and combines the structural plane network simulation with the block theory to realize the rapid evaluation and evaluation of the dangerous slope rock mass.The identification of the dangerous area on the empty surface of the slope also provides a basis for the treatment of the dangerous rock mass of the slope.