Research On Modeling And Application Of Tailings Reservoir Based On 3D Laser Scanning Technology

In recent years,accidents caused by tailing dams have occurred frequently,and the safety problems of tailing ponds become increasingly prominent.How to scientifically predict the damage scope of tailing dams is an important part of the risk analysis of tailing ponds.Using the numerical simulation,we can obtain the spatio-temporal patterns of the dam-breaking movement of the tailing reservoir,which is a significant method to determine the damage scope of the tailing dam.The two key preconditions for the numerical simulation of dam damage in the tailing reservoir are to accurately obtain the topographic data of tailings reservoir and to construct a geometric model which truly reflects the terrain relief conditions in the reservoir area.The traditional measurement method represented by the total stations not only consumes a lot of manpower and time,but also obtains very limited terrain information of the tailing database,which is impossible to achieve the refinement of the model construction.However,the ground 3D laser scanning technology can fast acquire the spatial information of the scanned objects and obtain the all-around terrain data point cloud of the tailings database.Moreover,it establishes a relatively realistic terrain model.This paper is based on the systematic analysis of terrestrial 3D laser scanning technology.It proposes an improved point cloud registration method,these technology and method were applied to the Sha Zi Ling tailing dam monitor.Which improves the precision of data registration and builds a DEM model of tailing library based on the scanned data in the study area.At the same time,the use of point cloud data in the tailing reservoir dam-break simulation improves the accuracy of the numerical calculation model for the dam breach in the tailing reservoir,and predicts the evolution of the tailing dam under real terrain conditions,reveals the temporal and spatial changes of the velocity and ground pressure of the dam-break sand flow law,it also provides guidance for disaster prevention and reduction of the tailing dam.The main results of this paper are as follows:1)The thesis summarizes the common methods of point cloud registration and proposes a way of basing local point cloud registration aiming at the problem of slow operation of computer in the process of regular point cloud registration.Through the precisely matching experiments of public areas,it is proved that the new method can eliminate a large number of non-correlated points,narrow the search scope of point cloud registration,and improve the accuracy of point cloud registration.2)The thesis obtains the topographic point cloud data of the study area by using the ground three-dimensional laser scanning technology.It constructs the high-precision digital elevation model of the sand tailing reservoir,plots the contours of the scan area,and calculates the volume of tailings accumulated downstream in the study zone,which provides the data base called "Health archives" for the numerical simulation of the tailing reservoir safety evaluation.3)This paper obtains the point cloud data of the study area based on the three-dimensional laser scanning,and compiles the log files that converted from point cloud data to the numerical calculation model,which can automatically construct the three-dimensional calculation model of the tailing dam of the study area by reading the prepared log files.Therefore,this study expands the scope of the application of laser scanning point clouds and improves the accuracy and efficiency of the construction of numerical models for dam-breaking dams.4)Based on the finite volume method,the evolution process of the tailings mortar along the downstream of the sand tailings reservoir dam is simulated by FLUENT software,besides the prediction of evolution process and impact range of the dam breaching mortar in the tailings dam,which reveals the velocity of the tailings mortar and the ground pressure changes.This study provides a basis for the preparation and quantitative assessment of the emergency plan for dam-break disasters in the Sha Zi Ling tailing dam.