Research On Monitoring And Investigation Of Typical Collapse And Landslide Disasters In The Three Gorges Reservoir Area Based On TLS

With the rapid development of infrastructure construction in China,the construction of large-scale projects will have a huge impact on the original natural ecological environment.Taking the Three Gorges Project as an example,the construction of the Three Gorges Dam brings a lot of environmental problems,such as collapses and landslides caused by the instability of mountains on both sides,rockfall caused by the collapse of dangerous rock mass and so on.The occurrence of these collapses and landslides will bring a huge threat to the safety of ships and people’s lives and property,and also affect the local production and life and economic development.Therefore,it is necessary to carry out efficient collapses and landslides monitoring in typical key areas prone to collapses and landslides,and take measures to prevent and reduce or eliminate the occurrence of disaster accidents.Terrestrial Laser Scanning(TLS)is a new measurement technology in the 21 st century.It can quickly acquire the three-dimensional information of the object without contact,and display it in the form of high-precision point cloud,which makes up for the shortcomings of low automation,low precision and low efficiency of traditional measurement equipment.In this paper,TLS technology is applied to the investigation and monitoring of the landslide disaster in the Three Gorges Reservoir area:(1)The basic ecological situation of the Three Gorges Reservoir area of the Yangtze River is introduced and the importance of investigation and monitoring of collapse and landslide disaster is expounded.In this paper,the research status of TLS technology and the progress of its application in collapse and landslide disaster investigation and monitoring are summarized.TLS technology can be applied to disaster monitoring and investigation,which has important research and practical significance for actual disaster prevention and control;(2)The general methods of collapse and landslide monitoring and investigation are summarized in this paper.At the same time,the principle of data acquisition and the methods in each processing flow using TLS technology are introduced in detail.TLS technology is used for deformation analysis,including single point and whole deformation analysis based on point cloud;(3)The semi-automatic information acquisition method of rock structural plane is studied in this paper,and the automatic extraction method of structural plane based on improved RANSAC is proposed.At the same time,the octree spatial index of point cloud is constructed,the sampling conditions of initial point set are added to extract structural plane,and the results are recombined.The normal vector information of structural plane is used to calculate the occurrence information of structural plane automatically and make statistics and drawing at the same time Make rose chart.The experimental results show that the method can automatically extract the feature of structural surface and calculate the occurrence information accurately;(4)The Visual Studio 2015 and C++/CLR.Net platform are used to develop a geological data interpretation and deformation monitoring system,programming to achieve multi-stage deformation analysis based on rock point cloud,semi-automatic and automatic extraction of structural plane,automatic calculation and statistics of occurrence;(5)The Wushan section of the Three Gorges Reservoir Area is taking as a typical research pilot area,multi-phase three-dimensional laser scanning is carried out to monitor and analyze the deformation of the dangerous rock body above the arrow hole,and the structural plane extraction and occurrence calculation and statistical work are carried out in the area of the lower dangerous rock mass falling zone.The analysis results show the feasibility of this scheme.