Research Of Comprehensive Application Of Three-dimensional Image Technology In Geologic Engineering

At the rapid changes in technology today, the major method of geologic technology investigation is collecting field data through compass and tape measure, which is labor-consuming, low-efficiency and low-veracity of data. With high mountains and steep slopes, geologic survey is arduous and dangerous, during which, excavation, slag conveying and support are carried out simultaneously. Therefore, it is difficult for investigators to conduct a detailed field survey with plenty of time and a safe space. Besides, China is a country frequently and severely hit by geologic disasters. A prompt and accurate access to basic geologic information in geologic hazard spots can save time for rescue and relief work and prevention and control of geological disaster. All problems mentioned above pose challenges and requests to traditional geologic investigation methods.All of these need to introduce fast and efficient investigative techniques with high adaptability of topographic conditions in geologic field investigation.Three- dimensional image technology refers to three-dimensional data capturing objects in a fast and convenient way featuring long-distance, non-contact, high precision and high density, including three-dimensional laser scanning technique and digital photogrammetry. Even though Three-dimensional image technology can solve many difficulties in geologic engineering investigation, the application of this new technology is not flawless, requiring a lot of research and improvements.This thesis has started writing with the research of the comprehensive application of three-dimensional technology based on its features, mainly including the next parts:(1)The status quo of the application of three-dimensional laser scanning technique and digital photogrammetry was summarized respectively, its operational principle and technical features was elaborated; a fusion method of three-dimensional laser scanning technique and digital photogrammetry was proposed so as to fully learn from each other’s strong points and offset their weakness;(2)The thesis discussed the data acquisition procedure and data processing method of three-dimensional image technology, covering a large amount of summary and conclusion of the hands-on experience; elaborated the choice and optimized principle of scanning unit point, acquisition methods and notice of colored point cloud data, usage of point cloud data gray scale information, setting the relationship between sample interval and time based on scanning goals directing towards field data acquisition of three-dimensional scanning; during the analysis of data processing of three-dimensional scanning, discussed the registration of color information, conversion of axes frame and rejection of vegetation noise data; on account of digital photogrammetry, summarized and studied the method of data acquisition from the perspective of close-up photogrammetry and low-altitude drone photogrammetry, elaboration the experience and techniques of camera setting, photographing method, drone flying line planning;(3)The application of three-dimensional image technology in topographic survey was studied, the method of evacuation and extraction of mass point cloud data was analyzed, in light of the requirements of traditional measurement, the survey point spacing of point cloud data was discussed, and the graphing method of geographic mapping, match between contour line and landmark and image frame were elaborated, based on the processing of three-dimensional data, the building method of topographic three-dimensional model was studied;(4)The research of geologic logging method of rock mass structure based on three-dimensional technology was done. The method of three-dimensional point cloud data structural plane recognition was analyzed; on the premise of structural plane point cloud recognition, the extracting method of structural plane was discussed, the features of plane equation fitting rocky structural plane development was proposed, and according to different characteristics of structural plane exposure, responding extraction and research were carried out, calculation procedure derivation of plane fitting structural plane occurrence was done, and according to the practical engineering needs, the plug-in program of structural plane automatic recognition and occurrence calculation in Ployworks, a three-dimensional point cloud processing software, was developed. Besides, the rose diagram plug-in program in structural plane data generation making use of point cloud data recognition was developed;(5)The comprehensive application of three-dimensional technology in geologic engineering was elaborated, research included geological disaster survey, such as dangerous rock mass, landslide and debris flow, according to different disastrous features, the application situation and method of three-dimensional image technology as well as application of this technology in rock cavity and tunnel were discussed respectively; moreover, the application of this technology in digitized storage of drilling cores physical model was also discussed; the application of deformation monitoring based on three-dimensional laser scanning technology was explored.Through these research outcomes, three-dimensional image technology is proved to have high engineering adaptability. It is of great academic value and practical significance to integrate three-dimensional image technology with traditional investigative methods of geologic engineering, combine theory, technology and innovation with practice, methods and tradition respectively and conduct a comprehensive application research in geologic engineering measurement.