EXTRACTION OF GROUND FISSURE MONITORING OBJECT BASED ON POINT CLOUD DATA-A CASE STUDY OF GUANGMING VILLAGE, WUXI, JIANGSU PROVINCE

Using 3D laser scanning technology in Wuxi Guangming Village, obtained the point cloud data and build a model. We used geomagic distinguish the characteristics of groung fissure, then evaluated itself and its influence on the surrounding construction. Using statistical principle and numerical calculation, we adopted the method of selecting feature points and feature lines to obtain ground fissure's tendency, direction, length, depth and dispersion. In addiction, we studied the influence of the number of feature points on the accuracy of the result. Besides, using the eigenvector of the fitting plane, obtained the tilt degree of the wall caused by the ground fissure through geometric transformation and calculation. Finally we obtianed qualitative and quantitative analysis of the effects of ground fissure. Through the analysis of the characteristics of the ground cracks and the influence of the surrounding walls, we can offer renovation suggestiond on this fissure, guide analysis of subsequent geological conditions. We can also provide a method of using geomagic to get the feature information of the monitored objects.