Application Of Ground 3D Laser Scanner In Building Inspection

As a new detection method in the surveying and mapping industry,the ground 3D laser scanning technology is a new generation of revolutionary innovation after the GPS system in the surveying and mapping field.Its technical advantages are reflected in the following aspects: the operation is simple,and the technology can greatly reduce the workload of field personnel;The information of buildings obtained by point clouds is relatively complete,and the data splicing between stations can be realized by placing target ball and pasting target paper,so as to obtain the complete information of large buildings.Because the ground 3D laser scanning has no contact with the measured object throughout the measurement process,it ensures the protection of the measured object and the personal safety of the surveyor.Meanwhile,its non-contact also enables it to obtain building information far away from dangerous objects and complex environment.Based on the above characteristics,the application of the ground 3D laser scanning technology to the traditional building detection field has a high development potential.The detection of cultural relics and ancient buildings has always been a difficult field in the detection industry with higher requirements for detection technology.Due to the non-destructiveness of cultural relics and ancient buildings,most cultural relics and ancient buildings are mainly focused on the relatively superficial detection items such as the verticality of buildings and the damage of exterior decoration,and the traditional detection means are usually unable to measure the structural bearing capacity of cultural relics and ancient buildings.Most of the ancient buildings are very old,so it is very necessary to detect the safety and carrying capacity of the historical relics and ancient buildings.Based on the characteristic of ground 3D laser scanning technology,its application in building detection field is inquired through point cloud processing technology,reverse modeling technology and MATLAB programming technique,etc.in combination with the current situation of the current detection industry.Research work is mainly divided into three points:(1)Application of ground 3D laser scanning technology in wall verticality detectionThe verticality detection of ground 3D laser scanning technology is researched and the vulnerable link of ground 3D laser scanning technology is combined to inquire a kind of method through which the fitting error of point cloud density to point cloud data can be reduced to some extent--point cloud skeleton method.Such method is applied to verticality detection of building facade,and its feasibility and innovation are inquired through instance.Such method provides a new way for facade verticality detection through ground 3D laser scanning technology.(2)Research on overall gradient detection of ground 3D laser scanning technologyOn the basis of point cloud skeleton method inquired in the above,the fitting method of existing ground 3D laser scanning technology in overall gradient of building is combined to inquire a kind of new fitting method of overall gradient of building.Such method simplifies point cloud data through fitting of the point cloud skeleton,and finally calculates the overall gradient of buildings through fitting of building centroid line.Taking the library in Daxing Campus of Beijing University of Civil Engineering and Architecture as an example,such method is used to calculate the overall gradient of such building.The calculation results show that such method can obtain the gradient condition of building simply and effectively,with very high practicality.(3)Research on cultural relic building protection through ground 3D laser scanningMost of ancient buildings were built a long time ago and their building materials and construction information are difficult to be obtained.Therefore,the detection of bearing ability and security performance of ancient buildings can provide a powerful basis for the overhaul reinforcement of ancient buildings and the protection of cultural relic.In view of the globality and non-contact of ground 3D laser scanning,the bearing ability of the Seventeen Hole Bridge in Summer Palace is analyzed through reverse modeling,finite element analysis,etc.The calculation results show that such cultural relic buildings are safe in bearing ability.The suggestions about overhaul and reinforcement of structure are offered.