Application of 3D Laser Scanning Technology in Large-Scale Soccer Field Engineering

In recent years, with the rapid development of science and technology, engineering survey technology is also constantly innovation, from the original theodolite, total station to GPS and now the 3D laser scanning technology, for the construction industry has made an important contribution to the leap-forward development. The application of 3D laser scanning technology in engineering has solved the problems of low measuring efficiency and large construction deviation caused by backward technology or equipment. The roof steel truss and cable-membrane structure used in the Kunshan Football Stadium project is faced with a series of construction problems, such as complex shape, long span, difficult assembly, high machining precision and complex construction technology. In order to solve the project construction problems, in this paper, the difficulties of field assembling precision control, precise positioning control of hoisting, deformation control of steel truss, forming quality control of K-type concrete column and shape control of membrane structure in the process of construction of football field are fully studied. The advantages of 3D laser scanning technology were made full use to solve the above difficulties: 1) in the field assembly of steel structure, because the components are large, the supporting frame should be used in the field assembly. In order to control the assembly precision, the 3D laser scanner is used to scan all the components in the field, the scanned point cloud data are compared with the BIM model by software analysis, and the assembly deviation is corrected in time to ensure the accuracy of the whole structure. Considering that the roof steel truss is affected by load and its end is deflected, it needs to be pre-arched and installed, and then it needs to be unloaded by stages, and the shape of the roof steel truss at each stage is monitored in time by means of the 3D laser scanning technology, by comparing the simulation data to control the construction process to ensure the safety of the structure. 2) The concrete structure of K-type column is a complex structure with a height of 43.9 m and a C-type steel column with an inclined angle of 55.57°. To ensure the accuracy of the 3D positioning of the K-type column, it is necessary to use 3D laser scanning technology for 3D scanning, and compared with BIM model data, to correct the structural deviation in time. 3) The membrane unit of this project has a large span. After the installation, the self-weight of the membrane will produce the problem of down deflection, and the middle part will appear a relatively smooth area, which will affect the overall shape of the membrane, and even will appear the phenomenon of water accumulation. For this problem, it is necessary to set the highest point coordinates in the 3D model to control the tensile stress of the membrane to ensure the design value of the tensile stress. In the field, each element membrane is scanned by 3D laser scanning technology, and the collected point cloud data is analyzed to ensure that the point position is controlled within the allowable range to ensure the installation accuracy.