Research On Linear Control Method Of Rigid Skeleton Arch Bridge Based On Ground Laser Scanning

In the past bridge construction management,due to the low degree of informatization during the construction period,unclear targets during construction monitoring,and backward monitoring methods,the true state of the bridge cannot be accurately monitored.In view of the above problems,this paper applies the three-dimensional scanning technology to the construction control of the arch bridge based on its unique advantages of high precision,high efficiency and comprehensiveness.The main researches are as follows:(1)The main problems existing in the current bridge construction and the urgent problems to be solved are described,and the current research status of 3D scanning technology and reinforced concrete arch bridge construction control is analyzed and summarized.(2)The deformation accuracy obtained by the scanner at different distances and resolutions is analyzed through experiments.The test results show that within a distance of 100 m,10m/0.8mm,10m/1.6mm,10m/3.1mm,10m/6.3mm are four The scanning deformation accuracy under this resolution can reach within 1mm.(3)Perform pre-processing research based on the point cloud data collected by the real bridge,analyze the noise reduction methods of different point clouds,and conduct the registration study,and use the self-made triangular pyramid to perform the rough registration of the feature points,and use it on this basis The improved ICP algorithm realizes fine registration,and it is found that the deviation of the point cloud after registration is all within 1mm.On the basis of the registration point cloud,a fast extraction method for the features of different structural components is proposed,and the extraction deviation is analyzed.(4)Propose a method for detecting the manufacturing line shape and length of the rigid skeleton prefabricated segment,and modify it according to the detection deviation to ensure the processing quality of the rigid skeleton segment;at the same time,it is based on the point cloud of the rigid skeleton segment.Virtual pre-assembly,proposes a method for predicting the assembly line shape of the stress-free state method,analyzes its assembly deviation,so as to make control and deviation correction before construction.In the segment hoisting,the construction line shape of the construction stage is obtained according to the three-dimensional scanning technology,compared with the theoretical line shape,and the cable force is adjusted according to the line shape deviation to make the construction line shape meet the requirements of the theoretical line shape;before closing the dragon,the deviation of the closing is performed based on the threedimensional scanning It is predicted that the deviation of the maximum cantilever section and the closing section is analyzed through point cloud data,and the cable force is adjusted according to the deviation to realize the smooth closing of the arch bridge.(5)Through experiments,the accuracy of three-dimensional scanning for the deformation extraction of concrete arches under different loads is verified,and the real bridge point cloud is used as the object to analyze the continuous deformation of the arch concrete during the pouring stage,relying on the difference between actual measurement and theoretical deformation.The deviation corrected the theoretical calculation in the concrete pouring construction stage,and obtained the theoretical model that can accurately reflect the actual characteristics of the bridge,so as to accurately grasp the structural state of the concrete pouring stage.The research results show that the use of 3D laser scanning technology can monitor and control the high-precision continuous line shape of the arch bridge construction process,and the accuracy of monitoring and control can reach the millimeter level.It can realize the line shape prediction before the construction of the reinforced concrete arch bridge and the continuous line shape during construction.Monitoring and control.In the concrete pouring stage,the finite element fine model can be revised according to the measured continuous deformation curve to make it more in line with the actual state of the arch bridge construction process.