三维激光扫描技术在面板堆石坝挤压边墙变形监测中的应用

为了分析挤压边墙的变形特性对混凝土面板的施工及应力变形影响，首次采用瑞士徕卡公司生产的ScanStationP40扫描仪对涔天河面板堆石坝挤压边墙进行3期扫描，将第1期扫描点云数据作为基准数据，将第2期、第3期扫描的点云数据分别与基准数据进行对比分析来获取挤压边墙的变形特性，然后与同期挤压边墙上的棱镜实测数据对比分析。结果表明挤压边墙中上部呈向下游位移的趋势，而下部呈向上游位移趋势;基于三维激光扫描的挤压边墙顺河向位移变化区域大于棱镜实测顺河向位移变化区域;挤压边墙中上部沉降较大，两岸沉降较小，挤压边墙处于变形发展阶段，尚不适合进行面板施工;2种监测手段得到的挤压边墙变形趋势基本一致。说明利用三维激光扫描技术对面板堆石坝挤压边墙表面变形进行监测是可行的，可为类似工程提供参考。

Application of Three-dimensional Laser Scanning Technique in Deformation Monitoring of Extrusion Sidewall of Concrete-faced Rockfill Dam

The deformation properties of extrusion sidewall of concrete-faced rockfill dam(CFRD) have great effect on the construction and stress deformation of concrete face in construction period.In the present research,Leica ScanStationP40 scanner was employed for the first time in deformation measurement for the extrusion sidewall of Centianhe CFRD.The scanning point cloud data in the first phase was taken as reference data to determine the deformation of the extrusion sidewall through comparison with data in the second and third phases.Furthermore,the point cloud data of the second and third phases were compared with those measured by prism in the same period.The comparison results reveal that,a) the middle and upper part of the extrusion sidewall shows a trend of displacement towards the downstream,while the lower part shows a displacement trend towards the upstream;b) the varying area of extrusion sidewall's displacement along stream direction obtained by 3-D laser scanning is greater than that measured by prism;c) settlement of the middle and upper part of extrusion sidewall is large,and that of both sides are relatively small,indicating that the deformation of extrusion sidewall is in a stage of development,hence is not suitable for panel construction.The deformation trend of extrusion side wall obtained by 3-D laser scanning monitoring is basically in accordance with that by prism,indicating that 3-D laser scanning is feasible in monitoring the deformation of the extrusion sidewall of CFRD.