Abstract: 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.

Key words: concrete-faced rockfill dam(CFRD), extrusion sidewall, 3-D laser scanning, point cloud data, deformation monitoring