多波束测深在漾头水电站下游冲坑测量中的应用

Application of multi-beam sounding technique in survey of scouringpit at downstream of Yangtou Hydropower Station

水电站经过长期运营,在水力因素和河床地质的综合作用下,大坝下游很容易形成冲坑,传统的坝后冲坑范围界定常采用人工巡查和逐点测量的方式,分辨率和测深精度较低。利用多波束测深技术进行全覆盖测量,对水下高精度点云数据进行三维建模,可以全面客观地反映冲坑现状。以漾头水电站消力戽下游冲坑测量为例,利用Kongsberg EM2040C(双探头)多波束测深系统和水下机器人,得到了冲坑水下三维地形图和视频资料,并与消能戽下游冲刷坑深度经验公式计算结果进行对比,为该电站冲坑的稳定性评价和发展演化提供了可靠的数据资料。应用成果对类似坝后冲坑的现状测量和加固修复具有一定的借鉴意义。

After long-term operation of hydropower stations,with the combination effects of hydraulic factors and river bed geology,scouring pits easily form at downstream of dams.The traditional method of artificial inspection and point by point survey adopted for the scour pit scope definition at the downstream of dam has low resolution and accuracy.In this paper,the multi-beam sounding technique was used to perform full-coverage scanning to obtain high-precision point cloud data,and the three-dimensional modeling of underwater high-precision point cloud data could reflect the current situation of scour pit comprehensively and objectively.Taking the scour pit downstream of roller bucket at Yangtou Hydropower Station as the case,the Kongsberg EM2040C(dual-probe)multi-beam sounding system and Remote Operated Vehicle were used to obtain the underwater 3D topographic map and video data.Then these data were compared with the calculation results of pit depth empirical formula,providing reliable data for the stability evaluation,development and evolution of the scour pit.The application results have certain reference significance for the current measurement and reinforcement and repair of similar scour pit downstream of the dam.