针对葛洲坝大江电厂排沙孔进水口检修门槽底槛磨损问题，采用水下摄像方法，记录了发电运行时机组进水口流态和排沙孔进水口门砾石运动轨迹。根据观测得到水流特性以及砾石运动规律，分析了底槛磨损影响因素，提出了避免磨损的基本措施。

 Aiming at the problem of the abrasion at the bottom sill of emergency gate of desilting outlet of Gezhouba Power Plant, we recorded the flow state of the generator set inlet and the movement of sediment and gravels in the sediment-flushing inlet while the generator sets were running by the underwater photography. By observation, the character of the flow and the law of the sediment movement were gotten, the influencing factors of the abrasion at the bottom sill were analyzed, and some basic measures for avoiding abrasion were given.