中文摘要：

某水利枢纽下游侧存在渗水、冒水等严重问题,采用横波冲击映像法对进水闸底板与基础围岩脱空情况进行探查,结果表明该法不受水和钢筋网等因素干扰,为修补加固设计方案提供可靠基础资料。文中阐述了检测方法原理、设备及检测过程,给出了数据处理流程,通过数值模拟制定脱空标准,完成闸底板脱空缺陷分布图。检测结论：（1）水闸底板存在脱空,部分底板脱空区形成渗漏通道,造成下游侧涌水;（2）脱空率大于20%的闸底板,需要及时进行灌浆处理,中等程度脱空的闸底板,还需做进一步探查,其他的脱空不严重水闸底板无需处理;（3）建议对水闸进行垂直变形和水平变形监控,严格控制最高运行水位,防范水闸塌陷和下滑。横波冲击映像法为类似工程缺陷问题的探查提供了借鉴。

英文摘要：

There are serious seepage and gushing problems on the downstream side of a certain hydraulic project.We investigated the void situation between the sluice floor and the foundation surrounding rocks using the shear-wave impact imaging method（SIIM）.The results showed that SIIM was free from the interference of water and steel mesh.The investigation provided reliable basic data for the repair and reinforcement designing scheme of the hydraulic project.This paper first describes the principle of the detection method and the procedures of detection and data processing,then develops void standards by numerical simulation,and finally presents the distribution of the void defects of the sluice floor.The conclusions are as follows：1）There were voids beneath the sluice floor and some voids formed leakage passages which caused water gushing on the downstream side.2）The sluice floors with greater than 20% void area needed timely grouting treatment;the floors with moderate void area needed further examination;the other floors with less severe voids needed no treatment.3）Measures should be taken to monitor the vertical deformation and horizontal deformation of the sluice,strictly control the maximum operating water level,and prevent sluices from collapsing and falling.SIIM provides a reference method for defects exploration in similar hydraulic projects.