扬压力是重力坝的主要荷载之一,当下游尾水位高时,降低扬压力对于提高坝的安全度和减少工程量更有重大意义。建国以来,我国坝工实践中曾在降低坝基扬压力方面,创造了“闭路式抽水减压排水系统”的概念,即在重力坝灌浆帷幕后的主排水幕下游,增设若干道辅助排水幕,并设有专门的排水廊道供其施工 Yang pressure is one of the main load of gravity dam, when the tailrace water level is high, it is more significant to reduce the uplift pressure to improve the dam safety and reduce the project volume. Since the founding of the People’s Republic of China, the concept of “closed-circuit pumping decompression drainage system” has been created in the dam work in China to reduce the pressure of dam foundation. In the downstream of the main drainage curtain behind the grouting curtain of gravity dam, a number of auxiliary drainage curtains are added, There is a dedicated drainage corridor for its construction