高坝联合泄洪消力塘底板上举力分布特性研究

Uplift Force Distribution on Plunge Pool Slab:Coalition Discharge from Surface and Bottom Outlets of High Dam

为研究多孔联合泄洪对上举力分布的影响,通过某工程1∶50模型试验对坝后水垫塘底板块上举力大小及分布特性进行了测试,并对多孔联合泄洪和表、深孔单独泄洪时的最大上举力大小和分布进行了比较。经比较分析得出:表深孔联合泄洪情况下表深孔水舌冲击点附近的上举力,与表孔或深孔单独泄洪下相应位置的上举力相比,要明显减小;最大上举力的位置也有所改变,表孔冲击点附近后移,深孔冲击点附近前移。结果表明:表深孔水舌入水后形成大的旋滚相互影响,得不到充分发展,对底板的卷吸作用明显减弱,进而导致相应上举力值明显减小,最大上举力的位置也有所改变。

To investigate the effect of discharge through surface outlets and bottom outlets simultaneously, we analyze the uplift force and its distribution on plunge pool slab through a 1：50 model test. Large water rolls formed by the nappes from surface outlets and bottom outlets interact with each other, and thereby weakening the entrainment effect on the slab. As a result, the uplift force near the impact point of water nappe by coalition discharge from surface outlets and bottom outlets is obviously smaller than that by separate discharge from surface outlets or bottom outlets alone. In the case of coalition discharge, the location of maximum uplift force also changes, moving forward near bottom outlets and moving backward near surface outlets.