平底型与反拱型水垫塘动水荷载对比试验研究

Comparison of hydrodynamic load characteristics between flat and inverted arch plunge pools

水垫塘结构是影响高坝泄洪消能的关键,优化水垫塘底板型式对有效地增加底板稳定性和减小动水荷载至关重要。平底型和反拱型底板作为两种常见的水垫塘结构型式被业界广泛采用,但关于两者的动水荷载特性对比研究尚不多见。基于白鹤滩水电站1∶50整体模型,采用物理模型试验的方法对比了平底型和反拱型水垫塘在时均压强和脉动压强方面的特性。结果表明:反拱型水垫塘底板的时均压强峰值小于平底型,来流方向上反拱型水垫塘底板的时均压强低谷值小于平底型;两种型式水垫塘脉动压强峰值差异较小,反拱型底板整体脉动压强大于平底型,但反拱型脉动压强梯度小于平底型。

The structure of plunge pool is a key factor influencing energy dissipation of high dams,and the optimization of bottom plate type is crucial to effectively increasing the stability of the bottom plate and decreasing hydrodynamic load.Flat bottom and inverted arch types are widely used as two common plunge pools;however,the comparative study of hydrodynamic load characteristics between these types is rare.Based on the 1:50 integral model of Baihetan Hydropower Station,the characteristics of average pressure and fluctuating pressure of flat and inverted arch plunge pools are compared using physical model test.The results show that the peak value of average pressure of inverted arch is smaller than that of flat bottom,so is the lowest value in flow direction.The difference of peak values of fluctuating pressure is negligible.The overall pressure fluctuation of inverted arch is larger than that of flat bottom;however,the gradient of the fluctuating pressure of inverted arch is smaller than that of flat bottom.