江口水电站泄洪消能设计

Design of flood-discharging and energy-dissipating structures of Jiangkou hydropower station

江口水电站坝址河谷狭窄 ,洪水峰高量大 ,枢纽最大泄洪功率为 12 730MW ,在国内拱坝中处于较高水平。通过方案比选 ,泄洪建筑物采用 5个表孔和 4个中孔的坝身集中泄洪方案 ,下游消能建筑物采用不抽排水垫塘方案。为均化水垫塘负担 ,降低水垫塘底板压力 ,泄洪表孔采用平面扩散加齿坎、中孔采用不对称宽尾墩的型式 ;结合泄洪雾化分析计算 ,对水垫塘两侧水上边坡采用喷混凝土保护 。

At the dam site of Jiangkou hydropower station, the river valley is narrow, flood peaks are rather high and flood volumes are large. The maximum power of flood flows released from the hydro project is up to 127300MW, standing at a higher level in all arch dams in China. Through comparison among various flood discharge schemes, the flood - discharging structure is designed to have 5 surface bays and 4 middle level outlets in dam body. The energy - dissipating structure is designed to be a plunge pool without any pumping and drainage system. In order to average hydrodynamic loads on the plunge pool and reduce hydrodynamic pressure on the plunge pool bottom, the flood - discharging surface bays are horizontally expanded and provided with a dentated sill at their exits, and the middle level outlets are provided with asymmetric flaring piers. In consideration of the atomization of water jets released from the reservoir, both side slopes of the plunge pool are protected by shotcreting and provided with system anchor rods and drain holes.