高拱坝表深孔碰撞泄洪消能水力特性

高拱坝坝身宣泄洪水产生高速水流,水流下泄时会对水垫塘底板产生极大的冲击压力.为保证下游冲刷安全,在有足够的深水垫消刹能量的同时,还需通过水舌在空中消耗部分能量.通过表深孔同轴碰撞的泄洪消能布置方式,研究不同表深孔流量比工况下水流特性及底板动水压强等水力特性.结果表明,表深孔上下水舌在空中碰撞、掺气,削弱射流的集中强度,能使下泄水流的冲击压力大大降低,有效提高下游水垫塘的抗冲安全性,为类似工程布置提供借鉴.

Study on Hydraulic Characteristics of Deep Hole Collision Discharge and Energy Dissipation in High Arch Dam

When high arch dam body discharges flood, due to the high upstream head, high-speed water flow will be generated during discharge, and great impact pressure will be generated on the bottom plate of the plunge pool during discharge. In order to ensure the safety of downstream scouring, it is necessary to consume part of the energy in the air through the water tongue while there is enough deep water cushion to dissipate the brake energy. On the other hand, the energy dissipation method of surface-deep hole collision can make the upper and lower water tongues collide and aerate in the air, weaken the concentrated intensity of the jet, and combine with the braking energy of the water cushion pond to greatly reduce the impact pressure of the discharged water flow. This method of flood discharge and energy dissipation has now been adopted by many large-scale projects at home and abroad. This paper studies the flow characteristics and hydraulic characteristics such as floor dynamic water pressure under different surface-to-depth hole flow ratios by adopting the arrangement of flood discharge and energy dissipation through coaxial collision of surface-to-depth holes, which can provide reference for similar engineering arrangements.