折坡消力池护坦稳定性分析

Stability Analysis of Resistance Floatation on Stilling Basin Connected to Sloping Apron

结合嘉陵江苍溪枢纽工程实际,对嘉陵江渠化梯级普遍采用的消能工形式——折坡消力池的抗浮稳定性进行了研究。结果表明,采用水跃消能时,消力池护坦上将产生强烈的脉动压力,而脉动上举力是造成折坡消力池护坦失稳的重要因素;苍溪枢纽折坡消力池护坦上脉动压力显示出明显的低频特性,其优势频率远低于护坦的自振频率,不会引起护坦共振;最不利工况下护坦抗浮稳定系数K=1.73>1,表明消力池护坦是稳定的。

Based on Cangxi hydro-junction on Jialing river, the stability of resistance floatation on stilling basin connected to sloping apron, which is widespread adopted to canalization hydro-junction on Jialing river, is analyzed. When the energy is dissipated by Hydraulic jump, intensive fluctuating pressure was generated on the stilling basin apron, then the fluctuating uplift force will make the apron unstable. The model tests results indicate that the fluctuating pressure on apron presents low-frequency characteristic, and the frequency is much lower than the natural vibration frequency of apron, which will not cause to resonance vibration. Through the calculation, the stability factor K=1.73〉1, which indicates that the stilling basin connected to sloping apron is stable.