溢洪道安设橡胶坝对其水力特性影响的试验研究

摘要

In order to solve the lack of energy dissipator and the low flood control capacity of spillway,rubber dam was constructed to improve the potential efficiency of spillway.To explore the effects of building rubber dam in the control segment on the hydraulic characteristics of spillway,factors such as the flood discharge capacity of spillway, the characteristics of flow and the effect of export energy dissipation were analyzed in association with engineering example.Research results show that:the discharge capacity of spillway decreases when being constructed with rub-ber dam,but safety operation of spillway can be guaranteed because the capacity still meets the damand of engi-neering design;the rubber dam has a little influence on flow velocity of spillway ,and flow velocity variation of front of the dam is bigger than that of back of the dam;under the condition of rubber dam collapse or water filling, variation trend of water surface profile is similar,and sudden changing points are located near rubber dam or the position where gradient changes;moreover,the effect of rubber dam on energy dissipation and scouring prevention is slight,so it is feasible to construct a rubber dam in the control segment of spillway.The results can also be taken as reference for similar engineering design and disaster relief and strengthening of small and medium-sized reser-voirs.%针对溢洪道无消能工和防洪能力不足等问题，修建橡胶坝可以提高其潜在效益。为了研究溢洪道控制段内修建橡胶坝对溢洪道水力特性的影响，结合工程实例，从溢洪道的泄流能力、水流特性以及出口消能防冲效果3个方面进行了对比分析。分析成果表明：安设橡胶坝的溢洪道泄流能力减小，但仍大于工程设计要求，可保障溢洪道安全运行；橡胶坝对溢洪道流速有较小影响，坝前流速变化幅度比坝后流速大；橡胶坝塌坝和充水2种工况下的溢洪道水面线变化趋势相近，突变点发生在坡度变化点附近和橡胶坝附近；溢洪道消能防冲能力几乎不受橡胶坝的影响。因此，有条件的溢洪道控制段内建设橡胶坝是可行的。研究成果可为类似工程的设计和中小型水库的除险加固提供参考依据。