突扩式跌坎消力池水动力荷载特性研究

In recent years, with the great development of society and economy, as well as the improvement of people's awareness of environmental protection and the requirements of ecology and environment, the influence of hydraulic engineering construction on ecological environment has become one of the engineering feasibility constraints. People's awareness and concern for the construction of hydropower projects is no longer merely the huge economic benefits, but considering the impact of construction projects on the ecological environment. On this basis, sudden-expansion stilling basin with drop sill was proposed as a new energy dissipator which can be used in high-head, large- unit discharge engineering.stilling basin with drop sill. Sudden-expansion stilling with basin drop ,as energy dissipation building of high dams, the stability of its own was of great significance to energy dissipation and erosion as well as the overall safety of hydraulic structures .Studies are carried out about the stability and the dynamic loads , the failure mechanism of protection structure was described, and the relationship between water conditions and hydrodynamic loads was given ,which had very important theoretical significance and practical significance for guiding the engineering design, preventing and avoiding structural damage.

近年来，随着我国社会经济的发展，人们的环保意识和对生态环境的要求也随之提高，水电工程建设对生态环境的影响成为工程可行性的制约条件之一。人们对水电工程建设的认识和关注发生了改变，不再是仅仅停留在巨大的经济效益上，而是综合考虑了项目建设对生态环境的影响。在此基础上，提出了一种应用于高水头、大单宽流量工程的新型的消能工——突扩式跌坎消力池。突扩式跌坎消力池作为高坝泄洪时的消能建筑物，其自身的稳定性对消能防冲以及整体水工结构的安全都具有重大意义。本课题拟通过理论分析、水力学模型试验结合流体数值计算的方法来开展突扩式跌坎消力池水动力荷载及稳定性研究，阐述防护结构破坏机理，给出水动力荷载与水利条件的量化关系，对于指导工程设计、预防及避免结构破坏具有非常重要的理论意义及现实意义。

作为应用于高水头、大单宽流量工程的新型的消能工——突扩型跌坎消力池，其自身的稳定性不论对消能防冲还是整体水工结构的安全都具有重大意义。本项目通过理论分析，模型试验和数值模拟相结合的方法，对突扩型跌坎消力池底板的水动力荷载进行了研究。主要研究成果及结论如下：.（1）通过模型实验和数值模拟，对比分析了突扩式与无突扩式跌坎消力池的底板临底流速分布特点，得出突扩式跌坎消力池临底流速分布与无突扩跌坎消力池相比有显著不同，有突扩存在时最大临底流速所在纵断面为中线与边墙距离的1/2处。研究了突扩比、入池能量、尾坎高度、池长对突扩式跌坎消力池临底流速最大值的影响，得到了突扩式跌坎消力池最大临底流速的预报经验公式。.（2）基于模型实验实测数据，对比分析了突扩式与无突扩式跌坎消力池的时均动水压强分布以及最大时均动水压强分布特性，得出突扩式跌坎消力池时均动水压强在消力池底板上的分布与无突扩跌坎消力池有显著不同，有突扩存在时最大时均动水压强所在纵断面为中线与边墙距离的1/2处。研究了突扩比、入池能量、尾坎高度、池长对突扩式跌坎消力池底板上最大时均动水压强的影响，得出了其随各影响因素的变化规律。.（3）分析比较了跌坎消力池与突扩式跌坎消力池的脉动压强分布以及最大脉动压强分布特性，得出了突扩式跌坎消力池较无突扩跌坎消力池脉动压强显著降低；研究了突扩比、入池能量、尾坎高度、池长对突扩式跌坎消力池底板最大脉动压强的影响，得出了其随各影响因素的变化规律。.（4）基于模型试验成果，研究了消力池板块所受上举力,分析了底板上举力的影响因素，得出了最大上举力的预报经验公式。