水跃消能对闸基渗流稳定的影响分析

水闸泄洪时，下泄水流的势能转化为动能，导致出闸水流的流速增加和水面下降，从而形成附加渗透水头．研究了闸孔泄洪条件下水跃区附加渗透水头对闸室基底渗流稳定的影响，结果表明：为保证工程安全，在进行闸基的防渗布置时不仅要考虑静态渗透水头的作用，还应考虑下泄水流水位变化所引起的附加渗透水头对闸基渗流稳定的影响．提出了减小附加渗透水头的工程措施，冒水孔应设置于消力池末端，而将消力池前段设为不透水底板，以利用跃后高水来提高渗流出逸点的压力水头，从而达到减小附加渗透水头的目的．

Effects of Hydraulic Jump Dissipation on Seepage Stability of Sluice Foundation

Under flood discharge conditions, the potential energy of water flow is converted into its kinetic en- ergy. The water flow velocity is thereby increased and the height of the water surface line is reduced. The fact induces the production of the additional seepage water-head. This paper mainly studies the effects of the addi- tional seepage water-head on the seepage stability of the sluice foundation under flood discharge conditions. The results show that the static and additional seepage waterheads both have a great influence on the seepage stability of the sluice foundation. The neglect of additional seepage water-head can result in the seepage insta- bility of the sluice foundation and endangers the engineering safety. The engineering measures for reducing the additional seepage water-head are proposed. The emit water pore should be placed at the behind of the stilling basin. The front of the stilling basin should be designed as impermeable. Then, the high water after hydraulic jump can induce the increase of the water-head of the seepage flow point. The additional seepage water-head is thereby reduced.