淤地坝坝面过水试验研究

作者提出应用土工膜衬护,直接在淤地坝坝面设置溢洪道的坝面过水技术方案,并以宋家沟试验淤地坝为依托工程,进行了现场大型试验.试验研究了平底式与阶梯式两种过水方案.试验结果表明：同等条件下,平底式方案末端最高流速达10.7m/s,而阶梯式方案则为3.1m/s,说明阶梯式方案具有较好的消能作用;在上述流速下,两种方案的结构整体稳定,说明土工膜的铺设结构形式与固定方法是合适的;从耐磨抗冲刷性能看,土工膜抗碎石的耐磨性尚待进一步研究;从施工难度、土工膜用量和成本等方面比较,平底方案具有较大的优越性.

Test of overflow spillway with geomembrane liner built on an earth check dam

The authors put forward a technical plan of building overflow spillway on the downstream slope of earth check dams by using geomembrane liner, A group of tests were carried out on the site of Songjiagou earth check dam, Two types of spillways with smooth slope and stepped slope were tested, The test results showed that both types of spillway were stable in structure, The stepped spillway was more effective in energy dissipation with a maximum velocity of 3.1 m/s at the end of spillway, while the other had its maximum velocity of 10.7m/s, The scour resistance capalility of geomembrane to sand and gravel needs further study, As far as the construction convenience, material consumption and the cost were concerned, the smooth slope spillway has more advantages, The authors believe that the two types of spillway would be applicable in earth check dam projects after some further improvement.