丹江口大坝基础帷幕中丙凝胶体耐久性研究

Study on Durability of Acrylamide Gel in Dam Foundation Curtain of Danjiangkou Dam

丹江口水利枢纽是南水北调中线水源工程,丹江口大坝河床坝段的防渗帷幕,已运行近40年,大坝加高后其运行条件发生变化,上游水头更高,须通过相应的试验研究对其耐久性做出客观评价。采取常规和加速老化试验方法,测试了老化前后丙烯酰胺(丙凝)胶体的质量和酰胺基团的变化及浸泡液中NH4+浓度、丙烯酰胺单体含量。试验结果表明,老化试验后丙凝胶体支链的部分酰胺基团发生了水解,但主链未发生水解,说明丙凝胶体耐久性较好。

Danjiangkou Hydroproject is the waterhead project of South-North Water Diversion. The anti-permeable grouting curtain of Danjiangkou Dam was constructed almost 40 years ago. The water pressure would become larger after the dam was heightened. So the durability of grouting curtain should be evaluated objectively by the eorresponding tests. In this study, the conventional and accelerated aging tests were completed. The quality of the acrylamide gel and the change of amide group, as well as the concentration of ammonium ion and content of acrylamide monomer in the aging solution were measured before and after aging. The test results indicate that the amide group of side chain of acrylamide gel was hydrolyzed after aging tests, but the main chain of acrylamide gel was not. The durability of acrylamide gel was proved to be good by the results of the tests.