极端条件下心墙泥浆料的渗透反滤试验研究

Experimental study on the seepage filter protection of core-wall material slurry under extreme conditions

高土石心墙坝的渗透稳定性在很大程度上依赖于反滤层对心墙料的反滤保护作用。心墙在大坝蓄水和长期运行的条件下,要经历复杂的填筑加载、浸水饱和与水荷载的作用,在差异沉降、复杂结构应力作用、水力劈裂和渗透水流作用下,心墙一旦出现裂缝,其渗透稳定性及反滤层的保护作用就将面临严峻的考验。针对这一问题,设计了专门非常规的抛填土料反滤试验和泥浆渗透反滤试验,模拟心墙裂缝条件下其颗粒被冲刷起动后,被反滤料阻挡和淤积过程。试验结果表明,心墙料和反滤料满足反滤准则条件下,心墙颗粒被拦截和淤积在反滤层上游表面,反滤料能有效防止心墙颗粒的流失,反滤层在极端条件下对心墙料仍能起到有效的反滤保护作用。

The seepage stability of high earth rockfill dam greatly depends on the protection of filter layer on core-wall material.Under impounding and long-term running conditions,the core wall undergoes complex structural load,saturation and water effects.Being affected by differential settlement,complex structural stress,hydraulic fracturing and seepage flow,the core wall when cracks formed will meet severe situations for seepage stability and filter layer of protection.To solve above problems,reverse filtration tests on unconventional filling material and slurry were designed to simulate the scouring and blocking of the particles under the cracking of the core wall by the reverse filter material and the deposition process in the crack.The results show that core wall particles are intercepted and deposited on the upstream surface of the filter layer.The filter material can effectively prevent the loss of clay particles.When the core-wall material and the filter material meet the filter criterion,the filter layer can still effectively protect the core-wall material under extreme conditions.