洱源县土官村水库黏土心墙坝的反滤设计及复核

Design and Review of Filter for Earth Dams with Clay Core Tuguancun Reservoir in Eryuan County

设计合理的反滤层是防止黏土心墙坝防渗体渗透破坏非常有效的措施,滤土排水是反滤层设计的根本要求,但当前的反滤设计中,仅通过保护料和被保护料级配曲线的特征粒径来确定相关反滤准则,忽略了密实度等因素对渗透性的影响,因此,根据排水准则确定了反滤料的级配后,仍需根据实际的碾压标准开展土体渗透特性试验,以验证在坝体实际填筑的条件下,反滤料和防渗土料是否满足层间排水关系;通过对有无保护情况下防渗土料抗渗透破坏能力的对比,且对于试验过程中反滤料是否发生淤塞失效的观察,可以判断反滤料是否能够对防渗土料起到一定的反滤保护作用,然而除了特征粒径,当前对于反滤层滤土能力仍缺乏最直接的判断依据,相关判别标准仍需进一步研究。

The reasonable design of the filter layer is a very effective measure to prevent the seepage failure of the anti-seepage body of the clay core wall dam.The drainage of the filter soil is the requirement of the filter layer design.However,in the current filter design,only the characteristic particle size of the grading curve of the protective material and the protected material is used to determine the relevant filter criteria,ignoring the influence of compactness and other factors on the permeability.Therefore,after determining the gradation of the filter material according to the drainage criteria,it is still necessary to carry out the soil permeability test according to the actual rolling standard to verify whether the filter material and the anti-seepage soil material meet the inter-layer drainage relationship under the actual filling condition of the dam body.Through the comparison of the anti-seepage damage ability of the impermeable soil material with or without protection,and the observation of whether the filter material has siltation failure during the test,it can be judged whether the filter material can play a certain role in the anti-seepage protection of the impermeable soil material.However,in addition to the characteristic particle size,there is still a lack of the most direct judgment basis for the filter capacity of the filter layer,and the relevant discriminant criteria still need further study.