含裂缝砾石土的反滤准则
Filter criteria for gravelly clayey soils with cracks
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摘要: 砾石土为高土石坝普遍采用的防渗材料。由于分层施工填筑或心墙拱效应,高土石坝的防渗心墙常会出现裂缝,对于含裂缝砾石土的反滤设计准则的研究成果缺乏。开展了不同含砾量的含裂缝砾石土在不同级配、不同密度的反滤料保护情况下的反滤试验研究。总结了现有的适用于砾石土的反滤设计准则并与试验结果进行对比分析。分析表明现有反滤准则都不能完全适用于含裂缝砾石土的反滤设计。基于试验和对比分析结果,同时考虑含裂缝砾石土及反滤料联合抗渗机理,提出了适用于含裂缝砾石土的反滤准则。用反滤试验结果进行验证表明本文提出的反滤准则适用于不同含砾量的含裂缝砾石土的反滤设计。Abstract: The gravelly clayey soils are commonly used as seepage resistant materials in high embankment dams. The core of the high embankment dam may crack owing to the layered construction placement or arch effect of the core. However, the filter design criteria for cracked gravelly clayey soils are not found. The filter tests are conducted using cracked gravelly clayey soils with different gravel contents and filters with different gradations and dry densities. The existing filter criteria for gravelly clayey soils are summarized and compared with the test results. The results show that the existing filter criteria cannot fully satisfy the need of filter design for cracked gravelly clayey soils. Based on the results of the tests and comparative analyses, the filter criteria for cracked gravelly clayey soils are proposed considering the combination seepage resistant mechanism of cracked gravelly clayey soils and the filters. The verification using the filter test results shows that the proposed filter criteria can be used for the filter design of cracked gravelly clayey soils with different gravel contents.