堰塞坝体材料渗透特性及其稳定性研究

发布时间：2018-03-06 20:33

本文选题：堰塞坝　切入点：渗透性　出处：《工程地质学报》2017年05期 　论文类型：期刊论文

【摘要】：堰塞坝是由于崩塌、滑坡、泥石流等形成的天然坝体,不同于人工土石坝,堰塞坝坝体结构松散,颗粒级配不均匀,在较高水头作用下坝体可能发生渗透破坏而导致溃坝,严重威胁下游人民群众的生命及财产安全。由于堰塞坝存在较大粒径颗粒,常规的渗透试验装置难以满足要求,本文研制了直径为60cm的大直径渗透试验仪,进行了不同堰塞坝级配材料的渗透破坏试验,并探讨了堰塞坝体材料渗透特性的主要影响因素。研究发现:(1)堰塞坝材料的渗透破坏形式取决于材料级配,粗颗粒含量较多时为管涌破坏,细颗粒含量较多或粒径缺失时为流土破坏;(2)堰塞坝渗透系数随干密度的增大而减小,主要取决于细料填充粗料孔隙的程度,单独使用不均匀系数或曲率系数不适用于评价渗透系数的变化;(3)基于试验数据提出了用于堰塞坝渗流破坏形式的判别公式,并推导出堰塞坝管涌破坏的临界水力坡降计算公式。
[Abstract]:Weir dam is a natural dam body formed by collapse, landslide and debris flow, which is different from artificial earth-rock dam. The structure of Weir dam is loose, the grain gradation is not uniform, and the dam body may break the dam under the action of higher water head. It is a serious threat to the life and property safety of the downstream people. Due to the large particle size in the dam and dam, it is difficult to meet the requirements of the conventional permeation test device. A large diameter permeation tester with a diameter of 60 cm has been developed in this paper. The seepage failure tests of different gradation materials of Weir and slug dams are carried out, and the main factors affecting the permeability characteristics of the materials of Weir and plug dams are discussed. It is found that the seepage failure forms of Weir and slug materials depend on the material gradation. The permeability coefficient of Weir dam decreases with the increase of dry density, which is mainly determined by the degree of filling coarse material porosity with the increase of dry density, and the permeability coefficient of Weir dam decreases with the increase of dry density, and when the content of fine particles is higher or the particle size is missing, the permeability coefficient decreases with the increase of dry density, and the permeability coefficient decreases with the increase of dry density. Using inhomogeneous coefficient or curvature coefficient alone is not suitable for evaluating the variation of permeability coefficient. Based on the experimental data, a discriminant formula for seepage failure form of Weir and plug dam is proposed, and the critical hydraulic slope slope calculation formula for pipe surge failure of Weir plug dam is derived.
【作者单位】：同济大学地下建筑与工程系;同济大学岩土及地下工程教育部重点实验室;中国中铁二院工程集团有限责任公司;
【基金】：国家自然科学基金项目(41372272,41402257) 水工岩石力学教育部重点实验室开放基金(RMHSE1501)资助
【分类号】：P642.2

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