基于渗透特性的面板堆石坝垫层料适用性研究

发布时间：2018-07-14 08:33

【摘要】：垫层是面板堆石坝的重要分区之一。青海石头峡水电站面板堆石坝填筑施工之前,河床砂砾石料场的检测成果显示,筛除100 mm以上直径颗粒后的土料(直接筛分料),其细颗粒含量很容易低于要求的垫层料范围下限。针对直接筛分料和过渡料开展了渗透变形和反滤试验,运用数值模拟方法预测了大坝渗流场分布及垫层与过渡区可能出现的最大渗透比降。从大坝渗漏控制和渗透稳定性功能要求出发,分析认为直接筛分料不适用于石头峡大坝垫层。针对直接筛分料提出了改进方案,即掺入粒径5 mm以下的颗粒,通过渗透变形和反滤试验复核了改进料作为垫层料的适用性。工程建成后,水库蓄水期间运行性态良好,并经受了地震的考验。通过实例研究,强调了填料特性研究应贯穿土石坝建设的全过程,尤其应重视填筑施工之前尽早开展实际用料适用性的复核试验与评价工作。
[Abstract]:Cushion is one of the important zoning of face rockfill dam. Before the construction of the face rockfill dam of Shixia Hydropower Station in Qinghai Province, the test results of the gravel and gravel field of the riverbed show that, The fine particle content of the soil material (direct sieving material) after removing the diameter particles over 100 mm is easily lower than the lower limit of the required cushion material range. Seepage deformation and filtration tests were carried out for direct sieve material and transition material. Numerical simulation method was used to predict the distribution of seepage field and the maximum permeability ratio drop between cushion and transition zone. Based on the functional requirements of seepage control and seepage stability of the dam, it is considered that the direct screening material is not suitable for the cushion of the dam. An improved method was put forward for direct sieving material, that is, adding particles with diameter less than 5 mm, the applicability of the improved material as cushion material was checked by permeation deformation and filtration test. After the completion of the project, the reservoir during the period of good performance, and withstand the test of earthquakes. Through the case study, it is emphasized that the study of filling characteristics should run through the whole process of earth-rockfill dam construction, especially the check test and evaluation of the applicability of practical materials should be carried out as early as possible before the construction of fill construction.
【作者单位】：长江科学院水利部岩土力学与工程重点实验室;国家大坝安全工程技术研究中心;青海引大济湟水电建设责任有限公司;
【基金】：国家自然科学基金项目(51279016,41402213) 中央级公益性科研院所基本科研业务费项目(CKSF2016021/YT)
【分类号】：TV41

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