石振明, 张公鼎, 彭铭, 刘思言. 2017: 堰塞坝体材料渗透特性及其稳定性研究. 工程地质学报, 25(5): 1182-1189. DOI: 10.13544/j.cnki.jeg.2017.05.002
    引用本文: 石振明, 张公鼎, 彭铭, 刘思言. 2017: 堰塞坝体材料渗透特性及其稳定性研究. 工程地质学报, 25(5): 1182-1189. DOI: 10.13544/j.cnki.jeg.2017.05.002
    SHI Zhenming, ZHANG Gongding, PENG Ming, LIU Siyan. 2017: STUDY ON THE PERMEABILITY AND STABILITY OF LANDSLIDE DAM MATERIALS. JOURNAL OF ENGINEERING GEOLOGY, 25(5): 1182-1189. DOI: 10.13544/j.cnki.jeg.2017.05.002
    Citation: SHI Zhenming, ZHANG Gongding, PENG Ming, LIU Siyan. 2017: STUDY ON THE PERMEABILITY AND STABILITY OF LANDSLIDE DAM MATERIALS. JOURNAL OF ENGINEERING GEOLOGY, 25(5): 1182-1189. DOI: 10.13544/j.cnki.jeg.2017.05.002

    堰塞坝体材料渗透特性及其稳定性研究

    STUDY ON THE PERMEABILITY AND STABILITY OF LANDSLIDE DAM MATERIALS

    • 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: Landslide dams are natural dams formed by collapse, landslide, debris flow, etc. Landslide dams are different from man-made dams for its lack of sufficient consolidation, leading to loose dam structure and highly non-homogeneous materials. Large water head caused by rising of water level could trigger seepage deformation of soil and influence landslide dam stability, which may lead to dam breach and catastrophic damage. Due to the presence of large diameter particles in landslide dams, the conventional penetration test device is difficult to meet the requirements. A large diameter infiltration device with the diameter of 60cm was developed. The paper reports the experimental study on the seepage characteristics of landslide dam material. It was observed that piping and soil flow are the two seepage failure modes of landslide dams. The landslide dams with coarse grain in majority are prone to piping failure, and the dams with fine grain in majority and gap-graded materials are prone to soil flow failure. The experiments showed the permeability coefficient reduces with the increase of the dry density and is influenced by the amount of fine particles. Using the nonuniformity coefficient or the curvature coefficient independently is not suitable for evaluating the permeability coefficient change. A discriminant formula for the seepage failure and a critical hydraulic gradient equation for piping are provided based on the experimental data.

       

    /

    返回文章
    返回