土工基础

土工基础 ›› 2022, Vol. 36 ›› Issue (3): 437-441.

• 测试技术 • 上一篇    下一篇

颗粒形状对钙质砂渗透性的影响试验研究

霍玉龙1,2,3,王雪晴3，姜开放1,2,3，王毅琨1,2,3，吴永洁1,2,3   

  1. （1.桂林理工大学土木与建筑工程学院，广西桂林 541004；2.广西岩土力学与工程重点实验室,广西桂林 541004；
    3.中国科学院 武汉岩土力学研究所，武汉 430071)
  • 收稿日期:2020-12-17 修回日期:2020-12-28 出版日期:2022-06-30 发布日期:2022-06-26
  • 作者简介:霍玉龙（1994-），男，硕士研究生，研究方向为水文地质与工程地质。
  • 基金资助:
    中科院科技先导专项A类子课题：XDA13010301

Experimental Study of the Effect of Particle Shape on the Permeability in Calcareous Sand

HUO Yulong1,2,3, WANG Xueqing3, Jiang Kaifan1,2,3, WANG Yikun1,2,3, WU Yongjie1,2,3   

  1. (1.School of Civil and Construction Engineering, Guilin University of Technology, Guilin 541004;
    2.Guangxi Key Laboratory of Rock and Soil Mechanics and Engineering, Guilin 541004;
    3.Wuhan Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan 430071)
  • Received:2020-12-17 Revised:2020-12-28 Online:2022-06-30 Published:2022-06-26

摘要： 钙质砂因其独特的生物成因，常常形态不规则，多孔且易碎，这对渗透性的影响值得深入探讨。选用相同粒级的钙质砂与贝壳砂，通过PartAn3D颗粒形貌测定确定了两种样品的形状参数，以孔隙比为控制参量进行常规渗透试验，对比分析颗粒形状对渗透性的影响，初步解释了颗粒形状所致的渗透性差异性。试验结果表明：钙质砂的长厚比、颗粒方差以及凹度值均小于贝壳砂，而磨圆度、球度以及圆形度大于贝壳砂。相同相对密实度条件下钙质砂渗透性要大于贝壳砂渗透性。中密状态下，钙质砂与贝壳砂渗透系数数值接近，差值小；密实状态时，钙质砂与贝壳砂渗透系数差值随相对密实度的增加而减小。两者孔隙比对渗透性的影响方面，当孔隙比小于1.45时，渗透系数随孔隙比的增加而缓慢增加；孔隙比大于1.45后，渗透系数随孔隙比的增加显著增大；相同孔隙比条件下，钙质砂的渗透系数大于贝壳砂，且差值随孔隙比的增加而增大。相同孔隙比条件下，钙质砂渗透系数大于贝壳砂渗透系数的原因可能是渗透液流经单位长度砂柱时水头损失的不同，这种不同可能由颗粒形状不同而引起。


关键词: 渗透系数, 颗粒形状, 孔隙比, 相对密实度

Abstract: The shape of the calcareous sand is often irregular, porous and it is fragile due to its unique biological origin. The influence of the particle shape on the permeability is a question worth of further evaluation. Therefore, this paper selected the calcareous sand and shelly sand of the same grain size distribution and the shape parameters of the two samples through PartAn3D particle morphology measurement were determined. The void ratio was used as the control parameter to perform conventional permeability tests and to compare and analyze the impact of particle shape on the permeability, which initially explained the difference in the permeability caused by the particle shape. The test results show that the length-to-thickness ratio, Pval, and the concavity degree of the calcareous sand sample are smaller than those of the shelly sand sample, while the roundness, sphericity and the circularity are larger than those of shelly sand samples. With the same relative density, the permeability of calcareous sand sample is greater than that of the shelly sand sample. In the medium relative dense samples, the hydraulic conductivity values of the calcareous sand sample and the shelly sand are close to a small difference. In dense samples, the difference in the hydraulic conductivity of the calcareous sand sample and the shelly sand sample decreases with the increase of the relative density. In terms of the influence of the void ratio on the permeability of two different types of samples, when the void ratio is less than 1.45, the hydraulic conductivity increases slowly with the increase of the void ratio; when the void ratio is greater than 1.45, the hydraulic conductivity increases significantly with the increase of the void ratio. Under the same void ratio conditions, the hydraulic conductivity of the calcareous sand sample is greater than that of shelly sand sample, and the difference increases with the increase of void ratio. The reason why the hydraulic conductivity of the calcareous sand sample is greater than that of shelly sand sample under the same void ratio might be explained by the difference in the head loss when the water flows through the sand column per unit length. This difference might be caused by the different particle shape. 

Key words: hydraulic conductivity, particle shape, void ratio, relative density

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