›› 2018, Vol. 39 ›› Issue (9): 3203-3212.doi: 10.16285/j.rsm.2016.3009

• 基础理论与实验研究 • 上一篇    下一篇

考虑钙质砂细观颗粒形状影响的液体拖曳力系数试验

吴 野,王 胤,杨 庆   

  1. 大连理工大学 海岸和近海工程国家重点实验室,辽宁 大连 116024
  • 收稿日期:2016-12-29 出版日期:2018-09-11 发布日期:2018-10-08
  • 通讯作者: 杨庆,男,1964年生,博士,教授,主要从事岩土工程及工程地质方面的研究工作。E-mail: qyang@dlut.edu.cn E-mail:13795135125@163.com
  • 作者简介:吴野,男,1991年生,硕士,主要从事海洋土试验研究方面的工作。
  • 基金资助:

    国家自然科学基金(No.41572252);国家自然科学基金青年基金(No.51409036)。

Experiment on drag force coefficient of calcareous sand in liquid considering the effect of particle shape

WU Ye, WANG Yin, YANG Qing   

  1. State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology, Dalian, Liaoning 116024, China
  • Received:2016-12-29 Online:2018-09-11 Published:2018-10-08
  • Supported by:

    This work was supported by the National Natural Science Foundation of China (41572252) and the Young Foudation of the National Natural Science of China (51409036).

摘要: 钙质砂作为南海岛礁填筑常用的岩土材料,其渗透性很大程度上决定着填筑后土体的固结和沉降。拖曳力系数是表达流体对土体颗粒表面力的参数,也是表征颗粒状土体渗透能力的一个重要参数,目前国内外对钙质砂拖曳力系数的研究十分有限。首先引入一个修正的三维参数 对钙质砂这种天然非规则颗粒材料的形状进行定量描述,然后开展一系列单个钙质砂颗粒在液体中沉降试验,利用高速相机记录颗粒沉降过程,结合图像处理技术获得颗粒沉降平衡速度Ut,进而计算出拖曳力系数CD和雷诺数Re,最后拟合出包含CD、Re及 三个参数的钙质砂拖曳力系数半经验模型。结果发现,在相同雷诺数条件下钙质砂的形状系数 越大,拖曳力系数越小。通过与其他研究结果对比发现,其表面微孔隙越发育,拖曳力系数越小的规律。该模型能够考虑不规则颗粒形状对拖曳力系数的影响,从而提高对土体渗透性预测的精度,对南海岛礁填筑工程中钙质砂固结和沉降的计算也具有重要意义。

关键词: 钙质砂, 形状系数, 拖曳力系数, 雷诺数, 沉降试验

Abstract: Calcareous sand is often used as filling material in construction of artificial islands in South China Sea. The permeability of calcareous sand has significant influence on the consolidation and settlement of soil mass. The drag force coefficient, which expresses the fluid drag force on particle surface, likewise an important parameter that characterizes the permeability of calcareous sand, is not extensively studied by researchers so far. In this study, a modified three-dimensional shape coefficient is introduced to quantitatively evaluate the shape of calcareous sand. A series of single calcareous sand particle settling tests is carried out in which a high-speed camera is employed to record the settling course and imaging technique is used to obtain the terminal equilibrium settling velocity of the sand particle. By doing so, the drag force coefficient-CD and Reynolds number-Re can be determined. The experimental results show that for the same Reynolds number, the drag force coefficient increases as the shape coefficient increases. Through a comparison with other test results, it is found that the richness of particle surface pores of calcareous sand can reduce the drag force coefficient. Finally, a semi-empirical model of the drag force coefficient for calcareous sand including CD, Re and , is obtained. This model will improve the prediction of permeability of soil mass especially with particles of irregular shapes. This improvement of drag force coefficient model has the significance on the analysis of the consolidation and settlement of foundations or artificial islands filled with calcareous sand in South China Sea.

Key words: calcareous sand, particle shape coefficient, drag force coefficient, Reynolds number, settling tests

中图分类号: 

  • TU 411
[1] 熊 峰,孙 昊,姜清辉,叶祖洋,薛道锐,刘乳燕,. 粗糙岩石裂隙低速非线性渗流模型及试验验证[J]. , 2018, 39(9): 3294-3302.
[2] 陈 杨,杨 敏,魏厚振,李卫超,孟庆山,. 钙质砂中单桩轴向抗拔模型试验研究[J]. , 2018, 39(8): 2851-2857.
[3] 金宗川. 钙质砂的休止角研究与工程应用[J]. , 2018, 39(7): 2583-2590.
[4] 黄宏翔,陈育民,王建平,刘汉龙,周晓智,霍正格, . 钙质砂抗剪强度特性的环剪试验[J]. , 2018, 39(6): 2082-2088.
[5] 任玉宾,王 胤,杨 庆. 颗粒级配与形状对钙质砂渗透性的影响[J]. , 2018, 39(2): 491-497.
[6] 王新志,谌 民,魏厚振,孟庆山,余克服,. 车辆荷载作用下钙质砂路基的动态响应试验研究[J]. , 2018, 39(11): 4093-4101.
[7] 何建乔,魏厚振,孟庆山,王新志,韦昌富,. 大位移剪切下钙质砂破碎演化特性[J]. , 2018, 39(1): 165-172.
[8] 汪轶群,洪 义,国 振,王立忠, . 南海钙质砂宏细观破碎力学特性[J]. , 2018, 39(1): 199-206.
[9] 胡明鉴,蒋航海,崔 翔,阮 洋,刘海峰,张晨阳,. 钙质砂电导率与相关性问题初探[J]. , 2017, 38(S2): 158-162.
[10] 钱 琨 ,王新志 ,陈剑文 ,刘鹏君,. 南海岛礁吹填钙质砂渗透特性试验研究[J]. , 2017, 38(6): 1557-1564.
[11] 胡明鉴,蒋航海,朱长歧,翁贻令,阮 洋,陈伟俊, . 钙质砂的渗透特性及其影响因素探讨[J]. , 2017, 38(10): 2895-2900.
[12] 王新志 ,王 星 ,翁贻令 ,吕士展 ,阎 钶 ,朱长歧,. 钙质砂的干密度特征及其试验方法研究[J]. , 2016, 37(S2): 316-323.
[13] 秦 月,孟庆山,汪 稔,朱长歧. 钙质砂地基单桩承载特性模型试验研究[J]. , 2015, 36(6): 1714-1720.
[14] 张家铭,邵晓泉,王霄龙,胡舫瑞,左鸿鹏. 沉桩过程中钙质砂颗粒破碎特性模拟研究[J]. , 2015, 36(1): 272-278.
[15] 朱长歧 ,陈海洋 ,孟庆山 ,汪 稔,. 钙质砂颗粒内孔隙的结构特征分析[J]. , 2014, 35(7): 1831-1836.
Viewed
Full text


Abstract

Cited

  Shared   
  Discussed   
[1] 刘 润,闫 玥,闫澍旺,乔春生. 某码头软黏土岸坡破坏机制分析及重建[J]. , 2009, 30(11): 3417 -3422 .
[2] 马远刚,杨春和. 极限状态及变形量控制下自平衡试桩承载力分析[J]. , 2009, 30(9): 2787 -2791 .
[3] 张春会,于永江,赵全胜. 非均匀煤岩渗流-应力弹塑性耦合数学模型及数值模拟[J]. , 2009, 30(9): 2837 -2842 .
[4] 江 浩,汪 稔,吕颖慧,孟庆山. 钙质砂中模型桩的试验研究[J]. , 2010, 31(3): 780 -784 .
[5] 赵明华,廖彬彬,刘思思. 基于拱效应的边坡抗滑桩桩间距计算[J]. , 2010, 31(4): 1211 -1216 .
[6] 朱剑锋,陈昌富,徐日庆. 土钉墙内部稳定性分析自适应禁忌变异遗传算法[J]. , 2010, 31(5): 1663 -1669 .
[7] 胡勇刚,罗 强,张 良,黄 晶,陈亚美. 基于离心模型试验的水泥土搅拌法加固斜坡软弱土地基变形特性分析[J]. , 2010, 31(7): 2207 -2213 .
[8] 唐晓武,应 丰,寇乃羽,王周庆. 吸附离子对粉质粘土及改良土特性的影响[J]. , 2010, 31(8): 2519 -2524 .
[9] 梁健伟,房营光,谷任国. 极细颗粒黏土渗流的微电场效应分析[J]. , 2010, 31(10): 3043 -3050 .
[10] 王明年,路军富,刘大刚,张建国. 大断面海底隧道CRD法绝对位移控制基准建立及应用研究[J]. , 2010, 31(10): 3354 -3360 .