主应力轴变化下各向异性钙质砂的定轴剪切特性

doi:10.11779/CJGE2020S1005

摘要
图/表
参考文献
相关文章 (15)

全文: PDF (1099 KB) HTML (1 KB)
输出: BibTeX | EndNote (RIS)

摘要为探究各向异性南海钙质砂的剪切特性,利用GDS空心圆柱扭剪仪,通过不同大主应力方向上的定轴剪切试验,对比分析了钙质砂和石英砂的原生各向异性,揭示了原生各向异性对强度和孔压的影响。结果表明：钙质砂和石英砂在强度上均表现出各向异性,随着大主应力方向角α（大主应力方向与竖直方向夹角）的增大,强度先降低后增加,在α=70°时最低;钙质砂原生各向异性更为显著,不同大主应力方向上钙质砂的强度变化幅度约为石英砂的1.4~1.5倍;钙质砂和石英砂破坏时的孔压值都随着α的增大而增大,破坏时的状态也都由趋于剪胀逐渐向趋于剪缩变化;与石英砂不同的是,钙质砂破坏时亨开尔孔压系数的最大值出现在α=70°,而非α=90°;钙质砂各应变分量开展程度在不同大主应力方向上表现出差异性,破坏时的径向应变随大主应力方向角变化幅度最小,破坏时的扭剪应变随大主应力方向角变化幅度最大。

	服务

	把本文推荐给朋友
	加入我的书架
	加入引用管理器
	E-mail Alert
	RSS
	作者相关文章
	沈扬
	梁晖
	葛华阳
	俞演名
	沈雪

关键词 ：钙质砂, 主应力轴变化, 各向异性, 定轴剪切特性

Abstract：In order to explore the shear characteristics of anisotropic calcareous sand, the GDS hollow cylinder torsional shear apparatus is used to compare and analyze the anisotropy of calcareous sand and quartz sand through the fixed-axis shear tests in different directions of large principal stress to reveal the effects of inherent anisotropy on strength and pore pressure. The results show that both the calcareous sand and the quartz sand exhibit anisotropy in strength. As the large principal stress direction angle α (the angle between the large principal stress direction and the vertical direction) increases, the strength decreases first and then increases, and reach the minimum when α = 70°. The anisotropy of calcareous sand is more pronounced, and the magnitude of change in strength of calcareous sand in different directions of large principal stress is about 1.4 to 1.5 times that of quartz sand. The pore pressure values of the calcareous sand and quartz sand both increase with the increase of α, and the state of failure also gradually changes from tending to dilatancy to shrinking. Different from that of the quartz sand, the maximum value of Henkel's pore pressure coefficient appears at α = 70° instead of α = 90°. The radial strain ε_r at the time of failure has the smallest amplitude change with the direction angle of the large principal stress, and the torsional shear strain γ_zθ has the largest one.

Key words： calcareous sand variation of principal stress axes anisotropy fixed-axis shear characteristic

收稿日期: 2020-06-03

ZTFLH:

TU435

基金资助:国家自然科学基金项目（51979087）

作者简介: 沈扬(1980— ),男,博士,教授,博士生导师,主要从事土体静动力学特性和本构方面理论的研究工作。E-mail: shenyang1998@163.com。

引用本文:

沈扬, 梁晖, 葛华阳, 俞演名, 沈雪. 主应力轴变化下各向异性钙质砂的定轴剪切特性[J]. 岩土工程学报, 2020, 42(S1): 22-26. SHEN Yang, LIANG Hui, GE Hua-yang, YU Yan-ming, SHEN Xue. Fixed-axis shear characteristics of anisotropic calcareous sand under variation of principal stress axes. Chinese J. Geot. Eng., 2020, 42(S1): 22-26.

链接本文:

http://manu31.magtech.com.cn/Jwk_ytgcxb/CN/10.11779/CJGE2020S1005 或 http://manu31.magtech.com.cn/Jwk_ytgcxb/CN/Y2020/V42/IS1/22

[1] ARTHUR J R F, MENZIES B K. Inherent anisotropy in a sand[J]. Géotechnique, 1972, 22(1): 115-128.
[2] ODA M.Experimental study of anisotropic shear strength of sand by plane strain tests[J]. Soils and Foundations, 1978, 18(1): 25-38.
[3] YAMADA Y, ISHIHARA K.Anisotropic deformation characteristics of sand under three-dimensional stress conditions[J]. Soils and Foundations, 1979, 19(2): 79-94.
[4] 于艺林, 张建民, 童朝霞, 等. 定轴排水剪切试验中各向异性砂土的力学响应[J]. 岩土力学, 2011, 32(6): 1637-1642.
(YU Yi-lin, ZHANG Jian-min, TONG Zhao-xia, et al.Behavior of anisotropic mica sand under fixed principal stress axes drained shear test[J]. Rock and Soil Mechanics, 2011, 32(6): 1637-1642. (in Chinese))
[5] 扈萍, 魏超, 杨令强, 等. 定轴剪切实验中砂土的非共轴变形特性[J]. 济南大学学报(自然科学版), 2017, 31(6): 478-484.
(HU Ping, WEI Chao, YANG Ling-qiang, et al.Non-coaxial behavior of sands in fixed principal stress axes shear tests[J]. Journal of University of Jinan (Science and Technology), 2017, 31(6): 478-484. (in Chinese))
[6] SYMES M J, GENS A, HIGHT D W.Undrained anisotropy and principal stress rotation in saturated sand[J]. Géotechnique, 1984, 34(1): 11-27.
[7] NATAKA Y, HYODO M, et al.Flow deformation of sands subjected to principal stress rotation[J]. Soils and Foundations, 1998, 38(2): 115-128.
[8] 吴京平, 楼志刚. 海洋桩基工程中的钙质土[J]. 中国海洋平台, 1994(增刊1): 462-465.
(WU Jing-ping, LOU Zhi-gang.Calcareous soil in marine pile foundation engineering[J]. The Ocean Engineering, 1994(Z1): 462-465. (in Chinese))
[9] WANG X Z, WANG X, JIN Z C, et al.Shear characteristics of calcareous gravelly soil[J]. Bulletin of Engineering Geology and the Environment, 2017, 76(2): 561-573.
[10] 沈扬, 沈雪, 俞演名, 等. 粒组含量对钙质砂压缩变形特性影响的宏细观研究[J]. 岩土力学, 2019, 40(10): 3733-3740.
(SHEN Yang, SHEN Xue, YU Yan-ming, et al.Macro-micro study on compressive deformation properties of calcareous sand with different gradations[J]. Rock and Soil Mechanics, 2019, 40(10): 3733-3740. (in Chinese))
[11] YANG Z X, LI X S, YANG J.Quantifying and modelling fabric anisotropy of granular soils[J]. Géotechnique, 2008, 58(4): 237-248.
[12] 庄丽, 宫全美. 减围压平面应变压缩试验条件下丰浦砂中剪切带特性研究[J]. 岩土力学, 2016, 37(增刊1): 201-208.
(ZHUANG Li, GONG Quan-mei.Shear band characteristics of Toyoura sand in plane strain compression with decreasing confining pressure[J]. Rock and Soil Mechanics, 2016, 37(S1): 201-208. (in Chinese))