Experimental Analysis of Clay Effect and Confining Pressure Effect on Mechanical Properties of Sea Sand
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摘要: 利用GDS标准应力路径三轴试验系统,对钦州港海砂开展不同有效围压、黏粒含量下固结排水三轴剪切试验,分析有效围压、黏粒含量对钦州港海砂强度、变形特性的影响。结果表明:同一有效围压下,随着黏粒含量的增加,含黏粒海砂应力-应变曲线由应变软化型曲线向应变硬化型曲线过渡,峰值强度、应力相对软化系数及体积应变不断减小,而峰值应变增加。同一黏粒含量下,试样峰值强度随有效围压的增加逐渐增大,纯砂试样有效围压为300 kPa时的峰值强度相比于有效围压为100 kPa时提高了1.517倍,峰值强度与有效围压之间呈现良好的线性关系; 而应力相对软化系数、体积应变则随有效围压的增大而减小。最后,建立了黏粒含量在0%~20%的应力相对软化系数与有效围压、黏粒含量之间的联系。Abstract: Triaxially consolidated drained shear tests by the GDS standard stress path were conducted on the Qinzhou Port sea sand under the different effective confining pressures and clay content, which was be analyzed the effect of effective confining pressure and clay content on the strength and deformation characteristics of sea sand in Qinzhou Port. The results showed:under the same effective confining pressure, as the clay content increased, the stress-strain curves of clay-contained sea sand converted from a strain-softening curve to a strain-hardening curve. The peak strength, relative stress softening coefficient, and volumetric strain decreased steadily; the peak strain increased simultaneously. In the same clay content, the peak strength of the specimens increased gradually with the increase of the effective confining pressure. When the effective confining pressure for specimens of pure sand was 300 kPa, the peak strength of specimens was 1.517 times higher than that whose confining pressure was 100 kPa. There was a good linear relation between the effective confining pressure and the peak strength. Simultaneously, the relative softening coefficient of stress and volumetric strain decreased with the increase of the effective confining pressure. Finally, in the range of 0% to 20% of the clay content, and the relation between the relative stress softening coefficient and the effective confining pressure and clay content was established.
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Key words:
- sea sand /
- clay content /
- effective confining pressure /
- mechanical property
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[1] BAZIAR M H, DOBRY R. Residual strength and large-deformation potential of loose silty sands[J]. ASCE Journal of Geotechnical Engineering, 1995, 121(12):896-906. [2] 吴子龙, 朱向阳, 邓永锋, 等. 砂-黏土混合物的压缩性状及其粗颗粒骨架形成机制[J]. 土木工程学报, 2016, 49(2):121-128. [3] 李玲, 刘金泉, 刘造保, 等. 砂-黏土混合物高压压实性能试验研究[J]. 岩土力学, 2019, 40(9):3502-3514. [4] 冯晓腊, 张睿敏, 崔德山, 等. 基质吸力与黏粒含量对砂土抗剪强度的影响[J]. 科学技术与工程, 2017, 17(34):97-103. [5] 杨果林, 钟正, 林宇亮. 砂黏土变形与强度特性的大型三轴试验研究[J]. 铁道科学与工程学报, 2010, 7(5):25-29. [6] 周莹, 蔡有庆, 朱志慧. 波浪荷载下含细粒砂土动力特性试验研究[J]. 工业建筑, 2020, 50(5):58-65,30. [7] 唐小微, 李涛, 马玲, 等. 黏粒和砂粒混合土体的动态液化性能研究[J]. 地震工程学报, 2015, 37(1):6-10. [8] SHAHNAZARI H, REZVANI R. Effective parameters for the particle breakage of calcareous sands[J]. Engineering Geology, 2013, 159(9):98-105. [9] 蔡正银, 侯贺营, 张晋勋, 等. 密度与应力水平对珊瑚砂颗粒破碎影响试验研究[J]. 水利学报, 2019, 50(2):184-192. [10] 陈火东, 魏厚振, 孟庆山, 等. 颗粒破碎对钙质砂的应力-应变及强度影响研究[J]. 工程地质学报, 2018, 26(6):1490-1498. [11] WANG X, ZHU C Q, WANG X Z, et al. Study of dilatancy behaviors of calcareous soils in a triaxial test[J]. Marine Georesources & Geotechnology, 2019, 37(9):1057-1070. [12] 文哲, 段志刚, 李守定, 等. 中国南海岛礁吹填珊瑚砂剪切力学特性[J]. 工程地质学报, 2020, 28(1):77-84. [13] 侯贺营, 曹永勇, 张绍栋, 等. 密度及应力水平对珊瑚砂强度变形特性影响[J]. 水利水运工程学报, 2020(1):92-97. [14] 刘萌成, 胡帅峰, 戴鹏飞. 南海钙质砂不排水剪切特性三轴试验研究[J]. 中国公路学报, 2022, 35(4):69-76. [15] 张季如, 罗明星, 彭伟珂, 等. 不同应力路径下钙质砂力学特性的排水三轴试验研究[J]. 岩土工程学报, 2021, 43(4):593-602. [16] 闫超萍, 龙志林, 周益春, 等. 钙质砂剪切特性的围压效应和粒径效应研究[J]. 岩土力学, 2020, 41(2):581-591,634. [17] 黄宏翔, 陈育民, 王建平, 等. 钙质砂抗剪强度特性的环剪试验[J]. 岩土力学, 2018, 39(6):2082-2088. [18] 王家全,陈胜前,唐毅,等.北部湾地区海砂填料的动力特性分析[J].海洋工程,2020,38(5):149-155.
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