Shear strength and crushing characteristics of calcareous sand in South China Sea under the influence of three factors
-
摘要:
作为一种海源土体，南海钙质砂具有多孔、形状不均匀、易破碎等特征，而目前从细观角度开展钙质砂力学性状的研究比较有限。为获得竖向压力、剪切程度及相对密实度对钙质砂强度和颗粒破碎特性的影响规律，开展了南海饱和钙质砂直剪试验，并与陆源硅砂（中国标准砂和福建中级砂）的试验结果进行对比。结果表明：（1）不同相对密实度下的钙质砂剪应力-位移曲线趋势大致相同，且剪应力峰值基本一致，这与中国标准砂和福建中级砂受相对密实度影响规律显著不同；（2）与陆源硅砂无黏结性不同，南海钙质砂有一定“似黏聚力”，其主要原因在于南海钙质砂颗粒形状不均匀，颗粒之间存在一定的咬合作用，进而呈现出一定的黏结特性；（3）随着竖向应力的增加，钙质砂破碎逐渐由大颗粒转变为小颗粒，同时剪切程度为50%时钙质砂的破碎面主要位于相对薄弱处，而剪切程度为100%时，破碎面主要分布在单颗粒钙质砂中间位置；（4）相对破碎势与竖向应力、相对密实度及剪切程度有很好的相关性，构建的破碎势计算模型涵盖了竖向应力、相对密实度及剪切程度的影响，可在工程中推广应用。研究结果可为我国南海岛礁工程建设提供依据。
Abstract:Calcareous sand, a type of marine soil found in the South China Sea, is characterized by its porous nature, irregular particle shape, and susceptibility to breakage. However, few studies have examined the mechanical properties of calcareous sand from the microscopic perspective. To investigate the impact of vertical pressure , shear degree and relative density on the strength and particle breakage characteristics of calcareous sand, direct shear tests were conducted on saturated calcareous sand from the South China Sea. A comparative analysis was performed with the test results of terrestrial silica sand, namely Chinese standard sand and Fujian intermediate sand. It is found that both the trend of stress-displacement curve and the peak shear stress values exhibit a similar behavior for calcareous sand under different relative compaction, which were distinctly different from the influence of relative compaction on Chinese standard sand and Fujian intermediate sand. The calcareous sand in the South China Sea exhibit a noteworthy “similar cohesion”, a feature that distinguishes it from the non-cohesiveness of terrigenous silica sand. This cohesion in calcareous sand is attributed to the non-uniform shape of its particles and featuring interlocking between particles, presenting certain bonding characteristics.As the vertical stress increases, the crushing of calcareous sand gradually changes from large particles to small particles. At a shear degree approaching 50%, the crushing surface of calcareous sand occurs mainly at a relatively weak position. However, at the shear degree approaching 100%, the primary crushing surface predominantly occurrs in the middle of individual calcareous sand particles. The relative breaking potential demonstrates a strong correlation with vertical stress, relative compaction, and shear degree. The developed empirical model for breaking potential, which takes all three factors into account, holds significant potential for practical applications in engineering. The findings provide valuable insights for the construction of islands and reefs in the South China Sea.
-
Key words:
- calcareous sand /
- direct shear test /
- crushing of particles /
- relative density /
- breaking potential
-
-
表 1 基本物理指标
Table 1. Basic physical indicators
材料 物理指标 Gs emax emin Cc Cu ISO砂 2.626 0.764 0.377 1.081 3.269 FJZ砂 2.672 0.928 0.647 0.925 1.443 钙质砂 2.639 1.344 1.094 0.894 2.173 
下载: 导出CSV
表 2 试验方案
Table 2. Test project
试样编号 试验对象 Sr/% Dr σv/kPa SD/% DS-1 ISO砂 100 0.2, 0.4,
0.6, 0.850, 100, 200,
300, 400— DS-2 FJZ砂 — DS-3 钙质砂 50, 100 注：Sr为试样饱和度。
下载: 导出CSV
表 3 不同Dr下饱和钙质砂直剪试验强度指标
Table 3. Strength parameters for direct shearing test of saturated calcareous sand under different Dr
强度指标 Dr 0.2 0.4 0.6 0.8 φ′/（°） 16.22 16.38 17.17 17.33 c′/kPa 4.160 4.265 4.413 4.637
下载: 导出CSV
表 4 不同Dr下南海饱和钙质砂破碎势实测值与预测值
Table 4. Measured values and predicted values of South China Sea saturated calcareous sand under different Dr
Dr 破碎势 实测值 预测值 相对误差/% 0.5 2.048 2.132 4.100 0.7 2.852 2.778 2.664
下载: 导出CSV
表 5 不同σv下南海饱和钙质砂破碎势实测值与预测值
Table 5. Measured values and predicted values of South China Sea saturated calcareous sand under different σv
σv/kPa 破碎势 实测值 预测值 相对误差/% 150 1.261 1.288 2.14 250 1.899 1.836 3.43
下载: 导出CSV
表 6 不同SD下南海饱和钙质砂破碎势实测值与预测值
Table 6. Measured values and predicted values of South China Sea saturated calcareous sand under different SD
SD/% 破碎势 实测值 预测值 相对误差/% 60 2.048 2.132 4.10 90 3.679 3.578 2.82
下载: 导出CSV
-
[1] 中国科学院南沙群岛综合科学考察队. 南沙群岛自然地理[M]. 北京:科学出版社,1996. [The Nansha Islands Comprehensive Scientific Expedition Team of the Chinese Academy of Sciences. Physical geography of Nansha Islands[M]. Beijing:Science Press,1996. (In Chinese)]
The Nansha Islands Comprehensive Scientific Expedition Team of the Chinese Academy of Sciences. Physical geography of Nansha Islands[M]. Beijing: Science Press, 1996. （In Chinese）
[2] 王新志,王星,刘海峰,等. 珊瑚礁地基工程特性现场试验研究[J]. 岩土力学,2017,38(7):2065 − 2070. [WANG Xinzhi,WANG Xing,LIU Haifeng,et al. Field test study of engineering behaviors of coral reef foundation[J]. Rock and Soil Mechanics,2017,38(7):2065 − 2070. (in Chinese with English abstract)]
WANG Xinzhi, WANG Xing, LIU Haifeng, et al. Field test study of engineering behaviors of coral reef foundation[J]. Rock and Soil Mechanics, 2017, 38（7）: 2065 − 2070. （in Chinese with English abstract）
[3] 朱长歧,陈海洋,孟庆山,等. 钙质砂颗粒内孔隙的结构特征分析[J]. 岩土力学,2014,35(7):1831 − 1836. [ZHU Changqi,CHEN Haiyang,MENG Qingshan,et al. Microscopic characterization of intra-pore structures of calcareous sands[J]. Rock and Soil Mechanics,2014,35(7):1831 − 1836. (in Chinese with English abstract)]
ZHU Changqi, CHEN Haiyang, MENG Qingshan, et al. Microscopic characterization of intra-pore structures of calcareous sands[J]. Rock and Soil Mechanics, 2014, 35（7）: 1831 − 1836. （in Chinese with English abstract）
[4] 张家铭,蒋国盛,汪稔. 颗粒破碎及剪胀对钙质砂抗剪强度影响研究[J]. 岩土力学,2015,30(7):2043 − 2048. [ZHANG Jiaming,JIANG Guosheng,WANG Ren. Study on the influence of particle breakage and dilatancy on the shear strength of calcareous sand[J]. Rock and Soil Mechanics,2015,30(7):2043 − 2048. (in Chinese with English abstract)]
ZHANG Jiaming, JIANG Guosheng, WANG Ren. Study on the influence of particle breakage and dilatancy on the shear strength of calcareous sand[J]. Rock and Soil Mechanics, 2015, 30（7）: 2043 − 2048. （in Chinese with English abstract）
[5] 秦月,姚婷,汪稔,等. 基于颗粒破碎的钙质沉积物高压固结变形分析[J]. 岩土力学,2014,35(11):3123 − 3128. [QIN Yue,YAO Ting,WANG Ren,et al. Particle breakage-based analysis of deformation law of calcareous sediments under high-pressure consolidation[J]. Rock and Soil Mechanics,2014,35(11):3123 − 3128. (in Chinese with English abstract)]
QIN Yue, YAO Ting, WANG Ren, et al. Particle breakage-based analysis of deformation law of calcareous sediments under high-pressure consolidation[J]. Rock and Soil Mechanics, 2014, 35（11）: 3123 − 3128. （in Chinese with English abstract）
[6] 钟丽,陈鑫莲,刘晓璇,等. 不同应力路径下钙质砂的力学及变形特性试验研究[J]. 岩土力学,2023,44(10):2929 − 2941. [ZHONG Li,CHEN Xinlian,LIU Xiaoxuan,et al. Experimental study on the mechanical and deformation characteristics of calcareous sand under different stress paths[J]. Rock and Soil Mechanics,2023,44(10):2929 − 2941. (in Chinese with English abstract)]
ZHONG Li, CHEN Xinlian, LIU Xiaoxuan, et al. Experimental study on the mechanical and deformation characteristics of calcareous sand under different stress paths[J]. Rock and Soil Mechanics, 2023, 44（10）: 2929 − 2941. （in Chinese with English abstract）
[7] 黄良,刘鑫,兰恒星. 钙质砂特征形状分析及不排水剪切强度研究[J]. 工程地质学报,2024,32(2):378 − 386. [HUANG Liang,LIU Xin,LAN Hengxing. Investigation on characteristic shape of calcareous sand and associated effect on undrained shear strength[J]. Journal of Engineering Geology,2024,32(2):378 − 386. (in Chinese with English abstract)]
HUANG Liang, LIU Xin, LAN Hengxing. Investigation on characteristic shape of calcareous sand and associated effect on undrained shear strength[J]. Journal of Engineering Geology, 2024, 32（2）: 378 − 386. （in Chinese with English abstract）
[8] 刘萌成,陈茂林,王涓. 钙质砂固结排水剪切特性三轴试验[J]. 中国公路学报,2023,36(1):47 − 57. [LIU Mengcheng,CHEN Maolin,WANG Juan. Investigation of shear behavior of calcareous sand in consolidated and drained triaxial tests[J]. China Journal of Highway and Transport,2023,36(1):47 − 57. (in Chinese with English abstract)]
LIU Mengcheng, CHEN Maolin, WANG Juan. Investigation of shear behavior of calcareous sand in consolidated and drained triaxial tests[J]. China Journal of Highway and Transport, 2023, 36（1）: 47 − 57. （in Chinese with English abstract）
[9] LADE P V,LIGGIO C D,NAM J,et al. Strain rate,creep,and stress drop-creep experiments on crushed coral sand[J]. Journal of Geotechnical and Geoenvironmental Engineering,2009,135(7):941 − 953. doi: 10.1061/(ASCE)GT.1943-5606.0000067
[10] 张家铭,张凌,刘慧,等. 钙质砂剪切特性试验研究[J]. 岩石力学与工程学报,2008(增刊1):3010 − 3015. [ZHANG Jiaming,ZHANG Ling,LIU Hui,et al. Experimental research on shear behavior of calcareous sand[J]. Chinese Journal of Rock Mechanics and Engineering,2008(Sup1):3010 − 3015. (in Chinese with English abstract)]
ZHANG Jiaming, ZHANG Ling, LIU Hui, et al. Experimental research on shear behavior of calcareous sand[J]. Chinese Journal of Rock Mechanics and Engineering, 2008（Sup1）: 3010 − 3015. （in Chinese with English abstract）
[11] BRANDES H G. Simple shear behavior of calcareous and quartz sands[J]. Geotechnical and Geological Engineering,2011,29(1):113 − 126. doi: 10.1007/s10706-010-9357-x
[12] WANG Xing,ZHU Changqi,WANG Xinzhi,et al. Study of dilatancy behaviors of calcareous soils in a triaxial test[J]. Marine Georesources & Geotechnology,2018,37(9):1057 − 1070.
[13] 高雪,高燕,孙可天,等. 剪切过程中钙质砂的颗粒破碎与能量演化[J]. 中山大学学报(自然科学版中英文),2023,62(6):11 − 21. [GAO Xue,GAO Yan,SUN Ketian,et al. Particle breakage and energy evolution of calcareous sand during shearing process[J]. Acta Scientiarum Naturalium Universitatis Sunyatseni,2023,62(6):11 − 21. (in Chinese with English abstract)]
GAO Xue, GAO Yan, SUN Ketian, et al. Particle breakage and energy evolution of calcareous sand during shearing process[J]. Acta Scientiarum Naturalium Universitatis Sunyatseni, 2023, 62（6）: 11 − 21. （in Chinese with English abstract）
[14] 高敏,何绍衡,夏唐代,等. 复杂应力路径下钙质砂颗粒破碎及抗剪强度特性[J]. 岩土力学,2022,43(增刊1):321 − 330. [GAO Min,HE Shaoheng,XIA Tangdai,et al. Particles breakage and shear strength characteristic of calcareous sand under complex stress path[J]. Rock and Soil Mechanics,2022,43(Sup1):321 − 330. (in Chinese with English abstract)]
GAO Min, HE Shaoheng, XIA Tangdai, et al. Particles breakage and shear strength characteristic of calcareous sand under complex stress path[J]. Rock and Soil Mechanics, 2022, 43（Sup1）: 321 − 330. （in Chinese with English abstract）
[15] 王青,侯贺营,康鑫睿,等. 直剪条件下钙质砂强度及颗粒破碎[J]. 科学技术与工程,2022,22(15):6240 − 6247. [WANG Qing,HOU Heying,KANG Xinrui,et al. Strength and particle breakage of calcareous sand under direct shear test[J]. Science Technology and Engineering,2022,22(15):6240 − 6247. (in Chinese with English abstract)] doi: 10.3969/j.issn.1671-1815.2022.15.036
WANG Qing, HOU Heying, KANG Xinrui, et al. Strength and particle breakage of calcareous sand under direct shear test[J]. Science Technology and Engineering, 2022, 22（15）: 6240 − 6247. （in Chinese with English abstract） doi: 10.3969/j.issn.1671-1815.2022.15.036
[16] LÜ Yaru,LIU Jiagui,XIONG Ziming. One-dimensional dynamic compressive behavior of dry calcareous sand at high strain rates[J]. Journal of Rock Mechanics and Geotechnical Engineering,2018,11(1):192 − 201.
[17] 张季如,华晨,罗明星,等. 三轴排水剪切下钙质砂的颗粒破碎特性[J]. 岩土工程学报,2020,42(9):1593 − 1602. [ZHANG Jiru,HUA Chen,LUO Mingxing,et al. Behavior of particle breakage in calcareous sand during drained triaxial shearing[J]. Chinese Journal of Geotechnical Engineering,2020,42(9):1593 − 1602. (in Chinese with English abstract)]
ZHANG Jiru, HUA Chen, LUO Mingxing, et al. Behavior of particle breakage in calcareous sand during drained triaxial shearing[J]. Chinese Journal of Geotechnical Engineering, 2020, 42（9）: 1593 − 1602. （in Chinese with English abstract）
[18] 吴野,王胤,杨庆. 考虑钙质砂细观颗粒形状影响的液体拖曳力系数试验[J]. 岩土力学,2018,39(9):3203 − 3212. [WU Ye,WANG Yin,YANG Qing. Experiment on drag force coefficient of calcareous sand in liquid considering the effect of particle shape[J]. Rock and Soil Mechanics,2018,39(9):3203 − 3212. (in Chinese with English abstract)]
WU Ye, WANG Yin, YANG Qing. Experiment on drag force coefficient of calcareous sand in liquid considering the effect of particle shape[J]. Rock and Soil Mechanics, 2018, 39（9）: 3203 − 3212. （in Chinese with English abstract）
[19] 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 Yanming,et al. Macro-micro study of compressive deformation properties of calcareous sand with different particle fraction contents[J]. Rock and Soil Mechanics,2019,40(10):3733 − 3740. (in Chinese with English abstract)]
SHEN Yang, SHEN Xue, YU Yanming, et al. Macro-micro study of compressive deformation properties of calcareous sand with different particle fraction contents[J]. Rock and Soil Mechanics, 2019, 40（10）: 3733 − 3740. （in Chinese with English abstract）
[20] XU Dongsheng,HUANG Ming,ZHOU Yang. One-dimensional compression behavior of calcareous sand and marine clay mixtures[J]. International Journal of Geomechanics,2020,20(9):04020137. doi: 10.1061/(ASCE)GM.1943-5622.0001763
[21] XU Dongsheng,LIU Huabei,RUI Rui,et al. Cyclic and postcyclic simple shear behavior of binary sand-gravel mixtures with various gravel contents[J]. Soil Dynamics and Earthquake Engineering,2019,123:230 − 241. doi: 10.1016/j.soildyn.2019.04.030
[22] XU Dongsheng,TANG Zhiyuan,ZHANG Lei. Interpretation of coarse effect in simple shear behavior of binary sand-gravel mixture by DEM with authentic particle shape[J]. Construction and Building Materials,2019,195:292 − 304. doi: 10.1016/j.conbuildmat.2018.11.059
[23] 中华人民共和国住房和城乡建设部. 土工试验方法标准:GB/T 50123—2019[S]. 北京:中国计划出版社,2019. [Ministry of Housing and Urban-Rural Development of the People’s Republic of China. Standard for geotechnical testing method:GB/T 50123—2019[S]. Beijing:China Planning Press,2019. (in Chinese)]
Ministry of Housing and Urban-Rural Development of the People’s Republic of China. Standard for geotechnical testing method: GB/T 50123—2019[S]. Beijing: China Planning Press, 2019. （in Chinese）
[24] 肖建勇,严伟,乔世范,等. 干密度与含水率对标准砂抗剪强度的影响研究[J]. 铁道科学与工程学报,2023,20(10):3789 − 3797. [XIAO Jianyong,YAN Wei,QIAO Shifan,et al. Experimental research on the influence of dry density and moisture content on the shear strength of standard sand[J]. Journal of Railway Science and Engineering,2023,20(10):3789 − 3797. (in Chinese with English abstract)]
XIAO Jianyong, YAN Wei, QIAO Shifan, et al. Experimental research on the influence of dry density and moisture content on the shear strength of standard sand[J]. Journal of Railway Science and Engineering, 2023, 20（10）: 3789 − 3797. （in Chinese with English abstract）
[25] 姚强岭,王伟男,杨书懿,等. 含水率影响下砂质泥岩直剪特性及声发射特征[J]. 煤炭学报,2021,46(9):2910 − 2922. [YAO Qiangling,WANG Weinan,YANG Shuyi,et al. Direct shear and acoustic emission characteristics of sandy mudstone under the effect of moisture content[J]. Journal of China Coal Society,2021,46(9):2910 − 2922. (in Chinese with English abstract)]
YAO Qiangling, WANG Weinan, YANG Shuyi, et al. Direct shear and acoustic emission characteristics of sandy mudstone under the effect of moisture content[J]. Journal of China Coal Society, 2021, 46（9）: 2910 − 2922. （in Chinese with English abstract）
[26] 王新志,翁贻令,王星,等. 钙质土颗粒咬合作用机制[J]. 岩土力学,2018,39(9):3113 − 3120. [WANG Xinzhi,WENG Yiling,WANG Xing,et al. Interlocking mechanism of calcareous soil[J]. Rock and Soil Mechanics,2018,39(9):3113 − 3120. (in Chinese with English abstract)]
WANG Xinzhi, WENG Yiling, WANG Xing, et al. Interlocking mechanism of calcareous soil[J]. Rock and Soil Mechanics, 2018, 39（9）: 3113 − 3120. （in Chinese with English abstract）
[27] TERZAGHI K,PECK R B,MESRI G. Soil mechanics in engineering practice[M]. 3rd ed. New York:Wiley,1996.
[28] 刘杰,姚志华,翁兴中,等. 三轴剪切下珊瑚砂颗粒破碎规律及强度特征[J]. 地下空间与工程学报,2021,17(5):1463 − 1471. [LIU Jie,YAO Zhihua,WENG Xingzhong,et al. Particles breaking regularity and strength characteristics of coral sand under triaxial shear conditions[J]. Chinese Journal of Underground Space and Engineering,2021,17(5):1463 − 1471. (in Chinese with English abstract)]
LIU Jie, YAO Zhihua, WENG Xingzhong, et al. Particles breaking regularity and strength characteristics of coral sand under triaxial shear conditions[J]. Chinese Journal of Underground Space and Engineering, 2021, 17（5）: 1463 − 1471. （in Chinese with English abstract）
[29] 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. [YAN Chaoping,LONG Zhilin,ZHOU Yichun,et al. Investigation on the effects of confining pressure and particle size of shear characteristics of calcareous sand[J]. Rock and Soil Mechanics,2020,41(2):581 − 591. (in Chinese with English abstract)]
YAN Chaoping, LONG Zhilin, ZHOU Yichun, et al. Investigation on the effects of confining pressure and particle size of shear characteristics of calcareous sand[J]. Rock and Soil Mechanics, 2020, 41（2）: 581 − 591. （in Chinese with English abstract）
[30] HARDIN B O. Crushing of soil particles[J]. Journal of Geotechnical Engineering,1985,111(10):1177 − 1192. doi: 10.1061/(ASCE)0733-9410(1985)111:10(1177)
-
图(16)
表(6)
计量
- 文章访问数: 20
- PDF下载数: 5
- 施引文献: 0