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| Analysis of the strength behaviour of cemented sands in true triaxial test with distinct element method |
| ZHANG Fuguang1，2，3，4，JIANG Mingjing3，4，5 |
(1. School of Civil Engineering，Shijiazhuang Tiedao University，Shijiazhuang，Hebei 050043，China；2. Key Laboratory of Roads and Railway Engineering Safety Control of Ministry of Education，Shijiazhuang Tiedao University，Shijiazhuang，Hebei 050043，China；3. Department of Geotechnical Engineering，Tongji University，Shanghai 200092，China；4. Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education，Tongji University，Shanghai 200092，China；5. Department of Civil Engineering，Tianjin University，Tianjin 300072，China)
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Abstract This paper presented three-dimensional(3D) distinct element method(DEM) at the micro- and macro- scale to investigate the strength behaviour of cemented sands in true triaxial tests. A DEM program incorporating a 3D bond contact model was used to simulate the true triaxial tests on cemented specimens under two mean stresses(i.e.，pre-yield and post-yield stresses，100 and 800 kPa，respectively)，and the DEM results were compared with the available experimental data. The underlying mechanism of the strength behaviour was discussed at the microscopic scale. The results show that，when the applied mean stress is lower than the structural yield stress，the stress-strain relationships exhibit obvious strain softening，and that，when the applied mean stress exceeds the structural yield stress，the strain hardening occurs. The stress-strain relationships are affected by the intermediate stress ratio. As the intermediate stress ratio increases，the normalized peak strength decreases gradually，which is in agreement with the experimental data. The modified Lade-Duncan failure criterion can predict the peak strength under p = 100 kPa and 800 kPa，while the extended SMP failure criterion can predict the peak strength under p = 100 kPa，but overestimate the peak strength under p = 800 kPa. At the microscopic scale，the macroscopic mechanical responses of cemented sands are primarily controlled by the contacts transmitting greater-than-average forces within the whole specimen. As the intermediate stress ratio increases，the distribution of the normal contact forces tends to be non-uniform，which leads to lower strength.
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[1] SANTAMARINA J C，KLEIN A，FAM M A. Soils and waves[M]. New York：John Wiley and Sons，2001：25–54.
[2] MITCHELL J K，SOGA K. Fundamentals of soil behavior，3rd edition[M]. New York：John Wiley and Sons，2005：5–33.
[3] BROMS B B，BOMAN P. Lime columns-a new foundation method[J]. Journal of Geotechnical and Geoenvironmental Engineering，1979，105(4)：539–556.
[4] 徐至钧，曹名葆. 水泥土搅拌法处理地基[M]. 北京：机械工业出版社，2004：1–7.(XU Zhijun，CAO Mingbao. Cement-soil mixing method and treatment of foundation[M]. Beijing：China Machine Press，2004：1–7.(in Chinese))
[5] CONSOLI N C，DALLA ROSA F，FONINI A. Plate load tests on cemented soil layers overlaying weaker soil[J]. Journal of Geotechnical and Geoenvironmental Engineering，2009，135(12)：1 846–1 856.
[6] 宋新江. 水泥土截渗墙渗透与力学特性研究[博士学位论文][D]. 南京：河海大学，2010.(SONG Xinjiang. Study on seepage behavior and mechanical property of cement-soil impermeable wall[Ph. D. Thesis][D]. Nanjing：Hohai University，2010.(in Chinese))
[7] VOOTTIPRUEX P，BERGADO D T，SUKSAWAT T，et al. Behavior and simulation of deep cement mixing(DCM) and stiffened deep cement mixing(SDCM) piles under full scale loading[J]. Soils and Foundations，2011，51(2)：307–320.
[8] REDDY K R，SAXENA S K. Effects of cementation on stress-strain and strength characteristics of sands[J]. Soils and Foundations，1993，33(4)：121–134.
[9] MATSUOKA H，SUN D A. Extension of spatially mobilized plane (SMP) to frictional and cohesive materials and its application to cemented sands[J]. Soils and Foundations，1995，35(4)：63–72.
[10] 宋新江，徐海波，周文渊，等. 水泥土应力–应变特性真三轴试验研究[J]. 岩土力学，2016，37(9)：2 489–2 495.(SONG Xinjiang，XU Haibo，ZHOU Wenyuan，et al. True triaxial test on stress-strain characteristics of cement-soil[J]. Rock and Soil Mechanics，2016，37(9)：2 489–2 495.(in Chinese))
[11] 陈昌禄，邵生俊，罗爱忠，等. 结构性对原状黄土强度影响规律的真三轴试验研究[J]. 岩土工程学报，2013，35(12)：2 322–2 327. (CHEN Changlu，SHAO Shengjun，LUO Aizhong，et al. True triaxial tests on structural effects on strength of intact loess[J]. Chinese Journal of Geotechnical Engineering，2013，35(12)：2 322–2 327. (in Chinese))
[12] 陈昌禄，邵生俊，张 喆. 人工制备结构性黄土的真三轴试验研究[J]. 岩土力学，2013，34(8)：2 231–2 237.(CHEN Changlu，SHAO Shengjun，ZHANG Zhe. Study of artificial structural loess under true triaxial tests[J]. Rock and Soil Mechanics，2013，34(8)：2 231–2 237. (in Chinese))
[13] CUNDALL P A，STRACK O D L. Discrete numerical model for granular assemblies[J]. Géotechnique，1979，29(1)：47–65.
[14] WANG Y H，LEUNG S C. A particulate-scale investigation of cemented sand behavior[J]. Canadian Geotechnical Journal，2008，45(1)：29–44.
[15] JIANG M J，LIU J D，SUN Y G，et al. Investigation into macroscopic and microscopic behaviors of bonded sands using distinct element method[J]. Soils and Foundations，2013，53(6)：804–819.
[16] ESTRADA N，TABOADA A. Yield surfaces and plastic potentials of cemented granular materials from discrete element simulations[J]. Computers and Geotechnics，2013，49：62–69.
[17] DE BONO J P，MCDOWELL G R. Discrete element modelling of one-dimensional compression of cemented sand[J]. Granular Matter，2014，16(1)：79–90.
[18] BROWN N J，CHEN J F，OOI J Y. A bond model for DEM simulation of cementitious materials and deformable structures[J]. Granular Matter，2014，16：299–311.
[19] JIANG M J，ZHANG F G，THORNTON C. A simple three-dimensional distinct element modeling of the mechanical behavior of bonded sands[J]. International Journal for Numerical and Analytical Methods in Geomechanics，2015，39(16)：1 791–1 820.
[20] 蒋明镜，廖优斌，刘 蔚，等. 考虑胶结强度正态分布下砂土力学特性离散元模拟[J]. 岩土工程学报，2016，38(增2)：1–6.(JIANG Mingjing，LIAO Youbin，LIU Wei，et al. DEM simulation of mechanical behaviour of cemented sand under normal distribution of cementation strength[J]. Chinese Journal of Geotechnical Engineering，2016，38(Supp.2)：1–6.(in Chinese))
[21] SCHÖPFER M P J，CHILDS C，MANZOCCHI T. Three-dimensional failure envelopes and the brittle-ductile transition[J]. Journal of Geophysical Research：Solid Earth，2013，118(4)：1 378–1 392.
[22] DUAN K，KWOK F，MA X. DEM simulations of sandstone under true triaxial compressive tests[J]. Acta Geotechnica，2017，12(3)：495–510.
[23] KIM B S，PARK S W，KATO S. DEM simulation of collapse behaviours of unsaturated granular materials under general stress states[J]. Computers and Geotechnics，2012，42(3)：52–61.
[24] JIANG M J，ZHANG N，CUI L，et al. A size-dependent bond failure criterion for cemented granules based on experimental studies[J]. Computers and Geotechnics，2015，69：182–198.
[25] ZHANG F G，JIANG M J. Three-dimensional DEM modelling of isotropic compression of cemented sand[J]. Japanese Geotechnical Society Special Publication，2015，2(17)：643–648.
[26] 张伏光，蒋明镜. 基坑土体卸荷平面应变试验离散元数值分析[J]. 岩土力学，2018，39(1)：339–348.(ZHANG Fuguang，JIANG Mingjing. Analysis of plane strain test on unloading of soil around foundation pit by distinct element method[J]. Rock and Soil Mechanics，2018，39(1)：339–348.(in Chinese))
[27] JIANG M J，KONRAD J，LEROUEIL S. An efficient technique for generating homogeneous specimens for DEM studies[J]. Computers and Geotechnics，2003，30(7)：579–597.
[28] 张伏光. 基于微观破损机理的结构性砂土三维本构模型研究[博士学位论文][D]. 上海：同济大学，2017.(ZHANG Fuguang. A study on the three-dimensional constitutive model for structured sands based on the micro-mechanism of structure degradation[Ph. D. Thesis][D]. Shanghai：Tongji University，2017.(in Chinese))
[29] HAERI S M，HOSSEINI S M，TOLL D G，et al. The behaviour of an artificially cemented sandy gravel[J]. Geotechnical and Geological Engineering，2005，23(5)：537–560.
[30] LADE P V. Elasto-plastic stress-strain theory for cohesionless soil with curved yield surfaces[J]. International Journal of Solids and Structures，1977，13(11)：1 019–1 035.
[31] MATSUOKA H，NAKAI T. Stress-deformation and strength characteristics of soil under three different principal stresses[C]// Proceedings of Japanese Society of Civil Engineering. [S. l.]：[s. n.]，1974，232：59–70.
[32] LADE P V. Three-parameter failure criterion for concrete[J]. Journal of the Engineering Mechanics Division，1982，108(5)：850–863.
[33] SATAKE M. Fabric tensor in granular materials[C]// Proceedings of IUTAM Symposium on Deformation and Failure of Granular Materials. Netherlands：Delft，1982：63–68.
[34] SAZZAD M M，SUZUKI K. Density dependent macro-micro behavior of granular materials in general triaxial loading for varying intermediate principal stress using DEM[J]. Granular Matter，2013，15(5)：583–593.
[35] THORNTON C，ANTONY S J. Quasi-static deformation of particulate media[J]. Philosophical Transactions of the Royal Society A，1998，356(1747)：2 763–2 782.
[36] BARRETO D，O?SULLIVAN C. The influence of inter-particle friction and the intermediate stress ratio on soil response under generalised stress conditions[J]. Granular Matter，2012，14(4)：505–521.
[37] O?SULLIVAN C，WADEE M A，HANLEY K J，et al. Use of DEM and elastic stability analysis to explain the influence of the intermediate principal stress on shear strength[J]. Géotechnique，2013，63(15)：1 298–1 309.
[38] 郑永来，邓树新，李文峋，等. 中主应力对散粒体材料强度和变形影响的数值模拟研究[J]. 岩石力学与工程学报，2015，34(增1)： 3 389–3 396.(ZHENG Yonglai，DENG Shuxin，LI Wenxun，et al. Numerical simulation study of influence of intermediate principal stress on strength and deformation of granular materials[J]. Chinese Journal of Rock Mechanics and Engineering，2015，34(Supp.1)：3 389–3 396.(in Chinese)) |
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2018, Vol. 37 
