Three-dimensional discrete element analysis of mechanical properties of sandstone considering water-rock chemical reaction
WANG Qi1，WANG Huaning1，2，JIANG Mingjing2，3，4
(1. School of Aerospace Engineering and Applied Mechanics，Tongji University，Shanghai 200092，China；2. State Key Laboratory for Disaster Reduction in Civil Engineering，Tongji University，Shanghai 200092，China；3. College of Civil Engineering，Tongji University，Shanghai 200092，China；4. Department of Civil Engineering，
Suzhou University of Science and Technology，Suzhou，Jiangsu 215009，China)
Abstract：The main reason for the deterioration of rock mechanical properties under water-rock chemical reaction is that the rock cement is dissolved in an aqueous solution to varying degrees. This paper proposes an improved discrete element three-dimensional cementation contact model based on reasonable assumptions. In the size-dependent discrete element contact model，the soluble bond proportion and the bond width coefficient related to chemical damage degree are introduced to consider the dissolution of water solution to randomly distributed soluble cement. The model is implanted into the discrete element to calibrate sandstone’s conventional and micro parameters after chemical damage. The uniaxial and triaxial compression tests of sandstone with different chemical damage degrees are numerically simulated. The stress-strain curves and micro information are obtained，and the influence of chemical damage on mechanical properties is analyzed from the macro and micro points of view. The simulation results show that the compression test of chemical damage sandstone is dominated by tensile shear and tensile bending failure，while the water-rock chemical reaction has a great influence on the bond number of tensile failure and little influence on compressive bending failure. With the increase in chemical damage degree，the number of macro cracks on the rock surface increases，and there is a changing trend from one through a crack to multiple cracks. The energy storage limit of rock is greatly reduced，and the energy storage limit and growth rate of elastic energy are reduced to varying degrees. The energy storage limit of bonded elastic energy tends to be stable after falling to a certain extent. With the increase of soluble bond proportion，the sensitivity of peak strength and elastic modulus of chemical damage rock to bond width increases. When the proportion is 50%，the rock strength is less than 1/3 of intact rock，while the mechanical properties decrease significantly.
[1] 王艳磊，唐建新，江 君，等. 水–岩化学作用下灰砂岩的力学特性与参数损伤效应[J]. 煤炭学报，2017，42(1)：227–235.(WANG Yanlei，TANG Jianxin，JIANG Jun，et al. Mechanical properties and parameter damage effect of malstone under chemical corrosion of water-rock interaction[J]. Journal of China Coal Society，2017，42(1)：227–235.(in Chinese))
[2] 汤连生，张鹏程，王思敬. 水–岩化学作用的岩石宏观力学效应的试验研究[J]. 岩石力学与工程学报，2002，21(4)：526–531.(TANG Liansheng，ZHANG Pengcheng，WANG Sijing. Testing study on macroscopic mechanics effect of chemical action of water on rocks[J]. Chinese Journal of Rock Mechanics and Engineering，2002，21(4)：526–531.(in Chinese))
[3] 冯夏庭，赖户政宏. 化学环境侵蚀下的岩石破裂特性—第一部分：试验研究[J]. 岩石力学与工程学报，2000，19(4)：403–407.(FENG Xiating，MASAHIRO Seto. Rock fracturing behaviors under chemical corrosion—part I：experimental study[J]. Chinese Journal of Rock Mechanics and Engineering，2000，19(4)：403–407.(in Chinese))
[4] LI N，ZHU Y，BO S，et al. A chemical damage model of sandstone in acid solution[J]. International Journal of Rock Mechanics and Mining Sciences，2003，40(2)：243–249.
[5] CIANTIA M O，HUECKEL T. Weathering of submerged stressed calcarenites：chemo-mechanical coupling mechanisms[J]. Géotechnique，2013，63(9)：768–785.
[6] CIANTIA M O，CASTELLANZA R，CROSTA G B. Effects of mineral suspension and dissolution on strength and compressibility of soft carbonate rocks[J]. Engineering Geology，2015，184：1–18.
[7] 韩铁林，陈蕴生，师俊平，等. 冻融循环下钙质砂岩力学特性及其损伤劣化机制的试验研究[J]. 岩土工程学报，2016，38(10)：1 802–1 812.(HAN Tielin，CHEN Yunsheng，SHI Junping，et al. Experimental study on mechanical properties and damage degradation mechanism of calcareous sandstone subjected to freeze-thaw cycles[J]. Chinese Journal of Geotechnical Engineering，2016，38(10)：1 802–1 812.(in Chinese))
[8] TAO M，WANG J，ZHAO H，et al. The influence of acid corrosion on dynamic properties and microscopic mechanism of marble[J]. Geomechanics and Geophysics for Geo-Energy and Geo-Resources，2022，8：36.
[9] POTYONDY D O. Simulating stress corrosion with a bonded-particle model for rock[J]. International Journal of Rock Mechanics and Mining Sciences，2007，44(5)：677–691.
[10] 蒋明镜，周雅萍，陈 贺. 不同胶结厚度下粒间胶结力学特性的试验研究[J]. 岩土力学，2013，34(5)：1 264–1 273.(JIANG Mingjing，ZHOU Yaping，CHEN He. Experimental study of mechanical behaviors of bonded granules under different bond thicknesses[J]. Rock and Soil Mechanics，2013，34(5)：1 264–1 273.(in Chinese))
[11] 蒋明镜，张 宁，陈 贺. 岩石化学风化时效效应的离散元模拟[J]. 岩土力学，2014，35(12)：3 577–3 584.(JIANG Mingjing，ZHANG Ning，CHEN He. Discrete element simulation of aging effect of chemical weathering on rock[J]. Rock and Soil Mechanics，2014，35(12)：3 577–3 584.(in Chinese))
[12] JIANG M J，LIAO Z W，ZHANG N，et al. Discrete element analysis of chemical weathering on rock[J]. European Journal of Environmental and Civil Engineering，2015，19(Supp.1)：15–28.
[13] LI H，ESHIET K I I，SHENG Y，et al. A parallel-bonded chemical corrosion model for discrete element modeling of chemically corroded limestone[J]. Engineering Fracture Mechanics，2018，202：297–310.
[14] 张 超. 基于离散元的水化学溶液作用下的钙质胶结砂岩细观模拟研究[博士学位论文][D]. 广州：华南理工大学，2020.(ZHANG Chao. Mesoscopic simulation research on calcareous cemented sandstone under the action of water chemical solution based on discrete element numerical method[Ph. D. Thesis][D]. Guangzhou：South China University of Technology，2020.(in Chinese))
[15] 胡训健，卞 康，刘 建，等. 基于平行黏结水弱化模型的页岩吸水软化离散元模拟[J]. 岩土工程学报，2021，43(4)：725–733.(HU Xunjian，BIAN Kang，LIU Jian，et al. Discrete element simulation of shale softening based on parallel-bonded water-weakening model[J]. Chinese Journal of Geotechnical Engineering，2021，43(4)：725–733. (in Chinese))
[16] JIANG M J，SHEN Z F，WANG J. A novel three-dimensional contact model for granulates incorporating rolling and twisting resistances[J]. Computers and Geotechnics，2015，65：147–163.
[17] 李 磊，蒋明镜，张伏光. 深部岩石考虑残余强度时三轴试验离散元定量模拟及参数分析[J]. 岩土力学，2018，39(3)：1 082–1 090. (LI Lei，JIANG Mingjing，ZHANG Fuguang. Quantitative simulation of triaxial test considering residual strength on deep rock using DEM and parameter analysis[J]. Rock and Soil Mechanics，2018，39(3)： 1 082–1 090.(in Chinese))
[18] SHEN Z F，JIANG M J，WAN R. Numerical study of inter‐particle bond failure by 3D discrete element method[J]. International Journal for Numerical and Analytical Methods in Geomechanics，2016，40(4)：523–545.
[19] 乔丽苹，刘 建，冯夏庭. 砂岩水物理化学损伤机制研究[J]. 岩石力学与工程学报，2007，26(10)：2 117–2 124.(QIAO Liping，LIU Jian，FENG Xiating. Study on damage mechanism of sandstone under hydro-physico-chemical effects[J]. Chinese Journal of Rock Mechanics and Engineering，2007，26(10)：2 117–2 124.(in Chinese))
[20] 柳万里，晏鄂川，戴 航，等. 巴东组泥岩水作用的特征强度及其能量演化规律研究[J]. 岩石力学与工程学报，2020，39(2)：311–326.(LIU Wanli，YAN Echuan，DAI Hang，et al. Study on characteristic strength and energy evolution law of Badong formation mudstone under water effect[J]. Chinese Journal of Rock Mechanics and Engineering，2020，39(2)：311–326.(in Chinese))
[21] 韩铁林，陈蕴生，师俊平，等. 水化学腐蚀对砂岩力学特性影响的试验研究[J]. 岩石力学与工程学报，2013，32(增2)：3 064–3 072. (HAN Tielin，CHEN Yunsheng，SHI Junping，et al. Experimental study of mechanical characteristics of sandstone subjected to hydrochemical erosion[J]. Chinese Journal of Rock Mechanics and Engineering，2013，32(Supp.2)：3 064–3 072.(in Chinese))
[22] BERA B，MITRA S K，VICK D. Understanding the micro structure of Berea Sandstone by the simultaneous use of micro-computed tomography(micro-CT) and focused ion beam-scanning electron microscopy (FIB-SEM)[J]. Micron，2011，42(5)：412–418.
[23] CUI L，QIN N，WANG S，et al. Experimental study on the mechanical properties of sandstone under the action of chemical erosion and freeze-thaw cycles[J]. Advances in Civil Engineering，2021，2021：1–14.
[24] 谢和平，鞠 杨，黎立云，等. 岩体变形破坏过程的能量机制[J]. 岩石力学与工程学报，2008，27(9)：1 729–1 740.(XIE Heping，JU Yang，LI Liyun，et al. Energy mechanism of deformation and failure of rock masses[J]. Chinese Journal of Rock Mechanics and Engineering，2008，27(9)：1 729–1 740.(in Chinese))
2023, Vol. 42 
