Experimental Study on Mechanical Properties and Microscopic Mechanism of Remolded Loess in Northern Xinjiang
ZHANG Lingkai1,2,*, DING Xusheng1,2, FAN Peipei1,2
1 College of Water and Civil Engineering, Xinjiang Agricultural University, Urumqi 830052, China 2 Xinjiang Key Laboratory of Water Conservancy Engineering Safety and Water Disaster Prevention, Urumqi 830052, China
Abstract: A water conveyance open channel project in Xinjiang passes through a large area of collapsible loess area. Land sliding often occurs at the channel since its operation. In order to deeply analyze its failure mechanism, the indoor direct shear, compression, penetration and SEM electron microscope scanning tests were carried out to analyze its mechanical characteristics and micro-physical mechanism from a macro-micro perspective. (i) Direct shear test result showes that:with the increase of water content, the cohesion increases first and then decreases, and gets the peak value when the water content is near the optimal water content, and the internal friction angle decreases. With the increase of dry density, the internal friction angle and cohesion increase. Through microscopic experimental analysis, with the increase of dry density, the skeleton particles are closely packed, the number of particles decreases, the area of each particle increases, the roundness of each particle decreases, and the orientation of these particles becomes worse. The roundness and orientation probability entropy of particles are the main factors affecting the cohesion and internal friction angle respectively. (ii) Compression test result showes that:with the increase of water content, the yield stress decreases linearly, while the plastic compression parameters and rebound index increase linearly. With the increase of dry density, the yield stress increases linearly, and the plastic compression parameters and rebound index decrease linearly. Through microscopic test analysis, with the increase of consolidation pressure, the particle aggregates with weak cementation ability are crushed to form new particle aggregates, the soil skeleton is reorganized to form a secondary structure dominated by flocculation, the number of particles reduces, the circularity increases, and the orientation is enhanced. the particle orientation probability entropy has the greatest influence on the compressibility of loess. (iii) Percolation test result showes that:the saturated permeability coefficient decreases with the increase of dry density. Through microscopic test analysis, with the increase of dry density, the number of overhead pores in the microstructure of the permeable loess decreases, the mosaic pores and intergranular pores increase, and the pore connectivity becomes worse. The number, area ratio, roundness, abundance and large pore area ratio of pores have a significant positive correlation with the saturated permeability coefficient, and the pore area ratio has the highest correlation among them.
1 Ma F L, Bai X H, Wang M, et al. In:Abstracts of the 12th national conference on rock mechanics and engineering, Nanjing, China, 2012, pp.50 (in Chinese). 马富丽, 白晓红, 王梅, 等. 第十二次全国岩石力学与工程学术大会会议论文摘要集. 南京, 2012, pp.50. 2 Zhang A J, Xing Y C, Hu X L, et al. Chinese Journal of Geotechnical Engineering, 2016, 38(S2), 117 (in Chinese). 张爱军, 邢义川, 胡新丽, 等. 岩土工程学报, 2016, 38(S2), 117. 3 Wang P, Xu S, Shao S, et al. Frontiers in Earth Science, 2022, 9, 762508. 4 Feng L, Zhang M S, Hu W, et al. Rock and Soil Mechanics, 2019, 40(1), 235 (in Chinese). 冯立, 张茂省, 胡炜, 等. 岩土力学, 2019, 40(1), 235. 5 Zhang Y Y, Ye W J. Civil Engineering Journal-Tehran, 2018, 4(4), 785. 6 Mu Q Y, Zhou C, Ng C W W. Transportation Geotechnics, 2020, 23, 100345. 7 Yang Z K, Chen G, Meng X M, et al. Journal of Lanzhou University (Natural Science), 2017, 53(3), 285 (in Chinese). 杨仲康, 陈冠, 孟兴民, 等. 兰州大学学报(自然科学版), 2017, 53(3), 285. 8 Gu T F, Wang J D, Wang C X, et al. Journal of Soils and Sediments, 2019, 19(10), 3463. 9 Cai G Q, Zhang C, Huang Z W, et al. Chinese Journal of Geotechnical Engineering, 2020, 42(S2), 32 (in Chinese). 蔡国庆, 张策, 黄哲文, 等. 岩土工程学报, 2020, 42(S2), 32. 10 Xu J, Wei W, Bao H, et al. Environmental Earth Sciences, 2020, 79(13), 346. 11 Kin D, Kang S S. Ksce Journal of Civil Engineering, 2013, 17(2), 335. 12 Jia Y J, Chen C L, Ping W. International Conference on Computational Science & Engineering, 2016, 68, 27. 13 Wang F, Li G Y, Mu Y H, et al. Rock and Soil Mechanics, 2016, 37(8), 2306 (in Chinese). 王飞, 李国玉, 穆彦虎, 等. 岩土力学, 2016, 37(8), 2306. 14 Wang F, Li G, Ma W, et al. Advances in Civil Engineering, 2020, 1, 8839347. 15 She H C, Hu Z Q, Qu Z. Mathematical Problems in Engineering, 2019, 2019, 4790250. 16 Hao L Y, Qiao J Y. Shanxi Building, 2010, 36(23), 155 (in Chinese). 郝立勇, 乔俊义. 山西建筑, 2010, 36(23), 155. 17 Wang B, Huang X F, Qiu M M, et al. Journal of Water Resources and Water Engineering, 2022, 33(2), 186 (in Chinese). 王博, 黄雪峰, 邱明明, 等. 水资源与水工程学报, 2022, 33(2), 186. 18 Zhou M R, Wang J W, Wang T, et al. Journal of Architecture and Civil Engineering, 2017, 34(1), 99 (in Chinese). 周茗如, 王晋伟, 王腾, 等. 建筑科学与工程学报, 2017, 34(1), 99. 19 Yang J, Deng M L, Bai X H. Chinese Journal of Underground Space and Engineering, 2017, 13(6), 1467 (in Chinese). 杨晶, 邓美林, 白晓红. 地下空间与工程学报, 2017, 13(6), 1467. 20 Hong B, Li X A, Wang L, et al. Environmental Earth Sciences, 2019, 78(15), 447. 21 Pan Z H, Xiao T, Li P. Rock and Soil Mechanics, 2022, 43(S1), 357 (in Chinese). 潘振辉, 肖涛, 李萍. 岩土力学, 2022, 43(S1), 357. 22 Wang H M, Ni W K. Rock and Soil Mechanics, 2022, 43(3), 729 (in Chinese). 王海曼, 倪万魁. 岩土力学, 2022, 43(3), 729. 23 Hu Z Q, Liang Z C, Guo J, et al. Chinese Journal of Geotechnical Engineering, 2020, 42(S2), 26 (in Chinese). 胡再强, 梁志超, 郭婧, 等. 岩土工程学报, 2020, 42(S2), 26. 24 Hu H J, Li C H, Cui Y J, et al. Journal of Hydraulic Engineering, 2018, 49(10), 1216 (in Chinese). 胡海军, 李常花, 崔玉军, 等. 水利学报, 2018, 49(10), 1216. 25 Xu J, Wang Z Q, Ren J W, et al. Geomechanics and Engineering, 2018, 14(4), 307. 26 Li X A, Sun J Q, Ren H Y, et al. Environmental Earth Sciences, 2022, 81, 290. 27 Sun J Q, Li X A, Geng Q, et al. Australian Journal of Earth Sciences, 2021, 68(6), 899. 28 Jian T, Kong L W, Bai W, et al. Frontiers in Earth Science, 2022, 10, 923358. 29 Guo Y, Ni W, Kou Z, et al. Soil Mechanics and Foundation Engineering, 2020, 57(5), 394. 30 Ministry of Water Resources of China. GB/T50123-2019 Geotechnical engineering test method and criterion. China Plan Publishing House, China, 2019 (in Chinese). 中华人民共和国水利部. GB/T50123-2019 土工试验方法标准. 中国计划出版社, 2019. 31 Wang G, Zhang X W, Liu X Y, et al. Rock and Soil Mechanics, 2021, 42(12), 3291 (in Chinese). 王港, 张先伟, 刘新宇, 等. 岩土力学, 2021, 42(12), 3291. 32 Cox M R, Budhu M. Engineering Geology, 2008, 96(1-2), 1. 33 Yuan Z H. Study on the strength and microstructure change mechanism of loess under dry-wet cycle. Ph. D. Thesis, Chang'an University, China, 2015 (in Chinese). 袁志辉. 干湿循环下黄土的强度及微结构变化机理研究. 博士学位论文, 长安大学, 2015. 34 Zhang K K. Study on anisotropic characteristics of natural loess with interface based on quantitative description of microstructure. Master's Thesis, Chang'an University, China, 2020 (in Chinese). 张科科. 基于微观结构定量描述的含界面天然黄土各向异性特征研究. 硕士学位论文, 长安大学, 2020. 35 Zhang F, Ye W M, Chen Y G, et al. Engineering Geology, 2016, 207, 48. 36 Lloret A, Villar M, Sanchez M, et al. Geotechnique, 2003, 53(1), 27. 37 Li P, Vanapalli S, Li T. Journal of Rock Mechanics and Geotechnical Engineering, 2016, 8(2), 256. 1 38 Zhang Y T. Study on the influence of temperature on the permeability of remolded Malan loess. Master's Thesis, Chang'an University, China, 2019 (in Chinese). 张瑜婷. 温度对重塑马兰黄土渗透性的影响研究. 硕士学位论文, 长安大学, 2019.
渝公网安备50019002502923号 版权所有：《材料导报》编辑部
2025, Vol. 39 
