Damage characteristics and mechanisms of soil structures under salt weathering
Received date: 2024-03-06
Revised date: 2024-05-09
Online published: 2025-01-02
This study investigates the damage characteristics of loess structures and the deterioration of loess strength under the influence of salt weathering, with a focus on unidirectional dehumidification conditions. The findings provide valuable references for soil and water conservation, as well as disaster prevention strategies in the Loess Plateau. Q2 loess from Fugu County, Shaanxi Province, China was selected for macro- and micro-scale observations and shear strength tests under varying sodium sulfate contents. The results indicate the following: (1) Macroscopic effects: An increase in salt content significantly impacts the apparent damage degree and expansion displacement of the samples. Samples with salt contents ranging from 1.0% to 2.5% exhibited contour scaling damage characteristics, transitioning from uneven surface crusts to extensive salt spots and expansion cracks. In contrast, samples with a lower salt content of 0.5% did not show salt swelling, salt spots, or crust formation. The salt weathering process progresses through three stages: germination, growth, and stability. (2) Microscopic effects: Salt weathering leads to the formation of agglomerates and expansive pores within loess. Sodium sulfate decahydrate crystals were observed as a direct result of the salt weathering process. (3) Shear characteristics: The shear behavior of the samples transitioned from strain softening to strain hardening after salt weathering, with significant degradation in peak strength and reduced cohesion. As sodium sulfate content increased, salt weathering intensified the effects of “salt crystallization-induced expansion” and “soil drying-induced coagulation” in loess. This process generated numerous expansion cracks and pores both on the surface and within the loess, ultimately causing severe structural and strength deterioration.
Key words： loess; sodium sulfate; salt weathering; shear strength; damage
DUAN Zhao , LI Ruiyi , SONG Kun , YAN Xusheng , ZHENG Licai , HE Ziguang . Damage characteristics and mechanisms of soil structures under salt weathering[J]. Arid Land Geography, 2024 , 47(12) : 2041 -2050 . DOI: 10.12118/j.issn.1000-6060.2024.152
| [1] | 吕洪波, 苏德辰, 章雨旭, 等. 中国不同气候带盐风化作用的地貌特征[J]. 地质论评, 2017, 63(4): 911-926. |
| [Lü Hongbo, Su Dechen, Zhang Yuxu, et al. Landform features of salt weathering in different climatic zones in China[J]. Geological Review, 2017, 63(4): 911-926.] | |
| [2] | 任科法, 谢振斌, 汪灵, 等. 四川仁寿牛角寨石窟盐风化作用机理与气候响应[J]. 地质论评, 2023, 69(4): 1368-1386. |
| [Ren Kefa, Xie Zhenbin, Wang Ling, et al. Salt weathering mechanism and climate response in Niujiaozhai Grottoes, Renshou, Sichuan[J]. Geological Review, 2023, 69(4): 1368-1386.] | |
| [3] | 周凤玺, 冉跃, 万旭升, 等. 盐渍土在蒸发过程中的水盐相变行为研究[J]. 岩土工程学报, 2024, 46(5): 1030-1038. |
| [Zhou Fengxi, Ran Yue, Wan Xusheng, et al. Water-salt phase transition of saline soils during evaporation[J]. Chinese Journal of Geotechnical Engineering, 2024, 46(5): 1030-1038.] | |
| [4] | 郭敏, 李新虎, 王弘超, 等. 盐结皮厚度对土壤水盐分布特征的影响[J]. 干旱区地理, 2023, 46(8): 1303-1313. |
| [Guo Min, Li Xinhu, Wang Hongchao, et al. Effect of salt crust thickness on distribution characteristics of soil water and salt[J]. Arid Land Geography, 2023, 46(8): 1303-1313.] | |
| [5] | 靳治良, 陈港泉, 夏寅, 等. 土质文物盐害中硫酸钠的研究——从微观到宏观[J]. 文物保护与考古科学, 2016, 28(1): 54-62. |
| [Jin Zhiliang, Chen Gangquan, Xia Yin, et al. Sodium sulfate behind earthen relics salt damages: From micro to macro[J]. Sciences of Conservation and Archaeology, 2016, 28(1): 54-62.] | |
| [6] | 刘彦辉. 碳酸盐渍土的膨胀特性研究[J]. 水土保持通报, 2012, 32(1): 119-121. |
| [Liu Yanhui. A study on expansion characteristics of carbonate saline soil[J]. Bulletin of Soil and Water Conservation, 2012, 32(1): 119-121.] | |
| [7] | 许健, 郑翔, 王掌权. 黄土边坡盐蚀剥落病害特征调查及其水盐迁移规律研究[J]. 工程地质学报, 2018, 26(3): 741-748. |
| [Xü Jian, Zheng Xiang, Wang Zhangquan. Investigation for water and salt migrations on spalling disease of loess slope caused by salification erosion[J]. Journal of Engineering Geology, 2018, 26(3): 741-748.] | |
| [8] | Duan Z, Cheng W C, Peng J B, et al. Interactions of landslide deposit with terrace sediments: Perspectives from velocity of deposit movement and apparent friction angle[J]. Engineering Geology, 2021, 280(5): 105913, doi: 10.1016/j.enggeo.2020.105913. |
| [9] | Dong C X, Duan Z, Li R. Impact liquefaction mechanism of sandy silt with a change in impact energy[J]. Quarterly Journal of Engineering Geology and Hydrogeology, 2023, 56(3): qjegh2022122, doi: 10.1144/qjegh2022-122. |
| [10] | Espinosa Marzal R M, Scherer G W. Crystallization of sodium sulfate salts in limestone[J]. Environmental Geology, 2008, 56(3): 605-621. |
| [11] | Wu S, Wu D, Huang Y. Evaluation of the crystallization pressure of sulfate saline soil solution by direct observation of crystallization behavior[J]. American Chemical Society Omega, 2021, 6(27): 17680-17689. |
| [12] | 李春清, 梁庆国, 吴旭阳, 等. 重塑黄土抗拉强度试验研究[J]. 地震工程学报, 2014, 36(2): 233-238, 248. |
| [Li Chunqing, Liang Qingguo, Wu Xuyang, et al. Study on the test of tensile strength of remolded loess[J]. China Earthquake Engineering Journal, 2014, 36(2): 233-238, 248.] | |
| [13] | Zehnder K, Arnold A. Crystal growth in salt efflorescence[J]. Journal of Crystal Growth, 1989, 97(2): 513-521. |
| [14] | 唐洋, 李新虎, 郭敏, 等. 不同初始盐分浓度下土壤盐结皮的形成过程及其对蒸发的影响机理[J]. 干旱区地理, 2022, 45(4): 1137-1145. |
| [Tang Yang, Li Xinhu, Guo Min, et al. Formation process of soil salt crust and its influence mechanism on evaporation under different initial salt concentrations[J]. Arid Land Geography, 2022, 45(4): 1137-1145.] | |
| [15] | Agudo E R, Mees F, Jacobs P, et al. The role of saline solution properties on porous limestone salt weathering by magnesium and sodium sulfates[J]. Environmental Geology, 2007, 52(2): 269-281. |
| [16] | Dai S, Shin H, Santamarina C J. Formation and development of salt crusts on soil surfaces[J]. Acta Geotechnica, 2016, 11(5): 1103-1109. |
| [17] | Espinosa Marzal R M, Scherer G W. Advances in understanding damage by salt crystallization[J]. Accounts of Chemical Research, 2010, 43(6): 897-905. |
| [18] | 靳治良, 刘端端, 张永科, 等. 盐分在文物本体中的迁移及毁损机理[J]. 文物保护与考古科学, 2017, 29(5): 102-116. |
| [Jin Zhiliang, Liu Duanduan, Zhang Yongke, et al. Salt migrations and damage mechanism in cultural heritage objects[J]. Sciences of Conservation and Archaeology, 2017, 29(5): 102-116.] | |
| [19] | 王策, 沐方元, 刘东浩, 等. 硫酸盐渍土盐胀结晶试验研究进展[J]. 低温建筑技术, 2021, 43(11): 120-124. |
| [Wang Ce, Mu Fang-yuan, Liu Donghao, et al. Progress in salt expansion crystallization test of sulphuric acid saline soil[J]. Low Temperature Architecture Technology, 2021, 43(11): 120-124.] | |
| [20] | 徐张建, 林在贯, 张茂省. 中国黄土与黄土滑坡[J]. 岩石力学与工程学报, 2007, 26(7): 1297-1312. |
| [Xu Zhangjian, Lin Zaiguan, Zhang Maosheng. Loess in China and loess landslides[J]. Chinese Journal of Rock Mechanics and Engineering, 2007, 26(7): 1297-1312.] | |
| [21] | 段钊, 李珍艳, 牛兵, 等. 孔压增速对黄土静态液化特性影响试验研究[J]. 干旱区资源与环境, 2022, 36(6): 179-186. |
| [Duan Zhao, Li Zhenyan, Niu Bing, et al. Influence of increasing in pore water pressure gradient on static liquefaction characteristics of loess[J]. Journal of Arid Land Resources and Environment, 2022, 36(6): 179-186.] | |
| [22] | 蒙慧敏, 占车生, 胡实, 等. 大型灌区土壤水盐运移模拟研究进展[J/OL]. [2024-08-04]. http://kns.cnki.net/kcms/detail/65.1103.X.20240403.1005.001.html. |
| [Meng Huimin, Zhan Chesheng, Hu Shi, et al. Research progress on simulation of soil water-salt transport in large-scale irrigation districts[J/OL]. [2024-08-04]. http://kns.cnki.net/kcms/detail/65.1103.X.20240403.1005.001.html.] | |
| [23] | Masato S, Tsuyoshi H. A laboratory experiment on salt weathering by humidity change: Salt damage induced by deliquescence and hydration[J]. Progress in Earth and Planetary Science, 2018, 5(1): 1-10. |
| [24] | Mokni N, Olivella S, Alonso E. Swelling in clayey soils induced by the presence of salt crystals[J]. Applied Clay Science, 2009, 47(1): 105-112. |
| [25] | 吕擎峰, 谷留杨, 郭连星, 等. 硫酸盐含量对黄土黏粒特性的影响研究[J]. 工程地质学报, 2023, 31(1): 12-20. |
| [Lü Qingfeng, Gu Liuyang, Guo Lianxing, et al. Effect of sulfate content on clay characteristics of loess[J]. Journal of Engineering Geology, 2023, 31(1): 12-20.] | |
| [26] | 许健, 任畅, 高靖寓, 等. 干湿循环效应下Na2SO4盐渍原状黄土渗透特性与细观机制[J]. 中南大学学报(自然科学版), 2021, 52(5): 1644-1654. |
| [Xu Jian, Ren Chang, Gao Jingyu, et al. Influence of dry-wet cycles on hydraulic conductivity and microstructure of saline undisturbed loess with sodium sulfate[J]. Journal of Central South University (Science and Technology Edition), 2021, 52(5): 1644-1654.] | |
| [27] | 黄佑芬, 吴道勇, 吴诗雨. 冻融循环条件下重塑硫酸盐渍土变形试验研究[J]. 冰川冻土, 2022, 44(2): 602-611. |
| [Huang Youfen, Wu Daoyong, Wu Shiyu. Experimental study on deformation of remolded sulfate saline soil under freeze-thaw cycles[J]. Journal of Glaciology and Geocryology, 2022, 44(2): 602-611.] | |
| [28] | 张殿发, 王世杰. 土地盐碱化过程中的冻融作用机制——以吉林省西部平原为例[J]. 水土保持通报, 2000(6): 14-17. |
| [Zhang Dianfa, Wang Shijie. Mechanism of freeze thaw action in land salinization process: As an sample in west Jilin Province[J]. Bulletin of Soil and Water Conservation, 2000(6): 14-17.] | |
| [29] | Lai Y, Wan X, Zhang M. An experimental study on the influence of cooling rates on salt expansion in sodium sulfate soils[J]. Cold Regions Science and Technology, 2016, 124: 67-76. |
| [30] | Nie Y, Ni W, Tuo W, et al. Collapsibility deterioration mechanism and evaluation of compacted loess with sodium sulfate under drying-wetting cycles[J]. Natural Hazards, 2023, 115(1): 971-991. |
| [31] | 马建全, 邱勇强, 赵晓杰, 等. 盐分及含水率对甘肃黑方台黄土强度的影响研究[J]. 地震工程学报, 2023, 45(4): 819-825, 886. |
| [Ma Jianquan, Qiu Yongqiang, Zhao Xiaojie, et al. Effects of salinity and moisture content on the strength of loess in Heifangtai, Gansu Province[J]. China Earthquake Engineering Journal, 2023, 45(4): 819-825, 886.] | |
| [32] | Fu J, Hu X, Li X, et al. Influences of soil moisture and salt content on loess shear strength in the Xining Basin, northeastern Qinghai-Tibet Plateau[J]. Journal of Mountain Science, 2019, 16(5): 1184-1197. |
| [33] | 李志强. 灌溉-蒸发耦合作用下黄土高原盐沼湿地水盐运移规律研究 ——以甘肃省黑方台为例[D]. 成都: 成都理工大学, 2021. |
| [Li Zhiqiang. Research on the laws of water and salt transport in salt marsh wetland of Loess Plateau under the coupling action of irrigation and evaporatio[D]. Chengdu: Chengdu University of Technology, 2021.] | |
| [34] | 邴慧, 武俊杰, 邓津. 黄土状盐渍土洗盐前后物理力学性质的变化[J]. 冰川冻土, 2011, 33(4): 796-800. |
| [Bing Hui, Wu Junjie, Deng Jin. Variations of physical and mechanical properties of saline loess before and after desalting[J]. Journal of Glaciology and Geocryology, 2011, 33(4): 796-800.] | |
| [35] | Duan Z, Li Z Y, Wu Y B, et al. Mechanical and microscopic properties of soil according to the rate of increase in pore water pressure[J]. Soil and Tillage Research, 2023, 225: 105530, doi: 10.1016/J.STILL.2022.105530. |
| [36] | Charola A E. Salts in the deterioration of porous materials: An overview[J]. Journal of the American Institute for Conservation, 2000, 39(3): 327-343. |
| [37] | 唐朝生, 施斌, 顾凯. 土中水分的蒸发过程试验研究[J]. 工程地质学报, 2011, 19(6): 875-881. |
| [Tang Chaosheng, Shi Bin, Gu Kai. Experimental investigation on evaporation process of water in soil during drying[J]. Journal of Engineering Geology, 2011, 19(6): 875-881.] | |
| [38] | Meng J, Li X A. Effects of carbonate on the structure and properties of loess and the corresponding mechanism: An experimental study of the Malan loess, Xi’an area, China[J]. Bulletin of Engineering Geology and the Environment, 2019, 78: 4965-4976. |
| [39] | Hu W, Cheng W C, Wen S, et al. Effects of chemical contamination on microscale structural characteristics of intact loess and resultant macroscale mechanical properties[J]. Catena, 2021, 203: 105361, doi: 10.1016/J.CATENA.2021.105361 |
| [40] | Moore R J. The chemical and mineralogical controls upon the residual strength of pure and natural clays[J]. Geotechnique, 1991,41: 35-47. |
| [41] | 唐大雄. 工程岩土学[M]. 北京: 地质出版社, 1999: 30-43. |
| [Tang Daxiong. Rock and soil engineering[M]. Beijing: Geology Press, Beijing, 1999: 30-43.] | |
| [42] | Kang X, Zou X, Sun H, et al. Molecular dynamics simulations of microstructure and dynamic shearing behaviors of kaolinite-water-salt system[J]. Applied Clay Science, 2022, 218: 106414, doi:10.1016/J.CLAY.2022.106414. |
| [43] | 唐朝生, 施斌, 刘春. 膨胀土收缩开裂特性研究[J]. 工程地质学报, 2012, 20(5): 663-673. |
| [Tang Chaosheng, Shi Bin, Liu Chun. Study on desiccation cracking behaviour of expansive soil[J]. Journal of Engineering Geology, 2012, 20(5): 663-673.] | |
| [44] | 李海燕, 王正伟, 刘亚伦. 某高原公路含盐冻土力学强度研究[J]. 路基工程, 2024(2): 95-100. |
| [Li Haiyan, Wang Zhengwei, Liu Yalun. Study on mechanical strength of saline frozen soil on a plateau highway[J]. Subgrade Engineering, 2024(2): 95-100.] | |
| [45] | 倪万魁, 师华强. 冻融循环作用对黄土微结构和强度的影响[J]. 冰川冻土, 2014, 36(4): 922-927. |
| [Ni Wankui, Shi Huaqiang. Influence of freezing-thawing cycles on micro-structure and shear strength of loess[J]. Journal of Glaciology and Geocryology, 2014, 36(4): 922-927.] | |
| [46] | 叶万军, 李长清, 杨更社, 等. 冻融环境下黄土体结构损伤的尺度效应[J]. 岩土力学, 2018, 39(7): 2336-2343, 2360. |
| [Ye Wanjun, Li Changqing, Yang Gengshe, et al. Scale effects of damage to loess structure under freezing and thawing conditions[J]. Rock and Soil Mechanics, 2018, 39(7): 2336-2343, 2360.] |
/
| 〈 |
|
〉 |
