Abstract: The mechanical loss of subgrade loess contacting with water impacts gravelythe line's circulation. Facing to the loess subgrade engineering issue, attempts to improve the loess strength using the EICP technology, a process of calcium carbonate precipitation induced by plant-extracted urease. Especially, replacing the traditional calcium source with environmentally friendly calcium lignosulfonate in the cementation process of the EICP technology improvement was studied systematically. The results show that firstly EICP solution of calcium lignosulfonate can significantly improve both the lateral unlimited compressive strength and shear strength of loess, wherein the compressive one increases to 0.232 MPa, increased by 20.8%, the C value of shear strength index increases to 69.06 kPa, increased by 31.2%, and the Φ value increases to 26.8°, increased by 52.3%. Secondly, the shear improvement effect of the loess with EICP solution of calcium lignosulfonate is obviously better than that of the loess with EICP solution of calcium chloride and the one of calcium acetate. The optimal concentration of each component of calcium lignosulfonate-EICP solution is 3 g/L for 1 000 U/g active urease, 1 mol/L for urea and 1 mol/L for calcium lignosulfonate. Moreover, with the increase of the dosage of calcium lignosulfonate-EICP solution, the shear strength of the loess primarily increases but then decreases. Finally, microscopic test results (XRD and SEM) demonstrate that the mechanism of the loess solidified by calcium lignosulfonate-EICP solution is mainly linked to the new calcium carbonate deposits. The deposits were induced both on the surface of the loess skeleton particles and in pore filling. As a result, the friction strength between the loess skeleton particles rise up, as well as the bonding connection strength reinforced, so that the mechanical properties of loess are improved in the end.
1 Xu Z J,Lin Z G,Zhang M S. Chinese Journal of Rock Mechanics and Engineering,2007(7),1297(in Chinese). 徐张建,林在贯,张茂省.岩石力学与工程学报,2007(7),1297. 2 Wu G H,Wang J D,Ma W,et al. Journal of Engineering Geology,2016,24(1),102(in Chinese). 吴光辉,王家鼎,马威,等.工程地质学报,2016,24(1),102. 3 Zhu F J,Nan J J,Wei Y Q,et al. Chinese Journal of Geological Hazards and Prevention,2019,30(2),128(in Chinese). 朱凤基,南静静,魏颖琪,等.中国地质灾害与防治学报,2019,30(2),128. 4 Zhang Y,Zhang X M,Zhou Z J. Highway,2020,65(8),69(in Chinese). 张瑜,张兴明,周志军.公路,2020,65(8),69. 5 Cheng Y J,Tang C S,Xie Y H,et al. Journal of Engineering Geology,2021,29(1),44 (in Chinese). 程瑶佳,唐朝生,谢约翰,等.工程地质学报, 2021,29(1), 44. 6 Zheng X Y. Transportation World,2019(26), 39(in Chinese). 郑翔友.交通世界,2019(26),39. 7 Zeng J J. Experimental study on physical and mechnical properties of expansive soil improvedby biological enzymes.Master's Thesis,Central South University of Forestry and Technology, China,2017(in Chinese). 曾娟娟.生物酶改良膨胀土物理力学特性试验研究.硕士学位论文,中南林业科技大学,2017. 8 Liang S H,Chen J T,Niu J G,et al. Marine Georesources & Geotechnology,2020,38(4),1. 9 Whiffin V S,Van Passen L A,Harkes M P. Geomicrobiology Journal,2007,24(5),417. 10 Van Paassen L A. Biogrout ground improvementby microbial induced carbonate precipitation. Ph.D.Thesis,Murdoch University,Australia,2009. 11 Xu L D. Sichuan Building Materials,2020,46(10),74(in Chinese). 徐柳笛.四川建材,2020,46(10),74. 12 Dilrukshi R A N,Watanabe J,Kawasaki S. Materials Transactions,2015,9(56),1565. 13 Wu L Y,Miao L C,Sun X H,et al. Chinese Journal of Geotechnical Engineering,2020,45(4),714(in Chinese). 吴林玉,缪林昌,孙潇昊,等.岩土工程学报, 2020,45(4),714. 14 Qabany A A,Soga K,Santamarina C. Journal of Geotechnical and Geoen-vironmental Engineering,2012,138(8),992. 15 Zhang J W,Wang X J,Li B B,et al. Chinese Journal of Civil and Environmental Engineering,2021,43(2),201(in Chinese). 张建伟,王小锯,李贝贝,等.土木与环境工程学报,2021,43(2),201. 16 Yin L Y,Tang C S,Xie Y H,et al. Rock and Soil Mechanics,2019,40(7),2525(in Chinese). 尹黎阳,唐朝生,谢约翰,等.岩土力学, 2019,40(7),2525. 17 Huang Y,Luo X G,Du F. Journal of Southwest University of Science and Technology, 2009,24(3),87(in Chinese). 黄琰,罗学刚,杜菲.西南科技大学学报, 2009,24(3),87. 18 Muynck W D,Verbeken K, de Belie N D, et al. Applied Microbiology and Biotechnology, 2013,97(3),1345. 19 Zhang Y,Guo H X,Cheng X H . Material Research Innovations,2014,18(2),79. 20 Neupane D,Yasuhara H,Kinoshita N,et al. Journal of Geotechnical and Geoenvironmental Engineering,2013,139(12),2201. 21 Wang J J. Study on dynamic characteristics of improved silt subgrade. Master's Thesis, Henan University, China, 2019(in Chinese). 王晶晶.改良粉砂土路基动力特性研究.硕士学位论文,河南大学,2019.
渝公网安备50019002502923号 版权所有：《材料导报》编辑部
2022, Vol. 36 
