Dynamic strength of fly ash-modified loess subgrade under influences of drying-wetting cycle

ZHONG Xiu-mei; WANG Qian; LIU Zhao-zhao; BAI Lan; MA Jin-lian; LIU Fu-qiang; LI Na; WANG Jun

doi:10.11779/CJGE2020S1019

Volume 42 Issue S1

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Chinese Journal of Geotechnical Engineering > 2020 > 42(S1): 95-99. > DOI: 10.11779/CJGE2020S1019

ZHONG Xiu-mei, WANG Qian, LIU Zhao-zhao, BAI Lan, MA Jin-lian, LIU Fu-qiang, LI Na, WANG Jun. Dynamic strength of fly ash-modified loess subgrade under influences of drying-wetting cycle[J]. Chinese Journal of Geotechnical Engineering, 2020, 42(S1): 95-99. DOI: 10.11779/CJGE2020S1019

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Dynamic strength of fly ash-modified loess subgrade under influences of drying-wetting cycle

1.
Key Laboratory of Loess Earthquake Engineering, China Earthquake Administration & Gansu Province, Lanzhou 730000, China
2.
School of Civil Engineering and Mechanics, Lanzhou University, Lanzhou 730000, China
3.
Xi'an Changqing Technology Engineering Co., Ltd., Xi'an 710018, China

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Received Date: June 04, 2020
Available Online: December 07, 2022

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Abstract

Abstract

The traffic load and the drying-wetting cycle have an important influence on the strength characteristics and stability of fly ash-modified loess subgrade. To illustrate the influences of drying-wetting cycle on the strength of the fly ash-modified loess, a series of dynamic triaxial tests on the fly ash-modified loess samples with different fly ash contents are conducted after different drying-wetting cycles. Based on the test results, the dynamic residual deformation and dynamic strength evolution characteristics of the fly ash-modified loess are analyzed. The influences of fly ash content and drying-wetting cycle on the residual dynamic deformation and dynamic strength of the modified loess are discussed. The optimum proportion of the fly ash-modified loess is proposed. The results show that the fly ash-modified loess can significantly improve the dynamic strength of the subgrade and effectively decrease the dynamic residual deformation of the modified loess. The critical dynamic stress of the modified loess is the largest and the dynamic residual deformation is the smallest when the fly ash content m=30%. After the drying-wetting cycle, the critical dynamic stress of the modified loess decreases whereas the dynamic residual deformation increases. The critical dynamic stress decreases firstly and then increases with the increase of the drying-wetting cycle. However, the decrease rate of the critical dynamic stress decreases with the increase of the drying-wetting cycle. The dynamic residual deformation of the fly ash-modified loess becomes stable after 2 drying-wetting cycles. In addition, the modified loess subgrade has an optimum behavior under the coupling effect between traffic load and drying-wetting cycle when the fly ash content m is between 25% and 30%.
- dynamic residual deformation,
- critical dynamic stress,
- fly ash content,
- drying-wetting cycle,
- dynamic triaxial test

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References

[1]	王兰民, 石玉成, 刘旭, 等. 黄土动力学[M]. 北京: 地震出版社, 2003: 85-143. WANG Lan-min, SHI Yu-cheng, LIU Xu, et al. Loess Dynamics[M]. Beijing: Seismological Press, 2003: 85-143. (in Chinese)
[2]	陈存礼, 胡再强, 骆亚生. 兰州黄土掺合无机结合料的力学特性试验研究[J]. 西安理工大学学报, 2001, 17(3): 288-291. doi: 10.3969/j.issn.1006-4710.2001.03.015 CHEN Cun-li, HU Zai-qiang, LUO Ya-sheng. Research on the mechanical characteristics of loess mixed into inorganic combinative material in Lanzhou[J]. Journal of Xi'an University of Technology, 2001, 17(3): 288-291. (in Chinese) doi: 10.3969/j.issn.1006-4710.2001.03.015
[3]	张向东, 曹启坤, 潘宇. 二灰改良土动力特性试验研究[J]. 岩土力学, 2010, 31(8): 2560-2564. doi: 10.3969/j.issn.1000-7598.2010.08.035 ZHANG Xiang-dong, CAO Qi-kun, PAN Yu. Experimental research of lime-fly ash soil's dynamics characteristics[J]. Rock and Soil Mechanics, 2010, 31(8): 2560-2564. (in Chinese) doi: 10.3969/j.issn.1000-7598.2010.08.035
[4]	祝艳波, 余宏明, 杨艳霞, 等. 红层泥岩改良土特性室内试验研究[J]. 岩石力学与工程学报, 2013, 32(2): 425-432. doi: 10.3969/j.issn.1000-6915.2013.02.026 ZHU Yan-bo, YU hong-ming, YANG Yan-xia, et al. Indoor Experimental research on characteriatics of improved red-mudstone[J]. Chinese Journal of Rock Mechanics and Engineering, 2013, 32(2): 425-432. (in Chinese) doi: 10.3969/j.issn.1000-6915.2013.02.026
[5]	王峻, 王谦, 王平, 等. 粉煤灰掺入量对改性黄土动本构关系的影响[J]. 岩土工程学报, 2013, 35(增刊1): 156-160. https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC2013S1025.htm WANG Jun, WANG Qian, WANG Ping, et al. Effect of adding amount of fly ash on dynamic constitutive relationship of modified loesss[J]. Chinese Journal of Geotechnical Engineering, 2013, 35(S1): 156-160. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC2013S1025.htm
[6]	王谦, 刘红玫, 马海萍, 等. 水泥改性黄土的抗液化特性与机制[J]. 岩土工程学报, 2016, 38(11): 2128-2134. doi: 10.11779/CJGE201611025 WANG Qian, LIU Hong-mei, MA Hai-ping. Liquefaction behavior and mechanism of the cement-stabilized loess[J]. Chinese Journal of Geotechnical Engineering, 2016, 38(11): 2128-2134. (in Chinese) doi: 10.11779/CJGE201611025
[7]	赵天宇, 王锦芳. 考虑密度与干湿循环影响的黄土土水特征曲线[J]. 中南大学学报(自然科学版), 2012, 43(6): 2445-2453. https://www.cnki.com.cn/Article/CJFDTOTAL-ZNGD201206062.htm ZHAO Tian-yu, WANG Jin-fang. Soil water characteristiccurve for unsaturated loess soil considering density and dry-wet cycle effects[J]. Journal of Central South University (Science and Technology), 2012, 43(6): 2445-2453. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-ZNGD201206062.htm
[8]	刘奉银, 张昭, 周冬, 等. 密度和干湿循环对黄土土-水特征曲线的影响[J]. 岩土力学, 2011, 32(2): 132-142. https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX2011S2021.htm LIU Feng-yin, ZHANG Zhao, ZHOU Dong, et al. Effects of initial density and dry-wetting cycle on soil water characteristic curve of unsaturated loess[J]. Rock and Soil Mechanics, 2011, 32(2): 132-142. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX2011S2021.htm
[9]	涂义亮, 刘新荣, 钟祖良, 等. 干湿循环下粉质黏土强度及变形特性试验研究[J]. 岩土力学, 2017, 38(12): 1001-1009. https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX201712025.htm TU Yi-liang, LIU Xin-rong, ZHONG Zu-liang. et al. Experimental study on the strength and deformation characteristics of silty clay during the wetting-drying cycles[J]. Rock and Soil Mechanics, 2017, 38(12): 1001-1009. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX201712025.htm
[10]	刘文化, 杨庆, 唐小薇, 等. 干湿循环条件下粉质黏土在循环荷载作用下的动力特性试验研究[J]. 水利学报, 2015, 46(4): 325-332. https://www.cnki.com.cn/Article/CJFDTOTAL-SLXB201504007.htm LIU Wen-hua, YANG Qing, TANG Xiao-wei, et al. Expermental study on the dynamic characteristics of silt clay subjected to drying-wetting cycles under cyclic loading[J]. Journal of Hydraulic Engineering, 2015, 46(4): 325-332. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-SLXB201504007.htm
[11]	杨和平, 张锐, 郑健龙. 有荷条件下膨胀土的干湿胀缩变形及强度变化规律[J]. 岩土工程学报, 2006, 28(11): 1936-1941. https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC200611003.htm YANG He-ping, ZHANG Rui, ZHENG Jian-long. Variation of deformation and strength of expansive soil during cyclic wetting and drying under loading condition[J]. Chinese Journal of Geotechnical Engineering, 2006, 28(11): 1936-1941. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC200611003.htm
[12]	杨和平, 王兴正, 肖杰. 干湿循环效应对南宁外环膨胀土抗剪强度的影响[J]. 岩土工程学报, 2014, 36(5): 949-954. https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC201405027.htm YANG He-ping, WANG Xing-zheng, XIAO Jie. Influence of dry-wet cycles on strength characteristics of Nanning expansive soils[J]. Chinese Journal of Geotechnical Engineering, 2014, 36(5): 949-954. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC201405027.htm
[13]	叶为民, 万敏, 陈宝, 等. 干湿循环条件下高压实膨润土的微观结构特征[J]. 岩土工程学报, 2011, 33(8): 1173-1177. https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC201108006.htm YE Wei-min, WAN Min, CHEN Bao, et al. Micro-structural behaviors of densely compacted GMZ01 bentonite under drying/wetting cycles[J]. Chinese Journal of Geotechnical Engineering, 2011, 33(8): 1173-1177. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC201108006.htm
[14]	住房和城乡建设部. 土工试验方法标准：GB/T50123—2019[S]. 北京: 中国计划出版社, 2019. Ministry of Housing and Urbar-Rural Development of the PRC. Standard for Geotechnical Testing Method: GB/T50123—2019[S]. Beijing: China Planning Press, 2019. (in Chinese)