Mechanical behavior of granite residual soil during wetting considering effects of initial unloading

SHU Rong-jun; KONG Ling-wei; WANG Jun-tao; JIAN Tao; ZHOU Zhen-hua

doi:10.11779/CJGE2022S1028

Volume 44 Issue S1

Turn off MathJax

Article Contents

Abstract

References

Chinese Journal of Geotechnical Engineering > 2022 > 44(S1): 154-159, 165. > DOI: 10.11779/CJGE2022S1028

SHU Rong-jun, KONG Ling-wei, WANG Jun-tao, JIAN Tao, ZHOU Zhen-hua. Mechanical behavior of granite residual soil during wetting considering effects of initial unloading[J]. Chinese Journal of Geotechnical Engineering, 2022, 44(S1): 154-159, 165. DOI: 10.11779/CJGE2022S1028

Citation:

PDF (1236 KB)

Mechanical behavior of granite residual soil during wetting considering effects of initial unloading

SHU Rong-jun^{1, 2,},
KONG Ling-wei^{1, 2, ,},
WANG Jun-tao^{1, 2},
JIAN Tao^{1, 2},
ZHOU Zhen-hua^{1, 2}

1.
State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan 430071, China
2.
University of Chinese Academy of Sciences, Beijing 100049, China

More Information

Received Date: September 26, 2022
Available Online: February 06, 2023

Graphical Abstract

Abstract

Abstract

The unloading caused by slope excavation may affect soil behavior during the subsequent rainfall-induced wetting. However, the previous wetting tests do not greatly consider this fact. For this reason, the unloading-wetting tests are carried out on granite residual soil, and the effects of consolidation pressure and stress ratio (reflecting the degree of the initial unloading) are investigated. The influences whether excavation takes place before or after rainfall are studied. It is found that the granite residual soil shows notable anisotropy during wetting, and the horizontal deformation is greater than the vertical one when wetted under isotropic stress condition. The overall level of wetting deformation increases with the increase of consolidation pressure. As the degree of the initial unloading increases, the wetting-induced axial and shear strains increase, the wetting-induced dilatancy becomes stronger, and the initially compressive lateral wetting deformation changes into extensional somewhere. Whether excavation takes place before or after rainfall makes a difference to the deformation behavior of soil. The soil specimen in the unloading-wetting tests shows larger axial and shear strains but smaller lateral and volumetric strains, compared with that in the wetting-unloading tests. The increasing degree of the initial unloading causes the strength properties, mainly cohesion, of wetted soil to decrease.
- granite residual soil,
- wetting test,
- initial unloading,
- stress path,
- wetting deformation,
- strength

FullText(HTML)

References (9)

References

[1]	程展林, 左永振, 丁红顺, 等. 堆石料湿化特性试验研究[J]. 岩土工程学报, 2010, 32(2): 243–247. http://cge.nhri.cn/cn/article/id/12059 CHENG Zhan-lin, ZUO Yong-zhen, DING Hong-shun, et al. Wetting characteristics of coarse-grained materials[J]. Chinese Journal of Geotechnical Engineering, 2010, 32(2): 243–247. (in Chinese) http://cge.nhri.cn/cn/article/id/12059
[2]	魏松, 朱俊高. 粗粒土料湿化变形三轴试验研究[J]. 岩土力学, 2007, 28(8): 1609–1614. doi: 10.3969/j.issn.1000-7598.2007.08.015 WEI Song, ZHU Jun-gao. Study on wettig behavior of coarse grained soil in triaxial test[J]. Rock and Soil Mechanics, 2007, 28(8): 1609–1614. (in Chinese) doi: 10.3969/j.issn.1000-7598.2007.08.015
[3]	WANG J D, ZHANG D F, WANG N Q, et al. Mechanisms of wetting-induced loess slope failures[J]. Landslides, 2019, 16(5): 937–953. doi: 10.1007/s10346-019-01144-4
[4]	刘翔, 陈国兴, 孙田. 花岗岩全风化土湿化变形及强度的试验研究[J]. 岩土力学, 2012, 33(11): 3313–3317. https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX201211019.htm LIU Xiang, CHEN Guo-xing, SUN Tian. Experimental research on wetting deformation and strength of weathered granite[J]. Rock and Soil Mechanics, 2012, 33(11): 3313–3317. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX201211019.htm
[5]	魏松. 粗粒料浸水湿化变形特性试验及其数值模型研究[D]. 南京: 河海大学, 2006. WEI Song. Study on Wetting Deformation Behaviour and Numerical Model of Coarse-Grained Materials[D]. Nanjing: Hohai University, 2006. (in Chinese)
[6]	贾宇峰, 姚世恩, 迟世春. 等应力比路径下粗粒土湿化试验研究[J]. 岩土工程学报, 2019, 41(4): 648–654. doi: 10.11779/CJGE201904007 JIA Yu-feng, YAO Shi-en, CHI Shi-chun. Wetting of coarse-grained soil under equal stress ratio path[J]. Chinese Journal of Geotechnical Engineering, 2019, 41(4): 648–654. (in Chinese) doi: 10.11779/CJGE201904007
[7]	张秀成, 王义重, 傅旭东. 不同应力路径下某高速公路路基黏性土湿化变形试验研究[J]. 岩土力学, 2010, 31(6): 1791–1796. doi: 10.3969/j.issn.1000-7598.2010.06.019 ZHANG Xiu-cheng, WANG Yi-zhong, FU Xu-dong. Experimental research on wetting deformation of clayey soil of a freeway subgrade with different stress paths[J]. Rock and Soil Mechanics, 2010, 31(6): 1791–1796. (in Chinese) doi: 10.3969/j.issn.1000-7598.2010.06.019
[8]	刘新宇, 张先伟, 孔令伟, 等. 冲击荷载作用下花岗岩残积土的动力损伤与破坏机理[J]. 岩土工程学报, 2019, 41(10): 1872–1881. doi: 10.11779/CJGE201910011 LIU Xin-yu, ZHANG Xian-wei, KONG Ling-wei, et al. Structural damage and dynamic failure mechanism of granite residual soils under impact loading[J]. Chinese Journal of Geotechnical Engineering, 2019, 41(10): 1872–1881. (in Chinese) doi: 10.11779/CJGE201910011
[9]	安然, 黎澄生, 孔令伟, 等. 花岗岩残积土原位力学特性的钻探扰动与卸荷滞时效应[J]. 岩土工程学报, 2020, 42(1): 109–116. doi: 10.11779/CJGE202001012 AN Ran, LI Cheng-sheng, KONG Ling-wei, et al. Effects of drilling disturbance and unloading lag on in situ mechanical characteristics of granite residual soil[J]. Chinese Journal of Geotechnical Engineering, 2020, 42(1): 109–116. (in Chinese) doi: 10.11779/CJGE202001012

[1]	LIU Weizheng, HUANG Xuanjia, XU Yang, LI Huili, WAN Jiale. Accumulative deformation law and control of compacted lateritic soil under coupled action of wetting and dynamic loading[J]. Chinese Journal of Geotechnical Engineering, 2025, 47(3): 535-547. DOI: 10.11779/CJGE20231281
[2]	ZHANG Xinrui, KONG Gangqiang, YANG Qing. Influences of temperature stress path on strength characteristics of undisturbed marine sediments[J]. Chinese Journal of Geotechnical Engineering, 2024, 46(2): 357-365. DOI: 10.11779/CJGE20221308
[3]	Mechanical behavior and constitutive modelling of expansive soil under conditions of wetting and low confining stress[J]. Chinese Journal of Geotechnical Engineering. DOI: 10.11779/CJGE20240079
[4]	ZHANG Zhen-hua, WANG Ye. Degradation mechanism of shear strength and compressive strength of red sandstone in drawdown areas during reservoir operation[J]. Chinese Journal of Geotechnical Engineering, 2019, 41(7): 1217-1226. DOI: 10.11779/CJGE201907005
[5]	ZHU Jun-gao, Mohamed A. ALsakran, GONG Xuan, XUANG Xiang-yang, JI En-yue. Triaxial tests on wetting deformation behavior of a slate rockfill material[J]. Chinese Journal of Geotechnical Engineering, 2013, 35(1): 170-174.
[6]	SHI Weicheng, ZHU Jungao, LIU Hanlong. Influence of intermediate principal stress on deformation and strength of gravel[J]. Chinese Journal of Geotechnical Engineering, 2008, 30(10): 1449-1453.
[7]	YANG Heping, ZHANG Rui, ZHENG Jianlong. 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.
[8]	Zhang Huiming, Zeng Qiaoling. Steady state strength of sand:concepts and experiment[J]. Chinese Journal of Geotechnical Engineering, 1999, 21(2): 95-100.
[9]	Chen Zhenghan. Deformation,strength,yield and moisture change of a remolded unsaturated loess[J]. Chinese Journal of Geotechnical Engineering, 1999, 21(1): 85-93.
[10]	You Mingqing, Hua Anzeng, Li Yushou. A study of triaxial strength and deformation of flawed specimen[J]. Chinese Journal of Geotechnical Engineering, 1998, 20(2): 97-101.