Article
Engineering, Geological
Tomas Mohyla, Jan Bohac, David Masin
Summary: Experimental data on small strain stiffness of unsaturated soils is essential for developing and calibrating advanced numerical models. The study found that both net stress and suction lead to increased stiffness in the soil. The experimental data were used to calibrate constitutive parameters and assess the capabilities of an advanced hypoplastic model for unsaturated soils, with good agreement between model predictions and laboratory measurements.
Article
Computer Science, Interdisciplinary Applications
Yunhan Huang, Yaning Wang, Zhongze Xu, Peipei Wang
Summary: This study developed an ensemble machine learning approach using Random Forest and XGBOOST models to improve the accuracy of predicting small-strain stiffness. The experimental equipment and database development process were described. The results showed that the ensemble machine learning approach had higher prediction accuracy compared to empirical models. Variable importance analysis identified water content as a key influencing factor in predicting G/Gmax and Gmax. Finally, a design procedure based on the ensemble machine learning approach and regression analysis was proposed for estimating small-strain stiffness of soil for design engineers.
COMPUTERS AND GEOTECHNICS
(2023)
Article
Chemistry, Multidisciplinary
Kai Yan, Yong Wang, Zhiyong Yang, Xianghua Lai, Cheng Chen
Summary: The small-strain stiffness of soil is crucial for accurately predicting the deformation caused by interactions between foundation soil and structures. The study investigated the shear modulus of unsaturated silty-fine sand in Hangzhou Bay, China using a BE-RC combined test system, and found that the shear modulus decayed non-linearly with increasing strain until reaching stable values.
APPLIED SCIENCES-BASEL
(2022)
Article
Engineering, Geological
Mustapha Abdellaziz, Mourad Karray, Jeudy Betegard, Pascal Locat, Catherine Ledoux, Remi Mompin, Mohamed Chekired
Summary: This study examines the strain rate effect on the behavior of eastern Canada soils through experimental results and literature data analysis. The findings indicate that the undrained shear strength increases proportionally with the strain rate, with approximately 6% -17% increase per log cycle of strain rate. The results also show that the shear modulus increases with the strain rate, especially at large strain amplitudes. Furthermore, the extent of the strain rate effect is found to be correlated with the shear strain amplitude and plasticity index.
CANADIAN GEOTECHNICAL JOURNAL
(2022)
Article
Engineering, Geological
Junbiao Yan, Lingwei Kong, Juntao Wang
Summary: Studying the nonlinear evolution law of the small strain shear modulus of expansive soil is of great significance for analyzing soil or geotechnical structure deformation behavior and seismic site response. The existing studies lack discussion on the damage mechanism and corresponding damage model for the small strain shear modulus. This study conducted resonance column tests to investigate the effects of stress, stress paths, and vibration cycles on the decay law of the small strain shear modulus, and proposed a novel damage model to describe the evolution law of small strain shear modulus of expansive soil.
ENGINEERING GEOLOGY
(2023)
Article
Geosciences, Multidisciplinary
Fansheng Kong, Lei Nie, Yan Xu, Xiangjian Rui, Yuanyuan He, Tao Zhang, Yuzheng Wang, Chao Du, Chonghao Bao
Summary: Freeze-thaw effects on soda-saline loessal soils in the Songnen Plain of Northeast China have a significant impact on soil erosion, with continued cycles leading to deterioration in soil erosion resistance until stabilization after approximately 10 cycles. The erosion resistance of the soil decreased by up to 59.2% after 15 freeze-thaw cycles, while disintegration velocity increased by up to 208.8%. The microstructure of the soil was continuously adjusted during the freeze-thaw process, with increased microcracks, weakened cementation, enhanced pore connectivity, and increased pore homogenization.
Article
Engineering, Geological
Zi Ying, Yu-Jun Cui, Nadia Benahmed, Myriam Duc
Summary: Lime treatment can significantly increase the small strain shear modulus (G(max)) of soil, providing good resistance to wetting-drying cycles. However, the effect can be altered depending on factors such as wetting fluid and soil state. While untreated soil softens and damages during wetting-drying cycles, lime-treated soil maintains its resistance and reversible pore size distributions.
ENGINEERING GEOLOGY
(2021)
Article
Engineering, Geological
Aparna Shrivastava, Ajanta Sachan
Summary: This study investigated the shear modulus of compacted coal ash under different anisotropic stress conditions simulating highway and railway embankment stress states. The small-strain shear modulus was obtained by performing bender element tests under consolidation and shearing stages of consolidated undrained triaxial testing. The effect of different consolidation stress paths on the small-strain shear modulus of coal ash was evaluated using experimental data obtained from a bender element system affiliated with a stress-path controlled advanced triaxial setup. The small-strain shear modulus of coal ash at different ranges of mean effective stresses was also determined under various anisotropic stress conditions.
SOIL DYNAMICS AND EARTHQUAKE ENGINEERING
(2023)
Article
Engineering, Geological
Mourad Karray, Mustapha Abdellaziz, Ibrahim Lashin
Summary: This paper discusses the impact of the driving system rigidity on the measurements performed on a Hardin-type RC device. It concludes that a rigid connection between the soil specimen and the driving mass can significantly affect the obtained results, and suggests that the apparatus resonant frequency should be lower than the resonant frequencies likely to be measured during testing.
CANADIAN GEOTECHNICAL JOURNAL
(2022)
Article
Environmental Sciences
Junbiao Yan, Tianguo Li, Lingwei Kong, Xiaoqian Luo, Zhenhua Zhou, Juntao Wang
Summary: The study investigates the dynamic behavior of lime-treated expansive soil in the small strain range. Resonant column tests show that the addition of lime significantly improves the dynamic shear modulus of expansive soil, and consolidation pressure and curing time also have an effect. It is recommended to use a lime content of 2-4% as the optimal ratio for improving the dynamic shear modulus of weak expansive soil in engineering practice.
JOURNAL OF SOILS AND SEDIMENTS
(2023)
Article
Engineering, Geological
Ke Liang, Guoxing Chen, Xiuli Du, Chengshun Xu, Jun Yang
Summary: This paper presents a new formula for predicting the small-strain shear modulus (G(0)) of sandy soils with different particle characteristics. The new formula utilizes extreme void ratios (maximum void ratio e(max) and minimum void ratio emin) as indexes to account for the effects of various factors. Power-law correlations were established between the minimum and maximum small-strain shear moduli (G(0min) and G(0max)) and the extreme void ratios. The formula was validated using extensive data from resonant column, bender element, and torsional shear tests on different types of sandy soils.
JOURNAL OF GEOTECHNICAL AND GEOENVIRONMENTAL ENGINEERING
(2023)
Article
Engineering, Environmental
Qionglin Li, Dongjie Zhang, Pangju Li, Kai Cui, Xiang Jing
Summary: This study investigates the variation of small-strain stiffness of frozen soils with temperature and initial water content. A double-upscaling mechanism is proposed to explain the changes in stiffness, and a predictive model is developed based on this mechanism. The model is validated using experimental data, and the predicted results show reasonable agreement with the measured data.
COLD REGIONS SCIENCE AND TECHNOLOGY
(2023)
Article
Engineering, Multidisciplinary
Gaohang Cui, Zhiqiang Liu, Shu Xian Ma, Zhuo Cheng
Summary: This study investigated the dynamic characteristics of carbonate saline soil under traffic load through a low-temperature dynamic cyclic triaxial test. The impact of salt content and the number of freeze-thaw cycles on the characteristics of saline soil was explored. It was found that saline soil exhibited typical nonlinear and strain-hardening characteristics, with higher salt content or more freeze-thaw cycles resulting in smaller dynamic shear modulus and larger damping ratio of the remodeled soil. The findings of this study provide valuable reference for the design and construction of structures in regions with seasonal freezing.
ALEXANDRIA ENGINEERING JOURNAL
(2023)
Article
Construction & Building Technology
Liwei Wen
Summary: This study investigated the influence of grain size on the shear modulus and damping ratio of calcareous sand through resonant column tests. The results showed that the shear modulus decreases with increasing shear strain, while the maximum shear modulus tends to increase with confining pressure and relative density. A revised empirical equation considering the effect of grain diameter was proposed to estimate the maximum shear modulus of calcareous sand.
ADVANCES IN CIVIL ENGINEERING
(2022)
Article
Engineering, Geological
Roya Davoodi-Bilesavar, Laureano R. Hoyos
Summary: Shear modulus and damping ratio are crucial soil parameters in seismic site-response analyses and geotechnical engineering applications. This study investigates the impact of soil temperature on these parameters using a resonant column apparatus.
CANADIAN GEOTECHNICAL JOURNAL
(2023)