Article
Construction & Building Technology
Yu Ding, Jiasheng Zhang, Xiaobin Chen, Xuan Wang, Yu Jia
Summary: This study investigated the static and dynamic characteristics of granulated rubber-sand mixtures as a new type of subgrade filler in railway engineering. The results showed that the addition of granulated rubber improved the shear strength and liquefaction resistance of the mixtures. A new equation for estimating peak deviatoric stress and maximum shear modulus was proposed. It was concluded that a granulated rubber content of less than 20% can meet engineering requirements related to shear stiffness. The damping ratio was found to be correlated with granulated rubber content and confining pressure. Additionally, the relationship between the damping ratio and shear strain conforms to the equation proposed by Hardin and Drnevich.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Engineering, Geological
Kazem Fakharian, Ali Ahmad
Summary: The study shows that adding granulated rubber decreases shear modulus and increases damping ratio of granulated rubber-sand mixtures, while also helping to reduce the degradation rate of shear modulus. Anisotropic consolidation has little effects on the variations of shear modulus and damping ratio of sand-rubber mixtures.
SOIL DYNAMICS AND EARTHQUAKE ENGINEERING
(2021)
Article
Engineering, Geological
Mengtao Wu, Wenhui Tian, Fangcheng Liu, Jun Yang
Summary: This technical note investigates the shear modulus and damping ratio of geocell-reinforced rubber sand mixtures (RSM). The results show that geocell reinforcement can increase the vertical confinement of the system, weaken the anti-S-shaped characteristics of hysteresis loops, and enhance the damping ratio of RSM at large strain amplitudes. The normalized shear modulus degradation curves demonstrate the influence range of geocell reinforcement, suggesting that a rubber content of 20% may be an optimal value for reinforced specimens.
SOIL DYNAMICS AND EARTHQUAKE ENGINEERING
(2023)
Article
Engineering, Civil
Chong Yue, Ke Liang, Chengshun Xu, Xiuli Du
Summary: In this study, undrained cyclic torsional shear tests were conducted to study the effect of cyclic loading frequency on the deformation properties of saturated Fujian sand. The test results showed that the shear modulus and damping ratio decreased with an increase in cyclic loading frequency in the shearing contractive and late shearing dilative periods. A modified method for calculating the damping ratio was proposed to compensate for analytical errors caused by the non-closure of hysteresis loop. The results showed that the modified method provided higher values for the damping ratio than the traditional method.
Article
Materials Science, Multidisciplinary
Qi Wu, Wei jia Ma, Qifei Liu, Kai Zhao, Guoxing Chen
Summary: The addition of rubber particles into clean sand significantly improves the dynamic performance of the host sandy soil, showing great potential in seismic isolation and reduction applications. A unified model was proposed to describe the dynamic properties of rubber-sand mixtures.
MATERIALS TODAY COMMUNICATIONS
(2021)
Article
Environmental Sciences
Ting Lu, Wensong Wang, Zuoan Wei, Yonghao Yang, Guansen Cao
Summary: The study found that phosphogypsum exhibits medium compressibility and medium to weak permeability characteristics. Shear strength and deformation modulus significantly increased with increasing dry density and consolidation confining pressure. Liquefaction resistance curves were expressed by power functions, shifting higher and becoming steeper with increasing dry density. The Davidenkov model was found to be more suitable for describing the relationship between the dynamic shear modulus ratio and damping ratio of PG compared to the Hardin-Drnevich model.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2021)
Article
Engineering, Geological
U. Veena, Naveen James
Summary: We propose a novel method to improve liquefaction resistance in sandy soil by treating it with natural rubber latex (NRL) using a pressurised permeation technique. NRL treatment reduces excess pore pressure development in the sand, thereby increasing liquefaction resistance. NRL-treated sand samples show resistance to progressive stiffness degradation even after many cycles due to interparticle bonding developed by virtue of the solidified NRL fibers. Hence, we propose the utilization of NRL as an environment-friendly soil stabilizer for mitigating liquefaction.
SOIL DYNAMICS AND EARTHQUAKE ENGINEERING
(2023)
Article
Chemistry, Physical
Zhaoyan Li, Liping Zhang, Haiyang Zhuang, Qi Wu
Summary: This study investigated the effects of cement on the static and dynamic characteristics of rubber-sand composite soil. The results showed that the addition of cement significantly improved the shear strength, elastic modulus, and cohesion of the composite soil. As the rubber content increased, the failure mode of the samples changed from strain-softening to hardening. The resonant column test revealed that increasing rubber content slowed down the modulus attenuation and increased the damping ratio, while increasing cement content enhanced the bonding force between particles, resulting in slower modulus attenuation and reduced damping ratio.
Article
Engineering, Geological
Shaoyan Zhang, Wenping Gong, Qi Wu, Tianzheng Li, Xiaoyu Zhao
Summary: This study investigates the liquefaction properties, dynamic modulus, undrained shear behavior, and seismic wave characteristics of sand during repeated liquefaction events through a series of undrained triaxial dynamic and compression tests. The results indicate that the undrained shear strength increases with the number of liquefaction events, whereas the liquefaction resistance, static stability, dynamic modulus, and shear wave velocity decrease after initial liquefaction and then increase after subsequent liquefaction events. Moreover, a novel index based on the shear wave velocity and primary wave velocity is formulated to assess the liquefaction history of sand, and it is found that this index is much lower for post-liquefaction sand compared to unliquefied sand.
Article
Engineering, Geological
Ninad Sanjeev Shinde, Jyant Kumar
Summary: The liquefaction potential of soils subjected to high frequency and low shearing strain excitation has been rarely studied. In this research, the liquefaction potential of a saturated sand specimen was assessed using resonant column tests. It was found that beyond a threshold shearing strain, there was a continuous rise in porewater pressure leading to liquefaction. The onset of liquefaction was also indicated by the Poisson ratio. The number of excitation cycles required for initial liquefaction increased with a decrease in cyclic stress ratio and an increase in sand relative density.
SOIL DYNAMICS AND EARTHQUAKE ENGINEERING
(2022)
Article
Engineering, Geological
Mahmoud Ghazavi, Masoud Kavandi
Summary: The large amount of waste tires entering the environment due to the high annual vehicle production creates environmental problems. This study investigates the dynamic properties of sand mixed with different percentages of waste tire grains in uniform and layered forms. The results show that layered mixtures exhibit better damping effects and the Sand-Tire-Sand configuration with 50% tire content performs the best.
SOIL DYNAMICS AND EARTHQUAKE ENGINEERING
(2022)
Article
Polymer Science
Jianhang Lv, Zhongnian Yang, Wei Shi, Zhaochi Lu, Qi Zhang, Xianzhang Ling
Summary: Using waste tire rubber to reinforce expansive soil can improve its engineering characteristics, but the damping properties of the rubber-reinforced soil vary with temperature. Experimental results show that selecting the appropriate rubber-reinforced soil for different temperature conditions can enhance the soil's shear performance and damping stability.
Article
Engineering, Geological
Hasan Ghasemzadeh, Mohammad Jafarzadeh, Shervin Ahmadi
Summary: This research conducted large-scale tests on geocell-reinforced soils and found that the placement depth and height of geocells have significant effects on soil characteristics. Under static loading conditions, placing geocells at 0.25 times the sample's height from the top surface can effectively control bulging and reduce settlement. Under cyclic loading conditions, placing geocells at 0.05 times the sample's height from the top surface can significantly reduce cumulative strains.
SOIL DYNAMICS AND EARTHQUAKE ENGINEERING
(2024)
Article
Engineering, Civil
Hadi Valizadeh, Nurhan Ecemis
Summary: The significant uplift of buried pipes observed during recent earthquakes has emphasized the need for further research in soil liquefaction remediation methods. This study conducted numerical modeling to investigate the effects of pipe size, burial depth, and shaking intensity on pipe uplift and liquefaction potential. An analytical formula was proposed to estimate the liquefaction-induced uplift of buried pipes, and the soil failure mode was categorized according to the burial depth ratio of the pipe.
TRANSPORTATION GEOTECHNICS
(2022)
Article
Engineering, Geological
Stefania Gobbi, Philippe Reiffsteck, Luca Lenti, Maria Paola Santisi d'Avila, Jean-Francois Semblat
Summary: This study assesses the influence of non-plastic fines and mixture-packing conditions on liquefaction triggering in sands. Experimental results show that the behavior of mixtures strongly depends on the packing configuration of coarse and fine particles.
