Article
Engineering, Geological
Ionut Dragos Moldovan, Antonio Gomes Correia
Summary: A novel procedure for optimizing the location of receiver bender elements to avoid distortion of output signals while maintaining shear wave signal strength is presented. Experimental validation confirms that this method leads to output signals that are easier to interpret.
SOIL DYNAMICS AND EARTHQUAKE ENGINEERING
(2021)
Article
Engineering, Environmental
Seyed Hassan Jafari, Seyed Hamid Lajevardi, Mohammad Sharifipour, Mohsen Kamalian
Summary: This study investigates the impact of adding nano-SiO2 and lime to the stabilization of clay soil, showing that a certain level of addition of these materials leads to a significant increase in soil characteristics and compressive strength. The correlation developed between small strain properties and unconfined compressive strength could serve as a quick and convenient reference for evaluating shear stiffness without the need for dynamic experiments.
BULLETIN OF ENGINEERING GEOLOGY AND THE ENVIRONMENT
(2021)
Article
Engineering, Civil
Alireza Hajian, Meysam Bayat
Summary: The maximum shear modulus (Gmax) of a soil mixture is influenced by factors such as void ratio, effective confining pressure, grading characteristics, consolidation, and initial fabric anisotropy. This study proposes an empirical equation to predict Gmax in granular soils based on bender element tests and evaluates the accuracy using artificial neural network (ANN) and Adaptive Neuro Fuzzy Inference System (ANFIS) models. The results show that all methods have high accuracy, with ANFIS achieving the highest accuracy.
GEOMECHANICS AND ENGINEERING
(2022)
Article
Engineering, Civil
Tennison Freire de Souza Junior, Karla Salvagni Heineck, Cezar Falavigna Silva, Francisco Dalla Rosa
Summary: This study focuses on the mechanical behavior of cohesive frictional soil in Passo Fundo, Brazil, improved by Portland cement of high initial strength. The results show the significant effects of cement content and dry density on soil behavior and provide normalized curves for practical dosages of ground improvement.
TRANSPORTATION GEOTECHNICS
(2022)
Article
Engineering, Environmental
Yousef Heidarizadeh, Seyed Hamid Lajevardi, Mohammad Sharifipour, Mohsen Kamalian
Summary: The study systematically investigated the small strain shear stiffness of soft clay stabilized with cement and nano-SiO2 through a series of bender element tests. Experimental results showed that the shear stiffness of the stabilized clay significantly increased with higher cement content, nano-SiO2 percentage, and longer curing time. The findings also suggested that nano-SiO2 can be used as a supplementary pozzolan to reduce the required cement content in the mixture for environmental considerations.
BULLETIN OF ENGINEERING GEOLOGY AND THE ENVIRONMENT
(2021)
Article
Engineering, Environmental
Ali Nosratian, Mohammad Sharifipour, Seyed Hamid Lajevardi, Mahboubeh Poor Kalhor, Reza Mastouri
Summary: Determining the shear modulus of contaminated soils is crucial in earthquake and dynamic load analysis. This study investigates the effects of hydrocarbon pollution on the maximum shear modulus of two types of sands. The results show that short-term analysis indicates greater sensitivity of poorly graded sand to pollution, while long-term analysis reveals the significant impact of weathering on both types of sands.
BULLETIN OF ENGINEERING GEOLOGY AND THE ENVIRONMENT
(2022)
Article
Construction & Building Technology
Yuan-shun Shen, Yong Tang, Jie Yin, Mei-ping Li, Ting Wen
Summary: The experimental investigation showed that adding lime or cement at a certain fiber content significantly increased the strength properties of the soil, with cement having a better improvement effect than lime. Fiber-reinforced specimens with lime or cement treatment exhibited strain-softening behavior, with higher residual strength compared to untreated specimens. The stress and strain curve for specimens with higher fiber content was higher than those with lower fiber content, indicating a better improvement effect in engineering applications.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Engineering, Geological
Danial Shirkavand, Kazem Fakharian
Summary: The shear modulus (G) in sands changes with variations in the degree of saturation. The matric suction in unsaturated sands increases the effective stress and consequently the shear modulus. The relationship between G/Gsat variations and matric suction is complex and requires in-depth evaluations.
ENGINEERING GEOLOGY
(2023)
Article
Green & Sustainable Science & Technology
Aghileh Khajeh, Reza Jamshidi Chenari, Meghdad Payan, Hossein MolaAbasi
Summary: Partial replacement of conventional stabilizers with environmentally-friendly and sustainable materials, such as natural zeolite and expanded polystyrene (EPS) beads, was studied in order to enhance the strength and stiffness properties of earthen materials. The addition of EPS beads resulted in a reduction in swelling and compaction properties of the samples, while still maintaining acceptable levels of strength and stiffness characteristics. Statistical modeling using a neural network was also carried out, resulting in highly accurate predictions for the studied mix designs.
ENVIRONMENT DEVELOPMENT AND SUSTAINABILITY
(2023)
Article
Construction & Building Technology
Zefeng Tao, Yu Zhang, Xinran Chen, Xiaoming Gu
Summary: The stability and durability of the subgrade structure in seasonally frozen areas can be enhanced by adding cement and fiber to silty clay. Results show that the mechanical properties of the composite treated soil change significantly after the first freeze-thaw process, but tend to stabilize after six cycles. Different types and dosages of fiber have an impact on the performance of the composite treated soil, with polypropylene fiber showing better results than basalt fiber.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Engineering, Geological
Abhishek Ghosh Dastider, Santiram Chatterjee, Prasenjit Basu
Summary: Fall cone tests provide estimates of undrained shear strength of fine-grained soils, with the accuracy greatly dependent on the selection of a fall cone factor K. Finite element analyses can simulate soil resistance evolution during cone penetration, aiding in quantifying the effects of various factors on undrained shear strength.
JOURNAL OF GEOTECHNICAL AND GEOENVIRONMENTAL ENGINEERING
(2021)
Article
Engineering, Civil
R. Latimer, D. Airey, F. Tatsuoka
Summary: The importance of soil degree of saturation in evaluating the effectiveness of using stiffness indexes to monitor and assess compaction is demonstrated through laboratory and field trial results and analysis. The results show a simple relationship between the small-strain shear modulus and dry density, and additional compaction beyond a critical saturation reduces the stiffness response.
TRANSPORTATION GEOTECHNICS
(2023)
Article
Construction & Building Technology
Andressa da Silva, Lucas Festugato, Joao Victor Linch Daronco, Estefano da Silva Menger
Summary: This research aimed to evaluate the mechanical response of a mixture of soil and reclaimed-asphalt pavement (RAP) stabilized with cement. The tests showed that the porosity/cement index controls the strength of the mixtures and the inclusion of RAP positively influenced the internal friction angle of the material. The study also found that the accumulated loss of mass increased when the cement content and dry unit weight decreased.
JOURNAL OF MATERIALS IN CIVIL ENGINEERING
(2022)
Article
Engineering, Geological
Bate Bate, Junnan Cao, Chi Zhang, Na Hao, Song Wang
Summary: SIP and BE techniques are highly sensitive to particle size, distribution, and hydration product content, impacting ground improvement efficiency. Integration of SIP and BE on a column setup enabled monitoring of lime and cement stabilization processes. Nondestructive monitoring of spatiotemporal chemical evolution processes by SIP and BE is beneficial for engineering applications.
JOURNAL OF ROCK MECHANICS AND GEOTECHNICAL ENGINEERING
(2021)
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.
