Article
Engineering, Geological
Maya El Kortbawi, Diane M. Moug, Katerina Ziotopoulou, Jason T. DeJong, Ross W. Boulanger
Summary: This paper presents a numerical simulation and experimental validation study on the effect of microbial induced calcite precipitation (MICP) treatment on soil improvement. The study proposes a relationship between apparent cohesion and cone tip resistance and analyzes the trends between different parameters.
JOURNAL OF GEOTECHNICAL AND GEOENVIRONMENTAL ENGINEERING
(2022)
Article
Chemistry, Multidisciplinary
Rafaela Cardoso, Joana Vieira, Ines Borges
Summary: Biocementation is a soil treatment technique that uses bacteria to promote the precipitation of calcium carbonate. It is especially effective in creating erosion-resistant covers on slopes, with the water retention curve of the treated material being essential for modeling infiltration. The study explores the use of MIP tests to derive water retention curves for soils suitable for biocementation treatment.
APPLIED SCIENCES-BASEL
(2022)
Article
Engineering, Geological
Yang Xiao, Guoliang Ma, Huanran Wu, Huaming Lu, Musharraf Zaman
Summary: Microbially induced calcite precipitation (MICP) was investigated as a potential solution to rainfall-induced erosion of sandy slopes. The results showed that MICP treatment effectively mitigated internal erosion of slopes with different uniformity coefficients, but caution is needed when considering its impact on surface erosion.
INTERNATIONAL JOURNAL OF GEOMECHANICS
(2022)
Article
Engineering, Geological
Ray Harran, Dimitrios Terzis, Lyesse Laloui
Summary: Soil biocementation is an emerging technique in sustainable and innovative geotechnics. This study investigates the stress- and time-dependent deformability of biocemented geomaterials. Experimental results show that biocementation treatment significantly enhances the stiffness properties and reduces the overall deformability of the geomaterials. The porosity-to-cement ratio is found to be a parameter that captures and expresses the behavior of biocemented sands. Time dependency analysis reveals an increase in the coefficient of secondary compression under sustained high stresses. The study emphasizes the interdependence of stress and time factors.
JOURNAL OF GEOTECHNICAL AND GEOENVIRONMENTAL ENGINEERING
(2022)
Article
Soil Science
Meghna Sharma, Neelima Satyam
Summary: MICP is a sustainable and effective biocementation technique that utilizes enzymes produced by microbes. Research indicates that using bacterial mixtures for bioaugmentation can enhance the effectiveness, while the durability aspects such as wetting-drying resistance and ageing require further investigation.
Article
Multidisciplinary Sciences
Emran Alotaibi, Mohamed G. Arab, Mohamed Abdallah, Nadia Nassif, Maher Omar
Summary: Integrating sustainability goals into soil stabilization techniques is a global trend. Enzyme Induced Carbonate Precipitation (EICP) is a promising bio-inspired soil stabilization technology with lower environmental impacts than traditional cement stabilization. However, EICP has higher acidification and eutrophication potentials due to byproducts during the process.
SCIENTIFIC REPORTS
(2022)
Article
Engineering, Geological
Jinquan Shi, Haoyu Li, Yang Xiao, Jian Hu, Wim Haegeman, Hanlong Liu
Summary: Particle size gradation is crucial for small strain stiffness of sand and can influence biocementation behavior. This study investigated the relationship between small strain shear modulus and particle distribution through isotropic consolidation tests on glass sand with light biocementation. Shear wave velocities were measured in multiple directions using bender elements. Results showed that uncemented sand exhibited a decrease in small strain shear modulus G(0) and an increase in stiffness anisotropy with increasing uniformity coefficient Cu. Biocemented sand showed a gradual disappearance of the G(0) decrement with biocementation level, indicating an increase in G(0) with Cu. The ratio of G(0) between biocemented and uncemented sand experienced four stages. Stiffness anisotropy also changed with biocementation, particularly during unloading stages. The changes in stiffness anisotropy were more pronounced for sands with higher Cu and biocementation level.
Article
Engineering, Civil
Aditya Bhatt, Hyunwook Choo, Susan E. Burns
Summary: Engineering properties of soils can differ significantly when coated with naturally occurring or artificially manufactured particles. This study focused on evaluating the impact of iron oxide coatings on the thermal conductivity of silica sands. The results showed that the thermal conductivity of coated sands was higher than that of uncoated sands, but both were influenced primarily by porosity rather than applied stress or coating.
KSCE JOURNAL OF CIVIL ENGINEERING
(2022)
Article
Materials Science, Ceramics
Anbang Chen, Lang Li, Weili Ren, Chong Wang, Qingyuan Wang
Summary: In this study, a series of porous ceramics were prepared using different ratios of small and large size hollow ceramic spheres as pore-forming agents. The thermal insulation properties of the porous ceramics were investigated. The results showed that increasing the proportion of small size hollow ceramic spheres effectively decreased the thermal conductivity and improved the compressive strength of the porous ceramics. The optimal porous ceramic had a thermal conductivity of 0.368 W/(m·K) and a compressive strength of 22.43 MPa.
CERAMICS INTERNATIONAL
(2023)
Article
Nanoscience & Nanotechnology
Ivan Rivera, Raul Salgado-Garcia, Federico Vazquez
Summary: In this study, the response of a rigid heat conductor graded material to an oscillating thermal signal applied on its boundary is characterized using the spectral diffusivity. A frequency window between 10(-2) and 10(2) Hz is found where the spectral diffusivity increases, showing a maximum. The average heat flowing through the material and the thermal rectification also increase in this frequency range.
Article
Thermodynamics
Juan He, Xiaosen Li, Zhaoyang Chen, Changyu You, Kefeng Yan, Zhiming Xia, Qingping Li
Summary: The distribution of hydrates in sediment affects the changing trends of effective thermal conductivity, especially influenced by gas saturation, water saturation or pressure. Different formation processes of hydrates exhibit various trends in thermal conductivity changes, with non-uniform distribution causing different behaviors.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Energy & Fuels
Omar A. Radwan, John D. Humphrey
Summary: This study documents the various roles of sand in improving the performance of solar thermal technologies, such as heat storage, supply for heating, drying, distillation, gasification, cooking, and electricity generation. It also mentions the commercialized or in-process technologies.
SOLAR ENERGY MATERIALS AND SOLAR CELLS
(2023)
Article
Chemistry, Multidisciplinary
Isabella Carlomagno, Vito Antonio Cimmelli, David Jou
Summary: We study heat rectification in composition-graded nanowires considering nonlocal and nonlinear effects in a generalized Guyer-Krumhansl equation. By solving the heat equation with a composition and temperature dependent thermal conductivity, we explore the conditions under which nonlocal or nonlinear effects or both contribute to heat rectification and how they can be controlled by external radiative flux. We also calculate the corresponding rectification coefficients and identify the physical conditions for the system to become a thermal diode.
Article
Nuclear Science & Technology
Chenlong Wei, Jigui Cheng, Mei Zhang, Rui Zhou, Bangzheng Wei, Xinxi Yu, Laima Luo, Pengqi Chen
Summary: A microwave sintering method was used to fabricate a four-layered W/Cu functionally graded material (FGM) and a four-layered diamond/W-Cu FGM. The addition of diamond improved the thermal conductivity and thermal shock resistance of the composite material.
NUCLEAR ENGINEERING AND TECHNOLOGY
(2022)
Article
Engineering, Geological
Xiaohao Sun, Linchang Miao, Runfa Chen, Hengxing Wang, Linyu Wu, Jinxin Xia
Summary: Microbially induced calcite precipitation (MICP) has been found to significantly improve the liquefaction resistance of loess soil samples by cementing soil particles with calcium carbonate (CaCO3) and filling voids. Different treatment conditions lead to varying changes in permeability coefficient of samples, and increasing treatment cycles enhances liquefaction resistance. The addition of bacterial suspension and cementation solution together or separately also affects the liquefaction mitigation effects. Increasing total solution volume per treatment cycle improves liquefaction resistance, and the relationship between CaCO3 content and liquefaction resistance parameters can be established for MICP-solidified loess soil.
JOURNAL OF GEOTECHNICAL AND GEOENVIRONMENTAL ENGINEERING
(2021)
Article
Engineering, Geological
Yang Yang, Jian Chu, Hanlong Liu, Liang Cheng
Summary: This paper presents a new method of acidified one-phase-low-pH injection to improve the uniformity of biocement treatment by extending the lag duration, and compares it with the method using HCl.
Article
Engineering, Geological
Hao Chen, Jian Chu, Wei Guo, Shifan Wu
Summary: The paper proposes a conceptual design for land reclamation using a horizontal drainage enhanced geotextile sheet (HDeGs) method combined with vacuum preloading. Large-scale model tests are conducted to verify the effectiveness of the HDeGs method. The results demonstrate that the proposed method is not only effective but also more efficient in reducing construction time for land reclamation compared to traditional methods.
GEOTEXTILES AND GEOMEMBRANES
(2023)
Article
Engineering, Geological
Zengchun Sun, Yang Xiao, Minqiang Meng, Hong Liu, Jinquan Shi
Summary: The deformation and strength of soil are significantly influenced by thermal loading, especially in thermal-related geotechnical infrastructures. This study investigates the behavior of sand-clay mixtures under thermal loading and found that the mixtures exhibit plastic volumetric contraction deformation and decrease in yield stress with increasing temperature.
Article
Engineering, Geological
Han-Jiang Lai, Ming-Juan Cui, Jian Chu
Summary: One-phase-low-pH MICP or EICP is a new biocementation method for soil improvement. An experimental study using different initial pH of urease (or bacterial) solution for EICP (or MICP) biocementation showed that the lower the pH, the longer the delay period. However, the EICP or MICP process becomes ineffective when the pH is equal to or lower than 4.5 or 4.0, respectively. The initial pH also significantly affects the strength of treated sand by influencing the morphology and crystallinity of calcium carbonate crystals, but has limited impact on the amount and distribution of calcium carbonate production in soil if the delay duration is sufficient.
Article
Engineering, Geological
Han-Jiang Lai, Ming-Juan Cui, Shi-Fan Wu, Yang Yang, Jian Chu
Summary: The study investigates the extraction of soybean urease using different ethanol contents and its effect on the cementation of EICP-treated sand. The proposed extraction method using ethanol can produce clearer crude urease solution from soybean powder. The extracted urease solution with optimal ethanol content contributes to improve the strength of the EICP-treated sand column.
SOILS AND FOUNDATIONS
(2023)
Article
Engineering, Geological
Chang Zhao, Yang Xiao, Jian Chu, Ran Hu, Hanlong Liu, Xiang He, Yi Liu, Xiang Jiang
Summary: Enzymatically induced carbonate precipitation (EICP) in heterogeneous subsurface was experimentally investigated using microfluidic cells with different pore networks. The impact of flow rate and pore-scale heterogeneity on the precipitation process and the morphology of calcium carbonate crystals was quantitatively evaluated. The analysis showed that low flow rates and strong heterogeneity in porous media favor the precipitation process due to more nucleation sites. Additionally, the complex pore structures generated by the precipitates limit the transport of reactants and result in permeability reduction. The study contributes significantly to the understanding of the advection-diffusion-reaction coupling effect and the role of pore network in the biomineralization process.
Article
Engineering, Geological
Han-Jiang Lai, Ming-Juan Cui, Jian Chu
Summary: The performance of geogrid reinforcement in sand can be enhanced by using a biocementation method that involves microbial-induced carbonate precipitation. Triaxial tests were conducted to study the stress-dilatancy behavior of biocemented coarse sand (Bio-CS) treated with the biocementation-enhanced geogrid reinforcement method. The results showed that the interlocking effect between the geogrid and Bio-CS was significantly improved, leading to enhanced stress-dilatancy behavior and mobilization of friction strength.
INTERNATIONAL JOURNAL OF GEOMECHANICS
(2023)
Article
Engineering, Geological
Shifan Wu, Bing Li, Jian Chu
Summary: Biogrouting, as a new method for ground improvement or seepage control, has been extensively studied in recent years. In this study, biogrouting tests were conducted on two 1 m(3) models to simulate in situ conditions. The results showed a significant reduction in permeability and an increase in shear strength after the biogrouting treatment. The mechanical characteristics of the biologically cemented sand were also studied.
PROCEEDINGS OF THE INSTITUTION OF CIVIL ENGINEERS-GROUND IMPROVEMENT
(2023)
Article
Computer Science, Interdisciplinary Applications
Hao-Qing Yang, Jian Chu, Xiaohui Qi, Shifan Wu, Kiefer Chiam
Summary: This study aims to evaluate the uncertainty of the soil-rock interface using the Bayesian evidential learning (BEL) framework without subjective assumptions. A borehole-intensive site is selected to investigate the impact of borehole number and layout on the estimation of the soil-rock interface. The results highlight the importance of borehole planning in reducing geological uncertainty.
COMPUTERS AND GEOTECHNICS
(2023)
Article
Engineering, Geological
Maryam Naeimi, Jian Chu
Summary: Prevention of erosion failure in river or coastal dikes has become increasingly important due to climate change. A study investigated the use of microbially induced carbonate precipitation to provide a sustainable solution for sandy dike erosion caused by overtopping. Model tests were conducted on biotreated sand dike models in a hydraulic flume, comparing surface spray and percolation methods. The results showed that biocementation using the percolation or surface spray method effectively prevented erosion.
Article
Engineering, Geological
Yang Xiao, Qingyun Fang, Armin W. Stuedlein, T. Matthew Evans
Summary: A series of drained triaxial tests were conducted on sandy soils with different mean particle sizes to investigate the effect of particle size and shape on soil strength and dilatancy. The results showed that the maximum and critical-state friction angles of rounded glass bead sands increased slightly with increasing particle size, while the critical-state friction angle of angular crushed glass sands decreased. The maximum dilation angle of both angular crushed glass and rounded glass bead sands increased with larger particle size. The comparison of different sands demonstrated that the strength and friction angle of granular soils are directly influenced by particle angularity and interparticle locking.
INTERNATIONAL JOURNAL OF GEOMECHANICS
(2023)
Article
Engineering, Geological
Yang Xiao, Bingyang Wu, Jinquan Shi, Lei Wang, Han-Long Liu
Summary: A meter-scale model test was conducted to validate the sustainable soil reinforcement technique of microbially induced calcite precipitation (MICP). Mechanical and physical testing methods were explored to evaluate the biocementation efficiency of the model tests. The results showed that the level of biotreatment increased the strength of the sand base, with the maximum strength achieved after eight cycles. The heterogeneity of the biotreatment was observed in the sand base, as evidenced by differences in dry density, shear-wave velocity, and unconfined compression strength.
INTERNATIONAL JOURNAL OF GEOMECHANICS
(2023)
Review
Engineering, Civil
Yang Xiao, Baofeng Cao, Jinquan Shi, Huanran Wu, Xiang He, Chang Zhao, Jian Chu, Hanlong Liu
Summary: This paper reviews the application of microfluidic techniques in biogeotechnology, discussing microbial behavior, reaction flow, and biomineralization. Microfluidic techniques can reveal the microscopic mechanisms of biogeotechnology, provide evidence for macroscopic experiments, and promote the practical application of biogeotechnology.
TRANSPORTATION GEOTECHNICS
(2023)
Proceedings Paper
Construction & Building Technology
Jeffrey T. Newgard, Tara Hutchinson, John S. McCartney
Summary: This study focuses on the load-deformation response of a heavily loaded rocking footing on sand reinforced by soil-cement columns via centrifuge-model scale shake table tests. The ground improvement technique consists of soil-cement mixed columns to control the kinematics of the footing while maintaining the enhanced energy dissipation characteristic of a rocking footing. The addition of paired soil-cement columns significantly reduce settlement during rocking and preserve recentering throughout demanding shaking events.
GEO-CONGRESS 2023: GEOTECHNICS OF NATURAL HAZARDS
(2023)
Article
Engineering, Geological
Lei Wang, Jian Chu, Shifan Wu
Summary: This study investigated the failure and stress-strain behavior of biocemented sand under plane strain conditions. The increase in calcium carbonate content led to increased brittleness and dilation of the biocemented sand. The friction angle and effective cohesion also increased with the increasing calcium carbonate content.