bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study on creep characteristics and reduction coefficient of geomembrane under top pressure
Authors: Wu D , Yi Y , Wu J , Liang T , Li D 
Published: May 2024

Abstract
A new top-pressure creep test device was developed to simulate the stress conditions of geomembrane in a real working state. CBR puncture and top pressure creep tests under different load levels were conducted using this device to study the creep characteristics of the geomembrane at top pressure. The top pressure creep reduction coefficients under different load levels and design lives were calculated and compared with the regular tensile creep reduction coefficients. Quantitative relationships between the creep-reduction coefficient, design life, and failure strain were established to predict the top-pressure creep-reduction coefficient. The results indicated that the top pressure creep reduction coefficient was greater than that of regular tensile creep. The creep reduction coefficient changed minimally with an increase in the design life. The top pressure creep reduction coefficient remained stable with an increase in the top pressure area strain for different design lives. Based on the results, to improve the safety and durability of engineering structures, the top pressure creep reduction coefficient should be used in the design of geosynthetics affected by the top pressure.
Numerical assessment of geocell-reinforced pavement performance subjected to cyclic loading conditions
Authors: Banerjee S , Manna B , Shahu J T 
Published: May 2024

Abstract
A numerical analysis was conducted using PLAXIS 3D software on a geocell-reinforced pavement over a soft subgrade under cyclic loading conditions. This study illustrates surface deformation and vertical stress within the subgrade layer of a reinforced pavement. The accuracy of the FE model was confirmed by comparing the results ofthe present study with those reported in the literature. This study investigated the influence of various factors, such as different infill and subgrade materials inreinforced pavements, on the overall pavement performance. These findings were compared with those observed for conventional planar-reinforced pavements. For improved infill and subgrade materials, the total surface deformation of the reinforced section decreased by approximately 15%–40%. Compared with the improvement in subgrade properties, a significant reduction of approximately 10% was observed inthe pressure response at the subbase-subgrade interface when using improved infill material. Moreover, compared to the planar-reinforced pavement, the geocell-reinforcedpavement reduced vertical stress at the interface between the base and subgrade by approximately 26%.
Study on preparation and property of coir fiber reinforced epoxy resin composite geogrid
Authors: Li L , Chen J , Cao W , Zhang Q. , Wang J , Li H 
Published: May 2024

Abstract
Based on the development and application of green composite building materials, this study prepared a coir fiber reinforced epoxy resin composite grid using coir fiber as the reinforcement material. Through tensile tests of a multi rib grid, the effects of coir fiber content, length, and rib spacing on the composite grid were studied. The results showed that with increase in the coir fiber content, the tensile yield force first increased and then decreased, reaching the maximum value at coir fiber content of 1%. When the coir fiber content exceeded 1%, the tensile properties of the composite grid were lower than that of pure epoxy resin. With the increase in the coir fiber length, the tensile yield force of composite grid also first increased and then decreased. At a fiber length of 1 cm, the maximum tensile yield force was obtained, which was 34.33% higher than that of pure epoxy resin grid. Compared with the influence of fiber length and content on the composite grid, the influence of rib spacing on the composite grid was more obvious. At a rib spacing of 1 cm, the tensile yield force reached its maximum.
Feasibility study of geosynthetic vegetation substrate for hard-surface ecological restoration part 1: Development of designated vegetation
Authors: Wu J Y , Guo J , Qiu T , Chen L Y , Qin C R , Chu J , Zhou Y , Zou B , Xu Y 
Published: May 2024

Abstract
Current ecological restoration techniques often face challenges on steep and hard surfaces (e.g., concrete or rock surfaces) because of their reliance on soil as a vegetation substrate. Two geosynthetic-based ecological restoration techniques are proposed in which a geosynthetic material is used to replace the soil as a vegetation substrate on hard-surface slopes. In the first technique, vegetation is planted directly on a geosynthetic vegetation substrate (GVS), where the GVS provides water to the vegetation and room for the growth of vegetation roots. In the second technique, Hygrophila ringens is first planted on the GVS. This plant exhibits rapid growth initially and then dies after three months, creating a layer of humus over the GVS. Subsequently, herbaceous vegetation can grow over the GVS. The effectiveness of the GVS restoration technique was verified by conducting a one-year-long experimental study. During the experiment, vegetation such as Tall Fescue, Bermuda grass, bentgrass, Chinese holly, and Tifdwarf were grown on the GVS. Vegetation growth parameters such as blade length, biomass production, and species iteration were monitored with respect to the vegetation species and seeding density. The experimental results suggest that both ecological restoration techniques based on the GVS can successfully sustain vegetation on concrete slopes.
Numerical analysis of the working performance of ring combination reinforced retaining wall
Authors: Zhang M X , Zhong W T 
Published: May 2024

Abstract
In this study, a new combined reinforcement structure suitable for reinforced soil-retaining walls is proposed. FLAC 3D finite element software was used to establish three-dimensional numerical models of reinforced soil retaining walls with different forms of reinforcement, and the effects of reinforced rings on the mechanical and deformation characteristics of retaining walls, as well as the mechanism of the reinforced rings working with horizontal geogrids, were investigated. The test results verified the superiority of the ring combination-reinforced structure in bearing and deformation under the same loading conditions. Moreover, the ring combination-reinforced soil retaining wall exhibited a stronger ability to resist deformation than the horizontal-reinforced soil retaining wall.
Numerical simulation of heavy metal migration in stabilized soils under multi-field coupling
Authors: Hua Yang , Suna Hui-Yang , Zhoua Shi-ji , Xua Yang , Zhanga Qing , Dua Yan-jun 
Published: May 2024

Abstract
Heavy metal contamination of soils has become a global issue. In pursuit of a reference for the management of heavy metal pollution, numerical simulations were used here to investigate the migration pattern of heavy metals in soil under multi-field coupling of rainfall, temperature, and hydraulic conductivity. Models were built using TOUGHREACT, and measured and simulated values were compared with those of existing studies to verify the accuracy of the software in simulating coupled water vapor-thermal transport and rainfall infiltration. Taking Nanjing rainfall data as an example, the transport pattern of zinc in soil under multi-field coupling was explored. Although evaporation and rainwater infiltration were found to increase with the temperature, the effects of evaporation and temperature counteracted each other, resulting in a weak influence of temperature on heavy metal transport. The hydraulic conductivity of stabilized soil was the main factor controlling zinc migration, with the saturation and heavy metal concentration clouds of soil columns tending to stabilize when the hydraulic conductivity of solidified soil was under 1 × 10-11 m/s.
Potassium permanganate oxidation of low-permeability phenanthrene contaminated soil under fracturing conditions
Authors: Shi Fu-Jiang , Feng Shi-Jin 
Published: May 2024

Abstract
In situ chemical oxidation (ISCO) technology has limitations in the remediation of low-permeability polycyclic aromatic hydrocarbon (PAHs)-contaminated sites because of the difficulty in oxidant delivery. Horizontal fractures created by hydraulic fracturing provide convenient channels for rapid oxidant delivery. However, limited studies have focused on potassium permanganate (KMnO4) oxidation in low-permeability PAH-contaminated sites under fracturing conditions considering in situ hydrological environments. Therefore, this study aimed to explore the effect of KMnO4 concentration on the remediation efficiency (including the removal rate of phenanthrene (PHE), remediation time, and total oxygen demand (TOD)) of low-permeability PHE-contaminated soil through a one-dimensional penetration-oxidation test, and the effect of KMnO4 oxidation on the physicochemical properties of the soil through a series of laboratory experiments. The results showed that an increase in KMnO4 concentration shortened the remediation time and increased the removal rate of PHE and TOD from PHE-contaminated soil. The oxidation of KMnO4 resulted in an increase in the pH, oxidation-reduction potential, dissolved organic carbon, cation exchange capacity, specific surface area, and fine particle content of the soil, and a decrease in the total organic carbon of the soil, but did not alter the permeability of the soil.
Assessing changes in geotechnical properties of soil caused by oil contaminants
Authors: Ali Shamshad , Nie Zhihong , Ismail Abubakar Sadiq , Sohel Rana 
Published: May 2024

Abstract
Soil pollution seriously threatens the integrity of geotechnical soil properties, considerably altering physical and mechanical characteristics. Therefore, the geotechnical characteristics of contaminated soils should be studied. Samples used in this study were obtained from Peshawar, Khyber Pakhtunkhwa Province, Pakistan. Tests such as Atterberg limits, direct shear strength, sieving analysis, consolidation, and unconfined compression were conducted. The internal friction angle, cohesiveness, and shear strength of the soil decreased when oil pollution was introduced, probably owing to the lubricating effect of oil, which also causes a decrease in the dielectric constant. Surprisingly, in certain cases, bioremediation could reduce soil swelling, relieve pressure from swelling, and prevent soil settlement. Oil contamination resulted in decreased permeability and mechanical strength in the analyzed soil samples. Importantly, the effect of oil contamination on the shear strength parameters is not uniform and depends on the soil type. A thorough study is required because of the long-term consequences of oil contamination, particularly the long-term aging effects on geotechnical soil properties and behavior. Therefore, these results must be compared with those of the most recent tests. Furthermore, future research should consider the complex interplay between the functional groups inherent in soil solids and the injected contaminated oil.
Impact of Industrial Solid Waste on Soil Geotechnical Properties
Authors: Sohel Rana , Nie Zhihong , Ali Shamshad , Ismail Abubakar Sadiq 
Published: May 2024

Abstract
In this study, the issue of industrial solid waste-contaminated soil and its consequences on various geotechnical parameters is examined. Soil health and geotechnical properties are affected by the global discharge of pollutants from chemical industries, including water, air, oil, and solids. Herein, the specific issue of soil contamination in Peshawar, Pakistan, is discussed. The goals of this study included examining variations in the Atterberg limits, direct shear strength, sieving analysis, consolidation behavior, and unconfined compression strength in contaminated soil samples. The process entailed analyzing soil samples taken from polluted sites in a laboratory. In contrast to uncontaminated soil, the results showed that contaminated soil deviated from the standard grading and exhibited lower liquid and plastic limits, higher moisture content, and lower specific gravity. Interestingly, the unconfined compression strength of the polluted soil was higher, indicating complicated interactions between the contaminants. Overall, this study highlights the need to understand and efficiently mitigate such human impacts by highlighting the extensive alterations in soil properties caused by industrial waste pollution.
Experimental study on the dynamic strength characteristics of combined heavy metals contaminated soil with nZVI treatment
Authors: Zou Meng , Wei Jing , Chen Yong-Zhan , Dong Qingxi , Chen Keyu , Fan Chen 
Published: May 2024

Abstract
Nanoscale zero-valent iron (nZVI), a high-performance nanomaterial, can treat heavy metal contaminants and is extensively employed for in-situ treatment of groundwater and contaminated subsoil. However, there are few studies that indicate trends in the dynamic strength parameters of nZVI-treated soils to assess site safety. In this study, three heavy metal contaminants, Zn(II), Pb(II), and Ni(II), were selected to contaminate virgin soil. The heavy-metal-contaminated soil was treated with nZVI at two concentrations (a low dose and high dose of 0.5% and 2%, respectively) of the soil's dry mass. Analyses of particle size distribution revealed a consistent shift towards larger particles upon nZVI treatment, and the percentage of sand gradually increased. Heavy metal contamination decreased the liquid and plastic limits of the virgin soil, while those of the treated soil increased with nZVI content. The dynamic triaxial results showed significantly lower maximum dynamic shear modulus for MS, MS-LdN, and MS-HdN than for NS. The damping ratios of all samples showed an S-shaped trend. Thus, nZVI has the potential to create cemented structures and immobilize heavy metals. However, its effectiveness is significantly modulated by the initial water content of the soil. While the application of nZVI proves beneficial in immobilizing heavy metal contaminants, careful consideration is imperative under dynamic loading conditions.
Engineering properties of microcapsules self-healing geopolymer cutoff wall backfill under dry-wet cycles
Authors: Xue Qin-Pei , Chen Hong-Xin , Feng Shi-Jin 
Published: May 2024

Abstract
Vertical cutoff wall has been employed for decades to control groundwater flow and subsurface contaminant transport. Environmental stress fluctuations induced by alternating dry and wet conditions impair the permeability and durability of the cutoff wall, leading to the dispersion of contaminants. The objective of this study is to incorporate self-healing microcapsules into existing geopolymer cutoff wall backfill (GCWB) to form self-healing geopolymer cutoff wall backfill (SHGCWB) that hold promise for better durability and performance. The in-situ polymerization method was used to develop single-walled and double-walled microcapsules. The microcapsules use sodium silicate as the healing agent encapsulated in single-walled polyurethane (PU) and double-walled polyurethane/melamine-formaldehyde (PU/MF) microcapsules. The effect of microcapsules on the unconfined compressive strength (UCS) and hydraulic conductivity of SHGCWB were elaborated. The durability and hydraulic conductivity variation of SHGCWB in dry-wet cycle was thoroughly investigated by Scanning Electron Microscopy (SEM) test for understanding the self-healing mechanism. The overall performance demonstrated the significant potential of the use microcapsules as a self-healing approach for cutoff walls.
Water balance estimation for an ordinary solid waste sanitary landfill in Costa Rica
Authors: Baltodano-Goulding R , Poveda-Montoya A 
Published: May 2024

Abstract
To assess the necessity of treatment systems for leachate generated by ordinary solid waste deposited in a sanitary fill, accurate estimation of the leachate and gas amount produced during biodegradation process is essential. Climatic conditions at the site significantly influence leachate generation; therefore, accurate estimation of rainfall, temperature, solar radiation, and infiltration into the fill is imperative. In this study, we analyzed the water balance of the Miramar landfill in Costa Rica, assessed the amount of leachate produced using various methodologies, and then compared these findings with the field data to identify the best methodology for specific environmental conditions. To comprehensively analyze landfill behavior, as well as the leachate and gases generated from waste decomposition, determining the hydraulic properties of the materials inside the cells is necessary. These properties must consider variables such as the types of materials present at the site, age of the ordinary waste, and their densities. The hydraulic properties of the materials were obtained from various laboratory tests, which included determining the soil–water characteristic curve necessary for assessing unsaturated conditions in the solid waste. These properties are compared with the results of studies conducted in other landfills to validate the current methodology and the obtained results, which can be used for conducting studies on leachate generation or slope stability analysis for sanitary landfill slopes. The amount of leachate generated was estimated using the methodology proposed by Delgado A. (2018). Additionally, the Hydrologic Evaluation of Landfill Performance model (HELP V 4.0) was employed, demonstrating superior estimation compared to recorded field data. The HELP V 4.0 model facilitated the incorporation of different material layers and thicknesses, weather information at the site, slopes, and drainage conditions.
Heating test of a silty sand in a short cylinder with a vertical hydronic grouted heating pipe
Authors: Kaneza N , Shrestha S , Lei G , Yu X B 
Published: May 2024

Abstract
Ground heat exchangers (GHEs) consist of HDPE pipes embedded in the ground to exchange thermal energy with the surrounding soils. Vertical GHEs are backfilled with grout materials to seal the soil boreholes, which are critical to the heat transfer at the pipe and soil interface. In this study, a short vertical soil cylinder was developed to measure the heat transfer process at the soil and pipe interface. The soil test cylinder consists of a 30 cm tall acrylic cylinder with a vertical 2.5 cm diameter (ID) HDPE pipe at its center. A grout of 85% bentonite and 15% graphite was compacted at 36% moisture content around the HDPE with a 1.4 cm radial thickness. A silty sand was chosen as the testing soil and compacted into the cylinder at 9% moisture and a dry density of 1.26 g/cm3. Moisture, temperature, and heat flux sensors were installed along the radial direction to measure the heat transfer process. The HDPE pipe was connected to a temperature-controlled water bath for a heating source at the specified constant temperature. The heating test of the silty sand with and without grout was compared. The thermal contact resistance at the pipe-grout interface was determined. The results demonstrated the impact of thermal grout on the heat transfer of GHEs, and the findings will help improve its design.
Coupled thermal-gas-mechanical phase-field modeling for fracture initiation and propagation in the underground caverns for compressed air energy storage
Authors: Xu Y J , Xia C C , Zhou S W , He X H 
Published: May 2024

Abstract
With the aim of addressing the large-scale engineering fracture problems in an underground cavern for compressed air energy storage (CAES), in this study, a coupled thermal-gas-mechanical (TGM) phase-field modeling for simulating fracture initiation and propagation in the CAES caverns is proposed. This study also focuses on COMSOL Multiphysics strategy of the TGM phase-field fracture modeling. The temperature field, air seepage field, displacement field, initial geostress field, and phase field are fully coupled and solved in COMSOL. A circular preexisting fracture zone is generated and used to initialize the fracture propagation according to the newly specified history strain field. The results indicate that the proposed TGM phase-field modeling and the corresponding COMSOL implementation strategy can simulate the thermodynamic responses and fracture initiation and propagation well. The lateral pressure coefficient and gravitational stress field have a strong impact on the fracture patterns and critical pressure, inducing fractures.
Thermal-hydro coupling model of methane hydrate reformation in porous media
Authors: Li Lili , Zhang Pengwei , Yang Ming , Liu Baoguo 
Published: May 2024

Abstract
Methane hydrates are crystalline compounds found in marine sediments and permafrost regions. Methane hydrates remain stable under both low-temperature and high-pressure conditions. When a methane hydrate reservoir is heated or depressurized, methane hydrates become unstable and decompose into water and methane gases. The heat absorption process during the decomposition of methane hydrates influences the temperature field. Methane hydrate reformation occurs during the extraction process, significantly reducing the hydraulic conductivity of the reservoir and hindering the long-term stable extraction of methane hydrates. In this paper, a numerical model is established by coupling seepage and heat processes. The temperature variation owing to the heat absorption process of methane hydrate decomposition is quantified based on the proposed model. The effect of spatial lithology on methane hydrate conversion is also analyzed, and the results for hydrate, water, gas, and permeability in the model are summarized. The numerical model also reflects the heterogeneity of marine sediments. Finally, the sensitivities of different physical parameters (permeability and porosity) and pressure gradients to the reformation rate of methane hydrate reforming are discussed. The results of this study provide scientific data supporting the influence of secondary hydrate formation on long-term extraction efficiency in the actual engineering hydrate extraction process.
Simulation of controlled modulus column installation using a large deformation finite element analysis
Authors: Amarathunga T , Liyanapathirana D S , Fuentes W , Leo C J , Hu P 
Published: May 2024

Abstract
Controlled modulus columns (CMC) are widely used in ground improvement techniques where grout columns are constructed by penetrating an auger into the ground using the displacement approach. Numerical simulation of this problem is challenging owing to the large soil deformations associated with installation. Small strain-based finite element analysis procedures available in commercial finite element modeling software are unsuitable for simulating this problem because they cannot simulate large soil deformations around the auger during column installation. Hence, this study presents a numerical approach based on the finite element method to simulate the installation of CMCs. The numerical modeling technique adopted in this study considers large soil deformations around columns during penetration, and the proposed approach is based on remeshing and interpolation techniques. This method was developed using the Python development environment (PDE) within the ABAQUS/standard finite element program. It can penetrate columns below the ground surface without causing large mesh distortions. In this study, silty sand-type soil was considered; hence, the constitutive behavior was simulated using the Mohr–Coulomb criteria. The load-carrying capacity of a controlled modulus column was predicted and compared with an empirical equation based on the cone penetration resistance. The influence zone and failure mechanism of the soil during installation were determined by considering the stress distribution and soil flow pattern around the column.