Environmental geotechnics最新文献

{"title":"Accurately Predicting Quartz Sand Thermal Conductivity Using Machine Learning and Grey-Box AI Models","authors":"Abolfazl Baghbani, H. Abuel-Naga, Danial Shirkavand","doi":"10.3390/geotechnics3030035","DOIUrl":"https://doi.org/10.3390/geotechnics3030035","url":null,"abstract":"The thermal conductivity of materials is a crucial property with diverse applications, particularly in engineering. Understanding soil thermal conductivity is crucial for designing efficient geothermal systems, predicting soil temperatures, and assessing soil contamination. This paper aimed to predict quartz sand thermal conductivity by using four mathematical models: multiple linear regression (MLR), artificial neural network (ANN), classification and regression random forest (CRRF), and genetic programming (GP). A grey-box AI method, GP, was used for the first time in this topic. Seven inputs affecting thermal conductivity were evaluated in the study, including sand porosity, degree of saturation, coefficient of uniformity, coefficient of curvature, mean particle size, and minimum and maximum void ratios. In predicting thermal conductivity, the MLR model performed poorly, with a coefficient of determination R2 = 0.737 and a mean absolute error MAE = 0.300. Both ANN models using the Levenberg–Marquardt algorithm and the Bayesian Regularization (BR) algorithm outperformed the MLR model with an accuracy of R2 = 0.916 and an error of MAE = 0.151. In addition, the CRRF model had the best accuracy of R2 = 0.993 and MAE = 0.045. In addition, GP showed acceptable performance in predicting sand thermal conductivity. The R2 and MAE values of GP were 0.986 and 0.063, respectively. This paper presents the best GP equation for evaluating other databases. Additionally, the porosity and saturation of the sand were found to have the greatest impact on the model results, while coefficients of curvature and uniformity had the least influence. Overall, the results of this study demonstrate that grey-box artificial intelligence models can be used to accurately predict quartz sand thermal conductivity.","PeriodicalId":11823,"journal":{"name":"Environmental geotechnics","volume":"1 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74317929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rocking Motion Analysis Using Structural Identification Tools","authors":"Ophélie Rohmer, Maria Paola Santisi d’Avila, E. Bertrand, J. Regnier","doi":"10.3390/geotechnics3030033","DOIUrl":"https://doi.org/10.3390/geotechnics3030033","url":null,"abstract":"This research investigates the convenience of structural identification tools to detect the rocking motion tendency, using as input the structural response to ambient vibrations. The rocking ratio and rocking spectrum are proposed as original tools to highlight the rocking motion and its frequency content. The proposed procedure allows the detection and quantification of rocking using only building vertical motion records in both cases of ambient vibration and earthquake. First, three-dimensional finite element models of reinforced concrete buildings are adopted to simulate the structural response to white noise vibration. Different low- and high-rise buildings are studied, having framed structure and frame–wall system, regular and irregular structure, shallow foundation and underground floors. The structural response obtained numerically is analyzed using different signal processing tools to obtain the dynamic features of buildings, and the rocking motion tendency is identified by comparison with a reference fixed base condition. Then, the reliability of the proposed methodology to detect rocking motion attitude, using only the structural motion, is verified and quantified using the proposed tools. Finally, the same approach is applied to real structural motion records of a high-rise reinforced concrete building.","PeriodicalId":11823,"journal":{"name":"Environmental geotechnics","volume":"31 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89587809","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Meta-Material Layout for the Blast Protection of Above-Ground Steel Pipes","authors":"Miltiadis Kontogeorgos, C. Fuggini","doi":"10.3390/geotechnics3030032","DOIUrl":"https://doi.org/10.3390/geotechnics3030032","url":null,"abstract":"The current study investigates the capacity of the proposed meta-material layout for the blast protection of above-ground steel pipes against explosions. The philosophy of the meta-material layout’s design is described adequately, and the 1D periodic structures’ theory is adopted for the analytical prediction of the layout’s band-gaps. The special characteristics of the blast loading are explained, and specific time-related parameters are calculated. The layout is tested numerically for nine explosion scenarios of various magnitude via the finite element program ABAQUS, and the CONWEP model is selected for the simulation of the explosions. The results demonstrate a significant reduction in the maximum displacements developed on the pipe’s spring line and crown within a blast loading. This study composes an extension of the author’s previous research on buried steel pipes and surface explosion, advancing now the applicability of the meta-material layouts for the cases of above-ground steel pipes towards explosions and blast hazards. The outer goal is the investigation and the further spreading of the beneficial exploitation of meta-materials concepts for the scope of the pipelines’ effective blast protection, readdressing that this way is a major hazard for this type of structure and a gap in the current literature.","PeriodicalId":11823,"journal":{"name":"Environmental geotechnics","volume":"184 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80687883","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electromagnetic Waves’ Impact on Hydraulic Conductivity of Granular Soils","authors":"Arvin M. Farid, Holly Gunderson, Rakesh Acharya, J. Browning","doi":"10.3390/geotechnics3030031","DOIUrl":"https://doi.org/10.3390/geotechnics3030031","url":null,"abstract":"Electromagnetic (EM) waves, traditionally used for purposes such as geophysical characterization, impact properties to be measured. This paper describes the effects of radio frequency (RF) waves on the hydraulic conductivity of glass beads and natural sand. A series of tests was conducted using a customized, rigid-wall, cylindrical permeameter inside a resonant cavity made of Plexiglas covered with electrically conductive transparent films. Constant-head ASTM-D2434 tests were performed to measure the samples’ hydraulic conductivity. RF stimulation was performed using a magnetically coupled loop antenna at various frequencies and input RF-power levels. The hydraulic conductivity of both natural sand and glass-bead samples increased with RF stimulation. Furthermore, the measurement of the electric field component of RF waves was also performed to illustrate the pattern of the electric field, as well as evaluate RF’s impact on the hydraulic conductivity tests. The electric field was numerically simulated and validated against experimentally measured electric fields. A finite-difference numerical model was developed in MATLAB to analyze the seepage flow, which was then validated against the experimental results. An optimization scheme was then used to develop a governing equation for RF’s impact on hydraulic conductivity.","PeriodicalId":11823,"journal":{"name":"Environmental geotechnics","volume":"87 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73516532","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The role of hydraulic and thermal properties of soil in evaporation: a numerical insight","authors":"G. Guida, Vincenzo Sergio Vespo, G. Musso, G. Della Vecchia","doi":"10.1680/jenge.22.00132","DOIUrl":"https://doi.org/10.1680/jenge.22.00132","url":null,"abstract":"Evaporation from geological formations results from the interaction between the geomaterial and the atmosphere. Geotechnical engineering issues, such as slope stability, pollution containment and soil heave/shrinkage, require a deep understanding of the soil–atmosphere interaction ruled by evaporation. Evaporation is a multiphase thermo-hydraulic phenomenon that includes liquid water, vapour and heat fluxes. It is generally modelled considering the thermal energy and water mass balance equations of unsaturated soils. This paper presents a numerical model for reproducing evaporation processes under controlled environmental conditions. The model was implemented in the Comsol Multiphysics finite-element software and first validated against experimental data from the literature. Then, it was used to investigate the role of hydraulic and thermal properties in the evaporative response. The numerical results revealed differences in the evolution of the water content profiles over time due to the interplay between hydraulic conductivity and retention properties. Hydraulic conductivity mainly impacts the shape of water content isochrones: fast drying of superficial layers and slow desaturation of deeper layers occur with decreasing hydraulic conductivity values. On the other hand, the moisture capacity primarily impacts the thickness of the desaturating layer, which decreases for higher values of the moisture capacity.","PeriodicalId":11823,"journal":{"name":"Environmental geotechnics","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49257472","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Attenuation of erythromycin-laden waste water using the constructed wetland technique","authors":"Avishek Adhikary, Tapabrata Chakraborty, Pradyumna Konar, S. Pal, Sudipta Ghosh","doi":"10.1680/jenge.22.00082","DOIUrl":"https://doi.org/10.1680/jenge.22.00082","url":null,"abstract":"Erythromycin (ERY) is environmentally resilient because of its aromatic nature, which hinders degradation. In the present study, silty–sandy soil, with a saturated hydraulic conductivity (K) value of 1.66 × 10−7 m/s, was studied for its potential to remove aqueous ERY using a laboratory-scale constructed wetland. With a dose of 10 g/l, a concentration of 25 mg/l and a contact time of 30 min, the maximum adsorption reached 89.79 ± 1.5%, as found from batch experiments. The Freundlich isotherm (R 2 = 0.983, n = 0.575, K f = 0.04 mg/g) was the best fitting among different user models. In the kinetic study, the pseudo-second-order model (q e = 1.297 mg/g, K 2 = 0.182 g/(mg min)) had the best fit with experimental data. A one-dimensional vertical column study exhibited an exhaustion time of 2.7 days for a 40 mm deep soil bed to remove ERY. A laboratory-scale constructed wetland model composed of silty–sandy soil showed a reduction of ERY of 92.44%. Finally, the results were validated with the CW2D wetland model of the Hydrus software, which corroborated the experimental results. The outcome exhorts that constructed wetlands with silty–sandy soil may be an effective technique for the reduction of ERY present in waste water, which has profound importance from a social health perspective.","PeriodicalId":11823,"journal":{"name":"Environmental geotechnics","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44043279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Low Frequency Cyclic Mechanical Loading of Till Deposits from Northern Germany under Oedometric Conditions","authors":"H. Hailemariam, F. Wuttke","doi":"10.3390/geotechnics3020029","DOIUrl":"https://doi.org/10.3390/geotechnics3020029","url":null,"abstract":"Glacial deposits are of significant importance to geotechnical engineers and geologists in northern Europe, North America, and Northern Asia, as vast areas of these land surfaces were historically covered with ice leading to the formation of a wide variety of till deposits. The use of these areas for various engineering purposes warrants their subjection to mechanical loads (of static and cyclic forms) from manmade structures, as well as natural hazards such as earthquakes. This paper focuses on the experimental investigation of the cyclic mechanical loading behavior of two glacial tills from northern Germany under one-dimensional loading or oedometric conditions, and in different soil wetting conditions. The experimental results show a significant dependence of the cyclic mechanical response of the glacial tills on wetting condition and number of loading cycles. The recorded values of accumulated plastic strains of the glacial tills generally increase with an increase in wetting or moisture content, with the highest measured value for the two tills being around 3.9% after 19 cycles of loading. The findings of the experimental cyclic mechanical tests of the glacial tills are discussed in view of the intrinsic soil behavior and fabric.","PeriodicalId":11823,"journal":{"name":"Environmental geotechnics","volume":"48 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78735170","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Dynamic Properties of Sand under Torsion: A Literature Review","authors":"M. Ahmad, Richard Ray","doi":"10.3390/geotechnics3020027","DOIUrl":"https://doi.org/10.3390/geotechnics3020027","url":null,"abstract":"Resonant column (RC) and the torsional simple shear (TOSS) tests have shown proven competency in acquiring precise and repeatable measurements regarding the shear modulus and damping ratio of soil. For most dynamic geotechnical problems, the shear modulus represents the stiffness of the soil, while the damping ratio describes energy dissipation. Many studies in the last few decades focused on developing the relevant equipment and investigating the effect of different soil properties on the dynamic behavior of soil. Researchers have introduced correlations to approximate this behavior without conducting dynamic torsional testing. Soil models (e.g., Ramberg-Osgood and Hardin-Drnevich) can simulate shear stress-strain curves after finding the curve-fitting parameters. Due to the complexity of dynamic behavior and its dependency on various factors in soils, the RO and HD equations help model the behavior more simply. This paper presents a literature review and evaluation of the studies, correlations, soil models, and parameters affecting the dynamic behavior of dry sand under torsion.","PeriodicalId":11823,"journal":{"name":"Environmental geotechnics","volume":"14 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72735345","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Sensitivity of Micro—Macro Mechanical Behaviour of Sand to the Inter-Particle Properties","authors":"A. Momeni, K. Eshiet, Y. Sheng","doi":"10.3390/geotechnics3020024","DOIUrl":"https://doi.org/10.3390/geotechnics3020024","url":null,"abstract":"Sand is a particulate material but is treated as a continuum solid in some engineering analyses. This approach is proven to be acceptable when dealing with geotechnical structures, provided an adequate factor of safety is applied so that there is no risk of failure. However, the continuum approach does not account for the effect of interparticle forces on the micro–macro behaviour of sand. Sand could be modelled as a particulate material using the discrete element method (DEM), taking into account its discrete nature. This paper shows how the microscopic contact properties between the idealised sand particles influence the macro-mechanical behaviour, highlighting the development of the fabric as the soil approaches failure. Thirty DEM biaxial tests were performed to study the sensitivity of the macro–micro mechanical properties of sand to the inter-particle properties of an idealised sand particle. The conditions of these simulations were the same (e.g., particle size distribution, number of particles, porosity after radius enlargement, boundary conditions, and rate of loading). The sensitivity of the pre-peak, peak, and post-peak behaviour of these simulations to the inter-particle properties of an idealised sand particle was studied. Two extra DEM biaxial tests under different confining pressures were performed to verify the cohesionless nature of the synthetic material used for this study. Since a two-dimensional DEM is used for this study, a detailed approach to interpret the results assuming either a plane strain or a plane stress situation was discussed. This study highlighted the critical inter-particle properties and the range over which these influence macro-mechanical behaviour. The results show that Young’s modulus is mainly dependent on the normal contact stiffness, and peak stress and the angle of internal friction are greatly dependent on the inter-particle coefficient of friction, while Poisson’s ratio and volumetric behaviour of particulate sand are dictated mainly by shear contact stiffness. A set of relationships were established between inter-particle properties and macro-machinal parameters such as Young’s modulus, Poisson’s ratio, and angle of internal friction. The elastoplastic parameters obtained from these tests are qualitatively in agreement with the typical medium and dense sand behaviour.","PeriodicalId":11823,"journal":{"name":"Environmental geotechnics","volume":"1 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84057984","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of Material Composition on Geotechnical Properties—Study on Synthetic Municipal Solid Waste","authors":"Vidit Singh, T. Uchimura","doi":"10.3390/geotechnics3020023","DOIUrl":"https://doi.org/10.3390/geotechnics3020023","url":null,"abstract":"The geotechnical properties of municipal solid waste (MSW) are required to design and maintain a landfill structure. Several landfill failures occurring in recent times have led to the loss of revenue and people. This study aims to investigate the impact of material composition on the geotechnical properties of fresh synthetic municipal solid waste (SMSW), which imitates the real waste produced in India. The study aims to understand the contribution of each material, such as paper, plastic, and organic matter, on the shear behavior of SMSW, which is essential for designing landfills and ensuring their safety and performance. A modified proctor test and a large-scale direct shear test were used to determine the unit weight and shear strength of SMSW, respectively. The synthetic waste’s unit weight and shear strength were found to be consistent with values that had already been published. The shear strength parameters of SMSW include cohesion, which was determined to be at the lower bound of the envelope, and friction angle within the envelope. Lower unit weight, less fine soil-like material, and dry material are thought to be the causes of the observed variation in the behavior of actual waste in synthetic waste. The findings of this experiment demonstrated that as the proportion of paper increases, the cohesion (C) increases, and the friction angle (Φ) decreases. Cohesion and friction angle both decrease as the proportion of plastic increases. Cohesion and friction angle both increase with an increase in the organic percentage. These findings demonstrate that each material contributes differently to the shear behavior of SMSW. Hence, the material composition’s effect should be considered while designing a landfill for improved safety and reliability.","PeriodicalId":11823,"journal":{"name":"Environmental geotechnics","volume":"16 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82924992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}