Environmental geotechnics最新文献_第3页

Temperature-dependent relationship between the water content and electrical conductivity of soils 土壤含水量与电导率的温度依赖关系

4区工程技术

Environmental geotechnics Pub Date : 2023-10-04 DOI: 10.1680/jenge.23.00013

Zhixiang Chen, Huayue Yu, Yong Wan, Xingxing He, Longfei Hua

引用次数: 0

Degradation of urban soil quality due to air and road traffic - relevant info and research 空气和道路交通造成的城市土壤质量退化——相关信息和研究

4区工程技术

Environmental geotechnics Pub Date : 2023-10-04 DOI: 10.1680/jenge.22.00043

Celeste Jorge

{"title":"Degradation of urban soil quality due to air and road traffic - relevant info and research","authors":"Celeste Jorge","doi":"10.1680/jenge.22.00043","DOIUrl":"https://doi.org/10.1680/jenge.22.00043","url":null,"abstract":"Aircraft operations at an airport result in the emission of various substances. Simultaneously, in an airport area, road traffic is very intense, also contributing to the emission of the same substances. In this work, potentially toxic elements (PTEs), essentially trace metals, and others not categorized as such (alloys elements and ceramic particles that constitute particulate matter) are considered, which end up being deposited on soils. The main purpose of this study is to identify soil quality degradation potentially connected to aircraft operations related to Lisbon Airport. At the same time, an attempt is made to differentiate the contribution of soil quality degradation resulting from road traffic. Several geotechnical and chemical parameters are determined for all the 102 collected samples. X-ray fluorescence analysis is performed to identify and quantify the main elements present in all samples. Some samples are also subjected to X-ray diffraction to determine the mineralogical composition. The data obtained allow the creation of distribution maps of the detected elements and, after multivariate statistical analysis, conclude which ones are related to very intense road traffic and which ones are related to aircraft-traffic emissions, in an urban area, based on a holistic interpretation of all intervenient variables.","PeriodicalId":11823,"journal":{"name":"Environmental geotechnics","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135592084","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}

引用次数: 0

Bio-cementation of tailings sands using ultraviolet induced urease-producing bacteria and its biomineralization mechanism 紫外光诱导产脲菌的尾矿砂生物胶结及其生物矿化机制

4区工程技术

Environmental geotechnics Pub Date : 2023-10-04 DOI: 10.1680/jenge.22.00075

Kai Xu, Ming Huang, Jinxuan Zhang, Mingjuan Cui, Chaoshui Xu

{"title":"Bio-cementation of tailings sands using ultraviolet induced urease-producing bacteria and its biomineralization mechanism","authors":"Kai Xu, Ming Huang, Jinxuan Zhang, Mingjuan Cui, Chaoshui Xu","doi":"10.1680/jenge.22.00075","DOIUrl":"https://doi.org/10.1680/jenge.22.00075","url":null,"abstract":"The disposal of tailings in a safe and environmentally friendly manner has always been a challenging issue. The microbially induced carbonate precipitation (MICP) technique is used to stabilise tailings sands. MICP is an innovative soil stabilisation technology. However, its field application in tailings sands is limited due to the poor adaptability of non-native urease-producing bacteria (UPB) in different natural environments. In this study, the ultraviolet (UV) mutagenesis technology was used to improve the performance of indigenous UPB, sourced from a hot and humid area of China. Mechanical property tests and microscopic inspections were conducted to assess the feasibility and the effectiveness of the technology. The roles played by the UV-induced UPB in the processes of nucleation and crystal growth were revealed by scanning electron microscopy imaging. The impacts of elements contained in the tailings sands on the morphology of calcium carbonate crystals were studied with Raman spectroscopy and energy-dispersive X-ray spectroscopy. The precipitation pattern of calcium carbonate and the strength enhancement mechanism of bio-cemented tailings were analysed in detail. The stabilisation method of tailings sands described in this paper provides a new cost-effective approach to mitigating the environmental issues and safety risks associated with the storage of tailings.","PeriodicalId":11823,"journal":{"name":"Environmental geotechnics","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135547537","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}

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Borehole Analysis with the Modification of RQD Value 修正RQD值的井眼分析

4区工程技术

Environmental geotechnics Pub Date : 2023-10-01 DOI: 10.3390/geotechnics3040055

Gábor Somodi, Balázs Vásárhelyi

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Evaluation of Shear Wave Velocity Prediction Models from Standard Penetration Test N Values Depending on Geologic Attributes: A Case Study in Busan, South Korea 基于地质属性的标准侵彻试验N值的横波速度预测模型评价:以韩国釜山为例

4区工程技术

Environmental geotechnics Pub Date : 2023-10-01 DOI: 10.3390/geotechnics3040054

Giseok Heo, Jaehwi Kim, Seokho Jeong, Dongyoup Kwak

{"title":"Evaluation of Shear Wave Velocity Prediction Models from Standard Penetration Test N Values Depending on Geologic Attributes: A Case Study in Busan, South Korea","authors":"Giseok Heo, Jaehwi Kim, Seokho Jeong, Dongyoup Kwak","doi":"10.3390/geotechnics3040054","DOIUrl":"https://doi.org/10.3390/geotechnics3040054","url":null,"abstract":"This study evaluates the effectiveness of the previously proposed Standard Penetration Test (SPT) N and shear wave velocity (VS) models in relation to the geological attributes of the Busan region, situated in the southeastern part of the Korean peninsula. The multiple empirical N-VS models, which used datasets collected from different regions in South Korea, resulted in distinct N-VS trends across models. To validate the predictive capabilities of each model, this study gathered boring logs containing SPT N and VS measurements within the Busan region, followed by a thorough residual analysis. The Busan area encompasses a delta region to the west and erosion basins within the mountains and hills to the east. Despite the relatively confined geographical scope, we found that models developed using data from fill areas exhibit superior performance for the delta region (western Busan), while models constructed from datasets within erosion basins perform better for the erosion basin region (eastern Busan). This comparative examination supports the dependence of the N-VS model on geologic attributes and offers the valuable insight that N-VS models developed with analogous geological attributes should be employed when estimating VS from SPT N values.","PeriodicalId":11823,"journal":{"name":"Environmental geotechnics","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135459216","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}

引用次数: 0

Effectiveness of Hybrid Geosynthetic Systems in Controlling Differential Heave in Flexible Pavements over Expansive Soils 混合土工合成材料控制膨胀土柔性路面差沉的有效性

4区工程技术

Environmental geotechnics Pub Date : 2023-09-29 DOI: 10.3390/geotechnics3040053

Mir Md. Tamim, Debakanta Mishra, Bhaskar C. S. Chittoori

{"title":"Effectiveness of Hybrid Geosynthetic Systems in Controlling Differential Heave in Flexible Pavements over Expansive Soils","authors":"Mir Md. Tamim, Debakanta Mishra, Bhaskar C. S. Chittoori","doi":"10.3390/geotechnics3040053","DOIUrl":"https://doi.org/10.3390/geotechnics3040053","url":null,"abstract":"The challenge of maintaining ride quality and serviceability in flexible pavements built over expansive soil deposits remains a critical concern for transportation agencies. These expansive subgrades exhibit swell-shrink behavior in response to moisture fluctuations, leading to differential heaving and subsequent costly maintenance. This paper explores the effectiveness of a Hybrid Geosynthetic Reinforcement System (HGRS)—a composite of geocell and geogrid—as a targeted mitigation strategy for differential heaving induced by expansive soils. A large-scale box test was designed to simulate a flexible pavement section, consisting solely of a base course layer and the underlying expansive subgrade. Four test conditions were investigated: an unreinforced control, a geocell-reinforced section, a geogrid-reinforced section, and an HGRS-reinforced section. Vertical displacements on the surface of the base course layer were longitudinally monitored and compared against the control. The results reveal that the use of geosynthetic reinforcements, and HGRS in particular, significantly mitigates both maximum surficial heave and differential swelling. Among the systems tested, flexible pavements featuring HGRS demonstrated the most effective performance in alleviating the challenges posed by expansive soil deposits.","PeriodicalId":11823,"journal":{"name":"Environmental geotechnics","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135246426","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}

引用次数: 0

An assessment of a simplified methodology for determining the thermal performance of thermo-active piles 热源桩热性能测定的简化方法评价

4区工程技术

Environmental geotechnics Pub Date : 2023-09-28 DOI: 10.1680/jenge.22.00199

Ryan Yin Wai Liu, David MG Taborda

{"title":"An assessment of a simplified methodology for determining the thermal performance of thermo-active piles","authors":"Ryan Yin Wai Liu, David MG Taborda","doi":"10.1680/jenge.22.00199","DOIUrl":"https://doi.org/10.1680/jenge.22.00199","url":null,"abstract":"Ground source energy systems provide low-carbon heating and cooling to buildings, but their efficient deployment requires a reliable estimate of their thermal performance. A simplified methodology is presented to determine the thermal performance of thermo-active piles when heating or cooling loads are specified with either inlet pipe temperatures or imposed heat fluxes. The proposed methodology avoids computationally expensive 3D analyses and the explicit simulation of heat exchanger pipes, relying instead on 2D thermal analyses. When the heating or cooling of a thermo-active pile is assessed by imposing inlet pipe temperatures, the proposed methodology allows the determination of the power of pile per unit length. Conversely, when heating or cooling loads are specified via extracted or injected heat fluxes, the inlet and outlet fluid temperatures, as well as average temperatures at pile wall, are determined. The proposed methodology has been shown to reproduce accurately the thermal performance of thermo-active piles modelled using 3D analyses where heat exchanger pipes are explicitly simulated, considering different patterns of heating and cooling cycles. The application of the proposed methodology to the case of a real thermo-active pile is demonstrated by comparing its predicted thermal performance with the results of a well-documented field thermal response test.","PeriodicalId":11823,"journal":{"name":"Environmental geotechnics","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135344572","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}

引用次数: 0

An Estimation of Clayey-Oriented Rock Mass Material Properties, Sited in Koropi, Athens, Greece, through Feed-Forward Neural Networks 基于前馈神经网络的希腊雅典Koropi粘土导向岩体材料特性估计

4区工程技术

Environmental geotechnics Pub Date : 2023-09-24 DOI: 10.3390/geotechnics3040052

Ambrosios-Antonios Savvides, Andreas A. Antoniou, Leonidas Papadopoulos, Anastasia Monia, Kalliopi Kofina

{"title":"An Estimation of Clayey-Oriented Rock Mass Material Properties, Sited in Koropi, Athens, Greece, through Feed-Forward Neural Networks","authors":"Ambrosios-Antonios Savvides, Andreas A. Antoniou, Leonidas Papadopoulos, Anastasia Monia, Kalliopi Kofina","doi":"10.3390/geotechnics3040052","DOIUrl":"https://doi.org/10.3390/geotechnics3040052","url":null,"abstract":"Rock mechanics and the estimation of their material properties through field tests are important aspects and challengees in civil and geotechnical engineering. However, this procedure is expensive and difficult to attain, while the machine learning and neural network theory provide a computational tool for estimating the material properties with limited data. In this work, an estimation of the Young Modulus and the cohesion of a clayey-originated rock through feed-forward neural networks constructed from in situ data measurements is given. The input values come from the Geological Strength Index (GSI) proposed values of the point load index Is50, the uniaxial compression strength σs, as well as the specific gravity γ of the rock mass. The convergence analysis revealed that the convergence occurs at approximately 2000 epochs, with the largest L2 mean square error norm being no greater than 10−5. In addition, it is demonstrated that augmenting γ results in the estimation of rock that is stiffer and stronger. The aforementioned increase in the specific site may be up to 20% for the stiffness and up to 25% for the cohesion. This model, aside from readability and accuracy, offers the convenience of enriching it with more in situ data, thereby enhancing the flexibility of the proposed numerical tool proposed. However, its applicability is limited to the specific data acquired from the particular site, so a more general estimation requires a substantially larger dataset. Finally, the justification of the proposed model has been carried out based on suggestions from the literature for common values of clayey-oriented rock, which is fairly disintegrated as seen in the field.","PeriodicalId":11823,"journal":{"name":"Environmental geotechnics","volume":"69 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135925983","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}

引用次数: 0

Calculation Method for Traffic Load-Induced Permanent Deformation in Soils under Flexible Pavements 柔性路面下交通荷载引起土体永久变形的计算方法

4区工程技术

Environmental geotechnics Pub Date : 2023-09-21 DOI: 10.3390/geotechnics3030051

Mate Janos Vamos, Janos Szendefy

{"title":"Calculation Method for Traffic Load-Induced Permanent Deformation in Soils under Flexible Pavements","authors":"Mate Janos Vamos, Janos Szendefy","doi":"10.3390/geotechnics3030051","DOIUrl":"https://doi.org/10.3390/geotechnics3030051","url":null,"abstract":"Rutting is one of the most common types of distress in flexible pavement structures. There are two fundamental methods of designing pavement structures: conventional empirical methods and analytical approaches. Many analytical and empirical design procedures assume that rutting is mostly of asphalt origin and can be reduced by limiting the vertical deformation or stress at the top of the subgrade, but they do not quantify the rutting depth itself. Mechanistic–empirical models to predict the permanent deformations of unbound pavement layers have been well investigated and are rather common in North America; however, they are not widely utilized in the rest of the world. To date, there is no generally accepted, widely recognized, and documented procedure for calculating permanent deformations and thus for determining the rutting depth in flexible pavement courses originating from the unbound granular layers. This paper presents a layered calculation method with which the deformation of soil layers (base, subbase, and subgrade courses) under flexible pavements due to repeated traffic load can be determined. In the first step, the cyclic strain amplitude is calculated using a nonlinear material model that is based on particle size distribution parameters (d50 and CU) and dependent on the mean normal stress, relative density, and actual strain level. In the second step, the HCA (High Cycle Accumulation) model is used to calculate the residual settlement of each sublayer as a function of the number of cycles. It is shown that the developed model is suitable for describing different types of subgrades and pavement cross-sections. It is also demonstrated with finite element calculations that the developed model describes both the elastic and plastic strains sufficiently accurately. The developed model can predict the settlement and rutting of pavement structures with sufficient accuracy based on easily available particle size distribution parameters without the need for complex laboratory and finite element tests.","PeriodicalId":11823,"journal":{"name":"Environmental geotechnics","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136236444","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}

引用次数: 0

Influence of Schistosity Orientation on Failure Mode and Indirect Tensile Strength of Mica Schist 片岩取向对云母片岩破坏模式及间接抗拉强度的影响

4区工程技术

Environmental geotechnics Pub Date : 2023-09-16 DOI: 10.3390/geotechnics3030050

Nick Hudyma, B. Burçin Avar, Bhaskar Chittoori

{"title":"Influence of Schistosity Orientation on Failure Mode and Indirect Tensile Strength of Mica Schist","authors":"Nick Hudyma, B. Burçin Avar, Bhaskar Chittoori","doi":"10.3390/geotechnics3030050","DOIUrl":"https://doi.org/10.3390/geotechnics3030050","url":null,"abstract":"The indirect tension test is an important laboratory test for rock characterization. The presence of rock fabric, such as schistosity, complicates the assessment of test results. One hundred and forty-five indirect tension tests were conducted on mica schist specimens to investigate the effect of schistosity orientation on failure mode and tensile strength. Tensile strength results did not provide a clear relationship between schistosity orientation and tensile strength, so the failure patterns were investigated. A new naming scheme for failure modes was developed, incorporating fracture patterns observed in the specimen faces and edges. The Single Mode failure group specimens had only one failure pattern that appeared on both specimen faces, either axial failure (seventy-three specimens), schistosity failure (six specimens), or out-of-plane failure (seven specimens). The Mixed Mode failure group had thirty-two specimens that exhibited one failure pattern on one face and another on the other. The Hybrid Mode failure group had twenty-seven specimens with multiple failure patterns on both specimen faces. It was noted that Mixed Mode and Hybrid Mode specimens with components of axial failure had higher indirect tensile strengths than specimens without elements of axial failures. Statistical analyses of the tensile strength data using Levene’s Test for equal variances and two-sample t-tests showed no statistical difference between the Mixed Mode and Hybrid Mode failure groups. However, there was a statistical difference between the tensile strengths of the Single Mode axial failure specimens and the combined Mixed Mode and Hybrid Mode failure groups. These results clearly emphasize that indirect tensile strength should be assessed using schistosity orientation and failure mode.","PeriodicalId":11823,"journal":{"name":"Environmental geotechnics","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135308414","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}

引用次数: 0