Geotechnical engineering spans a wide range of applications, including tunnels, foundations, dams, and retaining structures. It deals with a material known to be difficult to model: a particulate material whose mechanical response is affected by all three invariants of the stress tensor, by loading rate, by density and by fabric. New problems and greater complexity in old problems have come about with the effects of climate change. Progress in certain technologies—notably artificial intelligence—also defines the new landscape in which geotechnical engineers must operate. This paper focuses on mechanics-based geotechnical engineering applications. The paper reviews some of the major decisions that were made by the engineers and researchers who developed geotechnical engineering to the point at which it was an identifiable separate discipline and the consequences that these decisions have had on the development of the discipline and on its teaching. The paper identifies some key modelling choices that were made that have had an undeservedly disproportionate impact on the teaching and practice of geotechnical engineering. The focus of the paper is therefore on these decisions and choices, and what should be taught in their place today. Challenges that future geotechnical engineers may face, as well tools that will be available to them, are also discussed in the context of what should be taught in undergraduate and graduate courses.
{"title":"Forks in the road: decisions that have shaped and will shape the teaching and practice of geotechnical engineering","authors":"Rodrigo Salgado","doi":"10.28927/sr.2024.010123","DOIUrl":"https://doi.org/10.28927/sr.2024.010123","url":null,"abstract":"Geotechnical engineering spans a wide range of applications, including tunnels, foundations, dams, and retaining structures. It deals with a material known to be difficult to model: a particulate material whose mechanical response is affected by all three invariants of the stress tensor, by loading rate, by density and by fabric. New problems and greater complexity in old problems have come about with the effects of climate change. Progress in certain technologies—notably artificial intelligence—also defines the new landscape in which geotechnical engineers must operate. This paper focuses on mechanics-based geotechnical engineering applications. The paper reviews some of the major decisions that were made by the engineers and researchers who developed geotechnical engineering to the point at which it was an identifiable separate discipline and the consequences that these decisions have had on the development of the discipline and on its teaching. The paper identifies some key modelling choices that were made that have had an undeservedly disproportionate impact on the teaching and practice of geotechnical engineering. The focus of the paper is therefore on these decisions and choices, and what should be taught in their place today. Challenges that future geotechnical engineers may face, as well tools that will be available to them, are also discussed in the context of what should be taught in undergraduate and graduate courses.","PeriodicalId":43687,"journal":{"name":"Soils and Rocks","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2024-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140255296","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Federica Cotecchia, S. Guglielmi, F. Cafaro, Antonio Gens
This keynote lecture discusses the results of a long lasting experimental research, devoted to the investigation of clay microstructure and its evolution upon loading. Micro-scale analyses, involving scanning electron microscopy, image processing, mercury intrusion porosimetry and swelling paths to test the clay bonding, are presented on clays subjected to different loading paths, with the purpose of providing experimental evidence of the processes at the micro-scale which underlie the clay response at the macro-scale. Data from the literature on clays of different classes, either soft or stiff, are compared to original results on two stiff clays, Pappadai and Lucera clay, both in their natural state and after reconstitution in the laboratory. The results presented herein allow building a conceptual model of the evolution of clay microstructure upon different loading paths, providing microstructural insights into the macro-behaviour described by constitutive laws and advising their mathematical formalization in the framework of either continuum mechanics or micro-mechanics. For editorial purposes, the research results are presented in two parts. The first part, presented in this paper, concerns the results for reconstituted clays, whereas a second part, concerning the corresponding natural clays, is discussed in a second companion paper.
{"title":"Micro to macro investigation of clays advising their constitutive modelling - part I","authors":"Federica Cotecchia, S. Guglielmi, F. Cafaro, Antonio Gens","doi":"10.28927/sr.2024.011723","DOIUrl":"https://doi.org/10.28927/sr.2024.011723","url":null,"abstract":"This keynote lecture discusses the results of a long lasting experimental research, devoted to the investigation of clay microstructure and its evolution upon loading. Micro-scale analyses, involving scanning electron microscopy, image processing, mercury intrusion porosimetry and swelling paths to test the clay bonding, are presented on clays subjected to different loading paths, with the purpose of providing experimental evidence of the processes at the micro-scale which underlie the clay response at the macro-scale. Data from the literature on clays of different classes, either soft or stiff, are compared to original results on two stiff clays, Pappadai and Lucera clay, both in their natural state and after reconstitution in the laboratory. The results presented herein allow building a conceptual model of the evolution of clay microstructure upon different loading paths, providing microstructural insights into the macro-behaviour described by constitutive laws and advising their mathematical formalization in the framework of either continuum mechanics or micro-mechanics. For editorial purposes, the research results are presented in two parts. The first part, presented in this paper, concerns the results for reconstituted clays, whereas a second part, concerning the corresponding natural clays, is discussed in a second companion paper.","PeriodicalId":43687,"journal":{"name":"Soils and Rocks","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2024-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140082127","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In order to move towards discrete analyses of soil behaviour, we need to develop a new range of apparatus and testing techniques. The lecture describes attempts to develop these new apparatus and presents data for a range of coarse-grained geomaterials at the single particle scale. The roles of the particle morphology and hence geological origin are discussed and are shown to influence both the contact mechanics and particle breakage behaviour. The mechanics of single particles are shown to be more complex than generally assumed and will require new means of modelling to account for the significant plasticity that occurs at particle contacts and patterns of breakage that are strongly influenced by the origins of particles and their effect on their morphology.
{"title":"The 7th Bishop Lecture: The mechanics of coarse-grained geomaterials at meso- and micro-scales","authors":"Matthew Coop","doi":"10.28927/sr.2024.006723","DOIUrl":"https://doi.org/10.28927/sr.2024.006723","url":null,"abstract":"In order to move towards discrete analyses of soil behaviour, we need to develop a new range of apparatus and testing techniques. The lecture describes attempts to develop these new apparatus and presents data for a range of coarse-grained geomaterials at the single particle scale. The roles of the particle morphology and hence geological origin are discussed and are shown to influence both the contact mechanics and particle breakage behaviour. The mechanics of single particles are shown to be more complex than generally assumed and will require new means of modelling to account for the significant plasticity that occurs at particle contacts and patterns of breakage that are strongly influenced by the origins of particles and their effect on their morphology.","PeriodicalId":43687,"journal":{"name":"Soils and Rocks","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2024-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140438032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Carolina Lemos, Luiz Dias, Paulo Barbosa, E. Marques, R. Ferraz, G. Nalon
This article presents the incorporation of information and communication technologies on the teaching-learning process of geotechnical engineering to improve the quality of education and provide practical knowledge to civil engineering students. The content of this paper is divided into three main modules, which are: Treatment of laboratory tests results, Slope stability and Rock mass stability. For this, some software were used, including 2D limit equilibrium stability analysis, stability analysis of rock wedges and a dynamic mathematics, to obtain and analyze soil shear strength parameters, among others. Furthermore, a digital tool was developed to analyze the results gathered in compaction, one-dimensional consolidation, and direct soil shear tests, in order to clarify the relationship between theoretical concepts and practical results of the tests and analyses and to help students on doubts, in addition to increase their interest and motivation to perform the complete interpretation of the collected data. The activities were conducted in classes of geotechnical disciplines of the undergraduate course in Civil Engineering at the Federal University of Viçosa, aiming to promote active learning and improve teaching quality. Based on the results of an applied feedback questionnaire, it was observed that most students were satisfied with the resources used in the classroom, demonstrating that the implemented digital tools work as a didactic instrument that facilitates learning and comprehension of practical problems, in addition to enabling the resolution of several geotechnical engineering problems much more quickly and efficiently.
{"title":"Digital tools used on the teaching-learning process in geotechnical engineering","authors":"Carolina Lemos, Luiz Dias, Paulo Barbosa, E. Marques, R. Ferraz, G. Nalon","doi":"10.28927/sr.2024.004923","DOIUrl":"https://doi.org/10.28927/sr.2024.004923","url":null,"abstract":"This article presents the incorporation of information and communication technologies on the teaching-learning process of geotechnical engineering to improve the quality of education and provide practical knowledge to civil engineering students. The content of this paper is divided into three main modules, which are: Treatment of laboratory tests results, Slope stability and Rock mass stability. For this, some software were used, including 2D limit equilibrium stability analysis, stability analysis of rock wedges and a dynamic mathematics, to obtain and analyze soil shear strength parameters, among others. Furthermore, a digital tool was developed to analyze the results gathered in compaction, one-dimensional consolidation, and direct soil shear tests, in order to clarify the relationship between theoretical concepts and practical results of the tests and analyses and to help students on doubts, in addition to increase their interest and motivation to perform the complete interpretation of the collected data. The activities were conducted in classes of geotechnical disciplines of the undergraduate course in Civil Engineering at the Federal University of Viçosa, aiming to promote active learning and improve teaching quality. Based on the results of an applied feedback questionnaire, it was observed that most students were satisfied with the resources used in the classroom, demonstrating that the implemented digital tools work as a didactic instrument that facilitates learning and comprehension of practical problems, in addition to enabling the resolution of several geotechnical engineering problems much more quickly and efficiently.","PeriodicalId":43687,"journal":{"name":"Soils and Rocks","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2024-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140449460","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fagner França, Marcus Lyra, Matheus Carvalho, Wagner Opolski
The need to develop several students’ competencies is one of the leading challenges for Engineering instructors in undergraduate courses. It has been quite exhausting in many cases, mainly due to the lack of professors’ expertise in engineering education. Case studies may provide examples and help develop professors’ ability to design effective learning experiences. In this context, this paper presents a case study of implementing an in-class/ ex-class activity conducted in the Soil Mechanics-I course at the Federal University of Rio Grande do Norte. Additionally, it aims to discuss students’ perception regarding development of the proposed activity and competences. The activity comprised three phases: selection of Geotechnical Engineering problems on university campus, documentation and analysis of each situation, and presentation of solutions considering technical, environmental, and social aspects. Students’ perceptions were assessed using an anonymous online survey (18 Likert and open-ended questions), divided into three categories: general impressions, competencies development, and open statements. General impressions and competencies development were mostly positive, with deadlines reported as the most challenging aspect. Open questions responses provided positive feedback, emphasizing the main developed competencies, according to students’ perspective (e.g. leadership, interpersonal relationship, and analytical view of the problem). The need of dealing with real problems and work in groups appears to be a successful approach for teaching Geotechnical Engineering courses and developing competences in Engineering undergraduate courses. This case study can support innovation in teaching any engineering course and help students face future professional challenges.
{"title":"Students’ perception of the impact of a Geotechnical Engineering field activity on their competences development","authors":"Fagner França, Marcus Lyra, Matheus Carvalho, Wagner Opolski","doi":"10.28927/sr.2024.006423","DOIUrl":"https://doi.org/10.28927/sr.2024.006423","url":null,"abstract":"The need to develop several students’ competencies is one of the leading challenges for Engineering instructors in undergraduate courses. It has been quite exhausting in many cases, mainly due to the lack of professors’ expertise in engineering education. Case studies may provide examples and help develop professors’ ability to design effective learning experiences. In this context, this paper presents a case study of implementing an in-class/ ex-class activity conducted in the Soil Mechanics-I course at the Federal University of Rio Grande do Norte. Additionally, it aims to discuss students’ perception regarding development of the proposed activity and competences. The activity comprised three phases: selection of Geotechnical Engineering problems on university campus, documentation and analysis of each situation, and presentation of solutions considering technical, environmental, and social aspects. Students’ perceptions were assessed using an anonymous online survey (18 Likert and open-ended questions), divided into three categories: general impressions, competencies development, and open statements. General impressions and competencies development were mostly positive, with deadlines reported as the most challenging aspect. Open questions responses provided positive feedback, emphasizing the main developed competencies, according to students’ perspective (e.g. leadership, interpersonal relationship, and analytical view of the problem). The need of dealing with real problems and work in groups appears to be a successful approach for teaching Geotechnical Engineering courses and developing competences in Engineering undergraduate courses. This case study can support innovation in teaching any engineering course and help students face future professional challenges.","PeriodicalId":43687,"journal":{"name":"Soils and Rocks","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2024-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139683361","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This article presents an approach centered on a modification of the Failure Modes and Effects Analysis Method (FMEA) for risk management concerning geotechnical structures during the hydraulic circuit filling process within a hydroelectric power plant. In this work, the conventional FMEA method, typically employed in various projects and processes, was adapted through the development of specific classification criteria. The primary objective was to enhance the applicability of this method to geotechnical structures during the filling procedure. The validity of this method was confirmed through its application in a case study. This analysis suggests that the newly devised scoring tables have streamlined the risk analysis process by reducing the number of classification categories and adopting a color scale. In addition to their role in classifying failure modes, these tables also serve as a guide for mitigating the risks associated with the filling procedure. The appropriate course of action is determined based on the specific aspects presented in the analyzed geotechnical model. It is our belief that the insights generated by this research will offer valuable support to technical professionals responsible for hydraulic circuit filling in hydroelectric projects. This support aims to enhance the safety of this activity by minimizing the severity of failures and increasing the probability of their detection.
{"title":"Modified FMEA for risk management in geotechnical structures during hydraulic circuit filling of a hydroelectric power plant","authors":"Paola Dutra, Sidnei Teixeira, Claudia Wajdowicz, Joaquim Duarte","doi":"10.28927/sr.2024.014422","DOIUrl":"https://doi.org/10.28927/sr.2024.014422","url":null,"abstract":"This article presents an approach centered on a modification of the Failure Modes and Effects Analysis Method (FMEA) for risk management concerning geotechnical structures during the hydraulic circuit filling process within a hydroelectric power plant. In this work, the conventional FMEA method, typically employed in various projects and processes, was adapted through the development of specific classification criteria. The primary objective was to enhance the applicability of this method to geotechnical structures during the filling procedure. The validity of this method was confirmed through its application in a case study. This analysis suggests that the newly devised scoring tables have streamlined the risk analysis process by reducing the number of classification categories and adopting a color scale. In addition to their role in classifying failure modes, these tables also serve as a guide for mitigating the risks associated with the filling procedure. The appropriate course of action is determined based on the specific aspects presented in the analyzed geotechnical model. It is our belief that the insights generated by this research will offer valuable support to technical professionals responsible for hydraulic circuit filling in hydroelectric projects. This support aims to enhance the safety of this activity by minimizing the severity of failures and increasing the probability of their detection.","PeriodicalId":43687,"journal":{"name":"Soils and Rocks","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2024-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140488536","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Students often express an anxiety about how knowledge is classified (i.e., differentiated) and framed (i.e., prioritized, and sequenced) in capstone design problems. This anxiety is by design as capstone design courses are meant to test students’ ability to solve complex problems that are weakly classified and framed. Nevertheless, educators can play a role in scaffolding student progress, so students advance past a conceptual understanding of problems to applying technical acumen learnt in prior years. This paper presents three geotechnical design projects set by the author, along with three interventions used to scaffold student progress. Projects included the design of an industrial waste facility for dry filtered residue, design of remedial works for a clay river embankment subject to undercutting, and design of a remining method for mine slimes contained behind a sand embankment. Interventions included requiring students to prepare, present and critique presentations based on weekly stage gates, collaboratively brainstorming, and ranking high level implications of a design, and collaboratively brainstorming specific implications of a design. When implementing such interventions care must be taken to ensure they remain student driven, or the learning benefits of a capstone design course may be lost.
{"title":"Helping students classify and frame capstone geotechnical design courses","authors":"C. MacRobert","doi":"10.28927/sr.2024.009623","DOIUrl":"https://doi.org/10.28927/sr.2024.009623","url":null,"abstract":"Students often express an anxiety about how knowledge is classified (i.e., differentiated) and framed (i.e., prioritized, and sequenced) in capstone design problems. This anxiety is by design as capstone design courses are meant to test students’ ability to solve complex problems that are weakly classified and framed. Nevertheless, educators can play a role in scaffolding student progress, so students advance past a conceptual understanding of problems to applying technical acumen learnt in prior years. This paper presents three geotechnical design projects set by the author, along with three interventions used to scaffold student progress. Projects included the design of an industrial waste facility for dry filtered residue, design of remedial works for a clay river embankment subject to undercutting, and design of a remining method for mine slimes contained behind a sand embankment. Interventions included requiring students to prepare, present and critique presentations based on weekly stage gates, collaboratively brainstorming, and ranking high level implications of a design, and collaboratively brainstorming specific implications of a design. When implementing such interventions care must be taken to ensure they remain student driven, or the learning benefits of a capstone design course may be lost.","PeriodicalId":43687,"journal":{"name":"Soils and Rocks","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2024-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140490164","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Discussion of “Systematic literature review and mapping of the prediction of pile capacities”","authors":"Katia Bicalho, Reno Castello, Nelson Aoki","doi":"10.28927/sr.2024.011123","DOIUrl":"https://doi.org/10.28927/sr.2024.011123","url":null,"abstract":"","PeriodicalId":43687,"journal":{"name":"Soils and Rocks","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2024-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139443796","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Terzaghi (1943) developed an empirical method for primary consolidation due to a load applied at constant rate (ramp load) until the end of construction at time tc. The method considers that the settlement at a time t during construction, can be evaluated admitting the load applied instantaneously at time t/2. In this research, two alternative modifications are proposed for this Terzaghi’s empirical recommendation. The first one is based on a variable fraction of time t and the second modification keeps Terzaghi’s suggestion (t/2) but makes reductions in the average degree of consolidation Uv. Computed results for different construction time factors Tv were compared to Olson (1977) analytical solution. The first approach yielded a maximum difference of approximately 2.40% while the second alternative gave results that are practically the same as those calculated by Olson’s solution. The validity of these new approaches was also proven by reproducing odometer test results with good agreement.
Terzaghi（1943 年）开发了一种经验方法，用于计算在施工结束 tc 时以恒定速率施加荷载（斜坡荷载）引起的一次固结。该方法认为，施工过程中某一时刻 t 的沉降量可通过在时刻 t/2 时瞬时施加的荷载进行评估。在这项研究中，对 Terzaghi 的经验建议提出了两种可供选择的修改方案。第一种修改基于时间 t 的可变分量，第二种修改保留了特尔扎吉的建议（t/2），但降低了平均固结度 Uv。不同施工时间系数 Tv 的计算结果与奥尔森（1977 年）的分析方案进行了比较。第一种方法得出的最大差异约为 2.40%，而第二种方法得出的结果实际上与奥尔森解决方案计算出的结果相同。这些新方法的有效性还通过重现里程表测试结果得到了证明，两者吻合度很高。
{"title":"Primary consolidation settlement due to ramp loading: Terzaghi (1943) method revisited","authors":"Vitor Albuquerque, Celso Romanel, Raphael Carneiro","doi":"10.28927/sr.2024.003522","DOIUrl":"https://doi.org/10.28927/sr.2024.003522","url":null,"abstract":"Terzaghi (1943) developed an empirical method for primary consolidation due to a load applied at constant rate (ramp load) until the end of construction at time tc. The method considers that the settlement at a time t during construction, can be evaluated admitting the load applied instantaneously at time t/2. In this research, two alternative modifications are proposed for this Terzaghi’s empirical recommendation. The first one is based on a variable fraction of time t and the second modification keeps Terzaghi’s suggestion (t/2) but makes reductions in the average degree of consolidation Uv. Computed results for different construction time factors Tv were compared to Olson (1977) analytical solution. The first approach yielded a maximum difference of approximately 2.40% while the second alternative gave results that are practically the same as those calculated by Olson’s solution. The validity of these new approaches was also proven by reproducing odometer test results with good agreement.","PeriodicalId":43687,"journal":{"name":"Soils and Rocks","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2024-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139444026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zeena Al-Khazzaz, A. Aldaood, Muwafaq Awad, Mohammed Faris
Clayey soils are spread in many countries and require significant improvement. Recently, nanomaterial have been entered to the geotechnical research as a treatment material. Current study utilized magnesium oxide (MgO) as an additive to enhance swelling potential, compressibility characteristics, and index properties of clayey soil from Mosul city using different content of nano-MgO and under varies curing periods. The results showed that the free swell and swell pressure of the soil specimens have been reduced by 25%, and 19%, respectively for 0.25, and 0.75% content of nano material under 3 days of curing time at 25C. Results also showed that the compressibility characteristic represented by the compression index parameter has been reduced by 20.3% for 0.75% of nano-MgO material. Moreover, the soil plasticity index exhibited a maximum increase at 0.75% of nano content. Moreover, results showed that the pH value increased while the electrical conductivity (EC) decreased with the nano-MgO content. To evaluate the curing time effect, specimens were cured for varies curing time under curing temperature of 25 ºC. Then, the free swell, swell pressure, compression index, and Atterberg limits were measured. The results revealed that the free swell and swell pressure for both untreated and treated specimens were reduced during different periods of curing time. Furthermore, the compression index of treated soil was reduced by approximately half for curing time of 28 days. In sum, the swelling and consolidation reduction with curing brought significant improvement and promising results for the treated samples.
{"title":"Behavior of clayey soil treated with nano magnesium oxide material","authors":"Zeena Al-Khazzaz, A. Aldaood, Muwafaq Awad, Mohammed Faris","doi":"10.28927/sr.2024.014822","DOIUrl":"https://doi.org/10.28927/sr.2024.014822","url":null,"abstract":"Clayey soils are spread in many countries and require significant improvement. Recently, nanomaterial have been entered to the geotechnical research as a treatment material. Current study utilized magnesium oxide (MgO) as an additive to enhance swelling potential, compressibility characteristics, and index properties of clayey soil from Mosul city using different content of nano-MgO and under varies curing periods. The results showed that the free swell and swell pressure of the soil specimens have been reduced by 25%, and 19%, respectively for 0.25, and 0.75% content of nano material under 3 days of curing time at 25C. Results also showed that the compressibility characteristic represented by the compression index parameter has been reduced by 20.3% for 0.75% of nano-MgO material. Moreover, the soil plasticity index exhibited a maximum increase at 0.75% of nano content. Moreover, results showed that the pH value increased while the electrical conductivity (EC) decreased with the nano-MgO content. To evaluate the curing time effect, specimens were cured for varies curing time under curing temperature of 25 ºC. Then, the free swell, swell pressure, compression index, and Atterberg limits were measured. The results revealed that the free swell and swell pressure for both untreated and treated specimens were reduced during different periods of curing time. Furthermore, the compression index of treated soil was reduced by approximately half for curing time of 28 days. In sum, the swelling and consolidation reduction with curing brought significant improvement and promising results for the treated samples.","PeriodicalId":43687,"journal":{"name":"Soils and Rocks","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2023-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138972981","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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