Leone Meireles, Mario Riccio Filho, H. Pitanga, R. Ferraz, T. Silva, Sérgio Leandro Scher Dias Neto
This paper presents a numerical evaluation, using PLAXIS 2D finite element software, of the effects of varying the distance of the heavy compaction from the face in a geosynthetic reinforced soil wall (GRSW). The main effects studied were the tensions in the reinforcements and the horizontal deformations of the face, including the influence of the type of shear strength envelope (total stresses or effective stresses) of the soil. In this study, a young gneiss residual soil (silty sand) was studied to obtain the grain size distribution, index properties and parameters of strength and deformability. This soil was considered for backfill in hypothetical sections of GRSW. The numerical results contributed to a better understanding of the GRSW behaviour, with evaluations closer to real field conditions. In the analyses carried out, when increasing the heavy compaction distance from the face, there are tendencies pointing to the reduction of the tensions in the reinforcements, displacement toward the interior of the soil mass of the points at which the maximum reinforcement tension occurs and reduction of the horizontal deformations of the face.
{"title":"Numerical evaluation of the influence of compaction and soil strength parameters on GRSW","authors":"Leone Meireles, Mario Riccio Filho, H. Pitanga, R. Ferraz, T. Silva, Sérgio Leandro Scher Dias Neto","doi":"10.28927/sr.2022.003022","DOIUrl":"https://doi.org/10.28927/sr.2022.003022","url":null,"abstract":"This paper presents a numerical evaluation, using PLAXIS 2D finite element software, of the effects of varying the distance of the heavy compaction from the face in a geosynthetic reinforced soil wall (GRSW). The main effects studied were the tensions in the reinforcements and the horizontal deformations of the face, including the influence of the type of shear strength envelope (total stresses or effective stresses) of the soil. In this study, a young gneiss residual soil (silty sand) was studied to obtain the grain size distribution, index properties and parameters of strength and deformability. This soil was considered for backfill in hypothetical sections of GRSW. The numerical results contributed to a better understanding of the GRSW behaviour, with evaluations closer to real field conditions. In the analyses carried out, when increasing the heavy compaction distance from the face, there are tendencies pointing to the reduction of the tensions in the reinforcements, displacement toward the interior of the soil mass of the points at which the maximum reinforcement tension occurs and reduction of the horizontal deformations of the face.","PeriodicalId":43687,"journal":{"name":"Soils and Rocks","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2022-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47978447","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 research aims to present a deterministic and probabilistic analysis of the stability in 2D/3D of a road slope, located in the state of São Paulo, Brazil, in the Serra Pelada region, incorporating scenarios with and without surface suction and water level, and predict the movement of the mobilized-mass volume. The results of the stability analysis showed the variability of the safety factor, the probability of failure, and the mobilized-mass volume, in the twenty-six simulated scenarios. The results of the runout analysis of the mobilized-mass volume indicated that any possible landslide would interdict, at least, two of the three lanes of traffic, equivalent to 59.7% of the lanes. Therefore, it can be concluded that a 2D and 3D stability analysis combined with the material point method to predict the post-failure soil displacement provides a better understanding of all processes involved in a landslide, which helps to establish more adequate and effective mitigation and remedial measures for each situation. Finally, in conclusion, the studied slope, with a maximum failure probability of 1.24%, is safe in terms of its overall stability for all twenty-six simulated scenarios.
{"title":"Stability analysis of a slope and runout analysis movement of the mobilized-mass volume","authors":"Bianca Riselo, L. Passini, A. Kormann","doi":"10.28927/sr.2022.003822","DOIUrl":"https://doi.org/10.28927/sr.2022.003822","url":null,"abstract":"This research aims to present a deterministic and probabilistic analysis of the stability in 2D/3D of a road slope, located in the state of São Paulo, Brazil, in the Serra Pelada region, incorporating scenarios with and without surface suction and water level, and predict the movement of the mobilized-mass volume. The results of the stability analysis showed the variability of the safety factor, the probability of failure, and the mobilized-mass volume, in the twenty-six simulated scenarios. The results of the runout analysis of the mobilized-mass volume indicated that any possible landslide would interdict, at least, two of the three lanes of traffic, equivalent to 59.7% of the lanes. Therefore, it can be concluded that a 2D and 3D stability analysis combined with the material point method to predict the post-failure soil displacement provides a better understanding of all processes involved in a landslide, which helps to establish more adequate and effective mitigation and remedial measures for each situation. Finally, in conclusion, the studied slope, with a maximum failure probability of 1.24%, is safe in terms of its overall stability for all twenty-six simulated scenarios.","PeriodicalId":43687,"journal":{"name":"Soils and Rocks","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2022-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47823658","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}
Jean Lucas dos Passos Belo, P. Queiroz, Jefferson Silva
Engineering always deals with uncertainties, and efforts are needed to quantify them. A probabilistic analysis considers the statistical information of the problem to this quantification. In the geotechnical area, uncertainties play a particular role in structure design because it deals with naturally formed materials. Evaluating spatial variability has become progressively important. However, studies on the correct reproduction of this variability and conditional simulations are limited. In this paper, a geostatistical-based enhancement of the Random Finite Element Method (RFEM) is presented. The main aim of this study is to incorporate an advanced multivariate geostatistical technique (i.e., Turning Bands Co-simulation, TBCOSIM) to reproduce the coregionalization model of soil properties correctly in order to investigate the effects regarding this reproduction. It is illustrated in a real case of soil slope. The results showed that, for the unconditional simulation, the presented approach reached a perfect agreement with the coregionalization model, while the conditional simulation inserted some disturbances to this agreement, but it still satisfactorily reproduced the model. The original RFEM failed to reproduce this structure, leading to lower variances than the presented approach, which would cause a non-conservative design. Furthermore, disregarding the local uncertainty (i.e., the nugget effect) may introduce bias to analysis and, depending on its magnitude, may also lead the conditional analysis to not show a worthwhile reduction in variances of results. Finally, this paper shows that correctly determining the coregionalization model and reproducing it on probabilistic analysis may meaningfully influence the results.
{"title":"Geostatistical-based enhancement of RFEM regarding reproduction of spatial correlation structures and conditional simulations","authors":"Jean Lucas dos Passos Belo, P. Queiroz, Jefferson Silva","doi":"10.28927/sr.2022.076121","DOIUrl":"https://doi.org/10.28927/sr.2022.076121","url":null,"abstract":"Engineering always deals with uncertainties, and efforts are needed to quantify them. A probabilistic analysis considers the statistical information of the problem to this quantification. In the geotechnical area, uncertainties play a particular role in structure design because it deals with naturally formed materials. Evaluating spatial variability has become progressively important. However, studies on the correct reproduction of this variability and conditional simulations are limited. In this paper, a geostatistical-based enhancement of the Random Finite Element Method (RFEM) is presented. The main aim of this study is to incorporate an advanced multivariate geostatistical technique (i.e., Turning Bands Co-simulation, TBCOSIM) to reproduce the coregionalization model of soil properties correctly in order to investigate the effects regarding this reproduction. It is illustrated in a real case of soil slope. The results showed that, for the unconditional simulation, the presented approach reached a perfect agreement with the coregionalization model, while the conditional simulation inserted some disturbances to this agreement, but it still satisfactorily reproduced the model. The original RFEM failed to reproduce this structure, leading to lower variances than the presented approach, which would cause a non-conservative design. Furthermore, disregarding the local uncertainty (i.e., the nugget effect) may introduce bias to analysis and, depending on its magnitude, may also lead the conditional analysis to not show a worthwhile reduction in variances of results. Finally, this paper shows that correctly determining the coregionalization model and reproducing it on probabilistic analysis may meaningfully influence the results.","PeriodicalId":43687,"journal":{"name":"Soils and Rocks","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2022-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46485578","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 study investigated the use of the Formation Factor of the material as an alternative way to estimate soil-cement strength involving no destructive tests. This factor is obtained from Archie’s Law and consists of the ratio of pore water electrical conductivity to saturated porous material electrical conductivity, being related to porosity by constant terms. In this study, the electrical conductivity of the pore solution was obtained from a soil-cement leaching test after curing, and the conductivity of the monolithic soil-cement, by applying continuous voltage between 12-35 V onto electrodes of 1 mm thick copper plates. The influence of cement content and dry density on the electrical properties and water absorption was studied and discussed for curing times of 7 and 28 days. The samples molded with higher dry densities and cement contents presented higher Formation Factor for Soil Cement and higher unconfined compression strength. The Formation Factor and the unconfined compression strength are linearly related. Due to the methodology adopted, the Formation Factor was predominantly influenced by the conductivity of the pore solution and was related to the open porosity by means of a power function. Therefore, the Archie’s Law can be applied to soil-cement. In this case, the cementation coefficient varies until 28 days of curing, tending to stabilize around 8 from that age onwards. The volumetric coefficient can be adopted as a constant with a value of 1012.
{"title":"Soil-cement formation factor: methodological approach and relationship with unconfined compression strength","authors":"J. Vaillant, R. Cardoso","doi":"10.28927/sr.2022.072421","DOIUrl":"https://doi.org/10.28927/sr.2022.072421","url":null,"abstract":"This study investigated the use of the Formation Factor of the material as an alternative way to estimate soil-cement strength involving no destructive tests. This factor is obtained from Archie’s Law and consists of the ratio of pore water electrical conductivity to saturated porous material electrical conductivity, being related to porosity by constant terms. In this study, the electrical conductivity of the pore solution was obtained from a soil-cement leaching test after curing, and the conductivity of the monolithic soil-cement, by applying continuous voltage between 12-35 V onto electrodes of 1 mm thick copper plates. The influence of cement content and dry density on the electrical properties and water absorption was studied and discussed for curing times of 7 and 28 days. The samples molded with higher dry densities and cement contents presented higher Formation Factor for Soil Cement and higher unconfined compression strength. The Formation Factor and the unconfined compression strength are linearly related. Due to the methodology adopted, the Formation Factor was predominantly influenced by the conductivity of the pore solution and was related to the open porosity by means of a power function. Therefore, the Archie’s Law can be applied to soil-cement. In this case, the cementation coefficient varies until 28 days of curing, tending to stabilize around 8 from that age onwards. The volumetric coefficient can be adopted as a constant with a value of 1012.","PeriodicalId":43687,"journal":{"name":"Soils and Rocks","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2022-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41357568","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}
Cândida Bernardi, O. Oliveira, M. Espíndola, R. Higashi
This study had the objective to evaluate the application of the Marchetti Dilatometer Test (DMT) on compacted residual soil, analyzing the influence of suction on the parameters obtained. For this, a sample of residual diabase soil was collected and compacted in the laboratory at its optimum moisture content. Granular matrix suction sensors (GMS) were installed inside the compacted sample to monitor the suction during the experiment. The GMS allowed the monitoring of suction profile variations during the drying of the specimen submitted to ambient conditions. The DMT blade was statically inserted at 6 different points of the specimen surface with measurement of parameters A and B at every 10 cm deep. It was observed that with the increase of suction, there is an increase in both: material index value (ID) and dilatometric module (ED), but a reduction in the horizontal stress index (KD) value. The increase in ED value and reduction in KD value indicates that there is an increase in deformability modulus (E) and a decrease in coefficient of at-rest earth pressure (K0). The DMT correctly detected the trend in variations in geotechnical parameters as a function of variation in soil suction profiles.
{"title":"Influence of suction on the parameters of the Marchetti Dilatometer Test on a compacted residual soil","authors":"Cândida Bernardi, O. Oliveira, M. Espíndola, R. Higashi","doi":"10.28927/sr.2022.075921","DOIUrl":"https://doi.org/10.28927/sr.2022.075921","url":null,"abstract":"This study had the objective to evaluate the application of the Marchetti Dilatometer Test (DMT) on compacted residual soil, analyzing the influence of suction on the parameters obtained. For this, a sample of residual diabase soil was collected and compacted in the laboratory at its optimum moisture content. Granular matrix suction sensors (GMS) were installed inside the compacted sample to monitor the suction during the experiment. The GMS allowed the monitoring of suction profile variations during the drying of the specimen submitted to ambient conditions. The DMT blade was statically inserted at 6 different points of the specimen surface with measurement of parameters A and B at every 10 cm deep. It was observed that with the increase of suction, there is an increase in both: material index value (ID) and dilatometric module (ED), but a reduction in the horizontal stress index (KD) value. The increase in ED value and reduction in KD value indicates that there is an increase in deformability modulus (E) and a decrease in coefficient of at-rest earth pressure (K0). The DMT correctly detected the trend in variations in geotechnical parameters as a function of variation in soil suction profiles.","PeriodicalId":43687,"journal":{"name":"Soils and Rocks","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2022-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42193076","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}
The use of thin clayey soil as a liner plays an important role in many geotechnical and geo-environmental engineering applications, such as open channel and reservoir sealant, contaminant barrier etc. Their functional performance and sustainability depend primarily on the desiccation characteristics of these liners and barriers. A number of studies have been undertaken to quantify the degree of improvement achieved by using natural and synthetic fiber reinforcement. However, there is a lack of studies to understand the desiccation behavior of reinforced clay. This study aimed to explore the desiccation and cracking behavior of clayey soil reinforced with two natural fibers (coir and jute fiber) in addition to the degree of improvement in tensile strength. A series of direct tension and desiccation cracking tests have been conducted in the laboratory on clay-coir and clay-jute fiber mixes. The results demonstrate that when coir and jute fibers are used, the tensile strength of fiber-reinforced soil rises by up to 475 percent and 215 percent, respectively, when compared with the tensile strength of unreinforced soil at the same moisture content. Desiccation test results also show that blending of fibers reduces the breadth and depth of cracks significantly. The characteristics of unreinforced and fiber-reinforced clayey soil under desiccation and direct tension are briefly discussed in this paper. Findings of the present study will be important for professionals dealing with clay liners and trying to reduce cracking problems associated with drying soil.
{"title":"Desiccation characteristics and direct tension attributes of thin clayey soil containing discrete natural fibers","authors":"Abu Taiyab, Nazmun Islam, Mokhlesur M. Rahman","doi":"10.28927/sr.2022.074421","DOIUrl":"https://doi.org/10.28927/sr.2022.074421","url":null,"abstract":"The use of thin clayey soil as a liner plays an important role in many geotechnical and geo-environmental engineering applications, such as open channel and reservoir sealant, contaminant barrier etc. Their functional performance and sustainability depend primarily on the desiccation characteristics of these liners and barriers. A number of studies have been undertaken to quantify the degree of improvement achieved by using natural and synthetic fiber reinforcement. However, there is a lack of studies to understand the desiccation behavior of reinforced clay. This study aimed to explore the desiccation and cracking behavior of clayey soil reinforced with two natural fibers (coir and jute fiber) in addition to the degree of improvement in tensile strength. A series of direct tension and desiccation cracking tests have been conducted in the laboratory on clay-coir and clay-jute fiber mixes. The results demonstrate that when coir and jute fibers are used, the tensile strength of fiber-reinforced soil rises by up to 475 percent and 215 percent, respectively, when compared with the tensile strength of unreinforced soil at the same moisture content. Desiccation test results also show that blending of fibers reduces the breadth and depth of cracks significantly. The characteristics of unreinforced and fiber-reinforced clayey soil under desiccation and direct tension are briefly discussed in this paper. Findings of the present study will be important for professionals dealing with clay liners and trying to reduce cracking problems associated with drying soil.","PeriodicalId":43687,"journal":{"name":"Soils and Rocks","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2022-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44264282","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 paper presents the ‘load-transfer functions’ t-z and p-y methods for determining the axial and lateral displacements of single piles. They are based on the results of pressuremeter tests. The methods from the results of the Ménard pre-borehole pressuremeter tests (MPM) and the self-boring pressuremeter tests (PAF, for Pressiomètre AutoForeur in French) are described. Especially, the t-z and p-y methods derived from the MPM test results are commonly used in the French practice. For both t-z and p-y curves, some theoretical background (usually FEM calculations in linear elasticity) is given. The results of the t-z and p-y analyses are compared to the measurements from loading tests on full scale piles. A proposal concerning barrettes is also presented.
{"title":"Displacement of piles from pressuremeter test results - a summary of French research and practice","authors":"R. Frank","doi":"10.28927/sr.2022.006822","DOIUrl":"https://doi.org/10.28927/sr.2022.006822","url":null,"abstract":"This paper presents the ‘load-transfer functions’ t-z and p-y methods for determining the axial and lateral displacements of single piles. They are based on the results of pressuremeter tests. The methods from the results of the Ménard pre-borehole pressuremeter tests (MPM) and the self-boring pressuremeter tests (PAF, for Pressiomètre AutoForeur in French) are described. Especially, the t-z and p-y methods derived from the MPM test results are commonly used in the French practice. For both t-z and p-y curves, some theoretical background (usually FEM calculations in linear elasticity) is given. The results of the t-z and p-y analyses are compared to the measurements from loading tests on full scale piles. A proposal concerning barrettes is also presented.","PeriodicalId":43687,"journal":{"name":"Soils and Rocks","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2022-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42828054","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}
Rafaela Fernandes, A. Sieira, Armando Menezes Filho
Some studies that analyze the risk of dam failures estimate that between 2016 and 2025 about 30 major tragedies should be expected. Failure records between 1900 and 2014 indicate that there is an average of three ruptures every two years, considering only the failures that were officially registered and investigated. It can be said that the potential for dam failures will be driven by the economy, since cost has been the main variable considered in the design, construction, operation, monitoring and closing plan of these structures. As companies reduce investments in maintenance, risk management and failure prevention, there is an incentive for economic recovery, competitiveness of product value and debt reduction, required by investors. The result has been a decrease in specialized labor, to the point that companies no longer have sufficient knowledge about the engineering and operational skills that apply to tailings and water management. Learning from the dams’ tragedies is practically non-existent, in Brazil and worldwide, leading to catastrophic environmental and social consequences. Failures will occur as long as they are viewed and treated as unpredictable, thereby lacking risk management. The proposed risk management method, presented in this paper, considers the information of inspection and instrumentation, identifying risks from event trees, separately, intolerable, tolerable and acceptable risks. The intolerable risks are conducted for FMEA-type failure analysis, where severe, intermediate and mild failures are assessed. The objective is to enable the development of an assertive and effective action plan for dam safety management.
{"title":"Methodology for risk management in dams from the event tree and FMEA analysis","authors":"Rafaela Fernandes, A. Sieira, Armando Menezes Filho","doi":"10.28927/sr.2022.070221","DOIUrl":"https://doi.org/10.28927/sr.2022.070221","url":null,"abstract":"Some studies that analyze the risk of dam failures estimate that between 2016 and 2025 about 30 major tragedies should be expected. Failure records between 1900 and 2014 indicate that there is an average of three ruptures every two years, considering only the failures that were officially registered and investigated. It can be said that the potential for dam failures will be driven by the economy, since cost has been the main variable considered in the design, construction, operation, monitoring and closing plan of these structures. As companies reduce investments in maintenance, risk management and failure prevention, there is an incentive for economic recovery, competitiveness of product value and debt reduction, required by investors. The result has been a decrease in specialized labor, to the point that companies no longer have sufficient knowledge about the engineering and operational skills that apply to tailings and water management. Learning from the dams’ tragedies is practically non-existent, in Brazil and worldwide, leading to catastrophic environmental and social consequences. Failures will occur as long as they are viewed and treated as unpredictable, thereby lacking risk management. The proposed risk management method, presented in this paper, considers the information of inspection and instrumentation, identifying risks from event trees, separately, intolerable, tolerable and acceptable risks. The intolerable risks are conducted for FMEA-type failure analysis, where severe, intermediate and mild failures are assessed. The objective is to enable the development of an assertive and effective action plan for dam safety management.","PeriodicalId":43687,"journal":{"name":"Soils and Rocks","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2022-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47268050","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}
J. Rebolledo, Isabelle Santiago, H. Bernardes, T. Mendes
This study presents the evaluation of the performance of grain silos reinforced by rigid inclusions in soils of the Central-West region of Brazil, during its construction and operation. Therefore, a group of eight silos with 32.4 m in diameter, 30 m in height, and 12,000 t of storage capacity (each silo) was numerically analyzed using the three-dimensional Finite Element Method (FEM, Plaxis 3D). The stratigraphy of the Experimental Field of the University of Brasilia, Brazil (CEGUnB) was considered in the analysis. The performance of using a system of rigid inclusions to reinforce the soil beneath the raft was compared with the behavior of an isolated raft. Two models were developed: in the first one, an independent silo was considered, its behavior was analyzed during its construction and operation stages by varying the length of the inclusions; in the second model, the group of eight silos was considered and their behavior was studied for different combinations of loading. The rigid inclusions system proved to be an efficient foundation solution that allows controlling total and differential displacements during the construction and serviceability stages of the silo, helping to prevent the formation of cracks in the structural elements and grain contamination by the excessive opening of the raft-perimeter beam structural joint.
{"title":"Performance evaluation of rigid inclusions for settlement control of grain silos in tropical soils","authors":"J. Rebolledo, Isabelle Santiago, H. Bernardes, T. Mendes","doi":"10.28927/sr.2022.004822","DOIUrl":"https://doi.org/10.28927/sr.2022.004822","url":null,"abstract":"This study presents the evaluation of the performance of grain silos reinforced by rigid inclusions in soils of the Central-West region of Brazil, during its construction and operation. Therefore, a group of eight silos with 32.4 m in diameter, 30 m in height, and 12,000 t of storage capacity (each silo) was numerically analyzed using the three-dimensional Finite Element Method (FEM, Plaxis 3D). The stratigraphy of the Experimental Field of the University of Brasilia, Brazil (CEGUnB) was considered in the analysis. The performance of using a system of rigid inclusions to reinforce the soil beneath the raft was compared with the behavior of an isolated raft. Two models were developed: in the first one, an independent silo was considered, its behavior was analyzed during its construction and operation stages by varying the length of the inclusions; in the second model, the group of eight silos was considered and their behavior was studied for different combinations of loading. The rigid inclusions system proved to be an efficient foundation solution that allows controlling total and differential displacements during the construction and serviceability stages of the silo, helping to prevent the formation of cracks in the structural elements and grain contamination by the excessive opening of the raft-perimeter beam structural joint.","PeriodicalId":43687,"journal":{"name":"Soils and Rocks","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2022-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43125717","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}
Fine-grained soils usually have low shear strength and bearing capacity and high swelling potential in the wet state, therefore, they have often to be stabilized by additives. The main objective of this study is to determine the possible effects of ground-granulated blast-furnace slag on the physical and mechanical properties of fine-grained soil. For this purpose, a number of Atterberg, compaction, California bearing ratio (CBR), unconfined compression and freeze-thaw tests were conducted on fine-grained soil. Steel slag (SS) inclusion reduced plasticity index of soil from 44% to 20% when slag content increased from 0% to 55.0%. Moreover, the slag addition improved soil CBR with maximum improvement rate in the sample consists to 55% slag. This increment in CBR was about 140% and 154% for 2.54 mm and 5.08 mm penetration respectively. In addition, slag inclusion raised soil strength with a maximum increment of 132% for clay mixed with 55% slag. Water content and volume changes in freeze-thaw cycles also decreased with increasing percentage of SS, therefore mixtures durability increased.
{"title":"Effect of steel slag on the mechanical behavior of surficial yellow marl of Tabriz","authors":"Hossein Soltani-Jigheh, Hamed Golmohammadi, Manouchehr Tajrostami","doi":"10.28927/sr.2022.071821","DOIUrl":"https://doi.org/10.28927/sr.2022.071821","url":null,"abstract":"Fine-grained soils usually have low shear strength and bearing capacity and high swelling potential in the wet state, therefore, they have often to be stabilized by additives. The main objective of this study is to determine the possible effects of ground-granulated blast-furnace slag on the physical and mechanical properties of fine-grained soil. For this purpose, a number of Atterberg, compaction, California bearing ratio (CBR), unconfined compression and freeze-thaw tests were conducted on fine-grained soil. Steel slag (SS) inclusion reduced plasticity index of soil from 44% to 20% when slag content increased from 0% to 55.0%. Moreover, the slag addition improved soil CBR with maximum improvement rate in the sample consists to 55% slag. This increment in CBR was about 140% and 154% for 2.54 mm and 5.08 mm penetration respectively. In addition, slag inclusion raised soil strength with a maximum increment of 132% for clay mixed with 55% slag. Water content and volume changes in freeze-thaw cycles also decreased with increasing percentage of SS, therefore mixtures durability increased.","PeriodicalId":43687,"journal":{"name":"Soils and Rocks","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2022-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42536018","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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