Pub Date : 2019-01-01DOI: 10.12814/JKGSS.2019.18.2.023
Lee Soyen, Young-Je Kim, D. Oh, Y. Lee, Hyuk-sang Jung
In this paper, field measurement of the Block Type Mechanically Stabilized Earth (MSE) wall curved section was performed, and the reinforced area of the curved part is studied through the result. MSE method has been applied to various fields because of easy construction and excellent economic efficiency, so that it can be easily access in our life. However due to lack of compaction and stress concentration phenomenon, cracks and collapse occur in the curve of MSE wall, which is important for safety. The cause of collapse is lack of research on curved section, lack of design criteria, lack of construction due to economical efficiency and shortening of construction period, insufficient compaction space. In this study, therefore, it was examined the existing design and construction standards, analyzed the cause through accident examples of the curved section of the Block Type MSE wall. As a result, the horizontal displacement of the curved section was 90% higher than that of the straight section and 60% higher than that of the concave section. In the case of the convex section in the curved section reinforcement region, the maximum displacement is shown in the H/2 section in the horizontal direction from the center of the MSE wall, and the range of influence from H is shown. In the case of the concave section, the maximum displacement is shown in the center, The minimum displacement was confirmed in H/4 section in the horizontal direction from the center of the MSE wall. As a basic study on the reinforcement area rehabilitation through the actual construction of block type MSE wall, the behaviors of the straight part and the curved part were compared and analyzed. And analyzed the reinforced area in order to reduce the damage of the stress concentration phenomenon and secure the safety.
{"title":"A Study on Behavior Characteristics of Reinforcement Zone of Block Type Mechanically Stabilized E arth Wall by F ield Measurement in Curved Section","authors":"Lee Soyen, Young-Je Kim, D. Oh, Y. Lee, Hyuk-sang Jung","doi":"10.12814/JKGSS.2019.18.2.023","DOIUrl":"https://doi.org/10.12814/JKGSS.2019.18.2.023","url":null,"abstract":"In this paper, field measurement of the Block Type Mechanically Stabilized Earth (MSE) wall curved section was performed, and the reinforced area of the curved part is studied through the result. MSE method has been applied to various fields because of easy construction and excellent economic efficiency, so that it can be easily access in our life. However due to lack of compaction and stress concentration phenomenon, cracks and collapse occur in the curve of MSE wall, which is important for safety. The cause of collapse is lack of research on curved section, lack of design criteria, lack of construction due to economical efficiency and shortening of construction period, insufficient compaction space. In this study, therefore, it was examined the existing design and construction standards, analyzed the cause through accident examples of the curved section of the Block Type MSE wall. As a result, the horizontal displacement of the curved section was 90% higher than that of the straight section and 60% higher than that of the concave section. In the case of the convex section in the curved section reinforcement region, the maximum displacement is shown in the H/2 section in the horizontal direction from the center of the MSE wall, and the range of influence from H is shown. In the case of the concave section, the maximum displacement is shown in the center, The minimum displacement was confirmed in H/4 section in the horizontal direction from the center of the MSE wall. As a basic study on the reinforcement area rehabilitation through the actual construction of block type MSE wall, the behaviors of the straight part and the curved part were compared and analyzed. And analyzed the reinforced area in order to reduce the damage of the stress concentration phenomenon and secure the safety.","PeriodicalId":42164,"journal":{"name":"Journal of the Korean Geosynthetic Society","volume":"24 1","pages":"23-36"},"PeriodicalIF":0.5,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90721230","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}
Pub Date : 2019-01-01DOI: 10.12814/JKGSS.2019.18.4.299
Hobi Kim, Youngho Kim, Yoonsuk Park, S. You, Junggeun Han
In this study, a model experiment that simulates the behaviour of the ground composed of several compacted layer was intended to measure the loosened area in the event of a ground cavity through a LAD (Loosened area detector). It was confirmed that the size of the cone diameter was affected by the ground composed of fine grain + granulated soil layered through the model soil. In order to select the appropriate cone type, a scale effect experiment was conducted. From the test results, a micro-cone was chosen for the most suitable indoor model experiment. In the case of applying LAD in this study, the loosening condition of the ground was determined by the rapid change in penetration resistance caused by the difference in the boundary surface and relative density due to the compaction of the ground for indoor model testing. The range of loosened area occurring in the cavity was estimated through the penetration resistance characteristics on the ground, and the failure area was identified through the reduction rate of penetration resistance in the loosening area.
{"title":"An Experimental Study on the Detection of Loosened Areas in a Ground cavity Using a Micro Penetration Test","authors":"Hobi Kim, Youngho Kim, Yoonsuk Park, S. You, Junggeun Han","doi":"10.12814/JKGSS.2019.18.4.299","DOIUrl":"https://doi.org/10.12814/JKGSS.2019.18.4.299","url":null,"abstract":"In this study, a model experiment that simulates the behaviour of the ground composed of several compacted layer was intended to measure the loosened area in the event of a ground cavity through a LAD (Loosened area detector). It was confirmed that the size of the cone diameter was affected by the ground composed of fine grain + granulated soil layered through the model soil. In order to select the appropriate cone type, a scale effect experiment was conducted. From the test results, a micro-cone was chosen for the most suitable indoor model experiment. In the case of applying LAD in this study, the loosening condition of the ground was determined by the rapid change in penetration resistance caused by the difference in the boundary surface and relative density due to the compaction of the ground for indoor model testing. The range of loosened area occurring in the cavity was estimated through the penetration resistance characteristics on the ground, and the failure area was identified through the reduction rate of penetration resistance in the loosening area.","PeriodicalId":42164,"journal":{"name":"Journal of the Korean Geosynthetic Society","volume":"102 1","pages":"299-306"},"PeriodicalIF":0.5,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73539575","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}
Pub Date : 2019-01-01DOI: 10.12814/JKGSS.2019.18.1.055
Jeongjun Park, H. Shin, Yoonseok Chung, S. You, G. Hong
This paper describes results of experimental and numerical analyses, in order to analyze a reinforcement effect of concrete mat on open cut restoration of underground cavity. The plate loading tests were conducted to evaluate a reinforcement effect of concrete mat, at reinforcement depths from the ground surface of 10 cm, 20 cm, and 30 cm. The result showed that the reduction ratio of stress (earth pressure) was about 60% at all reinforcement depth. The reinforcement effect considering ground surface settlement and reduction ratio of stress based on laboratory tests and numerical analysis was significant, at reinforcement depths from the ground surface of 10 cm∼20 cm. LFWD test results showed that subgrade modulus was the largest when concrete mat was installed 20 cm below ground surface. Therefore, it is effective to reinforce concrete mat within 20 cm from the surface, when the underground cavity due to damage of underground utilities was formed in the height direction to the bottom of the pavement layer.
本文通过试验和数值分析，分析了混凝土垫块对地下空腔露天修复的加固效果。在距地面10 cm、20 cm和30 cm的钢筋深度处进行了钢板加载试验，以评估混凝土垫块的加固效果。结果表明，在各加固深度，应力(土压力)减小率约为60%。在距地表10 cm ~ 20 cm的加固深度处，基于室内试验和数值分析的考虑地表沉降和应力折减比的加固效果显著。LFWD试验结果表明，当混凝土垫块安装在地表以下20 cm时，路基模量最大。因此，在至路面底层高度方向上，由于地下公用设施破坏而形成地下空腔时，在距地表20 cm范围内进行混凝土垫层加固是有效的。
{"title":"A Study on the Open Cut Restoration of Underground Cavity Using Concrete Mat","authors":"Jeongjun Park, H. Shin, Yoonseok Chung, S. You, G. Hong","doi":"10.12814/JKGSS.2019.18.1.055","DOIUrl":"https://doi.org/10.12814/JKGSS.2019.18.1.055","url":null,"abstract":"This paper describes results of experimental and numerical analyses, in order to analyze a reinforcement effect of concrete mat on open cut restoration of underground cavity. The plate loading tests were conducted to evaluate a reinforcement effect of concrete mat, at reinforcement depths from the ground surface of 10 cm, 20 cm, and 30 cm. The result showed that the reduction ratio of stress (earth pressure) was about 60% at all reinforcement depth. The reinforcement effect considering ground surface settlement and reduction ratio of stress based on laboratory tests and numerical analysis was significant, at reinforcement depths from the ground surface of 10 cm∼20 cm. LFWD test results showed that subgrade modulus was the largest when concrete mat was installed 20 cm below ground surface. Therefore, it is effective to reinforce concrete mat within 20 cm from the surface, when the underground cavity due to damage of underground utilities was formed in the height direction to the bottom of the pavement layer.","PeriodicalId":42164,"journal":{"name":"Journal of the Korean Geosynthetic Society","volume":"92 1","pages":"55-65"},"PeriodicalIF":0.5,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79422857","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}
Pub Date : 2019-01-01DOI: 10.12814/JKGSS.2019.18.3.089
Rak-Young Kim, Dongwook Kim
The purpose of this study is to analyze the characteristics of bearing capacity of pre-bored super strength PHC (SSPHC) piles socketed in rocks based on dynamic load test results. Because the SSPHC piles have high compressive concrete strengths compared with those of regular high strength PHC piles, the allowable structural strengths of the SSPHC piles were increased. For optimal design of the super strength PHC piles, the geotechnical bearing capacity of the SSPHC piles should also increased to balance the increased allowable structural strength of the SSPHC piles. Current practices of pile installation apply the same amount of driving energy on both SSPHC and high strength PHC piles. As results of analyzing factors that influence bearing strength of SSPHC piles using dynamic load test, there was no relationship between SPT-N value at pile toe and end bearing capacity. But driving energy effects on end bearing capacity. In case of skin friction, driving energy had no effects. And reasonable method verifying design bearing strength is necessary because end bearing capacity is not considered sufficiently in restrike test results.
{"title":"Analysis of Bearing Capacity of Rock Socketed Pre-Bored Super Strength Piles Based on Dynamic Load Test Results","authors":"Rak-Young Kim, Dongwook Kim","doi":"10.12814/JKGSS.2019.18.3.089","DOIUrl":"https://doi.org/10.12814/JKGSS.2019.18.3.089","url":null,"abstract":"The purpose of this study is to analyze the characteristics of bearing capacity of pre-bored super strength PHC (SSPHC) piles socketed in rocks based on dynamic load test results. Because the SSPHC piles have high compressive concrete strengths compared with those of regular high strength PHC piles, the allowable structural strengths of the SSPHC piles were increased. For optimal design of the super strength PHC piles, the geotechnical bearing capacity of the SSPHC piles should also increased to balance the increased allowable structural strength of the SSPHC piles. Current practices of pile installation apply the same amount of driving energy on both SSPHC and high strength PHC piles. As results of analyzing factors that influence bearing strength of SSPHC piles using dynamic load test, there was no relationship between SPT-N value at pile toe and end bearing capacity. But driving energy effects on end bearing capacity. In case of skin friction, driving energy had no effects. And reasonable method verifying design bearing strength is necessary because end bearing capacity is not considered sufficiently in restrike test results.","PeriodicalId":42164,"journal":{"name":"Journal of the Korean Geosynthetic Society","volume":"36 1","pages":"89-100"},"PeriodicalIF":0.5,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89365244","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}
Pub Date : 2019-01-01DOI: 10.12814/JKGSS.2019.18.3.023
Daeho Yun, Yuntae Kim
This study investigated the scour characteristics of artificial reef according to unreinforced and reinforced artificial reefs through laboratory test and numerical analysis. In this study, geogrid was used as a reinforcement of seabed. Three different reinforced areas were selected; one time, three times and five times bottom area of artificial reef. Two-dimensional water channel test was carried out to investigate scour patten of sand and silt grounds. Numerical analysis was also performed to see the velocity vector and scouring patten around artificial reef which was same condition with experiment. The numerical results were in good agreements with the experimental test results. It was found that the geogrid-installed soft ground under artificial reef tends to reduce scour, compared to unreinforced soft ground.
{"title":"Scour Characteristics of Artificial Reef through Experiment and Numerical Analysis","authors":"Daeho Yun, Yuntae Kim","doi":"10.12814/JKGSS.2019.18.3.023","DOIUrl":"https://doi.org/10.12814/JKGSS.2019.18.3.023","url":null,"abstract":"This study investigated the scour characteristics of artificial reef according to unreinforced and reinforced artificial reefs through laboratory test and numerical analysis. In this study, geogrid was used as a reinforcement of seabed. Three different reinforced areas were selected; one time, three times and five times bottom area of artificial reef. Two-dimensional water channel test was carried out to investigate scour patten of sand and silt grounds. Numerical analysis was also performed to see the velocity vector and scouring patten around artificial reef which was same condition with experiment. The numerical results were in good agreements with the experimental test results. It was found that the geogrid-installed soft ground under artificial reef tends to reduce scour, compared to unreinforced soft ground.","PeriodicalId":42164,"journal":{"name":"Journal of the Korean Geosynthetic Society","volume":"21 1","pages":"23-32"},"PeriodicalIF":0.5,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78064272","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}
Pub Date : 2019-01-01DOI: 10.12814/JKGSS.2019.18.4.039
C. Yoo, S. Haider, Jaewon Yang, Tabish Ali
In this paper the development and implementation of an artificial intelligence (AI)-based Tunnelling Impact prediction and assessment program (SKKU-iTunnel) is presented. Program predicts tunnelling induced surface settlement and groundwater drawdown by utilizing well trained ANNs and uses these predicted values to perform the damage assessment likely to occur in nearby structures and pipelines/utilities for a given tunnel problem. Generalised artificial neural networks (ANNs) were trained, to predict the induced parameters, through databases generated by combining real field data and numerical analysis for cases that represented real field conditions. It is shown that program equipped with carefully trained ANN can predict tunnel impact assessments and perform damage assessments quiet efficiently and comparable accuracy to that of numerical analysis. This paper describes the idea and implementation details of the SKKU-iTunnel with an example for demonstration.
{"title":"Development of AI-based Prediction and Assessment Program for Tunnelling Impact","authors":"C. Yoo, S. Haider, Jaewon Yang, Tabish Ali","doi":"10.12814/JKGSS.2019.18.4.039","DOIUrl":"https://doi.org/10.12814/JKGSS.2019.18.4.039","url":null,"abstract":"In this paper the development and implementation of an artificial intelligence (AI)-based Tunnelling Impact prediction and assessment program (SKKU-iTunnel) is presented. Program predicts tunnelling induced surface settlement and groundwater drawdown by utilizing well trained ANNs and uses these predicted values to perform the damage assessment likely to occur in nearby structures and pipelines/utilities for a given tunnel problem. Generalised artificial neural networks (ANNs) were trained, to predict the induced parameters, through databases generated by combining real field data and numerical analysis for cases that represented real field conditions. It is shown that program equipped with carefully trained ANN can predict tunnel impact assessments and perform damage assessments quiet efficiently and comparable accuracy to that of numerical analysis. This paper describes the idea and implementation details of the SKKU-iTunnel with an example for demonstration.","PeriodicalId":42164,"journal":{"name":"Journal of the Korean Geosynthetic Society","volume":"122 1","pages":"39-52"},"PeriodicalIF":0.5,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88124647","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}
Pub Date : 2019-01-01DOI: 10.12814/JKGSS.2019.18.4.287
S. You, Ahn heechul, Youngho Kim, Junggeun Han, G. Hong, Jeongjun Park
In this study, a series of finite element numerical analyzes were performed considering the pavement thickness and traffic load for the purpose of stability analysis on the cavity ground. In order to verify the validity of this numerical method, the previous numerical analysis was used to simulate the mechanical behavior of cavity ground, and the results were compared and analyzed. Also, from the numerical results, it was possible to confirm the dynamic behavior of the ground by confirming the change of ground void ratio, surface settlement, and shear stress, and using the relationship between stress ratio, non-destructive depth and surface settlement, the safety of the was analyzed. As a result, as the pavement thickness decreased and the traffic load increased, the non-destructive depth and the overall stability of the ground decreased with the increase of surface settlement.
{"title":"A Numerical Analysis on Stability Analysis of Cavity Ground considering Pavement Thickness and Traffic Load","authors":"S. You, Ahn heechul, Youngho Kim, Junggeun Han, G. Hong, Jeongjun Park","doi":"10.12814/JKGSS.2019.18.4.287","DOIUrl":"https://doi.org/10.12814/JKGSS.2019.18.4.287","url":null,"abstract":"In this study, a series of finite element numerical analyzes were performed considering the pavement thickness and traffic load for the purpose of stability analysis on the cavity ground. In order to verify the validity of this numerical method, the previous numerical analysis was used to simulate the mechanical behavior of cavity ground, and the results were compared and analyzed. Also, from the numerical results, it was possible to confirm the dynamic behavior of the ground by confirming the change of ground void ratio, surface settlement, and shear stress, and using the relationship between stress ratio, non-destructive depth and surface settlement, the safety of the was analyzed. As a result, as the pavement thickness decreased and the traffic load increased, the non-destructive depth and the overall stability of the ground decreased with the increase of surface settlement.","PeriodicalId":42164,"journal":{"name":"Journal of the Korean Geosynthetic Society","volume":"27 1","pages":"287-297"},"PeriodicalIF":0.5,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74521846","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}
Pub Date : 2019-01-01DOI: 10.12814/JKGSS.2019.18.1.091
Jeongjun Park, H. Shin, J. Yuu, G. Hong
Recently, small-scale excavation like ground cavity restoration and buried pipe replacement works are being carried out in urban area, in order to improve living convenience. This paper describes experiment results on the ground reinforcement method that can reduce the buried pipe damage, when the differential settlement occurred due to poor compaction of ground below the buried pipe. Plate load tests were conducted to evaluate a reinforcement effect of ground using concrete mat and expansion mat in the ground below the buried pipe. The results showed that the stress reduction ratio by concrete mat and expansion mat according to the surcharge load was about 46%∼48% and 39%∼42%, respectively. Therefore, the differential settlement of the buried pipe and the ground deformation below the buried pipes were reduced by the reinforcement effect of the concrete mat and expansion mat. This means that it is possible to prevent a buried pipe damage due to underground cavity and ground subsidence, if concrete mat and expansion mat are reinforced in the ground below the buried pipe or on the ground between the buried pipes.
{"title":"An Experimental Study on Ground Reinforcement Effect of Concrete and Expansion Mat for Prevention of Buried Pipe Damage","authors":"Jeongjun Park, H. Shin, J. Yuu, G. Hong","doi":"10.12814/JKGSS.2019.18.1.091","DOIUrl":"https://doi.org/10.12814/JKGSS.2019.18.1.091","url":null,"abstract":"Recently, small-scale excavation like ground cavity restoration and buried pipe replacement works are being carried out in urban area, in order to improve living convenience. This paper describes experiment results on the ground reinforcement method that can reduce the buried pipe damage, when the differential settlement occurred due to poor compaction of ground below the buried pipe. Plate load tests were conducted to evaluate a reinforcement effect of ground using concrete mat and expansion mat in the ground below the buried pipe. The results showed that the stress reduction ratio by concrete mat and expansion mat according to the surcharge load was about 46%∼48% and 39%∼42%, respectively. Therefore, the differential settlement of the buried pipe and the ground deformation below the buried pipes were reduced by the reinforcement effect of the concrete mat and expansion mat. This means that it is possible to prevent a buried pipe damage due to underground cavity and ground subsidence, if concrete mat and expansion mat are reinforced in the ground below the buried pipe or on the ground between the buried pipes.","PeriodicalId":42164,"journal":{"name":"Journal of the Korean Geosynthetic Society","volume":"14 8","pages":"91-101"},"PeriodicalIF":0.5,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72402625","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}
Pub Date : 2019-01-01DOI: 10.12814/JKGSS.2019.18.2.045
S. You, H. Shin, K. Lee, Jeongjun Park, C. Choi, G. Hong
This paper describes the results of finite element analysis (FEA), in order to investigate a characteristics of pile pullout behavior according to the conditions of the relative density and fines content in original ground. In the FEA, a boundary elements and strength reduction factors ( ) on pile-soil interface were applied to simulate appropriately the shear behavior at the pile-soil interface, and then the reliability of numerical analysis method was verified by comparison of FEA results and previous experimental research(You et al., 2018). In addition, a the deformation characteristics at the pile-soil interface and determination method of value was laid out. The results showed that the FEA, based on the analytical model applied in this study simulates appropriately the characteristics of the pile-soil interface by pullout model test of pile. In order to apply the suggested value, it is necessary to consider the condition of the relative density and the fines content in ground.
本文介绍了有限元分析(FEA)的结果，探讨了在原地基相对密度和细粒含量条件下桩的拉拔行为特征。在有限元分析中，采用桩-土界面上的边界元和强度折减因子()对桩-土界面处的剪切行为进行了适当的模拟，并将有限元分析结果与前人的实验研究结果进行了对比，验证了数值分析方法的可靠性(You et al.， 2018)。给出了桩-土界面变形特征及值的确定方法。结果表明，通过桩拉拔模型试验，本文所采用的分析模型较好地模拟了桩-土界面的特性。为了应用建议的值，需要考虑相对密度和地面细粒含量的情况。
{"title":"A Study on Strength Reduction Factor of Pile-soil Interface for Evaluation of Pile Pullout Resistance by Soil Condition","authors":"S. You, H. Shin, K. Lee, Jeongjun Park, C. Choi, G. Hong","doi":"10.12814/JKGSS.2019.18.2.045","DOIUrl":"https://doi.org/10.12814/JKGSS.2019.18.2.045","url":null,"abstract":"This paper describes the results of finite element analysis (FEA), in order to investigate a characteristics of pile pullout behavior according to the conditions of the relative density and fines content in original ground. In the FEA, a boundary elements and strength reduction factors ( ) on pile-soil interface were applied to simulate appropriately the shear behavior at the pile-soil interface, and then the reliability of numerical analysis method was verified by comparison of FEA results and previous experimental research(You et al., 2018). In addition, a the deformation characteristics at the pile-soil interface and determination method of value was laid out. The results showed that the FEA, based on the analytical model applied in this study simulates appropriately the characteristics of the pile-soil interface by pullout model test of pile. In order to apply the suggested value, it is necessary to consider the condition of the relative density and the fines content in ground.","PeriodicalId":42164,"journal":{"name":"Journal of the Korean Geosynthetic Society","volume":"3 1","pages":"45-54"},"PeriodicalIF":0.5,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90408785","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}
Pub Date : 2019-01-01DOI: 10.12814/jkgss.2019.18.2.001
윤성열, 안현규, 오민아, Lee Jai-Young
This study was intended to evaluate the water permeability and structure for calcium bentonite-sand mixtures to utilize calcium bentonite as a liner. This study conducted physico-chemical properties tests, compaction tests, permeability test and Scanning Electron Microscopy analysis (SEM) analysis. It was found the higher the ratio of calcium bentonite, the lower the dry density with coefficient of permeability, and the higher the optimum moisture content. In particular, SEM analysis was found the higher the ratio of calcium bentonite, the higher the area of the montmorillonite particles. In conclusion, the optimum coefficient of permeability that finds the landfill liner condition (must be less than 1 × 10 cm/sec) was obtained when the ratio of calcium bentonite was 40% or higher. These findings may improve the understanding of the calcium bentonite as a liner. Calcium bentonite shows a similar permeability to sodium bentonite 7% when mixed at 40% or more. Therefore, it is considered that calcium bentonite can be utilized as a liner.
{"title":"A study on the Evaluation of Permeability and Structure for Calcium Bentonite-Sand Mixtures","authors":"윤성열, 안현규, 오민아, Lee Jai-Young","doi":"10.12814/jkgss.2019.18.2.001","DOIUrl":"https://doi.org/10.12814/jkgss.2019.18.2.001","url":null,"abstract":"This study was intended to evaluate the water permeability and structure for calcium bentonite-sand mixtures to utilize calcium bentonite as a liner. This study conducted physico-chemical properties tests, compaction tests, permeability test and Scanning Electron Microscopy analysis (SEM) analysis. It was found the higher the ratio of calcium bentonite, the lower the dry density with coefficient of permeability, and the higher the optimum moisture content. In particular, SEM analysis was found the higher the ratio of calcium bentonite, the higher the area of the montmorillonite particles. In conclusion, the optimum coefficient of permeability that finds the landfill liner condition (must be less than 1 × 10 cm/sec) was obtained when the ratio of calcium bentonite was 40% or higher. These findings may improve the understanding of the calcium bentonite as a liner. Calcium bentonite shows a similar permeability to sodium bentonite 7% when mixed at 40% or more. Therefore, it is considered that calcium bentonite can be utilized as a liner.","PeriodicalId":42164,"journal":{"name":"Journal of the Korean Geosynthetic Society","volume":"48 5 Suppl 1 1","pages":"1-10"},"PeriodicalIF":0.5,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88143266","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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