R. Khorrami, M. M. Tochaee, M. Payan, R. Jamshidi Chenari
The compression behaviour of the mixture of glass beads (representing rigid particles) and EPS beads (representing deformable particles) during the loading-unloading process is systematically examined through performing two sets of large-size oedometer experiments, including incremental step-by-step and one-step loading scenarios. At each step during the loading-unloading cycle, the void ratio (e) and the at-rest coefficient of lateral earth pressure (K0) are measured for pure rigid samples and rigid-soft particle mixtures. To consider the creep effect, the overburden pressure at the final loading step is maintained on the sample for 24 hours prior to unloading. The results show that at a given overburden pressure, with the addition of soft particles to the pure rigid aggregates, the values of e and K0 decrease. Additionally, for both pure rigid samples and rigid-soft particle mixtures, with increasing the overburden pressure, e decreases whereas K0 augments. Moreover, due to the creep behaviour during the constant loading step, K0 decreases over time for both samples; the phenomenon which is observed to be more pronounced for pure rigid aggregates compared to rigid-soft particle mixtures. Finally, a well-established creep model is used to simulate the creep behaviour of pure rigid samples and rigid-soft particle composites.
{"title":"Deformation characteristics and creep behaviour of rigid particulates-EPS beads composites","authors":"R. Khorrami, M. M. Tochaee, M. Payan, R. Jamshidi Chenari","doi":"10.1680/jgein.23.00145","DOIUrl":"https://doi.org/10.1680/jgein.23.00145","url":null,"abstract":"The compression behaviour of the mixture of glass beads (representing rigid particles) and EPS beads (representing deformable particles) during the loading-unloading process is systematically examined through performing two sets of large-size oedometer experiments, including incremental step-by-step and one-step loading scenarios. At each step during the loading-unloading cycle, the void ratio (<i>e</i>) and the at-rest coefficient of lateral earth pressure (<i>K</i><sub>0</sub>) are measured for pure rigid samples and rigid-soft particle mixtures. To consider the creep effect, the overburden pressure at the final loading step is maintained on the sample for 24 hours prior to unloading. The results show that at a given overburden pressure, with the addition of soft particles to the pure rigid aggregates, the values of <i>e</i> and <i>K</i><sub>0</sub> decrease. Additionally, for both pure rigid samples and rigid-soft particle mixtures, with increasing the overburden pressure, <i>e</i> decreases whereas <i>K</i><sub>0</sub> augments. Moreover, due to the creep behaviour during the constant loading step, <i>K</i><sub>0</sub> decreases over time for both samples; the phenomenon which is observed to be more pronounced for pure rigid aggregates compared to rigid-soft particle mixtures. Finally, a well-established creep model is used to simulate the creep behaviour of pure rigid samples and rigid-soft particle composites.","PeriodicalId":12616,"journal":{"name":"Geosynthetics International","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2024-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140199262","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. C. Qiu, G. Z. Xu, G. Q. Gu, W. Z. Song, D. H. Cao
This study investigated the performance of unreinforced and geogrid-encased cement-stabilized dredged slurry columns by uniaxial compression tests to simulate the extreme case where the surrounding soil offers no confinement. The objective was to understand the strength characteristics and visualize the deformation damage patterns of the columns with respect to the water content, cement content, length-to-diameter ratio, and geogrid strength. The results show that the unreinforced specimens exhibited strain-softening behavior, whereas geogrid encasement induced strain-hardening, with high-strength geogrids showing superior strain-hardening capacity. Notably, regardless of geogrid strength, encasement enhanced the resistance to deformation and ductility of the columns. Increasing the cement content, reducing the water content, and decreasing the length-to-diameter ratio all contributed to higher peak strength in both unreinforced and geogrid-encased specimens. Geogrid encasement provides confinement that enhances peak strength. The influence of geogrid encasement on peak strength becomes more pronounced at lower cement contents, higher water contents, and higher length-to-diameter ratios. Geogrid encasement also affects failure modes, altering the predominant inclined shear failure observed at the top of unreinforced specimens. Specimens encased with geogrids of higher tensile strength exhibit enhanced integrity and deformation resembling compression strut buckling, with a symmetrically inclined failure trend at the top and bottom.
{"title":"Uniaxial compression test of cement-solidified dredged slurry columns encased with geogrid","authors":"C. C. Qiu, G. Z. Xu, G. Q. Gu, W. Z. Song, D. H. Cao","doi":"10.1680/jgein.23.00132","DOIUrl":"https://doi.org/10.1680/jgein.23.00132","url":null,"abstract":"This study investigated the performance of unreinforced and geogrid-encased cement-stabilized dredged slurry columns by uniaxial compression tests to simulate the extreme case where the surrounding soil offers no confinement. The objective was to understand the strength characteristics and visualize the deformation damage patterns of the columns with respect to the water content, cement content, length-to-diameter ratio, and geogrid strength. The results show that the unreinforced specimens exhibited strain-softening behavior, whereas geogrid encasement induced strain-hardening, with high-strength geogrids showing superior strain-hardening capacity. Notably, regardless of geogrid strength, encasement enhanced the resistance to deformation and ductility of the columns. Increasing the cement content, reducing the water content, and decreasing the length-to-diameter ratio all contributed to higher peak strength in both unreinforced and geogrid-encased specimens. Geogrid encasement provides confinement that enhances peak strength. The influence of geogrid encasement on peak strength becomes more pronounced at lower cement contents, higher water contents, and higher length-to-diameter ratios. Geogrid encasement also affects failure modes, altering the predominant inclined shear failure observed at the top of unreinforced specimens. Specimens encased with geogrids of higher tensile strength exhibit enhanced integrity and deformation resembling compression strut buckling, with a symmetrically inclined failure trend at the top and bottom.","PeriodicalId":12616,"journal":{"name":"Geosynthetics International","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140199032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The application of waste rubber for soil improvement is feasible, and the static and dynamic properties of rubber-reinforced soils have been extensively studied. However, the mechanical properties of frozen rubber-reinforced expansive soils have not been effectively studied due to the complexity of multiphase media under the action of multiple fields, and no applicable constitutive models describe them. In this paper, the stress-strain relationship model for frozen rubber-reinforced expansive soils is investigated over a range of strain rates from 0.18% to 0.3% and the following conclusions were obtained: (1) The structural model of the frozen rubber-reinforced expansive soil can be considered a ternary medium model that consists of elasto-brittle bonding elements, elasto-plastic friction elements and elastic friction elements. (2) The stress-strain relationship can be divided into three stages: linear elastic stage, elasto-plastic stage and strain softening (RC ≤ 15%) or hardening (RC = 20%) stage. The ternary medium model can better describe the three stages deformation process. (3) The rubber content has a greater influence on the stress-strain relationship. When the rubber content reaches 20%, the expression of the stress-strain curve changes from strain softening to strain hardening, at which time the rubber dominates. (4) The maximum shear strength of frozen rubber-reinforced expansive soil is obtained at 10% rubber content.
{"title":"Ternary medium constitutive model of frozen rubber-reinforced expansive soil","authors":"Z. Yang, Z. Cheng, G. Cai, X. Ling, W. Shi","doi":"10.1680/jgein.23.00076","DOIUrl":"https://doi.org/10.1680/jgein.23.00076","url":null,"abstract":"The application of waste rubber for soil improvement is feasible, and the static and dynamic properties of rubber-reinforced soils have been extensively studied. However, the mechanical properties of frozen rubber-reinforced expansive soils have not been effectively studied due to the complexity of multiphase media under the action of multiple fields, and no applicable constitutive models describe them. In this paper, the stress-strain relationship model for frozen rubber-reinforced expansive soils is investigated over a range of strain rates from 0.18% to 0.3% and the following conclusions were obtained: (1) The structural model of the frozen rubber-reinforced expansive soil can be considered a ternary medium model that consists of elasto-brittle bonding elements, elasto-plastic friction elements and elastic friction elements. (2) The stress-strain relationship can be divided into three stages: linear elastic stage, elasto-plastic stage and strain softening (RC ≤ 15%) or hardening (RC = 20%) stage. The ternary medium model can better describe the three stages deformation process. (3) The rubber content has a greater influence on the stress-strain relationship. When the rubber content reaches 20%, the expression of the stress-strain curve changes from strain softening to strain hardening, at which time the rubber dominates. (4) The maximum shear strength of frozen rubber-reinforced expansive soil is obtained at 10% rubber content.","PeriodicalId":12616,"journal":{"name":"Geosynthetics International","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139793290","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The application of waste rubber for soil improvement is feasible, and the static and dynamic properties of rubber-reinforced soils have been extensively studied. However, the mechanical properties of frozen rubber-reinforced expansive soils have not been effectively studied due to the complexity of multiphase media under the action of multiple fields, and no applicable constitutive models describe them. In this paper, the stress-strain relationship model for frozen rubber-reinforced expansive soils is investigated over a range of strain rates from 0.18% to 0.3% and the following conclusions were obtained: (1) The structural model of the frozen rubber-reinforced expansive soil can be considered a ternary medium model that consists of elasto-brittle bonding elements, elasto-plastic friction elements and elastic friction elements. (2) The stress-strain relationship can be divided into three stages: linear elastic stage, elasto-plastic stage and strain softening (RC ≤ 15%) or hardening (RC = 20%) stage. The ternary medium model can better describe the three stages deformation process. (3) The rubber content has a greater influence on the stress-strain relationship. When the rubber content reaches 20%, the expression of the stress-strain curve changes from strain softening to strain hardening, at which time the rubber dominates. (4) The maximum shear strength of frozen rubber-reinforced expansive soil is obtained at 10% rubber content.
{"title":"Ternary medium constitutive model of frozen rubber-reinforced expansive soil","authors":"Z. Yang, Z. Cheng, G. Cai, X. Ling, W. Shi","doi":"10.1680/jgein.23.00076","DOIUrl":"https://doi.org/10.1680/jgein.23.00076","url":null,"abstract":"The application of waste rubber for soil improvement is feasible, and the static and dynamic properties of rubber-reinforced soils have been extensively studied. However, the mechanical properties of frozen rubber-reinforced expansive soils have not been effectively studied due to the complexity of multiphase media under the action of multiple fields, and no applicable constitutive models describe them. In this paper, the stress-strain relationship model for frozen rubber-reinforced expansive soils is investigated over a range of strain rates from 0.18% to 0.3% and the following conclusions were obtained: (1) The structural model of the frozen rubber-reinforced expansive soil can be considered a ternary medium model that consists of elasto-brittle bonding elements, elasto-plastic friction elements and elastic friction elements. (2) The stress-strain relationship can be divided into three stages: linear elastic stage, elasto-plastic stage and strain softening (RC ≤ 15%) or hardening (RC = 20%) stage. The ternary medium model can better describe the three stages deformation process. (3) The rubber content has a greater influence on the stress-strain relationship. When the rubber content reaches 20%, the expression of the stress-strain curve changes from strain softening to strain hardening, at which time the rubber dominates. (4) The maximum shear strength of frozen rubber-reinforced expansive soil is obtained at 10% rubber content.","PeriodicalId":12616,"journal":{"name":"Geosynthetics International","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139853285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper presents an experimental study on reduced scale geosynthetic reinforced soil (GRS) abutment models subjected to cyclic traffic loading, aimed at investigating the influences of cyclic load amplitude, self-weight of bridge superstructure, and reinforcement vertical spacing on the cumulative deformations. The GRS abutment models were constructed using sand backfill and geogrid reinforcement. A static load was first applied to account for the self-weight of bridge superstructure, and then the cyclic loads were applied in several phases with increasing amplitude. The results indicate that significant cumulative footing settlement under cyclic loading mainly occurs within the first few hundred loading cycles, and the settlement increases with increasing cyclic load amplitude. The cyclic load amplitude and reinforcement vertical spacing have significant impacts on the cumulative deformations of GRS abutments under cyclic loading. The maximum facing displacement under cyclic loading occurs near the top of the wall. The cyclic load has a greater impact on the reinforcement strains near the upper middle reinforcement layers, while it has a smaller impact on the lower reinforcement layers.
{"title":"Cumulative deformation behavior of GRS bridge abutments under cyclic traffic loading","authors":"Y. Jia, J. Zhang, L. Tong, J.-J. Zheng, Y. Zheng","doi":"10.1680/jgein.23.00144","DOIUrl":"https://doi.org/10.1680/jgein.23.00144","url":null,"abstract":"This paper presents an experimental study on reduced scale geosynthetic reinforced soil (GRS) abutment models subjected to cyclic traffic loading, aimed at investigating the influences of cyclic load amplitude, self-weight of bridge superstructure, and reinforcement vertical spacing on the cumulative deformations. The GRS abutment models were constructed using sand backfill and geogrid reinforcement. A static load was first applied to account for the self-weight of bridge superstructure, and then the cyclic loads were applied in several phases with increasing amplitude. The results indicate that significant cumulative footing settlement under cyclic loading mainly occurs within the first few hundred loading cycles, and the settlement increases with increasing cyclic load amplitude. The cyclic load amplitude and reinforcement vertical spacing have significant impacts on the cumulative deformations of GRS abutments under cyclic loading. The maximum facing displacement under cyclic loading occurs near the top of the wall. The cyclic load has a greater impact on the reinforcement strains near the upper middle reinforcement layers, while it has a smaller impact on the lower reinforcement layers.","PeriodicalId":12616,"journal":{"name":"Geosynthetics International","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2024-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139805884","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper presents an experimental study on reduced scale geosynthetic reinforced soil (GRS) abutment models subjected to cyclic traffic loading, aimed at investigating the influences of cyclic load amplitude, self-weight of bridge superstructure, and reinforcement vertical spacing on the cumulative deformations. The GRS abutment models were constructed using sand backfill and geogrid reinforcement. A static load was first applied to account for the self-weight of bridge superstructure, and then the cyclic loads were applied in several phases with increasing amplitude. The results indicate that significant cumulative footing settlement under cyclic loading mainly occurs within the first few hundred loading cycles, and the settlement increases with increasing cyclic load amplitude. The cyclic load amplitude and reinforcement vertical spacing have significant impacts on the cumulative deformations of GRS abutments under cyclic loading. The maximum facing displacement under cyclic loading occurs near the top of the wall. The cyclic load has a greater impact on the reinforcement strains near the upper middle reinforcement layers, while it has a smaller impact on the lower reinforcement layers.
{"title":"Cumulative deformation behavior of GRS bridge abutments under cyclic traffic loading","authors":"Y. Jia, J. Zhang, L. Tong, J.-J. Zheng, Y. Zheng","doi":"10.1680/jgein.23.00144","DOIUrl":"https://doi.org/10.1680/jgein.23.00144","url":null,"abstract":"This paper presents an experimental study on reduced scale geosynthetic reinforced soil (GRS) abutment models subjected to cyclic traffic loading, aimed at investigating the influences of cyclic load amplitude, self-weight of bridge superstructure, and reinforcement vertical spacing on the cumulative deformations. The GRS abutment models were constructed using sand backfill and geogrid reinforcement. A static load was first applied to account for the self-weight of bridge superstructure, and then the cyclic loads were applied in several phases with increasing amplitude. The results indicate that significant cumulative footing settlement under cyclic loading mainly occurs within the first few hundred loading cycles, and the settlement increases with increasing cyclic load amplitude. The cyclic load amplitude and reinforcement vertical spacing have significant impacts on the cumulative deformations of GRS abutments under cyclic loading. The maximum facing displacement under cyclic loading occurs near the top of the wall. The cyclic load has a greater impact on the reinforcement strains near the upper middle reinforcement layers, while it has a smaller impact on the lower reinforcement layers.","PeriodicalId":12616,"journal":{"name":"Geosynthetics International","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2024-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139865544","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-01DOI: 10.1680/jgein.2024.31.1.1
{"title":"Note of appreciation to paper reviewers","authors":"","doi":"10.1680/jgein.2024.31.1.1","DOIUrl":"https://doi.org/10.1680/jgein.2024.31.1.1","url":null,"abstract":"","PeriodicalId":12616,"journal":{"name":"Geosynthetics International","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140469049","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The vacuum consolidation behavior of dredged slurry improved by horizontal drainage-enhanced geotextile (HDeG) application was investigated. For comparison, vacuum consolidation tests using a prefabricated vertical drain (PVD) and layered prefabricated horizontal drains (PHDs) were conducted. Based on the test results, it was found that by using HDeG, the consolidation rate of the dredged slurry was significantly increased. Thus, the effectiveness of the HDeG method was verified. The nonwoven geotextile sheet of HDeG could provide a sufficient vacuum pressure and drainage and therefore greatly shorten the drainage path. The HDeG-induced consolidation settlement generally matched the calculated 1D consolidation settlement well using a representative coefficient of consolidation. The analysis of scanning electron microscopy images shows that after the vacuum consolidation test, the porosity of the PHD filter (vacuum PHD treatment) was only 11% (21.1% of the initial porosity), while the porosity of the PHD filter of the HDeG was 22.16% (42.6% of the initial porosity), suggesting that the geotextile effectively reduced the apparent clogging of the drains.
{"title":"Vacuum consolidation of dredged slurry improved by horizontal drainage-enhanced geotextile","authors":"J. Wang, R. Anda, H. Fu, X. Hu, X. Li, Y. Cai","doi":"10.1680/jgein.23.00087","DOIUrl":"https://doi.org/10.1680/jgein.23.00087","url":null,"abstract":"The vacuum consolidation behavior of dredged slurry improved by horizontal drainage-enhanced geotextile (HDeG) application was investigated. For comparison, vacuum consolidation tests using a prefabricated vertical drain (PVD) and layered prefabricated horizontal drains (PHDs) were conducted. Based on the test results, it was found that by using HDeG, the consolidation rate of the dredged slurry was significantly increased. Thus, the effectiveness of the HDeG method was verified. The nonwoven geotextile sheet of HDeG could provide a sufficient vacuum pressure and drainage and therefore greatly shorten the drainage path. The HDeG-induced consolidation settlement generally matched the calculated 1D consolidation settlement well using a representative coefficient of consolidation. The analysis of scanning electron microscopy images shows that after the vacuum consolidation test, the porosity of the PHD filter (vacuum PHD treatment) was only 11% (21.1% of the initial porosity), while the porosity of the PHD filter of the HDeG was 22.16% (42.6% of the initial porosity), suggesting that the geotextile effectively reduced the apparent clogging of the drains.","PeriodicalId":12616,"journal":{"name":"Geosynthetics International","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2024-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139605308","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study investigates the quasi-static bearing stress-settlement response of shallow foundations in monolithic tire derived aggregate (TDA) layers having a total thickness of 3 m using a large-scale container and loading system. Tests were performed on footings having a range of widths, embedment depths, shapes, and loading inclinations. In tests where tilting was restricted, a clear bearing capacity was not observed for settlements up to 1.2B, where B is the footing width, but in tests where tilting was permitted bearing capacity was observed between settlements of 0.2B to 0.7B. Surface settlements indicate a dragdown response of the TDA adjacent to the footing extending out to more than 3B from the footing center, while settlement plates beneath the footing indicate a zone of influence of induced settlements of 14% at a depth of 4B. While bearing capacity theories for frictional geomaterials provided a reasonable prediction of the bearing capacity of footings in TDA for most tests, the corresponding settlements may be excessive for engineering applications. Accordingly, a correlation was developed between the theoretical bearing capacity and bearing stress at a settlement of 0.1B. A test with sustained loading indicates slight creep settlements with some stress dependency with magnitudes consistent with past studies.
{"title":"Response of shallow foundations in tire derived aggregate","authors":"A. Yarahuaman, J. S. McCartney","doi":"10.1680/jgein.23.00147","DOIUrl":"https://doi.org/10.1680/jgein.23.00147","url":null,"abstract":"This study investigates the quasi-static bearing stress-settlement response of shallow foundations in monolithic tire derived aggregate (TDA) layers having a total thickness of 3 m using a large-scale container and loading system. Tests were performed on footings having a range of widths, embedment depths, shapes, and loading inclinations. In tests where tilting was restricted, a clear bearing capacity was not observed for settlements up to 1.2B, where B is the footing width, but in tests where tilting was permitted bearing capacity was observed between settlements of 0.2B to 0.7B. Surface settlements indicate a dragdown response of the TDA adjacent to the footing extending out to more than 3B from the footing center, while settlement plates beneath the footing indicate a zone of influence of induced settlements of 14% at a depth of 4B. While bearing capacity theories for frictional geomaterials provided a reasonable prediction of the bearing capacity of footings in TDA for most tests, the corresponding settlements may be excessive for engineering applications. Accordingly, a correlation was developed between the theoretical bearing capacity and bearing stress at a settlement of 0.1B. A test with sustained loading indicates slight creep settlements with some stress dependency with magnitudes consistent with past studies.","PeriodicalId":12616,"journal":{"name":"Geosynthetics International","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2024-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139605540","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Five centrifuge models of geosynthetic reinforced soil (GRS) abutments with segmental block facing were loaded in acceleration field under plane strain condition. Influences factors including reinforcement tensile strength, setback and bearing area width were considered and analysed. Results show that the abutment with stronger reinforcement remained stable under the maximum loading capacity. However, abutments with weaker reinforcement showed excessive vertical strain, local deformation or even collapse. The ultimate bearing capacity increased with the lengthening of setback while decreased due to a larger bearing area. The rupture of reinforcements was observed and considered as the cause of the failures. Comparing with the measured ultimate bearing capacity, the values calculated by the semi-empirical formula of design guideline were significantly conservative. The failure surface of failed abutment developed from rear edge of the bearing area to the middle height of the abutment at an angle of nearly 45°+φ/2. The setback and the bearing area width affected the form and position of the failure surface. The difference between the potential failure surface predicted by available methods and the measured failure surfaces has been discussed, and suggestions for the design and ultimate bearing capacity prediction of GRS abutments with segmental block facing were provided.
{"title":"Ultimate bearing capacity of geosynthetic reinforced soil abutment centrifuge model tests","authors":"C. Zhao, C. Xu, Y. Yang, Q. Wang, C. Du, G. Li","doi":"10.1680/jgein.23.00154","DOIUrl":"https://doi.org/10.1680/jgein.23.00154","url":null,"abstract":"Five centrifuge models of geosynthetic reinforced soil (GRS) abutments with segmental block facing were loaded in acceleration field under plane strain condition. Influences factors including reinforcement tensile strength, setback and bearing area width were considered and analysed. Results show that the abutment with stronger reinforcement remained stable under the maximum loading capacity. However, abutments with weaker reinforcement showed excessive vertical strain, local deformation or even collapse. The ultimate bearing capacity increased with the lengthening of setback while decreased due to a larger bearing area. The rupture of reinforcements was observed and considered as the cause of the failures. Comparing with the measured ultimate bearing capacity, the values calculated by the semi-empirical formula of design guideline were significantly conservative. The failure surface of failed abutment developed from rear edge of the bearing area to the middle height of the abutment at an angle of nearly 45°+φ/2. The setback and the bearing area width affected the form and position of the failure surface. The difference between the potential failure surface predicted by available methods and the measured failure surfaces has been discussed, and suggestions for the design and ultimate bearing capacity prediction of GRS abutments with segmental block facing were provided.","PeriodicalId":12616,"journal":{"name":"Geosynthetics International","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2024-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139604670","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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