L. Sakellariadis, E. Bleiker, M. Iten, H. Buschor, A. Kieper, R. Herzog, A. Marin, O. Adamidis, I. Anastasopoulos
Motivated by the need to develop rational design methods for the retrofit of existing bridges on pile groups, the paper introduces recent experimental developments at the ETHZ Drum centrifuge. Four setups are developed for vertical, pushover, combined, and vibration testing. Their capabilities and limitations are demonstrated using as example a 2x1 pile group on dense saturated sand. Single piles are subjected to vertical loading, exploring the role of installation effects and interface roughness. Pushover loading is employed to measure the moment capacity (Mult) of a lightly- and a heavily-loaded group. In contrast to intuitive expectations, the heavily-loaded system mobilises larger Mult. The developed combined loading apparatus is proof-tested for a shallow foundation. Combined loading under constant vertical load is conducted to derive failure envelopes, revealing significant coupling between lateral and moment loading, and confirming the expansion of the failure envelope with increasing static vertical load. The vibration testing setup is proof-tested, confirming the possibility to identify the natural frequency of the system and the small-strain stiffness of the foundation through non-destructive testing. Although the study is fuelled by our ongoing work on pile groups, the developed experimental setups are of general applicability for the study of deep and shallow foundation systems.
{"title":"Testing Pile Foundations at the ΕΤΗ Zurich Drum Centrifuge: Recent Developments","authors":"L. Sakellariadis, E. Bleiker, M. Iten, H. Buschor, A. Kieper, R. Herzog, A. Marin, O. Adamidis, I. Anastasopoulos","doi":"10.1680/jphmg.21.00067","DOIUrl":"https://doi.org/10.1680/jphmg.21.00067","url":null,"abstract":"Motivated by the need to develop rational design methods for the retrofit of existing bridges on pile groups, the paper introduces recent experimental developments at the ETHZ Drum centrifuge. Four setups are developed for vertical, pushover, combined, and vibration testing. Their capabilities and limitations are demonstrated using as example a 2x1 pile group on dense saturated sand. Single piles are subjected to vertical loading, exploring the role of installation effects and interface roughness. Pushover loading is employed to measure the moment capacity (Mult) of a lightly- and a heavily-loaded group. In contrast to intuitive expectations, the heavily-loaded system mobilises larger Mult. The developed combined loading apparatus is proof-tested for a shallow foundation. Combined loading under constant vertical load is conducted to derive failure envelopes, revealing significant coupling between lateral and moment loading, and confirming the expansion of the failure envelope with increasing static vertical load. The vibration testing setup is proof-tested, confirming the possibility to identify the natural frequency of the system and the small-strain stiffness of the foundation through non-destructive testing. Although the study is fuelled by our ongoing work on pile groups, the developed experimental setups are of general applicability for the study of deep and shallow foundation systems.","PeriodicalId":48816,"journal":{"name":"International Journal of Physical Modelling in Geotechnics","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2022-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45604501","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shafts are frequently constructed to allow access to subsurface infrastructure and the resulting excavation generally deep and narrow. Shafts may be constructed using a variety of methods and plan forms dependent on ground conditions and intended use. An axisymmetric (cylindrical) geometry is often preferred due to the relatively simple structural analysis, construction method and for a number of approaches that are available to estimate the ground movements around such an excavation. In certain cases, particularly when there is restricted space both above and below surface, non-circular shafts could be a preferred solution. The assessment of surface movements around non-circular shafts is difficult as little information exists and there are few empirical prediction methods available. In this study, a series of centrifuge tests have been conducted to investigate the effects of modifying the cross-sectional profile of a shaft (i.e. circular in plan compared with elliptical). Analysis of measurements obtained from centrifuge tests undertaken at City, University of London's geotechnical centrifuge facility are presented and compared with existing predictive methods. An addendum to the empirical equations and procedures for predicting surface settlements arising from circular shafts is presented to allow for the assessment of movements around elliptical shafts in clay.
{"title":"Surface settlements arising from elliptical shaft excavation in clay","authors":"R. Goodey, S. Divall, B. Le","doi":"10.1680/jphmg.21.00080","DOIUrl":"https://doi.org/10.1680/jphmg.21.00080","url":null,"abstract":"Shafts are frequently constructed to allow access to subsurface infrastructure and the resulting excavation generally deep and narrow. Shafts may be constructed using a variety of methods and plan forms dependent on ground conditions and intended use. An axisymmetric (cylindrical) geometry is often preferred due to the relatively simple structural analysis, construction method and for a number of approaches that are available to estimate the ground movements around such an excavation. In certain cases, particularly when there is restricted space both above and below surface, non-circular shafts could be a preferred solution. The assessment of surface movements around non-circular shafts is difficult as little information exists and there are few empirical prediction methods available. In this study, a series of centrifuge tests have been conducted to investigate the effects of modifying the cross-sectional profile of a shaft (i.e. circular in plan compared with elliptical). Analysis of measurements obtained from centrifuge tests undertaken at City, University of London's geotechnical centrifuge facility are presented and compared with existing predictive methods. An addendum to the empirical equations and procedures for predicting surface settlements arising from circular shafts is presented to allow for the assessment of movements around elliptical shafts in clay.","PeriodicalId":48816,"journal":{"name":"International Journal of Physical Modelling in Geotechnics","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2022-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44182457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper has studied the failure mechanism of geocell reinforced vertical anchors in sand through a series of tests and numerical analyses. It is observed that the anchor load carrying capacity significantly increases with the application of geocell reinforcement, which is primary associated with the rupture behaviour of reinforced anchor beds. The rupture surfaces are found to have originated from bottom edge of the geocell mattress and propagated to the soil surface in a curvilinear shape. The size of rupture surface tends to increase with increase in length, width and height of geocell mattress leading to increased load carrying capacity of the system. However, beyond certain length, width, and height of geocell mattress, further increase in size of the rupture surfaces was marginal. Geocells of relatively smaller pocket size (i.e., close to anchor size) can effectively confine the soil leading to a coherent structure that inhibits potential rupture close to the anchors. But with geocells of wider pocket openings enable the formation of rupture within the geocell mattress. Hence, it is concluded that the load carrying capacity of reinforced anchors which is dependent on the size of the rupture surface is influenced by the geometry of the geocell mattress.
{"title":"Failure Mechanism of Geocell Reinforced Vertical Plate Anchor Subjected to Lateral Loading","authors":"A. K. Choudhary, S. Dash","doi":"10.1680/jphmg.21.00009","DOIUrl":"https://doi.org/10.1680/jphmg.21.00009","url":null,"abstract":"This paper has studied the failure mechanism of geocell reinforced vertical anchors in sand through a series of tests and numerical analyses. It is observed that the anchor load carrying capacity significantly increases with the application of geocell reinforcement, which is primary associated with the rupture behaviour of reinforced anchor beds. The rupture surfaces are found to have originated from bottom edge of the geocell mattress and propagated to the soil surface in a curvilinear shape. The size of rupture surface tends to increase with increase in length, width and height of geocell mattress leading to increased load carrying capacity of the system. However, beyond certain length, width, and height of geocell mattress, further increase in size of the rupture surfaces was marginal. Geocells of relatively smaller pocket size (i.e., close to anchor size) can effectively confine the soil leading to a coherent structure that inhibits potential rupture close to the anchors. But with geocells of wider pocket openings enable the formation of rupture within the geocell mattress. Hence, it is concluded that the load carrying capacity of reinforced anchors which is dependent on the size of the rupture surface is influenced by the geometry of the geocell mattress.","PeriodicalId":48816,"journal":{"name":"International Journal of Physical Modelling in Geotechnics","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2022-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43047014","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Cemented paste backfill (CPB) is fine-grained soil undergoing cementation. It is widely used in underground mining operations for ground support and mine waste (tailings) disposal. In the field, CPB may be placed in one layer (continuous filing), or multiple layers (discontinuous or sequential filling). Till today, no studies have addressed the effect of the different filling strategies on the response of CPB during cyclic events by using the shaking table technique. This manuscript presents new findings of investigating the effect of the different filling strategies of CPB on its geotechnical response to dynamic loading. CPB samples were prepared with different scenarios, including one Layered-CPB (discontinuous filling) sample at which each layer was cured to different curing time, and two unlayered-CPB (continuous filling) that were cured to 2.5 hrs and 4.0 hrs, respectively. All samples were exposed to same cyclic loading conditions using 1-D Shaking table. Geotechnical parameters or characteristics, including pore-water pressure, settlement, volumetric water content and liquefaction susceptibility were monitored or determined before, during, and after shaking. Obtained results indicate that Layered-CPB samples are resistant to liquefaction under the studied loading conditions, while the unlayered-CPB samples are prone to liquefaction under the studied conditions when they are cured to less than 4.0 hrs of curing time.
{"title":"Pore water pressure and liquefaction response of layered fine soils undergoing cementation","authors":"Imad Alainachi, M. Fall","doi":"10.1680/jphmg.21.00019","DOIUrl":"https://doi.org/10.1680/jphmg.21.00019","url":null,"abstract":"Cemented paste backfill (CPB) is fine-grained soil undergoing cementation. It is widely used in underground mining operations for ground support and mine waste (tailings) disposal. In the field, CPB may be placed in one layer (continuous filing), or multiple layers (discontinuous or sequential filling). Till today, no studies have addressed the effect of the different filling strategies on the response of CPB during cyclic events by using the shaking table technique. This manuscript presents new findings of investigating the effect of the different filling strategies of CPB on its geotechnical response to dynamic loading. CPB samples were prepared with different scenarios, including one Layered-CPB (discontinuous filling) sample at which each layer was cured to different curing time, and two unlayered-CPB (continuous filling) that were cured to 2.5 hrs and 4.0 hrs, respectively. All samples were exposed to same cyclic loading conditions using 1-D Shaking table. Geotechnical parameters or characteristics, including pore-water pressure, settlement, volumetric water content and liquefaction susceptibility were monitored or determined before, during, and after shaking. Obtained results indicate that Layered-CPB samples are resistant to liquefaction under the studied loading conditions, while the unlayered-CPB samples are prone to liquefaction under the studied conditions when they are cured to less than 4.0 hrs of curing time.","PeriodicalId":48816,"journal":{"name":"International Journal of Physical Modelling in Geotechnics","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2022-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44085842","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Cone penetrometer test is widely used for in-situ site investigations and for establishing direct penetrometer to foundation or anchor design correlations. This paper focuses on the soil flow mechanisms during the continuous penetration of a cone penetrometer in layered clays. A series of centrifuge tests was conducted with the cone penetrating through soft-stiff, stiff-soft, soft-stiff-soft, and stiff-soft-stiff clay profiles. Particle image velocimetry allowed accurate resolution of the soil flow mechanism around the cone where a half cone model was penetrated into layered clays against a transparent window. The observed soil movement was compared with both previous observations for pile/cone, and with movement from shallow strain path method (SSPM). The comparison with SSPM results showed that SSPM can provide reasonable evaluations on maximum lateral and vertical displacements even though the upheave movement can be overestimated. The effect of soil layering on the failure mechanisms was studied extensively by exploring soil flow mechanisms and soil displacement paths at various distances from the advancing cone centreline and soil layer interface. The reported characteristics of cone penetration in layered soils provided in-depth understanding of cone penetration responses that will lead to the development of mechanism-based theoretical model for cone penetration in layered fine-grained soils.
{"title":"Soil Flow Mechanisms around Cone Penetrometer in Layered Clay – PIV Analysis in Centrifuge","authors":"Yue Wang, M. S. Hossain, Yuxia Hu","doi":"10.1680/jphmg.21.00042","DOIUrl":"https://doi.org/10.1680/jphmg.21.00042","url":null,"abstract":"Cone penetrometer test is widely used for in-situ site investigations and for establishing direct penetrometer to foundation or anchor design correlations. This paper focuses on the soil flow mechanisms during the continuous penetration of a cone penetrometer in layered clays. A series of centrifuge tests was conducted with the cone penetrating through soft-stiff, stiff-soft, soft-stiff-soft, and stiff-soft-stiff clay profiles. Particle image velocimetry allowed accurate resolution of the soil flow mechanism around the cone where a half cone model was penetrated into layered clays against a transparent window. The observed soil movement was compared with both previous observations for pile/cone, and with movement from shallow strain path method (SSPM). The comparison with SSPM results showed that SSPM can provide reasonable evaluations on maximum lateral and vertical displacements even though the upheave movement can be overestimated. The effect of soil layering on the failure mechanisms was studied extensively by exploring soil flow mechanisms and soil displacement paths at various distances from the advancing cone centreline and soil layer interface. The reported characteristics of cone penetration in layered soils provided in-depth understanding of cone penetration responses that will lead to the development of mechanism-based theoretical model for cone penetration in layered fine-grained soils.","PeriodicalId":48816,"journal":{"name":"International Journal of Physical Modelling in Geotechnics","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2022-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47312524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
During previous earthquakes, displacements of shallow foundations on liquefiable sites caused significant damage to overlying super-structures leading to casualties and catastrophic economic loss. Various countermeasures have been developed to minimize liquefaction-related damages while minimizing cost and environmental impact. This study aims to evaluate the use of helical piles as a possible technique to mitigate the settlement, tilting, and sliding of shallow foundations on the liquefiable ground in seismic conditions. For this purpose, twelve 1g shaking table tests were conducted on uniform loose saturated Babolsar sand subjected to harmonic base input motion for (1) free-field condition, (2) a model foundation on the soil surface, and (3) a model foundation underpinned by helical piles. The effects of input motion amplitudes and the number of helical piles were investigated in terms of acceleration response, excess pore water pressure (EPWP), and foundation displacements. The results confirmed the satisfactory performance of helical piles in reducing shallow foundation displacements. In particular, the mean permanent settlements were reduced by 45% and 75% when using four and eight helical piles, respectively. Similar trends were observed for the shallow foundation permanent tilting and sliding; permanent tilting was reduced by 30% and 59% when using four and eight helical piles, respectively, while these results were 45% and 68% for the sliding.
{"title":"Mitigating Liquefaction-Induced Displacements of Shallow Foundation using Helical Piles","authors":"P. Esmaeilpour, Y. Jafarian, A. Cerato","doi":"10.1680/jphmg.21.00039","DOIUrl":"https://doi.org/10.1680/jphmg.21.00039","url":null,"abstract":"During previous earthquakes, displacements of shallow foundations on liquefiable sites caused significant damage to overlying super-structures leading to casualties and catastrophic economic loss. Various countermeasures have been developed to minimize liquefaction-related damages while minimizing cost and environmental impact. This study aims to evaluate the use of helical piles as a possible technique to mitigate the settlement, tilting, and sliding of shallow foundations on the liquefiable ground in seismic conditions. For this purpose, twelve 1g shaking table tests were conducted on uniform loose saturated Babolsar sand subjected to harmonic base input motion for (1) free-field condition, (2) a model foundation on the soil surface, and (3) a model foundation underpinned by helical piles. The effects of input motion amplitudes and the number of helical piles were investigated in terms of acceleration response, excess pore water pressure (EPWP), and foundation displacements. The results confirmed the satisfactory performance of helical piles in reducing shallow foundation displacements. In particular, the mean permanent settlements were reduced by 45% and 75% when using four and eight helical piles, respectively. Similar trends were observed for the shallow foundation permanent tilting and sliding; permanent tilting was reduced by 30% and 59% when using four and eight helical piles, respectively, while these results were 45% and 68% for the sliding.","PeriodicalId":48816,"journal":{"name":"International Journal of Physical Modelling in Geotechnics","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2022-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42754865","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Debris flow, landslides and material run-outs have significant environmental and economic consequences for numerous industries. High quality experimental data with controlled boundary conditions can help validate and calibrate the predictive capabilities of mechanistic and semi-empirical numerical models. A novel centrifuge container to model dewatering and run-outs induced by a rapid loss of confinement is presented. The design features a pair of vertical doors opened in-flight to simulate failure of the containing structure. Illustrative centrifuge results investigating the run-out characteristics of a fully saturated, densely deposited class-F fly ash are presented. Modified soil moisture probes to monitor the distributions and time-varying fly ash water content throughout the testing are explored. Further, successful use of depth sensing cameras to reconstruct progressive deformations of the material front at various time scales is demonstrated. Combined water content, pore pressure and deformation measurements provides insight into the material behaviour during the run-out, revealing two-time scales at which the deformations occur. However, discrepancies between water contents inferred from the dielectric measurements and electrical conductivities highlights the need for independent verification of the bulk material water content when using the modified probes. Overall, the potential of these innovative instrumentation techniques to complement traditional geotechnical instrumentation is shown.
{"title":"Design and Instrumentation of a Novel Centrifuge Container for Fly Ash Run-out Experiments","authors":"S. Madabhushi, A. Martínez, D. Wilson, B. Kutter","doi":"10.1680/jphmg.21.00044","DOIUrl":"https://doi.org/10.1680/jphmg.21.00044","url":null,"abstract":"Debris flow, landslides and material run-outs have significant environmental and economic consequences for numerous industries. High quality experimental data with controlled boundary conditions can help validate and calibrate the predictive capabilities of mechanistic and semi-empirical numerical models. A novel centrifuge container to model dewatering and run-outs induced by a rapid loss of confinement is presented. The design features a pair of vertical doors opened in-flight to simulate failure of the containing structure. Illustrative centrifuge results investigating the run-out characteristics of a fully saturated, densely deposited class-F fly ash are presented. Modified soil moisture probes to monitor the distributions and time-varying fly ash water content throughout the testing are explored. Further, successful use of depth sensing cameras to reconstruct progressive deformations of the material front at various time scales is demonstrated. Combined water content, pore pressure and deformation measurements provides insight into the material behaviour during the run-out, revealing two-time scales at which the deformations occur. However, discrepancies between water contents inferred from the dielectric measurements and electrical conductivities highlights the need for independent verification of the bulk material water content when using the modified probes. Overall, the potential of these innovative instrumentation techniques to complement traditional geotechnical instrumentation is shown.","PeriodicalId":48816,"journal":{"name":"International Journal of Physical Modelling in Geotechnics","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2022-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43315537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper presents experimental data associated with the reactions on the spudcan during the reinstallation of a jack-up foundation near a footprint with and without infilling. All experiments mentioned in this paper were conducted in a 1-g model spudcan testing facility. Loose Ottawa sand was used as the seabed and infilling material, and the diameter D of the conical model spudcan was 200 mm. Based on the experimental data, it was found that, with the infilling of the footprint crater, a flat bearing surface was generated on the seabed, therefore the hazardous stamp-on-void situation was prevented. This was the major contribution of the infilling method. At the small reinstallation depth of 0.05D, between the small offsets 0 and 0.25D, the stamp-on-void condition was eliminated by infilling, and the infilling effect was especially significant. At the large offset 2.0D, since the reinstallation was conducted far from the influence of the first penetration and the footprint crater, therefore the infilling effect nearly vanished. The effect of infilling decreased with increasing reinstallation depth and increasing offset distance.
{"title":"Reduction of footprint problems on spudcan in sand with infilling method","authors":"Yu Fang, Ying-Chu Shih, Cheng Liu, Jyun-Yi Hsieh","doi":"10.1680/jphmg.21.00066","DOIUrl":"https://doi.org/10.1680/jphmg.21.00066","url":null,"abstract":"This paper presents experimental data associated with the reactions on the spudcan during the reinstallation of a jack-up foundation near a footprint with and without infilling. All experiments mentioned in this paper were conducted in a 1-g model spudcan testing facility. Loose Ottawa sand was used as the seabed and infilling material, and the diameter D of the conical model spudcan was 200 mm. Based on the experimental data, it was found that, with the infilling of the footprint crater, a flat bearing surface was generated on the seabed, therefore the hazardous stamp-on-void situation was prevented. This was the major contribution of the infilling method. At the small reinstallation depth of 0.05D, between the small offsets 0 and 0.25D, the stamp-on-void condition was eliminated by infilling, and the infilling effect was especially significant. At the large offset 2.0D, since the reinstallation was conducted far from the influence of the first penetration and the footprint crater, therefore the infilling effect nearly vanished. The effect of infilling decreased with increasing reinstallation depth and increasing offset distance.","PeriodicalId":48816,"journal":{"name":"International Journal of Physical Modelling in Geotechnics","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2022-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48631359","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-01DOI: 10.1680/jphmg.2022.22.3.111
Conleth D. O'Loughlin
{"title":"Editorial","authors":"Conleth D. O'Loughlin","doi":"10.1680/jphmg.2022.22.3.111","DOIUrl":"https://doi.org/10.1680/jphmg.2022.22.3.111","url":null,"abstract":"","PeriodicalId":48816,"journal":{"name":"International Journal of Physical Modelling in Geotechnics","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2022-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42737511","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ultra-Thin Continuously Reinforced Concrete Pavements (UTCRCP) is an innovative pavement type that consists of a 50 mm High Strength Steel Fibre Reinforced Concrete (HS-SFRC) layer overlain on a pavement substructure. The thickness results in a flexural stiffness significantly smaller than for conventional concrete pavements. In this paper, the conceptual understanding of the response of UTCRCP to traffic loading was investigated using centrifuge modelling. Simplified pavement models were subjected to a bidirectional moving axle load. The results indicated that axle loading, and not single wheel loading, should be used to investigate the response of UTCRCP as there is significant interaction in substructure deformation caused by the wheels on the ends of an axle. Due to the flexural toughness of the highly reinforced concrete layer, a gap forms between the ultra-thin HS-SFCR overlay and its substructure. Brittle, cemented bases between the HS-SFRC overlay and subgrade should be used with caution, as the flexible nature of the layers above and below the stabilized layer may result in rapid degeneration of the brittle layer.
{"title":"Centrifuge modelling of ultra-thin High Strength Steel Fibre Reinforced Concrete Pavements","authors":"M. S. Smit, E. Kearsley","doi":"10.1680/jphmg.21.00011","DOIUrl":"https://doi.org/10.1680/jphmg.21.00011","url":null,"abstract":"Ultra-Thin Continuously Reinforced Concrete Pavements (UTCRCP) is an innovative pavement type that consists of a 50 mm High Strength Steel Fibre Reinforced Concrete (HS-SFRC) layer overlain on a pavement substructure. The thickness results in a flexural stiffness significantly smaller than for conventional concrete pavements. In this paper, the conceptual understanding of the response of UTCRCP to traffic loading was investigated using centrifuge modelling. Simplified pavement models were subjected to a bidirectional moving axle load. The results indicated that axle loading, and not single wheel loading, should be used to investigate the response of UTCRCP as there is significant interaction in substructure deformation caused by the wheels on the ends of an axle. Due to the flexural toughness of the highly reinforced concrete layer, a gap forms between the ultra-thin HS-SFCR overlay and its substructure. Brittle, cemented bases between the HS-SFRC overlay and subgrade should be used with caution, as the flexible nature of the layers above and below the stabilized layer may result in rapid degeneration of the brittle layer.","PeriodicalId":48816,"journal":{"name":"International Journal of Physical Modelling in Geotechnics","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2022-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45391981","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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