Pub Date : 2023-02-01DOI: 10.1680/jgeen.2023.176.1.103
{"title":"Award-winning paper in 2021","authors":"","doi":"10.1680/jgeen.2023.176.1.103","DOIUrl":"https://doi.org/10.1680/jgeen.2023.176.1.103","url":null,"abstract":"","PeriodicalId":54572,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Geotechnical Engineering","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136362588","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}
Many examples of earthquake damage show that liquefied lateral spreading is the main cause of pile foundation failure. Rigid-drainage piles installed two drainage grooves with plastic drainage plates are a new type of liquefaction-resistant pile that can take into account the bearing capacity and drainage function. In this paper, a series of 1-g shaking table tests were carried out to analyse the seismic response of a rigid-drainage pile-superstructure-quay (RSQ) wall system subjected to lateral spreading. Three levels of earthquake intensities, including small earthquakes (peak ground acceleration, PGA=0.05 g), moderate earthquakes (PGA=0.1 g), and large earthquakes (PGA=0.2 g), were investigated. The improvement in the anti-liquefaction performance of the rigid-drainage piles was comparatively analysed. Moreover, the influences of far-field and near-field ground motions were also discussed. The experimental results showed that rigid-drainage piles could effectively reduce the liquefaction degree and the horizontal flow of the sand stratum. In addition, the internal force and displacement of the superstructure built on drainage piles were small. The observations of the influence of far-field and near-field ground motions indicated that the seismic response of near-field ground motion was more significant than that of far-field ground motion, but the effect of far-field ground motion could not be disregarded. The results of these tests could provide useful information for the design of rigid-drainage pile groups in a typical pile-superstructure-quay wall system.
{"title":"Seismic response of rigid-drainage pile-superstructure-quay wall system subjected to lateral spreading","authors":"Zhi-xiong Chen, Can Liu, Chenglong Wang, Xuan-chen Ding, Yu-min Chen, Wengang Zhang","doi":"10.1680/jgeen.22.00147","DOIUrl":"https://doi.org/10.1680/jgeen.22.00147","url":null,"abstract":"Many examples of earthquake damage show that liquefied lateral spreading is the main cause of pile foundation failure. Rigid-drainage piles installed two drainage grooves with plastic drainage plates are a new type of liquefaction-resistant pile that can take into account the bearing capacity and drainage function. In this paper, a series of 1-g shaking table tests were carried out to analyse the seismic response of a rigid-drainage pile-superstructure-quay (RSQ) wall system subjected to lateral spreading. Three levels of earthquake intensities, including small earthquakes (peak ground acceleration, PGA=0.05 g), moderate earthquakes (PGA=0.1 g), and large earthquakes (PGA=0.2 g), were investigated. The improvement in the anti-liquefaction performance of the rigid-drainage piles was comparatively analysed. Moreover, the influences of far-field and near-field ground motions were also discussed. The experimental results showed that rigid-drainage piles could effectively reduce the liquefaction degree and the horizontal flow of the sand stratum. In addition, the internal force and displacement of the superstructure built on drainage piles were small. The observations of the influence of far-field and near-field ground motions indicated that the seismic response of near-field ground motion was more significant than that of far-field ground motion, but the effect of far-field ground motion could not be disregarded. The results of these tests could provide useful information for the design of rigid-drainage pile groups in a typical pile-superstructure-quay wall system.","PeriodicalId":54572,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Geotechnical Engineering","volume":"15 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75844454","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}
The mechanism that can explain pile shaft resistance during vibratory driving is discussed. One hypothesis is that horizontally oscillating stresses temporarily reduce the shaft resistance. To investigate this hypothesis, vibration measurements were carried out in medium-dense to dense sand during the vibratory driving. A vibrator with variable frequency was used to install a large compaction probe. The driving process and ground response were documented in detail. Geophones were installed on and below the ground surface. Horizontal ground vibrations were measured at three levels below the ground surface. The difference in vibration response of the ground during driving at a high frequency (27 Hz) and at the system resonance frequency (15 Hz) showed the effect of the vibrator operating frequency on penetration speed and emitted ground vibrations. During vibratory driving, horizontal stress pulses are emitted along the probe shaft, which can temporarily reduce static horizontal stresses acting against the probe shaft. This phenomenon can explain the temporary reduction of the shaft resistance and the efficiency of vibratory driving in granular soils. As a result of the horizontal stress pulses, the horizontal stresses are increased permanently. By using a monitoring and process control system, it is also possible to determine the system resonance frequency in the field, which is a critical parameter for vibratory driving resistance, emission of ground vibrations, and vibratory compaction of granular soils.
{"title":"Soil resistance during vibratory driving in sand","authors":"K. Massarsch","doi":"10.1680/jgeen.22.00193","DOIUrl":"https://doi.org/10.1680/jgeen.22.00193","url":null,"abstract":"The mechanism that can explain pile shaft resistance during vibratory driving is discussed. One hypothesis is that horizontally oscillating stresses temporarily reduce the shaft resistance. To investigate this hypothesis, vibration measurements were carried out in medium-dense to dense sand during the vibratory driving. A vibrator with variable frequency was used to install a large compaction probe. The driving process and ground response were documented in detail. Geophones were installed on and below the ground surface. Horizontal ground vibrations were measured at three levels below the ground surface. The difference in vibration response of the ground during driving at a high frequency (27 Hz) and at the system resonance frequency (15 Hz) showed the effect of the vibrator operating frequency on penetration speed and emitted ground vibrations. During vibratory driving, horizontal stress pulses are emitted along the probe shaft, which can temporarily reduce static horizontal stresses acting against the probe shaft. This phenomenon can explain the temporary reduction of the shaft resistance and the efficiency of vibratory driving in granular soils. As a result of the horizontal stress pulses, the horizontal stresses are increased permanently. By using a monitoring and process control system, it is also possible to determine the system resonance frequency in the field, which is a critical parameter for vibratory driving resistance, emission of ground vibrations, and vibratory compaction of granular soils.","PeriodicalId":54572,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Geotechnical Engineering","volume":"7 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89726644","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 study is concentrated on the influence of the pile end soil on the torsional vibration of a pile based on the fictitious soil pile model considering the stress diffusion. The pile end soil is simulated as a cone-shaped fictitious soil pile whose parameters still remain the same with the soil. The dynamic equilibrium equations for the pile–soil system subjected to torsional dynamic loadings are developed and are solved to obtain the corresponding analytical solution. Then, comparisons with other solutions are conducted to verify the reliability of the proposed solution. Finally, parametric analysis results are presented based on the proposed solution to portray the influence of the stress diffusion angle, thickness and shear wave velocity of the pile end soil.
{"title":"Influence of pile end soil on the torsional vibration of a pile based on the cone-shaped fictitious soil pile model considering the stress diffusion","authors":"Tugen Feng, Zhenya Li, Jian Zhang","doi":"10.1680/jgeen.21.00058","DOIUrl":"https://doi.org/10.1680/jgeen.21.00058","url":null,"abstract":"This study is concentrated on the influence of the pile end soil on the torsional vibration of a pile based on the fictitious soil pile model considering the stress diffusion. The pile end soil is simulated as a cone-shaped fictitious soil pile whose parameters still remain the same with the soil. The dynamic equilibrium equations for the pile–soil system subjected to torsional dynamic loadings are developed and are solved to obtain the corresponding analytical solution. Then, comparisons with other solutions are conducted to verify the reliability of the proposed solution. Finally, parametric analysis results are presented based on the proposed solution to portray the influence of the stress diffusion angle, thickness and shear wave velocity of the pile end soil.","PeriodicalId":54572,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Geotechnical Engineering","volume":"9 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90978397","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 the settlement performance of immersed tunnel in Hong Kong-Zhuhai-Macau Bridge (HZMB) transportation project. The geological profile underlying the immersed tunnel was presented and the corresponding field monitoring system was introduced as well. The function of the semi-rigid element is analyzed. The observed results related to longitudinal deformation patterns during construction, e.g., long-term settlement, differential settlement, and structural behaviors are described and analyzed. The differential settlement happened in the following situations: (a) large variations of soil properties; (b) at the joint of two adjacent elements; (c) different segments of the same element. The differential settlement not only occurred in the longitudinal direction but also in the transverse direction. During the operational period, permanent settlement is strongly related to back-silting. The tide loading and the immersion of adjacent element may cause transient settlement related to the elastic deformation, however, tide loading has less influence on the permanent settlement. Highlights: • The long-term settlement behavior of immersed tunnel of Hong Kong-Zhuhai-Macao Bridge (HZMB) project is presented; • The geological condition and field observational system of immersed tunnel are presented; • The mechanism of macroscopical longitudinal settlement and microscopic differential settlement are explained; • The influencing factors led to various deformation patterns are discussed.
{"title":"Settlement characteristics of immersed tunnel of Hong Kong-Zhuhai-Macau Bridge project","authors":"Yan-ning Wang, Le-Chen Wang, Lin-shuang Zhao","doi":"10.1680/jgeen.22.00200","DOIUrl":"https://doi.org/10.1680/jgeen.22.00200","url":null,"abstract":"This paper presents the settlement performance of immersed tunnel in Hong Kong-Zhuhai-Macau Bridge (HZMB) transportation project. The geological profile underlying the immersed tunnel was presented and the corresponding field monitoring system was introduced as well. The function of the semi-rigid element is analyzed. The observed results related to longitudinal deformation patterns during construction, e.g., long-term settlement, differential settlement, and structural behaviors are described and analyzed. The differential settlement happened in the following situations: (a) large variations of soil properties; (b) at the joint of two adjacent elements; (c) different segments of the same element. The differential settlement not only occurred in the longitudinal direction but also in the transverse direction. During the operational period, permanent settlement is strongly related to back-silting. The tide loading and the immersion of adjacent element may cause transient settlement related to the elastic deformation, however, tide loading has less influence on the permanent settlement. Highlights: • The long-term settlement behavior of immersed tunnel of Hong Kong-Zhuhai-Macao Bridge (HZMB) project is presented; • The geological condition and field observational system of immersed tunnel are presented; • The mechanism of macroscopical longitudinal settlement and microscopic differential settlement are explained; • The influencing factors led to various deformation patterns are discussed.","PeriodicalId":54572,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Geotechnical Engineering","volume":"7 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74621138","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}
Fin piles are manufactured foundations which are utilized for most kinds of constructions like radar towers, transmission towers, tall chimneys, bridge piers, offshore structures, buried pipelines under water etc. Fin piles are structural elements utilized in civil engineering implementations to provide resistance against lateral loadings. The purpose of this investigation is to highlight the technique of shaft pile with fins embedded in dry sand. In this study, torsional capacities of shaft piles with fins are experimentally examined. A total number of sixty-three model experimental tests were studied on fin piles installed in dry sand. For comparison, model experimental tests were performed on conventional piles without such fins to investigate the behavior of fin piles on the torsional capacity under diverse parameters. The influence of such fins which are constructed at the top of the shaft at diversified values of width and length was investigated. The test results elucidated that; the fin efficiency of torsional capacities of fin piles ameliorates with the increase both of fin width/pile diameter ratio, (Wf/Dp) and sand relative density. The adopted fins of the shaft play a vital function in its torsional capacity. This is attributed to the section modulus of fin pile shaft is augmented at the top of the shaft due to the presence of fins which lead to a soil–pile-fins interaction. Utilization of fins at the top of the shafts are efficacious in ameliorating the torsional capacity of fin piles. In addition, augmenting the fin width will provide an appreciably higher soil resistance and a stiffer performance due to an augmentation of the passive zone of earth pressure in front of the shaft compared with conventional piles. This guides to an amelioration in the torsional capacity for fin piles.
{"title":"Performance of Fin pile subjected to torsional loads embedded in dry sand","authors":"A. Sallam","doi":"10.1680/jgeen.22.00150","DOIUrl":"https://doi.org/10.1680/jgeen.22.00150","url":null,"abstract":"Fin piles are manufactured foundations which are utilized for most kinds of constructions like radar towers, transmission towers, tall chimneys, bridge piers, offshore structures, buried pipelines under water etc. Fin piles are structural elements utilized in civil engineering implementations to provide resistance against lateral loadings. The purpose of this investigation is to highlight the technique of shaft pile with fins embedded in dry sand. In this study, torsional capacities of shaft piles with fins are experimentally examined. A total number of sixty-three model experimental tests were studied on fin piles installed in dry sand. For comparison, model experimental tests were performed on conventional piles without such fins to investigate the behavior of fin piles on the torsional capacity under diverse parameters. The influence of such fins which are constructed at the top of the shaft at diversified values of width and length was investigated. The test results elucidated that; the fin efficiency of torsional capacities of fin piles ameliorates with the increase both of fin width/pile diameter ratio, (Wf/Dp) and sand relative density. The adopted fins of the shaft play a vital function in its torsional capacity. This is attributed to the section modulus of fin pile shaft is augmented at the top of the shaft due to the presence of fins which lead to a soil–pile-fins interaction. Utilization of fins at the top of the shafts are efficacious in ameliorating the torsional capacity of fin piles. In addition, augmenting the fin width will provide an appreciably higher soil resistance and a stiffer performance due to an augmentation of the passive zone of earth pressure in front of the shaft compared with conventional piles. This guides to an amelioration in the torsional capacity for fin piles.","PeriodicalId":54572,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Geotechnical Engineering","volume":"266 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89198795","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}
A limit plasticity solution for evaluating the effective stress friction angle in clays from piezocone tests was assessed and compared with the popular notion of using laboratory Atterberg limits on remoulded specimens. The results showed that the in-situ piezocone- based method provided a far more accurate and robust interpretation of the friction angle values of 155 separate clays than empirical correlations with plasticity index when compared with laboratory benchmark values obtained from triaxial compression tests. For illustration, the piezocone-based method was shown successfully to capture the effective stress parameter of four clays with friction angles of 20−37°: normally consolidated kaolin clay in chamber tests, natural soft clay deposit located at Bothkennar UK, Troll offshore clay in the North Sea and soft plastic lacustrine deposits in Bogota, Colombia.
{"title":"Evaluating friction angles for clays: piezocone tests versus Atterberg limits","authors":"Z. Ouyang, P. Mayne","doi":"10.1680/jgeen.22.00135","DOIUrl":"https://doi.org/10.1680/jgeen.22.00135","url":null,"abstract":"A limit plasticity solution for evaluating the effective stress friction angle in clays from piezocone tests was assessed and compared with the popular notion of using laboratory Atterberg limits on remoulded specimens. The results showed that the in-situ piezocone- based method provided a far more accurate and robust interpretation of the friction angle values of 155 separate clays than empirical correlations with plasticity index when compared with laboratory benchmark values obtained from triaxial compression tests. For illustration, the piezocone-based method was shown successfully to capture the effective stress parameter of four clays with friction angles of 20−37°: normally consolidated kaolin clay in chamber tests, natural soft clay deposit located at Bothkennar UK, Troll offshore clay in the North Sea and soft plastic lacustrine deposits in Bogota, Colombia.","PeriodicalId":54572,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Geotechnical Engineering","volume":"692 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74744273","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}
In this study, a series of consolidated, undrained triaxial compression tests were conducted to investigate peat shear behaviour on samples from 1.65 m depth when subjected to different stress levels from 10.4 kPa to 40.5 kPa. At the consolidation stage, the triaxial test specifically investigated the peat isotropic compressibility at low stress levels, showing an agreement with oedometer test data available in literature. The subsequent triaxial shearing stage results show most of the test data failed to reach the tension cut-off line (q/p’ = 3), which indicated that the deviator stress may represent more of an interparticle connection than the tension of fibres and woods in peaty soils. For peat, the membrane correction effect on peat shear resistance is strain dependent; generally, small within 10% shear strain, but becomes significant above 10% shear strain. A critical state line for peat was determined based on the maximum curvature approach, where the Mohr-Coulomb model has difficulty in determining the friction angle for peat. Of the data recorded for the peat, 78% fell within the range of 30 to 60 degrees, increasing to 90.4% when ignoring points lower than 10 kPa; the previous test data for very low stress level (less than 10kPa) might not be sufficiently reliable due to limitations of conventional triaxial testing apparatus, specimen preparation and etc. In addition, organic content also plays an important role on the peat shear behaviour. In general, when the organic content exceeds 75%, the deviator stress behaves like organic soils, otherwise, the peat behaves more like a mineral soil. In peat samples with organic content higher than 75%, the direct shear box test gives higher estimates of shear strength than the triaxial shear test, but not necessarily accurate — the mechanism of direct shear acts only at the centre of a specimen, while triaxial shear can shear throughout the specimens.
{"title":"Shear behaviour of peat at different stress levels","authors":"Di Wang, Zili Li","doi":"10.1680/jgeen.22.00058","DOIUrl":"https://doi.org/10.1680/jgeen.22.00058","url":null,"abstract":"In this study, a series of consolidated, undrained triaxial compression tests were conducted to investigate peat shear behaviour on samples from 1.65 m depth when subjected to different stress levels from 10.4 kPa to 40.5 kPa. At the consolidation stage, the triaxial test specifically investigated the peat isotropic compressibility at low stress levels, showing an agreement with oedometer test data available in literature. The subsequent triaxial shearing stage results show most of the test data failed to reach the tension cut-off line (q/p’ = 3), which indicated that the deviator stress may represent more of an interparticle connection than the tension of fibres and woods in peaty soils. For peat, the membrane correction effect on peat shear resistance is strain dependent; generally, small within 10% shear strain, but becomes significant above 10% shear strain. A critical state line for peat was determined based on the maximum curvature approach, where the Mohr-Coulomb model has difficulty in determining the friction angle for peat. Of the data recorded for the peat, 78% fell within the range of 30 to 60 degrees, increasing to 90.4% when ignoring points lower than 10 kPa; the previous test data for very low stress level (less than 10kPa) might not be sufficiently reliable due to limitations of conventional triaxial testing apparatus, specimen preparation and etc. In addition, organic content also plays an important role on the peat shear behaviour. In general, when the organic content exceeds 75%, the deviator stress behaves like organic soils, otherwise, the peat behaves more like a mineral soil. In peat samples with organic content higher than 75%, the direct shear box test gives higher estimates of shear strength than the triaxial shear test, but not necessarily accurate — the mechanism of direct shear acts only at the centre of a specimen, while triaxial shear can shear throughout the specimens.","PeriodicalId":54572,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Geotechnical Engineering","volume":"27 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84767902","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}
A two-dimensional discrete element modeling is adopted to study engineering and fundamental aspects of shear band formation in reverse faulting through sandy soils with varying densities. The employed DEM modeling methodology is verified with the experimental centrifuge result. From an engineering perspective, results show that the shear bands formed due to reverse fault consist of multiple ruptures formed at the different fault raise. These ruptures may deviate toward the hanging or footing wall depending on the faulting angle. The distortion zone outcropping location is captured by the W/H ratio at the 1% normalized fault throw (h/H) step. Various micro and macro aspects of shear banding, such as porosity, coordination number, and strong contact forces within the localized areas along the shear bands, are studied. Moreover, a link is established between the micro and macro events occurring inside the shear bands. The results show that the wedge pressure formed between the shear band and back-thrust rupture in the fault with a dip angle smaller than 45° significantly affects the back-thrust formation and micro-macro parameters in the shearing region.
{"title":"Micro-macro analysis of shear band formation due to reverse fault in various normalized fault throw","authors":"Saman Ghaderi, Alireza Saeedi Azizkandi","doi":"10.1680/jgeen.22.00095","DOIUrl":"https://doi.org/10.1680/jgeen.22.00095","url":null,"abstract":"A two-dimensional discrete element modeling is adopted to study engineering and fundamental aspects of shear band formation in reverse faulting through sandy soils with varying densities. The employed DEM modeling methodology is verified with the experimental centrifuge result. From an engineering perspective, results show that the shear bands formed due to reverse fault consist of multiple ruptures formed at the different fault raise. These ruptures may deviate toward the hanging or footing wall depending on the faulting angle. The distortion zone outcropping location is captured by the W/H ratio at the 1% normalized fault throw (h/H) step. Various micro and macro aspects of shear banding, such as porosity, coordination number, and strong contact forces within the localized areas along the shear bands, are studied. Moreover, a link is established between the micro and macro events occurring inside the shear bands. The results show that the wedge pressure formed between the shear band and back-thrust rupture in the fault with a dip angle smaller than 45° significantly affects the back-thrust formation and micro-macro parameters in the shearing region.","PeriodicalId":54572,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Geotechnical Engineering","volume":"195 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2022-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83809761","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}
In this contribution observed median collapse frequencies and calculated median failure probabilities of retaining structures are compared. Such comparisons have already been carried out for bridges, dams, tunnels, buildings, stadiums, and wind turbines. The comparison is carried out as a meta-analysis using values from the literature. Furthermore, collapse frequencies due to earthquakes were determined by own calculations. The comparison of median collapse frequencies and median failure probabilities of retaining structures shows a good agreement. The ratio of the median failure probability and the median collapse frequency is in the range of other engineering structures. However, the comparison with other engineering structures shows an above-average frequency of collapses. This seemingly accepted high frequency of collapse seems to be justified by the lower number of victims and lower damage costs when retaining structures fail.
{"title":"The collapse frequency and failure probability of retaining structures","authors":"D. Proske, Christof Hofmann","doi":"10.1680/jgeen.21.00128","DOIUrl":"https://doi.org/10.1680/jgeen.21.00128","url":null,"abstract":"In this contribution observed median collapse frequencies and calculated median failure probabilities of retaining structures are compared. Such comparisons have already been carried out for bridges, dams, tunnels, buildings, stadiums, and wind turbines. The comparison is carried out as a meta-analysis using values from the literature. Furthermore, collapse frequencies due to earthquakes were determined by own calculations. The comparison of median collapse frequencies and median failure probabilities of retaining structures shows a good agreement. The ratio of the median failure probability and the median collapse frequency is in the range of other engineering structures. However, the comparison with other engineering structures shows an above-average frequency of collapses. This seemingly accepted high frequency of collapse seems to be justified by the lower number of victims and lower damage costs when retaining structures fail.","PeriodicalId":54572,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Geotechnical Engineering","volume":"36 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2022-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80945465","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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