Caisson foundations are typically adopted for critical facilities, such as long-span bridges and viaducts, which are designed against intense and combined loading. Seismic-induced waves propagating within the soil deposit add a detrimental contribution, which reduces the bearing capacity of the soil-foundation system: this phenomenon, known as “kinematic effects”, is typically not considered in the standard design of caisson foundations. In this paper, pseudo-static IDs of caisson foundations are obtained through effective-stress Finite Element pushover analyses for different embedment ratios and initial loading factors and then validated against numerical and experimental results available in the literature. In the analyses, the hypothesis of a constant and uniform seismic coefficient kh is made: nonetheless, the assumption of a non-uniform distribution of the horizontal seismic coefficient is also considered via independent FE Limit Analysis. An analytical interpretation of the obtained IDs is finally provided, which may be successfully used for a preliminary design under seismic actions.
{"title":"Pseudo-static interaction domains for caisson foundations","authors":"Domenico Gaudio, Cristian Passeri, Sebastiano Rampello","doi":"10.1016/j.soildyn.2025.109242","DOIUrl":"10.1016/j.soildyn.2025.109242","url":null,"abstract":"<div><div>Caisson foundations are typically adopted for critical facilities, such as long-span bridges and viaducts, which are designed against intense and combined loading. Seismic-induced waves propagating within the soil deposit add a detrimental contribution, which reduces the bearing capacity of the soil-foundation system: this phenomenon, known as “<em>kinematic effects”</em>, is typically not considered in the standard design of caisson foundations. In this paper, pseudo-static IDs of caisson foundations are obtained through effective-stress Finite Element pushover analyses for different embedment ratios and initial loading factors and then validated against numerical and experimental results available in the literature. In the analyses, the hypothesis of a constant and uniform seismic coefficient <em>k</em><sub>h</sub> is made: nonetheless, the assumption of a non-uniform distribution of the horizontal seismic coefficient is also considered via independent FE Limit Analysis. An analytical interpretation of the obtained IDs is finally provided, which may be successfully used for a preliminary design under seismic actions.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"191 ","pages":"Article 109242"},"PeriodicalIF":4.2,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143095198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-22DOI: 10.1016/j.soildyn.2025.109228
Wei Guo , Yongkang He , Yao Hu , Zian Xu
The seismic analysis of Chinese high-speed railway bridge-track system (i.e., CRTS II ballastless track structure) is crucial for assessing vehicle operational safety and facilitating the seismic design of bridge bearings and piers. Currently, the design code utilizes bridge models for seismic design but neglects the influence of the track structure situated above the bridge, thereby overlooking the vulnerability of components in the track structure. Developing full models of bridge-track systems would significantly increase computational intensity and time costs, especially for assessing the seismic performance of high-speed railway bridge lines. To tackle this issue, this paper introduces a transfer learning-enhanced neural network to rapidly predict the seismic responses of bridge-track systems with limited labeled data. Pairs of bridge models, one with and one without the presence of track structure, are developed to establish the relationship of seismic responses between bridge-only and bridge-track system models. The seismic responses derived from bridge models are utilized as input, while seismic responses from bridge-track system models serve as output for training gated recurrent unit neural networks. Transfer learning techniques, based on Maximum Mean Discrepancy (MMD), are employed to facilitate feature transfer between various high-speed railway bridge-track systems with varying spans, pier heights, and different types of bearings. The application of transfer learning significantly decreases data acquisition costs while improving the predictive accuracy of neural networks. Analysis results indicate that the proposed framework displays strong generalizability across new models and is both computationally efficient and effective in predicting the seismic responses of high-speed railway bridge-track systems. This method provides an alternative for rapidly evaluating the seismic performance of high-speed railway bridge lines.
{"title":"Transfer learning-enhanced neural networks for seismic response prediction of high-speed railway simply supported bridges","authors":"Wei Guo , Yongkang He , Yao Hu , Zian Xu","doi":"10.1016/j.soildyn.2025.109228","DOIUrl":"10.1016/j.soildyn.2025.109228","url":null,"abstract":"<div><div>The seismic analysis of Chinese high-speed railway bridge-track system (i.e., CRTS II ballastless track structure) is crucial for assessing vehicle operational safety and facilitating the seismic design of bridge bearings and piers. Currently, the design code utilizes bridge models for seismic design but neglects the influence of the track structure situated above the bridge, thereby overlooking the vulnerability of components in the track structure. Developing full models of bridge-track systems would significantly increase computational intensity and time costs, especially for assessing the seismic performance of high-speed railway bridge lines. To tackle this issue, this paper introduces a transfer learning-enhanced neural network to rapidly predict the seismic responses of bridge-track systems with limited labeled data. Pairs of bridge models, one with and one without the presence of track structure, are developed to establish the relationship of seismic responses between bridge-only and bridge-track system models. The seismic responses derived from bridge models are utilized as input, while seismic responses from bridge-track system models serve as output for training gated recurrent unit neural networks. Transfer learning techniques, based on Maximum Mean Discrepancy (MMD), are employed to facilitate feature transfer between various high-speed railway bridge-track systems with varying spans, pier heights, and different types of bearings. The application of transfer learning significantly decreases data acquisition costs while improving the predictive accuracy of neural networks. Analysis results indicate that the proposed framework displays strong generalizability across new models and is both computationally efficient and effective in predicting the seismic responses of high-speed railway bridge-track systems. This method provides an alternative for rapidly evaluating the seismic performance of high-speed railway bridge lines.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"191 ","pages":"Article 109228"},"PeriodicalIF":4.2,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143095191","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-22DOI: 10.1016/j.soildyn.2025.109219
Jun Kurima , Bodhinanda Chandra , Kenichi Soga
This study focuses on solving the numerical challenges of imposing absorbing boundary conditions for dynamic simulations in the material point method (MPM). To attenuate elastic waves leaving the computational domain, the current work integrates the Perfectly Matched Layer (PML) theory into the implicit MPM framework. The proposed approach introduces absorbing particles surrounding the computational domain that efficiently absorb outgoing waves and reduce reflections, allowing for accurate modeling of wave propagation and its further impact on geotechnical slope stability analysis. The study also includes several benchmark tests to validate the effectiveness of the proposed method, such as several types of impulse loading and symmetric and asymmetric base shaking. The conducted numerical tests also demonstrate the ability to handle large deformation problems, including the failure of elasto-plastic soils under gravity and dynamic excitations. The findings extend the capability of MPM in simulating continuous analysis of earthquake-induced landslides, from shaking to failure.
{"title":"Absorbing boundary conditions in material point method adopting perfectly matched layer theory","authors":"Jun Kurima , Bodhinanda Chandra , Kenichi Soga","doi":"10.1016/j.soildyn.2025.109219","DOIUrl":"10.1016/j.soildyn.2025.109219","url":null,"abstract":"<div><div>This study focuses on solving the numerical challenges of imposing absorbing boundary conditions for dynamic simulations in the material point method (MPM). To attenuate elastic waves leaving the computational domain, the current work integrates the Perfectly Matched Layer (PML) theory into the implicit MPM framework. The proposed approach introduces absorbing particles surrounding the computational domain that efficiently absorb outgoing waves and reduce reflections, allowing for accurate modeling of wave propagation and its further impact on geotechnical slope stability analysis. The study also includes several benchmark tests to validate the effectiveness of the proposed method, such as several types of impulse loading and symmetric and asymmetric base shaking. The conducted numerical tests also demonstrate the ability to handle large deformation problems, including the failure of elasto-plastic soils under gravity and dynamic excitations. The findings extend the capability of MPM in simulating continuous analysis of earthquake-induced landslides, from shaking to failure.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"191 ","pages":"Article 109219"},"PeriodicalIF":4.2,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143094833","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
(Real-time) Hybrid simulation with model updating (HSMU/RTHSMU) can correct the numerical substructure in an online manner based on the measured information of corresponding physical substructure, which enables more economical and efficient seismic performance assessment of structures. Unscented Kalman Filter (UKF) is the widely used model updating method in HSMU/RTHSMU so far, but its performance is often affected by its parameters and currently there exists no general guidance. This study proposes an adaptive calibration method for the UKF parameters in RTHSMU/HSMU. Two objective functions are constructed according to the loading characteristics of the physical substructure, and Kriging is used to approximate the response surface of corresponding objective function. Efficient Global Optimization and optimal Latin hypercube design are integrated to estimate the optimal parameters to minimize objective function. A two-story steel moment resisting frame with self-centering viscous dampers is selected as prototype structure, and two series of experimental evaluations are conducted to verify the efficacy of proposed method. Independent of whether PS is non-reloadable or reloadable, the results demonstrate that the proposed method facilitates cost-effective calibration of initial UKF parameters within RTHSMU. The calibrated UKF parameters significantly reduce errors associated with parametric and model uncertainties and exhibit robustness across various ground motions, thereby supporting optimal model updating in both HS and RTHS applications.
{"title":"Adaptive parameter calibration of UKF towards optimal model updating in real-time hybrid simulation","authors":"Weipeng Zhong , Changle Peng , Zaixian Chen , Cheng Chen , Weijie Xu","doi":"10.1016/j.soildyn.2025.109239","DOIUrl":"10.1016/j.soildyn.2025.109239","url":null,"abstract":"<div><div>(Real-time) Hybrid simulation with model updating (HSMU/RTHSMU) can correct the numerical substructure in an online manner based on the measured information of corresponding physical substructure, which enables more economical and efficient seismic performance assessment of structures. Unscented Kalman Filter (UKF) is the widely used model updating method in HSMU/RTHSMU so far, but its performance is often affected by its parameters and currently there exists no general guidance. This study proposes an adaptive calibration method for the UKF parameters in RTHSMU/HSMU. Two objective functions are constructed according to the loading characteristics of the physical substructure, and Kriging is used to approximate the response surface of corresponding objective function. Efficient Global Optimization and optimal Latin hypercube design are integrated to estimate the optimal parameters to minimize objective function. A two-story steel moment resisting frame with self-centering viscous dampers is selected as prototype structure, and two series of experimental evaluations are conducted to verify the efficacy of proposed method. Independent of whether PS is non-reloadable or reloadable, the results demonstrate that the proposed method facilitates cost-effective calibration of initial UKF parameters within RTHSMU. The calibrated UKF parameters significantly reduce errors associated with parametric and model uncertainties and exhibit robustness across various ground motions, thereby supporting optimal model updating in both HS and RTHS applications.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"191 ","pages":"Article 109239"},"PeriodicalIF":4.2,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143095193","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 : 2025-01-22DOI: 10.1016/j.soildyn.2025.109245
Zhiqiang Wang , Jiyan Zhang , Hongya Qu , Wenhao Li
In this study, quasi-static test and numerical simulation of five 1/3-scale precast segmental bridge column specimens are conducted. The five specimens are of the same design details in terms of outer dimension, while different cross-sectional types, number of segments, connection reinforcement types, and energy dissipation strategy are compared in terms of seismic performance. Based on the experimental results, hollow section exhibits similar seismic performance to the solid cross-section bridge column, and specimens with prestressed tendons have shown lower energy dissipation capacity, while energy dissipation tubes are effective in improving the capacity. Joint interfaces within the plastic hinge region are of greater influence of the structural integrity. A new finite element model is proposed, and maximum deviation from test results are less than 6 % in terms of stiffness and peak strength. This demonstrates that the Parallel material for rebar modeling and ZeroLength element for joint interface (including bond-slip behavior of rebar) simulation are both effective. Based on the parametric study, the recommended factors of the material elements are proposed for optimal numerical modeling accuracy.
{"title":"Seismic performance of precast segmental square hollow columns with different design details: Experimental and numerical study","authors":"Zhiqiang Wang , Jiyan Zhang , Hongya Qu , Wenhao Li","doi":"10.1016/j.soildyn.2025.109245","DOIUrl":"10.1016/j.soildyn.2025.109245","url":null,"abstract":"<div><div>In this study, quasi-static test and numerical simulation of five 1/3-scale precast segmental bridge column specimens are conducted. The five specimens are of the same design details in terms of outer dimension, while different cross-sectional types, number of segments, connection reinforcement types, and energy dissipation strategy are compared in terms of seismic performance. Based on the experimental results, hollow section exhibits similar seismic performance to the solid cross-section bridge column, and specimens with prestressed tendons have shown lower energy dissipation capacity, while energy dissipation tubes are effective in improving the capacity. Joint interfaces within the plastic hinge region are of greater influence of the structural integrity. A new finite element model is proposed, and maximum deviation from test results are less than 6 % in terms of stiffness and peak strength. This demonstrates that the Parallel material for rebar modeling and ZeroLength element for joint interface (including bond-slip behavior of rebar) simulation are both effective. Based on the parametric study, the recommended factors of the material elements are proposed for optimal numerical modeling accuracy.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"191 ","pages":"Article 109245"},"PeriodicalIF":4.2,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143094777","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 : 2025-01-22DOI: 10.1016/j.soildyn.2025.109238
Narsiram Gurjar, Dhiman Basu
The routine practice of seismic design and performance assessment employs three translational components of ground motion, but their spatial variability is rarely considered. A comprehensive framework that integrates the conditional simulation of multicomponent (three translational and three rotational) spatially varying ground motion field (accounting for the site-specific epistemic uncertainties) with the seismic performance assessment of a structure is not yet explored in the prior art. Along the same line, this paper is aimed to develop such a comprehensive framework and demonstrating its application to a medium-span reinforced concrete highway bridge. This is to offer dual objectives: i) understanding the influence of Spatially varying ground motion (SVGM) field on different engineering demand parameters (EDPs); and ii) influence of multicomponent excitation on the EDPs. Two types of bridges, namely, one simply supported and one 4-span continuous, are considered for this purpose. Probabilistic seismic hazard assessment (PSHA) employing the logic tree approach is carried out for selection and scaling of translational ground motion components. Conditional simulation of SVGM field for translational components is carried out using an evolutionary power spectral density-based framework accounting for the coherency and site-specific effects. Subsequently, the rotational components at each station are extracted using a single-station procedure. Nonlinear time history analysis of the bridge is carried out while considering various combinations of translational and rotational components of ground motion, and the results from SVGM field are compared with that computed using spatially uniform ground motion (SUGM). Overall, the nature and extent of influence contributed from the consideration of multicomponent SVGM field is contingent to the EDPs of interest as well as the structural configuration. The demand for a given EDP when subjected to SVGM field may either be amplified or deamplified depending on the structural configuration.
{"title":"A framework to integrate conditional simulation of multicomponent spatially varying ground motion field with seismic performance assessment and its application to medium-span bridges","authors":"Narsiram Gurjar, Dhiman Basu","doi":"10.1016/j.soildyn.2025.109238","DOIUrl":"10.1016/j.soildyn.2025.109238","url":null,"abstract":"<div><div>The routine practice of seismic design and performance assessment employs three translational components of ground motion, but their spatial variability is rarely considered. A comprehensive framework that integrates the conditional simulation of multicomponent (three translational and three rotational) spatially varying ground motion field (accounting for the site-specific epistemic uncertainties) with the seismic performance assessment of a structure is not yet explored in the prior art. Along the same line, this paper is aimed to develop such a comprehensive framework and demonstrating its application to a medium-span reinforced concrete highway bridge. This is to offer dual objectives: i) understanding the influence of Spatially varying ground motion (SVGM) field on different engineering demand parameters (EDPs); and ii) influence of multicomponent excitation on the EDPs. Two types of bridges, namely, one simply supported and one 4-span continuous, are considered for this purpose. Probabilistic seismic hazard assessment (PSHA) employing the logic tree approach is carried out for selection and scaling of translational ground motion components. Conditional simulation of SVGM field for translational components is carried out using an evolutionary power spectral density-based framework accounting for the coherency and site-specific effects. Subsequently, the rotational components at each station are extracted using a single-station procedure. Nonlinear time history analysis of the bridge is carried out while considering various combinations of translational and rotational components of ground motion, and the results from SVGM field are compared with that computed using spatially uniform ground motion (SUGM). Overall, the nature and extent of influence contributed from the consideration of multicomponent SVGM field is contingent to the EDPs of interest as well as the structural configuration. The demand for a given EDP when subjected to SVGM field may either be amplified or deamplified depending on the structural configuration.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"191 ","pages":"Article 109238"},"PeriodicalIF":4.2,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143095192","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 : 2025-01-21DOI: 10.1016/j.soildyn.2025.109232
Sandyapogu Peddaiah, Jyant Kumar
The objective of the current research is to examine the effect of large number (up to half a million) of high frequency (30–100 Hz) excitation cycles on shear moduli and damping of dry silty sand with varying percentages (0–70 %) of non-plastic fines (NPF). Resonant column (RC) tests were performed with a provision of vibrating the specimen to a large number of excitation cycles for different values of confining pressure, relative density (RD), and shear strain amplitudes. The study invariably reveals that for chosen relative density in the range of 55–75 %, a continuous reduction in shear modulus along with an increase in the damping ratio of silty sand occurs with an increase in the number of excitation cycles. This finding is on account of an increase in the shear strain with an increase in the number of excitation cycles. At a given RD, an addition of NPF leads to a further reduction in shear moduli and an increase in the damping. This observation is primarily attributed to an increase in the void ratio of silty sand with an addition of NPF.
{"title":"Effect of high frequency excitation cycles on shear moduli and damping of dry silty sand","authors":"Sandyapogu Peddaiah, Jyant Kumar","doi":"10.1016/j.soildyn.2025.109232","DOIUrl":"10.1016/j.soildyn.2025.109232","url":null,"abstract":"<div><div>The objective of the current research is to examine the effect of large number (up to half a million) of high frequency (30–100 Hz) excitation cycles on shear moduli and damping of dry silty sand with varying percentages (0–70 %) of non-plastic fines (NPF). Resonant column (RC) tests were performed with a provision of vibrating the specimen to a large number of excitation cycles for different values of confining pressure, relative density (RD), and shear strain amplitudes. The study invariably reveals that for chosen relative density in the range of 55–75 %, a continuous reduction in shear modulus along with an increase in the damping ratio of silty sand occurs with an increase in the number of excitation cycles. This finding is on account of an increase in the shear strain with an increase in the number of excitation cycles. At a given RD, an addition of NPF leads to a further reduction in shear moduli and an increase in the damping. This observation is primarily attributed to an increase in the void ratio of silty sand with an addition of NPF.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"191 ","pages":"Article 109232"},"PeriodicalIF":4.2,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143095196","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}
There are often some cavity structures in engineering slopes, such as early structural fracture cavities, dissolution fracture cavities, existing seismic fracture cavities, abandoned mines, etc. The excess pore gas pressure generated in engineering slopes with cavities under the action of sudden seismic loads, as well as the damage characteristics and mechanisms of the slope, the action laws of excess pore gas pressure, the mechanism of gas-rock interactions, and the triggering mechanism of seismic landslides, are all important research topics. This study, on the one hand, provides a valuable supplement to the theoretical foundation for understanding the deformation and failure mechanisms of slopes under seismic action; on the other hand, it provides a scientific basis for seismic slope stability evaluation and disaster prevention. In this study, a large-scale shaking table physical model test was designed for the slope with cavity. Under certain similar conditions, by inputting different seismic waves, the correlation between the excess cavity gas pressure and the dynamic response of the slope under strong earthquake conditions was systematically studied. The study found that: (1) Under the condition of low-intensity earthquake, there is almost no excess cavity gas pressure in the slope cavity, and the dynamic response of the slope has the same characteristics as that of the ordinary slope. (2) Under the condition of strong earthquake, the slope cavity will produce instantaneous excess cavity gas pressure, and the peak of air pressure will change with the change of cavity elevation, excitation intensity and excitation frequency. (3) Under the condition of strong earthquake, the peak value of acceleration response in the slope with cavity often appears after the peak pressure, which proves that the excess cavity gas pressure has a significant effect on the dynamic response of the slope.
{"title":"Correlation between the excess cavity gas pressure and the dynamic response of a slope cavity under strong earthquake conditions","authors":"Xiaoqun Wang, Yupei Wang, Yuanzheng Li, Qiang Huang, Lie Xiao, Lin Feng","doi":"10.1016/j.soildyn.2025.109222","DOIUrl":"10.1016/j.soildyn.2025.109222","url":null,"abstract":"<div><div>There are often some cavity structures in engineering slopes, such as early structural fracture cavities, dissolution fracture cavities, existing seismic fracture cavities, abandoned mines, etc. The excess pore gas pressure generated in engineering slopes with cavities under the action of sudden seismic loads, as well as the damage characteristics and mechanisms of the slope, the action laws of excess pore gas pressure, the mechanism of gas-rock interactions, and the triggering mechanism of seismic landslides, are all important research topics. This study, on the one hand, provides a valuable supplement to the theoretical foundation for understanding the deformation and failure mechanisms of slopes under seismic action; on the other hand, it provides a scientific basis for seismic slope stability evaluation and disaster prevention. In this study, a large-scale shaking table physical model test was designed for the slope with cavity. Under certain similar conditions, by inputting different seismic waves, the correlation between the excess cavity gas pressure and the dynamic response of the slope under strong earthquake conditions was systematically studied. The study found that: (1) Under the condition of low-intensity earthquake, there is almost no excess cavity gas pressure in the slope cavity, and the dynamic response of the slope has the same characteristics as that of the ordinary slope. (2) Under the condition of strong earthquake, the slope cavity will produce instantaneous excess cavity gas pressure, and the peak of air pressure will change with the change of cavity elevation, excitation intensity and excitation frequency. (3) Under the condition of strong earthquake, the peak value of acceleration response in the slope with cavity often appears after the peak pressure, which proves that the excess cavity gas pressure has a significant effect on the dynamic response of the slope.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"191 ","pages":"Article 109222"},"PeriodicalIF":4.2,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143095195","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 : 2025-01-21DOI: 10.1016/j.soildyn.2025.109231
Weiting Deng , Xuanming Ding , Chunyan Wang , Changwei Yang , Qiang Ou , Hong Wang
In this study, large-scale shaking table tests were conducted to investigate the seismic performance of high -fill railway subgrade reinforced by pile-slab structure and geogrids in sloping terrain. The distribution and evolution of acceleration, displacement, and soil pressure were measured and analyzed in detail, and the failure mode of the reinforced embankment was captured by CCD camera. In addition, the distribution and evolution of total energy, along with frequency band energy, were calculated and discussed through small packet wave decomposition. The results showed that the composite-reinforced high-fill embankment exhibited a notable acceleration and energy magnified effect, and its surface tendency effect gradually heightened with the increase of seismic intensity. Meanwhile, the dominant frequency band of energy transitioned from around the model's dominant frequency to the seismic wave's dominant frequency as the magnitude increased. The significant horizontal and vertical displacements were observed in the crest slope of the embankment, but the difference in residual displacement between different measurement points was very small. The peak soil pressure behind the anti-slip pile was greater than that behind the retaining plate due to the arching effect of anti-slip pile. Moreover, the embankment retained good integrity under high-intensity seismic with only cracks appearing on the surface. The findings validated that this composite-reinforced high-fill embankment was still in a stable and effective state under high-intensity earthquake conditions, which was expected to provide valuable guidance for practical applications.
{"title":"Seismic behavior and energy evolution of high-fill embankment reinforced by pile-slab structure and geogrids on slope accumulation","authors":"Weiting Deng , Xuanming Ding , Chunyan Wang , Changwei Yang , Qiang Ou , Hong Wang","doi":"10.1016/j.soildyn.2025.109231","DOIUrl":"10.1016/j.soildyn.2025.109231","url":null,"abstract":"<div><div>In this study, large-scale shaking table tests were conducted to investigate the seismic performance of high -fill railway subgrade reinforced by pile-slab structure and geogrids in sloping terrain. The distribution and evolution of acceleration, displacement, and soil pressure were measured and analyzed in detail, and the failure mode of the reinforced embankment was captured by CCD camera. In addition, the distribution and evolution of total energy, along with frequency band energy, were calculated and discussed through small packet wave decomposition. The results showed that the composite-reinforced high-fill embankment exhibited a notable acceleration and energy magnified effect, and its surface tendency effect gradually heightened with the increase of seismic intensity. Meanwhile, the dominant frequency band of energy transitioned from around the model's dominant frequency to the seismic wave's dominant frequency as the magnitude increased. The significant horizontal and vertical displacements were observed in the crest slope of the embankment, but the difference in residual displacement between different measurement points was very small. The peak soil pressure behind the anti-slip pile was greater than that behind the retaining plate due to the arching effect of anti-slip pile. Moreover, the embankment retained good integrity under high-intensity seismic with only cracks appearing on the surface. The findings validated that this composite-reinforced high-fill embankment was still in a stable and effective state under high-intensity earthquake conditions, which was expected to provide valuable guidance for practical applications.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"190 ","pages":"Article 109231"},"PeriodicalIF":4.2,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102227","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}
In previous train operations, traffic loads were typically considered continuous, disregarding the intermittent effects of successive trains on subgrade loess. To investigate the cumulative plastic strain behavior and critical dynamic stress of subgrade loess under intermittent train loads, a series of dynamic triaxial tests were conducted considering factors such as cyclic stress ratio, confining pressure, and frequency. The deformation characteristics of subgrade soil under different stress levels were analyzed, and the dynamic behavior of specimens was categorized based on the development trends of strain rate and cumulative plastic strain. Then the critical dynamic stress levels for plastic shakedown and plastic creep states were determined. The results indicate that intermittent effects suppress the development of cumulative plastic strain and excess pore water pressure in the soil. The more cycles of the unloading-drainage stage the soil undergoes, the stronger its resistance to failure. Under intermittent loads, cumulative plastic strain increases with higher cyclic stress ratios and frequencies. When the cyclic stress ratio is constant, the increase in confining pressure enhances soil stiffness, but this increase is insufficient to counteract the strain induced by greater dynamic stress amplitude, resulting in increased cumulative strain. Combining cumulative plastic strain and plastic strain rate, a classification standard for the deformation behavior of subgrade loess under intermittent loading conditions was established, and the critical dynamic stress was identified. The critical dynamic stress increases with higher confining pressure but decreases with frequency. Accordingly, empirical formulas for critical dynamic stress concerning confining pressure and frequency were proposed. These findings are crucial for understanding the mechanism of intermittent train load effects and analyzing subgrade settlement.
{"title":"Cumulative plastic strain and shakedown analysis in loess subgrades under intermittent loads","authors":"Duan Yang, Xinshan Zhuang, Gaoliang Tao, Xiaofei Li, Jiahui Fang","doi":"10.1016/j.soildyn.2025.109224","DOIUrl":"10.1016/j.soildyn.2025.109224","url":null,"abstract":"<div><div>In previous train operations, traffic loads were typically considered continuous, disregarding the intermittent effects of successive trains on subgrade loess. To investigate the cumulative plastic strain behavior and critical dynamic stress of subgrade loess under intermittent train loads, a series of dynamic triaxial tests were conducted considering factors such as cyclic stress ratio, confining pressure, and frequency. The deformation characteristics of subgrade soil under different stress levels were analyzed, and the dynamic behavior of specimens was categorized based on the development trends of strain rate and cumulative plastic strain. Then the critical dynamic stress levels for plastic shakedown and plastic creep states were determined. The results indicate that intermittent effects suppress the development of cumulative plastic strain and excess pore water pressure in the soil. The more cycles of the unloading-drainage stage the soil undergoes, the stronger its resistance to failure. Under intermittent loads, cumulative plastic strain increases with higher cyclic stress ratios and frequencies. When the cyclic stress ratio is constant, the increase in confining pressure enhances soil stiffness, but this increase is insufficient to counteract the strain induced by greater dynamic stress amplitude, resulting in increased cumulative strain. Combining cumulative plastic strain and plastic strain rate, a classification standard for the deformation behavior of subgrade loess under intermittent loading conditions was established, and the critical dynamic stress was identified. The critical dynamic stress increases with higher confining pressure but decreases with frequency. Accordingly, empirical formulas for critical dynamic stress concerning confining pressure and frequency were proposed. These findings are crucial for understanding the mechanism of intermittent train load effects and analyzing subgrade settlement.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"190 ","pages":"Article 109224"},"PeriodicalIF":4.2,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102226","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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