Soil Dynamics and Earthquake Engineering最新文献_第10页

Seismic response of steel frames with hysteretic dampers designed according to second generation of Eurocode 8 and comparison with conventional frames

IF 4.2 2区工程技术 Q1 ENGINEERING, GEOLOGICAL

Soil Dynamics and Earthquake Engineering

Pub Date : 2024-12-18 DOI: 10.1016/j.soildyn.2024.109171

Víctor Martinez-Reyes , Amadeo Benavent-Climent , Santiago Mota-Páez

This paper investigates the seismic response of a steel moment-resisting frame with hysteretic energy dissipation devices, designed with the energy-balance-based method implemented in the forthcoming second generation of Eurocode 8. Its response is compared with that of a counterpart conventional frame without energy dissipation devices designed under the force-based approach, also following the second generation of Eurocode 8. The response of both systems is obtained through nonlinear time history analyses with a suite of scaled accelerograms. The results of these analyses serve as well to judge the goodness of the prediction —in terms of maximum interstory drifts and energy dissipation demands— of the energy-balance-based method. Both structures are assumed to be in a region of high seismicity. A quantitative comparison is also made in terms of residual displacements and amount of steel required, and cost. The results demonstrate that the energy-based formulation of the second generation of Eurocode 8 provides for structures with much better performance and lower cost than conventional steel frames designed according to the force-based approach. It is furthermore shown that the energy-balance-based method affords a safe-side estimation of the maximum interstory drifts and of the expected damage on the main structure of the system with energy dissipation devices. The latter consumes about one half of the steel required by the conventional structure, while reducing the maximum interstory drifts to nearly one half and the residual drifts to nearly one third.

{"title":"Seismic response of steel frames with hysteretic dampers designed according to second generation of Eurocode 8 and comparison with conventional frames","authors":"Víctor Martinez-Reyes , Amadeo Benavent-Climent , Santiago Mota-Páez","doi":"10.1016/j.soildyn.2024.109171","DOIUrl":"10.1016/j.soildyn.2024.109171","url":null,"abstract":"<div><div>This paper investigates the seismic response of a steel moment-resisting frame with hysteretic energy dissipation devices, designed with the energy-balance-based method implemented in the forthcoming second generation of Eurocode 8. Its response is compared with that of a counterpart conventional frame without energy dissipation devices designed under the force-based approach, also following the second generation of Eurocode 8. The response of both systems is obtained through nonlinear time history analyses with a suite of scaled accelerograms. The results of these analyses serve as well to judge the goodness of the prediction —in terms of maximum interstory drifts and energy dissipation demands— of the energy-balance-based method. Both structures are assumed to be in a region of high seismicity. A quantitative comparison is also made in terms of residual displacements and amount of steel required, and cost. The results demonstrate that the energy-based formulation of the second generation of Eurocode 8 provides for structures with much better performance and lower cost than conventional steel frames designed according to the force-based approach. It is furthermore shown that the energy-balance-based method affords a safe-side estimation of the maximum interstory drifts and of the expected damage on the main structure of the system with energy dissipation devices. The latter consumes about one half of the steel required by the conventional structure, while reducing the maximum interstory drifts to nearly one half and the residual drifts to nearly one third.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"190 ","pages":"Article 109171"},"PeriodicalIF":4.2,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143097704","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}

引用次数: 0

Dynamic interaction between an asymmetric V-shaped canyon and a nearby structure under oblique incident SH waves

IF 4.2 2区工程技术 Q1 ENGINEERING, GEOLOGICAL

Soil Dynamics and Earthquake Engineering

Pub Date : 2024-12-18 DOI: 10.1016/j.soildyn.2024.109178

Haijun Lu , Ning Zhang , Jiasuo Pan , Yu Zhang , Denghui Dai

To investigate the dynamic interaction between irregular topography and the nearby structure, a rigorous analytical solution is derived for an asymmetric V-shaped canyon and a simplified structure under SH waves. The structure is represented by an idealized single-degree-of-freedom (SDOF) oscillator. The analytical model is validated by degrading into either a single SDOF oscillator model or an asymmetric V-shaped canyon model. Based on the proposed solution, the dynamic interaction between the V-shaped canyon and the nearby SDOF oscillator is analyzed in time domain. The results indicate that the canyon asymmetry can significantly influence the seismic response of the structure due to its “shielding effect” or “focusing effect” on seismic waves. In addition, the nearby structure either amplifies or attenuates the seismic responses at the canyon's shoulders and bottom.

引用次数: 0

Gravel content effect on site response of sand-like gravelly soil deposits by centrifuge model tests

IF 4.2 2区工程技术 Q1 ENGINEERING, GEOLOGICAL

Soil Dynamics and Earthquake Engineering

Pub Date : 2024-12-17 DOI: 10.1016/j.soildyn.2024.109169

Peng Xia , Yan-Guo Zhou , Yun-Min Chen

The sand-like gravelly soils are more prone to suffer from liquefaction disasters than those with gravel-like features and cause comparable liquefaction phenomena to sands. However, the gravel content effect on site response of such soil deposits was poorly understood. In this study, three dynamic centrifuge model tests with gravel contents of 0, 20 %, and 60 % were conducted under the same equivalent skeleton void ratio, which aims to reveal the gravel content effect on site response from small to large shear strains. The test results show that the ground stiffness increases with the increase of gravel content, which in turn leads to the increase of site natural frequency and the decrease of acceleration amplification factor. The gravel content effect is not evident under small sine wave motion, and the GC60 model ground exhibits the poorest liquefaction susceptibility. On the contrary, the gravel content effect is sufficiently mobilized to maintain the skeleton stability of sand-gravel mixtures under large sine wave motion, and the GC60 model ground shows the best liquefaction performance. For submerged and homogeneous gravelly soil deposits, the gravel content effect on site classification and the related seismic design parameters is significant. However, the overestimation of the site classification due to the gravel content effect on soil stiffness is unsafe for gravelly soil deposits with high gravel contents when the seismic intensity is low. Therefore, obtaining suitable and economical seismic design parameters for superstructures built on gravelly soil sites deserves further study.

{"title":"Gravel content effect on site response of sand-like gravelly soil deposits by centrifuge model tests","authors":"Peng Xia , Yan-Guo Zhou , Yun-Min Chen","doi":"10.1016/j.soildyn.2024.109169","DOIUrl":"10.1016/j.soildyn.2024.109169","url":null,"abstract":"<div><div>The sand-like gravelly soils are more prone to suffer from liquefaction disasters than those with gravel-like features and cause comparable liquefaction phenomena to sands. However, the gravel content effect on site response of such soil deposits was poorly understood. In this study, three dynamic centrifuge model tests with gravel contents of 0, 20 %, and 60 % were conducted under the same equivalent skeleton void ratio, which aims to reveal the gravel content effect on site response from small to large shear strains. The test results show that the ground stiffness increases with the increase of gravel content, which in turn leads to the increase of site natural frequency and the decrease of acceleration amplification factor. The gravel content effect is not evident under small sine wave motion, and the GC60 model ground exhibits the poorest liquefaction susceptibility. On the contrary, the gravel content effect is sufficiently mobilized to maintain the skeleton stability of sand-gravel mixtures under large sine wave motion, and the GC60 model ground shows the best liquefaction performance. For submerged and homogeneous gravelly soil deposits, the gravel content effect on site classification and the related seismic design parameters is significant. However, the overestimation of the site classification due to the gravel content effect on soil stiffness is unsafe for gravelly soil deposits with high gravel contents when the seismic intensity is low. Therefore, obtaining suitable and economical seismic design parameters for superstructures built on gravelly soil sites deserves further study.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"190 ","pages":"Article 109169"},"PeriodicalIF":4.2,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143097697","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}

引用次数: 0

Propagation characteristics of flexural waves in piles and the transient response at the pile-top under lateral excitation

IF 4.2 2区工程技术 Q1 ENGINEERING, GEOLOGICAL

Soil Dynamics and Earthquake Engineering

Pub Date : 2024-12-16 DOI: 10.1016/j.soildyn.2024.109173

Zhitang Lu , Pan Sun , Xiaohui Tan , Haichun Ma , Shanwei Liu

As a complement to the longitudinal wave-based method, the flexural wave-based method has been used to evaluate the pile integrity. This paper reveals dispersion and attenuation characteristics of F-(flexural) waves in piles and emphasizes the importance of capturing the axial velocity response for evaluating the pile integrity. The characteristics of F-wave propagation in piles and the transient dynamic response at the pile-top in the time domain are investigated to provide guidance for pile integrity testing. The pile is simplified as an elastic TM (Timoshenko) beam and the surrounding soil is simplified as a Winkler foundation. The dispersion and attenuation relations of the first propagating F-wave in the free and embedded piles are analyzed. The transient axial and lateral velocity responses of intact and defective (necking, bulging and mud clamping) piles in the time domain are obtained using the FDM (finite difference method) when the pile is subjected to a transient lateral excitation afterwards. The effects of pile and soil properties on the transient F-wave propagation and the dynamic response of the pile-top are investigated through a comprehensive parametric study. The finite difference solution based on the pile-soil model established in this paper is validated through comparisons with the 3D finite difference solution and experimental results. It is found that the stiffness of the surrounding soil has a great influence on the dispersion and attenuation characteristics of low-frequency F-wave. Shorter pulse durations or larger pile diameters can result in stronger reflections at the pile-tip; however, they can also enhance the thickness-shear mode and lead to the appearance of high-frequency interference. Reflections from the pile-tip or defects are more pronounced in axial velocity than in lateral velocity, so it is recommended that axial velocity should be collected in addition to lateral velocity during pile testing using the F-wave-based method. A method for eliminating the high-frequency interference using the difference between axial velocity responses on both sides of the pile-top is proposed, based on 3D simulation results. The TM model cannot adequately characterize the 3D effects of F-wave propagation in piles.

{"title":"Propagation characteristics of flexural waves in piles and the transient response at the pile-top under lateral excitation","authors":"Zhitang Lu , Pan Sun , Xiaohui Tan , Haichun Ma , Shanwei Liu","doi":"10.1016/j.soildyn.2024.109173","DOIUrl":"10.1016/j.soildyn.2024.109173","url":null,"abstract":"<div><div>As a complement to the longitudinal wave-based method, the flexural wave-based method has been used to evaluate the pile integrity. This paper reveals dispersion and attenuation characteristics of F-(flexural) waves in piles and emphasizes the importance of capturing the axial velocity response for evaluating the pile integrity. The characteristics of F-wave propagation in piles and the transient dynamic response at the pile-top in the time domain are investigated to provide guidance for pile integrity testing. The pile is simplified as an elastic TM (Timoshenko) beam and the surrounding soil is simplified as a Winkler foundation. The dispersion and attenuation relations of the first propagating F-wave in the free and embedded piles are analyzed. The transient axial and lateral velocity responses of intact and defective (necking, bulging and mud clamping) piles in the time domain are obtained using the FDM (finite difference method) when the pile is subjected to a transient lateral excitation afterwards. The effects of pile and soil properties on the transient F-wave propagation and the dynamic response of the pile-top are investigated through a comprehensive parametric study. The finite difference solution based on the pile-soil model established in this paper is validated through comparisons with the 3D finite difference solution and experimental results. It is found that the stiffness of the surrounding soil has a great influence on the dispersion and attenuation characteristics of low-frequency F-wave. Shorter pulse durations or larger pile diameters can result in stronger reflections at the pile-tip; however, they can also enhance the thickness-shear mode and lead to the appearance of high-frequency interference. Reflections from the pile-tip or defects are more pronounced in axial velocity than in lateral velocity, so it is recommended that axial velocity should be collected in addition to lateral velocity during pile testing using the F-wave-based method. A method for eliminating the high-frequency interference using the difference between axial velocity responses on both sides of the pile-top is proposed, based on 3D simulation results. The TM model cannot adequately characterize the 3D effects of F-wave propagation in piles.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"190 ","pages":"Article 109173"},"PeriodicalIF":4.2,"publicationDate":"2024-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143097696","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}

引用次数: 0

Maximum credible ground motion evaluation based on broadband stochastic finite-fault method: A case study for Baihetan dam in China

IF 4.2 2区工程技术 Q1 ENGINEERING, GEOLOGICAL

Soil Dynamics and Earthquake Engineering

Pub Date : 2024-12-16 DOI: 10.1016/j.soildyn.2024.109168

Ruifang Yu , Qianli Yang , Jianrong Xu , Yisheng Song , Hong Zhou , Yanxiang Yu

For the 300-m-high dam, reasonable estimation of the maximum credible earthquake ground motion at the site is crucial to prevent dam failure under near-field strong earthquakes. The primary aim of this study is to develop a broadband ground motion simulation method based on the stochastic finite fault method. This method can capture the low-frequency components of ground motion while maintaining high computational efficiency, thereby rendering it suitable for engineering applications. Firstly, we incorporate a random slip, which follows a k-squared distribution, into the deterministic asperity model to better simulate the fault rupture process. Subsequently, we adopt a dynamic corner frequency model, incorporating a non-uniform stress drop across sub-sources, to refine the theoretical source spectrum. Lastly, a low-frequency filtering function is incorporated into the sub-source amplitude spectrum to mitigate low-frequency simulation inaccuracies arising from uncertainties, such as simplified path effects. The proposed methodology was validated through simulations of the Wenchuan earthquake records, demonstrating its effectiveness in accurately reconstructing the amplitude and spectrum of ground motion at the bedrock site. However, the reasonable estimation of low-frequency components in ground motion hinges on the choice of the prior target spectrum. The proposed simulation methodology was employed to comprehensively assess the maximum credible ground motions at the Baihetan dam site, yielding ground motion scenarios for various risk levels. This research offers a practical and efficient method for estimating ground motion, facilitating seismic safety assessments of high dams subjected to near-field earthquake excitations.

{"title":"Maximum credible ground motion evaluation based on broadband stochastic finite-fault method: A case study for Baihetan dam in China","authors":"Ruifang Yu , Qianli Yang , Jianrong Xu , Yisheng Song , Hong Zhou , Yanxiang Yu","doi":"10.1016/j.soildyn.2024.109168","DOIUrl":"10.1016/j.soildyn.2024.109168","url":null,"abstract":"<div><div>For the 300-m-high dam, reasonable estimation of the maximum credible earthquake ground motion at the site is crucial to prevent dam failure under near-field strong earthquakes. The primary aim of this study is to develop a broadband ground motion simulation method based on the stochastic finite fault method. This method can capture the low-frequency components of ground motion while maintaining high computational efficiency, thereby rendering it suitable for engineering applications. Firstly, we incorporate a random slip, which follows a k-squared distribution, into the deterministic asperity model to better simulate the fault rupture process. Subsequently, we adopt a dynamic corner frequency model, incorporating a non-uniform stress drop across sub-sources, to refine the theoretical source spectrum. Lastly, a low-frequency filtering function is incorporated into the sub-source amplitude spectrum to mitigate low-frequency simulation inaccuracies arising from uncertainties, such as simplified path effects. The proposed methodology was validated through simulations of the Wenchuan earthquake records, demonstrating its effectiveness in accurately reconstructing the amplitude and spectrum of ground motion at the bedrock site. However, the reasonable estimation of low-frequency components in ground motion hinges on the choice of the prior target spectrum. The proposed simulation methodology was employed to comprehensively assess the maximum credible ground motions at the Baihetan dam site, yielding ground motion scenarios for various risk levels. This research offers a practical and efficient method for estimating ground motion, facilitating seismic safety assessments of high dams subjected to near-field earthquake excitations.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"190 ","pages":"Article 109168"},"PeriodicalIF":4.2,"publicationDate":"2024-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143097695","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}

引用次数: 0

Nonuniform response spectrum incorporating real mode decomposition for seismic response analysis of boundary-SSI systems featuring dual nonclassical damping

IF 4.2 2区工程技术 Q1 ENGINEERING, GEOLOGICAL

Soil Dynamics and Earthquake Engineering

Pub Date : 2024-12-14 DOI: 10.1016/j.soildyn.2024.109125

Guohuan Liu , Qixiang Fei

This paper aims to develop a nonuniform seismic response spectrum to enhance both the accuracy and efficiency of seismic analysis of viscoelastic boundary-soil-structure systems with dual nonclassical damping (VBSS-DNCD). Dual nonclassical damping consists of structural nonclassical damping (induced by structural dampers) and boundary nonclassical damping (induced by artificial boundaries). Compared with systems with only boundary nonclassical damping, the presence of structural nonclassical damping complicates the implementation of real mode decomposition. Consequently, deriving the corresponding real multipoint response spectrum (RMSRS) becomes substantially more complex. First, leveraging the inherent characteristics of both boundary and structural nonclassical damping, a theoretical framework and implementation strategy for orthogonalizing dual nonclassical damping is introduced. Subsequently, using our proposed orthogonally transformed real mode decomposition, the dynamic equations for the VBSS-DNCD system in the absolute coordinate system are decoupled, overcoming the limitations associated with complex mode decomposition. Additionally, an RMSRS based on real mode decomposition (RMSRS-DNCD) for the VBSS-DNCD system under nonuniform excitations is developed. The innovation lies in orthogonalizing dual nonclassical damping and deriving the response spectrum through real mode decomposition. Finally, to validate the accuracy and efficiency of the proposed method, a boundary-soil-bridge system with dual nonclassical damping under nonuniform seismic excitations is investigated using various methods. The results indicate that the proposed method exhibits a straightforward derivation process, adequate precision and computational efficiency. Compared with the conventional complex multipoint response spectrum (CMSRS) method, the RMSRS-DNCD method reduces the modal participation and cross-correlation coefficients by 3 and 12 terms, respectively.

{"title":"Nonuniform response spectrum incorporating real mode decomposition for seismic response analysis of boundary-SSI systems featuring dual nonclassical damping","authors":"Guohuan Liu , Qixiang Fei","doi":"10.1016/j.soildyn.2024.109125","DOIUrl":"10.1016/j.soildyn.2024.109125","url":null,"abstract":"<div><div>This paper aims to develop a nonuniform seismic response spectrum to enhance both the accuracy and efficiency of seismic analysis of viscoelastic boundary-soil-structure systems with dual nonclassical damping (VBSS-DNCD). Dual nonclassical damping consists of structural nonclassical damping (induced by structural dampers) and boundary nonclassical damping (induced by artificial boundaries). Compared with systems with only boundary nonclassical damping, the presence of structural nonclassical damping complicates the implementation of real mode decomposition. Consequently, deriving the corresponding real multipoint response spectrum (RMSRS) becomes substantially more complex. First, leveraging the inherent characteristics of both boundary and structural nonclassical damping, a theoretical framework and implementation strategy for orthogonalizing dual nonclassical damping is introduced. Subsequently, using our proposed orthogonally transformed real mode decomposition, the dynamic equations for the VBSS-DNCD system in the absolute coordinate system are decoupled, overcoming the limitations associated with complex mode decomposition. Additionally, an RMSRS based on real mode decomposition (RMSRS-DNCD) for the VBSS-DNCD system under nonuniform excitations is developed. The innovation lies in orthogonalizing dual nonclassical damping and deriving the response spectrum through real mode decomposition. Finally, to validate the accuracy and efficiency of the proposed method, a boundary-soil-bridge system with dual nonclassical damping under nonuniform seismic excitations is investigated using various methods. The results indicate that the proposed method exhibits a straightforward derivation process, adequate precision and computational efficiency. Compared with the conventional complex multipoint response spectrum (CMSRS) method, the RMSRS-DNCD method reduces the modal participation and cross-correlation coefficients by 3 and 12 terms, respectively.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"190 ","pages":"Article 109125"},"PeriodicalIF":4.2,"publicationDate":"2024-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143097694","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}

引用次数: 0

Influence of ballastless track types on the vehicle running on HSR bridges during earthquakes

IF 4.2 2区工程技术 Q1 ENGINEERING, GEOLOGICAL

Soil Dynamics and Earthquake Engineering

Pub Date : 2024-12-13 DOI: 10.1016/j.soildyn.2024.109175

Zhipeng Lai , Jiahui Han , Yuanjun Chen , Chenbei Jiao , Yuxi Xie , Tianxing Wen , Lizhong Jiang

Recently, high-speed railway (HSR) lines have extended into near-fault earthquake zones in China. In these regions, due to the limited early warning times of near-fault earthquakes, the presence of vehicles on HSR bridges during such events can be unavoidable. This study introduces a refined numerical model to simulate the vehicle-track-bridge (VTB) coupling vibration under near-fault earthquakes. It uses this model to examine the impact of various ballast-less track types on the real-time dynamic behavior of the VTB during an earthquake. The results indicated that the longitudinal continuous track offers superior performance in limiting the displacements of bridge girders compared to the unit slab track, resulting in fewer fluctuations in the vehicle's dynamic responses at the girder ends for the former track type. In addition, the effects of the randomness of near-fault earthquakes on vehicle running safety performance on HSR bridges equipped with different tracks are assessed. The outcomes of vehicle running fragility on HSR bridges during earthquakes demonstrated that the longitudinal continuous track can decrease the vehicle running fragility relative to the unit slab track. These results provide insights for constructing HSR bridges in near-fault earthquake zones.

{"title":"Influence of ballastless track types on the vehicle running on HSR bridges during earthquakes","authors":"Zhipeng Lai , Jiahui Han , Yuanjun Chen , Chenbei Jiao , Yuxi Xie , Tianxing Wen , Lizhong Jiang","doi":"10.1016/j.soildyn.2024.109175","DOIUrl":"10.1016/j.soildyn.2024.109175","url":null,"abstract":"<div><div>Recently, high-speed railway (HSR) lines have extended into near-fault earthquake zones in China. In these regions, due to the limited early warning times of near-fault earthquakes, the presence of vehicles on HSR bridges during such events can be unavoidable. This study introduces a refined numerical model to simulate the vehicle-track-bridge (VTB) coupling vibration under near-fault earthquakes. It uses this model to examine the impact of various ballast-less track types on the real-time dynamic behavior of the VTB during an earthquake. The results indicated that the longitudinal continuous track offers superior performance in limiting the displacements of bridge girders compared to the unit slab track, resulting in fewer fluctuations in the vehicle's dynamic responses at the girder ends for the former track type. In addition, the effects of the randomness of near-fault earthquakes on vehicle running safety performance on HSR bridges equipped with different tracks are assessed. The outcomes of vehicle running fragility on HSR bridges during earthquakes demonstrated that the longitudinal continuous track can decrease the vehicle running fragility relative to the unit slab track. These results provide insights for constructing HSR bridges in near-fault earthquake zones.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"190 ","pages":"Article 109175"},"PeriodicalIF":4.2,"publicationDate":"2024-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143101522","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}

引用次数: 0

Intensity-dependent site amplification factors using non-linear ground response analysis for Greater Srinagar Metropolitan in the deep sedimentary basin of Kashmir

IF 4.2 2区工程技术 Q1 ENGINEERING, GEOLOGICAL

Soil Dynamics and Earthquake Engineering

Pub Date : 2024-12-12 DOI: 10.1016/j.soildyn.2024.109120

Falak Zahoor , K. Seshagiri Rao , Faizan Ul Haq Mir , Neelima Satyam

This paper includes 1D nonlinear site-response analyses at 154 sites in key geological deposits of the Kashmir Valley, North-Western Himalayas. Responses to a suite of 22 motions of varying intensity (peak accelerations ∼0.01 g–0.86 g) from global and regional records were studied, using the entire depth to geological bedrock for the sedimentary deposits. Acceleration response spectra and amplification factors (AFs) were proposed for different geomorphological units of the region. Rock sites showed AF ≈ 1 for long periods (>1 s), and 1–1.5 for shorter periods (<1 s) at all intensities. Deep sedimentary sites had AFs as large as 2.76 for low-intensity motions, and as low as 0.11 for high-intensity motions. Short-period factor, F_a, was lower (∼0.29–2.32) compared to the long-period factor, F_v, for the deep deposits. This indicates that seismic codes underestimate response at long periods in deep soil deposits, which could cause undesirable seismic performance of tall buildings.

{"title":"Intensity-dependent site amplification factors using non-linear ground response analysis for Greater Srinagar Metropolitan in the deep sedimentary basin of Kashmir","authors":"Falak Zahoor , K. Seshagiri Rao , Faizan Ul Haq Mir , Neelima Satyam","doi":"10.1016/j.soildyn.2024.109120","DOIUrl":"10.1016/j.soildyn.2024.109120","url":null,"abstract":"<div><div>This paper includes 1D nonlinear site-response analyses at 154 sites in key geological deposits of the Kashmir Valley, North-Western Himalayas. Responses to a suite of 22 motions of varying intensity (peak accelerations ∼0.01 g–0.86 g) from global and regional records were studied, using the entire depth to geological bedrock for the sedimentary deposits. Acceleration response spectra and amplification factors (<em>AFs</em>) were proposed for different geomorphological units of the region. Rock sites showed <em>AF</em> ≈ 1 for long periods (>1 s), and 1–1.5 for shorter periods (<1 s) at all intensities. Deep sedimentary sites had <em>AFs</em> as large as 2.76 for low-intensity motions, and as low as 0.11 for high-intensity motions. Short-period factor, <em>F</em><sub><em>a</em></sub>, was lower (∼0.29–2.32) compared to the long-period factor, <em>F</em><sub><em>v</em></sub>, for the deep deposits. This indicates that seismic codes underestimate response at long periods in deep soil deposits, which could cause undesirable seismic performance of tall buildings.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"190 ","pages":"Article 109120"},"PeriodicalIF":4.2,"publicationDate":"2024-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143101514","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}

引用次数: 0

Experimental comparison of air entrapment capacity in sandy soils for liquefaction mitigation: Evaluating air injection method efficiency in soil desaturation

IF 4.2 2区工程技术 Q1 ENGINEERING, GEOLOGICAL

Soil Dynamics and Earthquake Engineering

Pub Date : 2024-12-12 DOI: 10.1016/j.soildyn.2024.109166

Saeed Sarajpoor , Yumin Chen , Yi Han , Runze Chen , Zhongling Fu , Ke Ma

The air injection method has been identified as a promising liquefaction mitigation technique to enhance the liquefaction resistance of sand. This innovative approach involves reducing the saturation degree of sand by injecting air, ultimately mitigating the generation of excess pore pressure during seismic events. This paper thoroughly investigates the potential of sandy soil to entrap air bubbles to reduce saturation degree. Fujian silica sand and the South China Sea calcareous sand, with varying gradation curves, were selected to evaluate the influence of key parameters such as uniformity coefficient, void ratio, and relative density on the air entrapment capacity. Box model experiments utilizing the air injection method were performed to evaluate the air entrapment capacity of sands. The findings reveal that the physical properties of sand can influence both the air distribution pattern and the air entrapment capacity. Finally, two additional tests were performed on transparent fused quartz sand to further examine the air injection process. The ability to observe air bubble distribution within the pore structure of the transparent sand enabled a qualitative comparison, facilitating the analysis of results obtained from experiments on natural sand samples.

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引用次数: 0

Centrifuge test study on the influence mechanism of anchor cable installation on the seismic response of pile‒anchor structures

IF 4.2 2区工程技术 Q1 ENGINEERING, GEOLOGICAL

Soil Dynamics and Earthquake Engineering

Pub Date : 2024-12-12 DOI: 10.1016/j.soildyn.2024.109160

Yu Wang , Tong Zheng , Rui Sun , Qiangqiang Sun , Xiao Long , Hongshuai Liu , Wenhao Qi

Anchored stabilizing piles (ASPs) are composed of ordinary stabilizing piles (SPs) and anchor cables and have been widely used in seismic reinforcement projects for high and steep slopes. However, the differences in the seismic responses and their underlying mechanisms caused by the installation of anchor cables remain unclear. To this end, based on two sets of centrifuge model tests, the seismic response differences of the same slope reinforced with ASPs and SPs were compared. The impact and mechanism of anchor cable installation were analyzed from multiple perspectives, including slope failure characteristics, structural internal forces and pile‒soil contact stress. Compared with SPs, ASPs showed the following results: (1) the addition of anchor cables caused abnormal acceleration amplification on the slope near the anchoring point of the pile, and seismic motion propagated along the anchor cables. (2) The stability of the reinforced slope surface was significantly improved, and the peak settlement at the top of the slope was reduced by 75.8 %. (3) The seismic soil pressure on the upper part of the pile had significantly increased, an overall 'inverted trapezoidal' distribution was observed, and the stability of the soil arch between the piles was significantly improved. (4) The residual value of the dynamic bending moment was significantly reduced, but the positive and negative peak values were not significantly different from those of the SPs. (5) Anchor cables mainly played a role in changing the load-bearing mode of the pile rather than being the main load-bearing components.

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引用次数: 0