This paper presents a multi-hazard risk analysis of high-rise buildings exposed to earthquakes and strong winds. A concurrent hazard database was first collected, consisting of 35,687 sets of concurrent hazards from 1901 to 2020, with earthquakes greater than M 4.0 and wind speeds exceeding 10 m/s. The probability of simultaneous occurrence of earthquakes and strong winds was theoretically derived and verified through Monte Carlo simulation and statistical result. Afterward, numerical simulation was performed on two high-rise buildings, with special focus on the fragility of the structures exposed to both individual and multiple hazards. The maximum top displacement of the structure under multiple hazards exceeded 0.9 %−24.6 % of the superposition of responses under individual hazards. The annual failure probability of the structure was analyzed through convolution of the disaster risk function and the structure fragility function. It was indicated that the annual failure probability under concurrent hazard conditions was 1.12 −2.05 times of that under individual hazard conditions in the damaged state of IDR (Inter-story Drift Ratio)> 1.5 %.
{"title":"Probabilistic multi-hazard risk assessment of high-rise buildings subjected to concurrent earthquakes and strong winds","authors":"Qian-Qian Yu , Ling-Han Liu , Xiang-Lin Gu , Yao-Yao Zhang","doi":"10.1016/j.engstruct.2025.119972","DOIUrl":"10.1016/j.engstruct.2025.119972","url":null,"abstract":"<div><div>This paper presents a multi-hazard risk analysis of high-rise buildings exposed to earthquakes and strong winds. A concurrent hazard database was first collected, consisting of 35,687 sets of concurrent hazards from 1901 to 2020, with earthquakes greater than M 4.0 and wind speeds exceeding 10 m/s. The probability of simultaneous occurrence of earthquakes and strong winds was theoretically derived and verified through Monte Carlo simulation and statistical result. Afterward, numerical simulation was performed on two high-rise buildings, with special focus on the fragility of the structures exposed to both individual and multiple hazards. The maximum top displacement of the structure under multiple hazards exceeded 0.9 %−24.6 % of the superposition of responses under individual hazards. The annual failure probability of the structure was analyzed through convolution of the disaster risk function and the structure fragility function. It was indicated that the annual failure probability under concurrent hazard conditions was 1.12 −2.05 times of that under individual hazard conditions in the damaged state of IDR (Inter-story Drift Ratio)> 1.5 %.</div></div>","PeriodicalId":11763,"journal":{"name":"Engineering Structures","volume":"331 ","pages":"Article 119972"},"PeriodicalIF":5.6,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550320","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2025-03-03DOI: 10.1016/j.engstruct.2025.119985
Xin Nie, Da Huang, Liangdong Zhuang, Jiansheng Fan, Niankai Deng
In prefabricated structures, densely distributed stirrups and splicing of longitudinal reinforcement extending from precast components can result in rebar congestion in precast concrete connections, obstructing the assembly of precast components and proper concrete compaction. To address these issues, five types of joint details less susceptible to reinforcement congestion have been thoroughly reviewed. Mechanical connectors, as a substitute for lap splices of protruding rebars, are incorporated in dry and hybrid connections, which exhibit semi-rigid behavior under seismic loading. Notched connections, typified by evenly spaced notches at the side surfaces of precast components, employ post-installed connecting bars to replace projecting reinforcement. Design guides for notch geometry and anchorage length of connecting bars inserted in notches were proposed based on pull-out test results. Precast rocking systems with self-centering capability can be established by unbonded post-tensioning, which clamps structural components together without the necessity for rebar splicing. Energy dissipation is achieved by metallic, viscoelastic, or friction dampers. Furthermore, the ultra-high bond strength of reinforcing bars anchored in UHPC allows for short lap-spliced joints, while employing ECC as grouting materials enhances joint confinement and shear strength, enabling a reduction or total elimination of stirrups in precast concrete connections. Reinforcement congestion can be also relieved by separating beam-to-column connections into beam-to-beam and column-to-column joints, which effectively reduces the amount of reinforcement intersecting in the joint core.
{"title":"Precast concrete connections for alleviating reinforcement congestion: A state-of-the-art review","authors":"Xin Nie, Da Huang, Liangdong Zhuang, Jiansheng Fan, Niankai Deng","doi":"10.1016/j.engstruct.2025.119985","DOIUrl":"10.1016/j.engstruct.2025.119985","url":null,"abstract":"<div><div>In prefabricated structures, densely distributed stirrups and splicing of longitudinal reinforcement extending from precast components can result in rebar congestion in precast concrete connections, obstructing the assembly of precast components and proper concrete compaction. To address these issues, five types of joint details less susceptible to reinforcement congestion have been thoroughly reviewed. Mechanical connectors, as a substitute for lap splices of protruding rebars, are incorporated in dry and hybrid connections, which exhibit semi-rigid behavior under seismic loading. Notched connections, typified by evenly spaced notches at the side surfaces of precast components, employ post-installed connecting bars to replace projecting reinforcement. Design guides for notch geometry and anchorage length of connecting bars inserted in notches were proposed based on pull-out test results. Precast rocking systems with self-centering capability can be established by unbonded post-tensioning, which clamps structural components together without the necessity for rebar splicing. Energy dissipation is achieved by metallic, viscoelastic, or friction dampers. Furthermore, the ultra-high bond strength of reinforcing bars anchored in UHPC allows for short lap-spliced joints, while employing ECC as grouting materials enhances joint confinement and shear strength, enabling a reduction or total elimination of stirrups in precast concrete connections. Reinforcement congestion can be also relieved by separating beam-to-column connections into beam-to-beam and column-to-column joints, which effectively reduces the amount of reinforcement intersecting in the joint core.</div></div>","PeriodicalId":11763,"journal":{"name":"Engineering Structures","volume":"331 ","pages":"Article 119985"},"PeriodicalIF":5.6,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143549990","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2025-03-03DOI: 10.1016/j.engstruct.2025.120012
Vinicius Moura de Oliveira , Vinicius Brother dos Santos , Alexandre Rossi , André Vitor Benedito , Pablo Augusto Krahl , Carlos Humberto Martins , Flávio de Andrade Silva , Daniel Carlos Taissum Cardoso
Continuous steel-concrete composite beams provide bending moment redistribution, slight deflection, the capability to cover longer spans and cost-effectiveness. Employing steel alveolar I-sections and Ultra-High-Performance Concrete (UHPC) slabs in these composite beams can significantly dematerialize the structure. Differently from conventional concrete, UHPC slabs are usually thinner, but can still provide restrain and increase buckling capacity of metallic parts, although less effectively when the slab is loaded in tension. The present paper investigates the Web-Post Buckling (WPB) behavior of steel-UHPC composite castellated beams under three-point hogging bending tests for two different patterns, namely Peiner and Anglo-Saxon. The experimental results are used to validate the numerical model and assess the accuracy of the design procedures for predicting these beams' WPB resistance, and a numerical parametric study is also discussed. Both specimens reached failure by WPB coupled with the Vierendeel mechanism (VM). This way, the length of the web openings' hexagon horizontal edge (tee length) influenced the bearing capacity of the castellated beam, in which the specimen with a higher tee length had a lower ultimate load, which was also observed in the numerical parametric study. In addition, the numerical models with the shortest web-post width were more critical for the WPB occurrence. Composite castellated beams with UHPC slabs showed higher initial bending stiffness and ultimate loads than those with NC slabs, even though the WPB and VM phenomenon restricted their bearing capacity. Finally, the procedure from EN 1993–1–13 for WPB resistance prediction provided more conservative results, and the Steel Design Guide 31 overestimated the WPB resistance of castellated beams significantly affected by the VM phenomenon on their ultimate loads.
{"title":"Steel-UHPC composite castellated beams under hogging bending: Experimental and numerical investigation","authors":"Vinicius Moura de Oliveira , Vinicius Brother dos Santos , Alexandre Rossi , André Vitor Benedito , Pablo Augusto Krahl , Carlos Humberto Martins , Flávio de Andrade Silva , Daniel Carlos Taissum Cardoso","doi":"10.1016/j.engstruct.2025.120012","DOIUrl":"10.1016/j.engstruct.2025.120012","url":null,"abstract":"<div><div>Continuous steel-concrete composite beams provide bending moment redistribution, slight deflection, the capability to cover longer spans and cost-effectiveness. Employing steel alveolar I-sections and Ultra-High-Performance Concrete (UHPC) slabs in these composite beams can significantly dematerialize the structure. Differently from conventional concrete, UHPC slabs are usually thinner, but can still provide restrain and increase buckling capacity of metallic parts, although less effectively when the slab is loaded in tension. The present paper investigates the Web-Post Buckling (WPB) behavior of steel-UHPC composite castellated beams under three-point hogging bending tests for two different patterns, namely Peiner and Anglo-Saxon. The experimental results are used to validate the numerical model and assess the accuracy of the design procedures for predicting these beams' WPB resistance, and a numerical parametric study is also discussed. Both specimens reached failure by WPB coupled with the Vierendeel mechanism (VM). This way, the length of the web openings' hexagon horizontal edge (tee length) influenced the bearing capacity of the castellated beam, in which the specimen with a higher tee length had a lower ultimate load, which was also observed in the numerical parametric study. In addition, the numerical models with the shortest web-post width were more critical for the WPB occurrence. Composite castellated beams with UHPC slabs showed higher initial bending stiffness and ultimate loads than those with NC slabs, even though the WPB and VM phenomenon restricted their bearing capacity. Finally, the procedure from EN 1993–1–13 for WPB resistance prediction provided more conservative results, and the Steel Design Guide 31 overestimated the WPB resistance of castellated beams significantly affected by the VM phenomenon on their ultimate loads.</div></div>","PeriodicalId":11763,"journal":{"name":"Engineering Structures","volume":"331 ","pages":"Article 120012"},"PeriodicalIF":5.6,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550325","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2025-03-03DOI: 10.1016/j.engstruct.2025.119976
Wenze Wang , Jianze Wang , Mengtao Wu , Kaoshan Dai , Chao Liang , Zhenning Ba , Ashraf El Damatty
The advancement of efficient and clean wind power is crucial for realizing the global energy transition and meeting "dual-carbon" goals. In recent decades, wind turbines have experienced unprecedented growth, while the installation of more wind farms in earthquake-prone areas has significantly increased the associated seismic risk. The characteristics of the seismic source, propagation path, and site conditions are critical factors influencing seismic risk and the design of wind turbine structures. To this end, this study develops a wind farm risk assessment procedure using scenario-based ground motion simulations. Initially, a hybrid source model and frequency-wavenumber domain (FK) method are established for simulating broadband seismic wave propagation from finite fault sources within crustal layers. Subsequently, scenario ground motion predictions based on physical processes from the source to the site are performed, yielding multi-dimensional and multi-supported excitations for the target region. Thereafter, a numerical model of onshore wind turbines (WTs) is built using OpenSees, undergoing validation and dynamic response-history analysis, thereby achieving a full-process source-to-structure deterministic modeling. Ultimately, the "cloud method" is employed to establish a fragility model for the wind turbine tower. A comprehensive comparison and discussion are conducted on the seismic response and fragility of WTs at the Sanweishan fault, resulting from ruptures at different sub-faults. The results indicate that the middle sub-fault has a significant impact on the WTs, with a more pronounced risk of damage. Fragility results would provide valuable insights on design, location selection, risk reduction of wind farms.
{"title":"Risk assessment for wind farms using scenario-based ground motion simulations","authors":"Wenze Wang , Jianze Wang , Mengtao Wu , Kaoshan Dai , Chao Liang , Zhenning Ba , Ashraf El Damatty","doi":"10.1016/j.engstruct.2025.119976","DOIUrl":"10.1016/j.engstruct.2025.119976","url":null,"abstract":"<div><div>The advancement of efficient and clean wind power is crucial for realizing the global energy transition and meeting \"dual-carbon\" goals. In recent decades, wind turbines have experienced unprecedented growth, while the installation of more wind farms in earthquake-prone areas has significantly increased the associated seismic risk. The characteristics of the seismic source, propagation path, and site conditions are critical factors influencing seismic risk and the design of wind turbine structures. To this end, this study develops a wind farm risk assessment procedure using scenario-based ground motion simulations. Initially, a hybrid source model and frequency-wavenumber domain (FK) method are established for simulating broadband seismic wave propagation from finite fault sources within crustal layers. Subsequently, scenario ground motion predictions based on physical processes from the source to the site are performed, yielding multi-dimensional and multi-supported excitations for the target region. Thereafter, a numerical model of onshore wind turbines (WTs) is built using OpenSees, undergoing validation and dynamic response-history analysis, thereby achieving a full-process source-to-structure deterministic modeling. Ultimately, the \"cloud method\" is employed to establish a fragility model for the wind turbine tower. A comprehensive comparison and discussion are conducted on the seismic response and fragility of WTs at the Sanweishan fault, resulting from ruptures at different sub-faults. The results indicate that the middle sub-fault has a significant impact on the WTs, with a more pronounced risk of damage. Fragility results would provide valuable insights on design, location selection, risk reduction of wind farms.</div></div>","PeriodicalId":11763,"journal":{"name":"Engineering Structures","volume":"331 ","pages":"Article 119976"},"PeriodicalIF":5.6,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550321","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2025-03-03DOI: 10.1016/j.engstruct.2025.119966
Shuhong Lin , Bing Zhang , Sumei Zhang
In humid and corrosive environments, FRP-concrete-steel double-skin tubular columns (DSTCs) have demonstrated significant potential as bridge piers. Vehicular collisions are a major cause of bridge pier failures during their service life. While existing studies on DSTCs under lateral impact loading have primarily focused on single-column configurations, double-column bridge piers are commonly employed in bridge designs due to their enhanced resistance to overturning. These double-column piers may exhibit different impact resistance characteristics compared to single-column piers. However, there has been no experimental research to date investigating the dynamic behavior of double-column DSTC piers (DC-DSTCs) under vehicular impact. To address this gap, this study conducted experimental investigations on two large-scale DC-DSTC specimens subjected to vehicular impact. This study specifically examined key parameters such as the impact velocity, the void ratio of tubular DSTC pier, and the support provided by the adjacent DSTC pier. Experimental results illustrated that: (1) the DC-DSTC specimen exhibited localized damage at the impact position of the impacted DSTC pier, while an overall flexural deformation was observed in both the impacted and adjacent DSTC piers; (2) the impact force, global deformation and localized concave deformation increased with higher impact velocities; (3) under high-speed impact (around 5 m/s), a larger void ratio in the tubular DSTC pier resulted in more significant local dent deformation but reduced global lateral displacement; (4) when subjected to high-speed impact (around 5 m/s), the support of adjacent DSTC pier played a significant role on the dynamic behavior of DC-DSTC with a smaller void ratio, while has a limited influence on DC-DSTC with a larger void ratio. Subsequently, FE models were constructed and validated to accurately simulate the dynamic behavior of DC-DSTC specimens under lateral vehicular impact. Finally, a refined FE simulation of a Ford F800 medium truck colliding with a prototype DC-DSTC bridge was conducted to study the effect of both vehicle velocity and vehicle mass.
{"title":"Dynamic behavior of double-column FRP-concrete-steel tubular bridge piers subjected to vehicular impact: Experimental study and numerical analysis","authors":"Shuhong Lin , Bing Zhang , Sumei Zhang","doi":"10.1016/j.engstruct.2025.119966","DOIUrl":"10.1016/j.engstruct.2025.119966","url":null,"abstract":"<div><div>In humid and corrosive environments, FRP-concrete-steel double-skin tubular columns (DSTCs) have demonstrated significant potential as bridge piers. Vehicular collisions are a major cause of bridge pier failures during their service life. While existing studies on DSTCs under lateral impact loading have primarily focused on single-column configurations, double-column bridge piers are commonly employed in bridge designs due to their enhanced resistance to overturning. These double-column piers may exhibit different impact resistance characteristics compared to single-column piers. However, there has been no experimental research to date investigating the dynamic behavior of double-column DSTC piers (DC-DSTCs) under vehicular impact. To address this gap, this study conducted experimental investigations on two large-scale DC-DSTC specimens subjected to vehicular impact. This study specifically examined key parameters such as the impact velocity, the void ratio of tubular DSTC pier, and the support provided by the adjacent DSTC pier. Experimental results illustrated that: (1) the DC-DSTC specimen exhibited localized damage at the impact position of the impacted DSTC pier, while an overall flexural deformation was observed in both the impacted and adjacent DSTC piers; (2) the impact force, global deformation and localized concave deformation increased with higher impact velocities; (3) under high-speed impact (around 5 m/s), a larger void ratio in the tubular DSTC pier resulted in more significant local dent deformation but reduced global lateral displacement; (4) when subjected to high-speed impact (around 5 m/s), the support of adjacent DSTC pier played a significant role on the dynamic behavior of DC-DSTC with a smaller void ratio, while has a limited influence on DC-DSTC with a larger void ratio. Subsequently, FE models were constructed and validated to accurately simulate the dynamic behavior of DC-DSTC specimens under lateral vehicular impact. Finally, a refined FE simulation of a Ford F800 medium truck colliding with a prototype DC-DSTC bridge was conducted to study the effect of both vehicle velocity and vehicle mass.</div></div>","PeriodicalId":11763,"journal":{"name":"Engineering Structures","volume":"331 ","pages":"Article 119966"},"PeriodicalIF":5.6,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2025-03-03DOI: 10.1016/j.engstruct.2025.119941
Adel Al Ekkawi, Raafat El-Hacha
This study explores an innovative method for enhancing the seismic performance of deficient RC bridge piers through a novel flexural strengthening system incorporating prestressed Iron-based Shape Memory Alloy (Fe-SMA) plates. The novelty of this system lies in implementing a robust anchorage technique, effectively addressing challenges typically accompanied by enhancing the flexural performance of RC piers using prestressed systems. Three RC circular columns were built representing 1/3 to scale bridge piers. The first column remained unstrengthened, while the second was strengthened in flexure using prestressed Fe-SMA plates. The third column was strengthened using vertical externally bonded (EB) Carbon Fibre-Reinforced Polymer (CFRP) sheets – a passive system chosen for comparison with the prestressed Fe-SMA system. The columns were simultaneously subjected to a constant axial and a lateral cyclic loading applied at their tops. The results showed that the Fe-SMA strengthened column exhibited the most stable hysteretic response with only 13.88 % strength degradation at 8.84 % drift, in addition to witnessing a significant increase of 35.32 % and 72.60 % in its lateral strength and energy dissipation, respectively. Also, the vertical Fe-SMA plates successfully mitigated the column’s extensive damage and reduced its residual displacements by 17.79 %, thereby preserving the column’s concrete core and preventing the buckling of its reinforcements.
{"title":"Experimental comparative study on novel flexural strengthening systems for seismically deficient RC piers: Prestressed Fe-SMA plates vs. externally bonded CFRP sheets","authors":"Adel Al Ekkawi, Raafat El-Hacha","doi":"10.1016/j.engstruct.2025.119941","DOIUrl":"10.1016/j.engstruct.2025.119941","url":null,"abstract":"<div><div>This study explores an innovative method for enhancing the seismic performance of deficient RC bridge piers through a novel flexural strengthening system incorporating prestressed Iron-based Shape Memory Alloy (Fe-SMA) plates. The novelty of this system lies in implementing a robust anchorage technique, effectively addressing challenges typically accompanied by enhancing the flexural performance of RC piers using prestressed systems. Three RC circular columns were built representing 1/3 to scale bridge piers. The first column remained unstrengthened, while the second was strengthened in flexure using prestressed Fe-SMA plates. The third column was strengthened using vertical externally bonded (EB) Carbon Fibre-Reinforced Polymer (CFRP) sheets – a passive system chosen for comparison with the prestressed Fe-SMA system. The columns were simultaneously subjected to a constant axial and a lateral cyclic loading applied at their tops. The results showed that the Fe-SMA strengthened column exhibited the most stable hysteretic response with only 13.88 % strength degradation at 8.84 % drift, in addition to witnessing a significant increase of 35.32 % and 72.60 % in its lateral strength and energy dissipation, respectively. Also, the vertical Fe-SMA plates successfully mitigated the column’s extensive damage and reduced its residual displacements by 17.79 %, thereby preserving the column’s concrete core and preventing the buckling of its reinforcements.</div></div>","PeriodicalId":11763,"journal":{"name":"Engineering Structures","volume":"331 ","pages":"Article 119941"},"PeriodicalIF":5.6,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550319","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2025-03-03DOI: 10.1016/j.engstruct.2025.119914
Gang Shi , Naizhou Zhang , Lianjin Bao , Xiaoming Chen , Feng Zhou , Sheng Jiang , Huatian Zhao
In this study, the structural behaviour of cruciform welded connections obtained from thick-flange steel H-beams to square concrete-filled steel tubular column joints is investigated. Cruciform welded connections include horizontal steel plates of thickness 80 mm and vertical steel plates of thicknesses 40–100 mm, which have rarely been reported in previous studies. After the development of a new cyclic loading protocol and the corresponding evaluation criteria, experiments were conducted on four cyclic loading specimens and four monotonic tensile specimens, in which various thickness ratios (ηbc) of the horizontal plate to the vertical plate were used. Based on the test results, the two failure modes of horizontal plate necking in the monotonic specimens and weld fracture between the horizontal and vertical plates in the cyclic specimens were observed. Moreover, the vertical plate thickness exhibited no apparent effect on the performance of the specimens, and all the monotonic and cyclic specimens met the corresponding evaluation criteria for beam-to-column joints of composite special moment frames. Furthermore, the range of ηbc and relevant configuration suggestions were proposed for the cruciform welded connections with thick steel plates.
{"title":"Experimental study on cruciform welded connections with thick steel plates in moment-resisting beam-to-column joints","authors":"Gang Shi , Naizhou Zhang , Lianjin Bao , Xiaoming Chen , Feng Zhou , Sheng Jiang , Huatian Zhao","doi":"10.1016/j.engstruct.2025.119914","DOIUrl":"10.1016/j.engstruct.2025.119914","url":null,"abstract":"<div><div>In this study, the structural behaviour of cruciform welded connections obtained from thick-flange steel H-beams to square concrete-filled steel tubular column joints is investigated. Cruciform welded connections include horizontal steel plates of thickness 80 mm and vertical steel plates of thicknesses 40–100 mm, which have rarely been reported in previous studies. After the development of a new cyclic loading protocol and the corresponding evaluation criteria, experiments were conducted on four cyclic loading specimens and four monotonic tensile specimens, in which various thickness ratios (<em>η</em><sub>bc</sub>) of the horizontal plate to the vertical plate were used. Based on the test results, the two failure modes of horizontal plate necking in the monotonic specimens and weld fracture between the horizontal and vertical plates in the cyclic specimens were observed. Moreover, the vertical plate thickness exhibited no apparent effect on the performance of the specimens, and all the monotonic and cyclic specimens met the corresponding evaluation criteria for beam-to-column joints of composite special moment frames. Furthermore, the range of <em>η</em><sub>bc</sub> and relevant configuration suggestions were proposed for the cruciform welded connections with thick steel plates.</div></div>","PeriodicalId":11763,"journal":{"name":"Engineering Structures","volume":"331 ","pages":"Article 119914"},"PeriodicalIF":5.6,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2025-03-03DOI: 10.1016/j.engstruct.2025.120002
S. Elias , M. Beer , J. Chen
In earthquake-prone regions like Iceland, where an average of 500 earthquakes occurs weekly, modular buildings constructed according to EU standards encounter significant seismic challenges. This study investigates the seismic performance of nonlinear modular building models under both near-field pulse-type ground motions and fully non-stationary non-pulse-like stochastic ground motions, generated through Monte Carlo Simulation (MCS) and Latinized Partially Stratified Sampling (LPSS) methods. Key structural response parameters, including inter-story drift, base shear, and acceleration, are analyzed, with their probability distribution functions (PDFs) and fragility functions evaluated against industry-standard limit states, such as those defined by FEMA. Results reveal that pulse-type ground motions, characterized by large, high-velocity pulses, result in a higher probability of failure, especially in the width direction, compared to non-pulse-like stochastic ground motions. The top floor exhibits greater vulnerability under seismic forces, underscoring the need for focused structural reinforcement. The findings highlight the importance of considering both pulse-type and non-pulse-like stochastic ground motions in structural design practices and seismic codes to enhance the resilience and safety of modular buildings in earthquake-prone areas. This study contributes to the seismic engineering field by providing insights into the vulnerability and robustness of modular structures under diverse seismic loading conditions.
{"title":"Assessing seismic vulnerability of modular buildings under earthquake ground motions","authors":"S. Elias , M. Beer , J. Chen","doi":"10.1016/j.engstruct.2025.120002","DOIUrl":"10.1016/j.engstruct.2025.120002","url":null,"abstract":"<div><div>In earthquake-prone regions like Iceland, where an average of 500 earthquakes occurs weekly, modular buildings constructed according to EU standards encounter significant seismic challenges. This study investigates the seismic performance of nonlinear modular building models under both near-field pulse-type ground motions and fully non-stationary non-pulse-like stochastic ground motions, generated through Monte Carlo Simulation (MCS) and Latinized Partially Stratified Sampling (LPSS) methods. Key structural response parameters, including inter-story drift, base shear, and acceleration, are analyzed, with their probability distribution functions (PDFs) and fragility functions evaluated against industry-standard limit states, such as those defined by FEMA. Results reveal that pulse-type ground motions, characterized by large, high-velocity pulses, result in a higher probability of failure, especially in the width direction, compared to non-pulse-like stochastic ground motions. The top floor exhibits greater vulnerability under seismic forces, underscoring the need for focused structural reinforcement. The findings highlight the importance of considering both pulse-type and non-pulse-like stochastic ground motions in structural design practices and seismic codes to enhance the resilience and safety of modular buildings in earthquake-prone areas. This study contributes to the seismic engineering field by providing insights into the vulnerability and robustness of modular structures under diverse seismic loading conditions.</div></div>","PeriodicalId":11763,"journal":{"name":"Engineering Structures","volume":"331 ","pages":"Article 120002"},"PeriodicalIF":5.6,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550324","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2025-03-03DOI: 10.1016/j.engstruct.2025.120011
Jiawei Chen , Zhen He , Yang Wei , Ruiming Wang , Tomoki Furuta , Haibei Xiong
The energy-consumption capacity and failure mechanisms of conventional metal connections in cross-laminated timber (CLT) structures need improvement when considering seismic resilience, which limits the promotion of CLT structures in mid- and high-rise buildings in high-intensity seismic areas. This paper presents an experimental and numerical study on the seismic performance of CLT shear walls anchored with the innovative energy-dissipation connections, i.e., EDSR-ABs and EDSR-HDs, which are characterized by a dual energy-consumption principle utilizing yielding of soft steel and shear deformation of rubber. Full-scale CLT shear wall specimens were tested under monotonic and cyclic loading. Failure modes and mechanical properties of the walls were revealed, and their energy dissipation characteristics were analyzed. The superior seismic performance of the walls with energy-dissipation connections was validated by the comparison with the walls with conventional metal connections. On the other hand, non-linear numerical OpenSees models were established and verified, after which parametric analysis was conducted to evaluate the influence of vertical load, aspect ratio, and connection arrangement. The results show that the primary failure modes of the walls involve dissipative ribs’ yielding and fracturing and rubber’s debonding in EDSR-ABs and EDSR-HDs. The walls’ hysteresis curves exhibit an inverse S-shape, and their ductility varies from 2.96 to 5.49. The distribution of input energy, elastic strain energy, and hysteretic energy during each loading cycle are nearly symmetrical for positive and negative directions, and the input energy is mainly dissipated by the hysteretic energy provided by the dissipative connections, eventually contributing to over 60 % of the total. The parametric analysis shows that vertical loads enhance the wall’s load-carrying capacity, but this improvement plateaus once the shear capacity of EDSR-ABs is reached. An increase in the aspect ratio leads to increased rocking deformation, diminishing the shear contribution of EDSR-ABs, thereby reducing the wall’s load-carrying capacity. For various connection arrangements, enhancing the mechanical properties of EDSR-HDs significantly increases seismic performance with high efficiency.
{"title":"Seismic performance of CLT shear walls anchored with energy-dissipation connections: Experimental investigation and parametric analysis","authors":"Jiawei Chen , Zhen He , Yang Wei , Ruiming Wang , Tomoki Furuta , Haibei Xiong","doi":"10.1016/j.engstruct.2025.120011","DOIUrl":"10.1016/j.engstruct.2025.120011","url":null,"abstract":"<div><div>The energy-consumption capacity and failure mechanisms of conventional metal connections in cross-laminated timber (CLT) structures need improvement when considering seismic resilience, which limits the promotion of CLT structures in mid- and high-rise buildings in high-intensity seismic areas. This paper presents an experimental and numerical study on the seismic performance of CLT shear walls anchored with the innovative energy-dissipation connections, i.e., EDSR-ABs and EDSR-HDs, which are characterized by a dual energy-consumption principle utilizing yielding of soft steel and shear deformation of rubber. Full-scale CLT shear wall specimens were tested under monotonic and cyclic loading. Failure modes and mechanical properties of the walls were revealed, and their energy dissipation characteristics were analyzed. The superior seismic performance of the walls with energy-dissipation connections was validated by the comparison with the walls with conventional metal connections. On the other hand, non-linear numerical OpenSees models were established and verified, after which parametric analysis was conducted to evaluate the influence of vertical load, aspect ratio, and connection arrangement. The results show that the primary failure modes of the walls involve dissipative ribs’ yielding and fracturing and rubber’s debonding in EDSR-ABs and EDSR-HDs. The walls’ hysteresis curves exhibit an inverse S-shape, and their ductility varies from 2.96 to 5.49. The distribution of input energy, elastic strain energy, and hysteretic energy during each loading cycle are nearly symmetrical for positive and negative directions, and the input energy is mainly dissipated by the hysteretic energy provided by the dissipative connections, eventually contributing to over 60 % of the total. The parametric analysis shows that vertical loads enhance the wall’s load-carrying capacity, but this improvement plateaus once the shear capacity of EDSR-ABs is reached. An increase in the aspect ratio leads to increased rocking deformation, diminishing the shear contribution of EDSR-ABs, thereby reducing the wall’s load-carrying capacity. For various connection arrangements, enhancing the mechanical properties of EDSR-HDs significantly increases seismic performance with high efficiency.</div></div>","PeriodicalId":11763,"journal":{"name":"Engineering Structures","volume":"331 ","pages":"Article 120011"},"PeriodicalIF":5.6,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143529240","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2025-03-03DOI: 10.1016/j.engstruct.2025.119978
Shaodong Jiang , Ruisheng Ma , Kaiming Bi , Huan Li , Xiuli Du
Traditional seismic isolators, such as the friction pendulum system (FPS), exhibit high isolation efficiency during slight-to-moderate earthquakes, but their ability to constrain isolation deformations under severe earthquakes remains limited. The negative stiffness enhanced tuned mass dampers (NS-TMDs), which exist in two configurations (NS-TMD I and NS-TMD II), have been successfully employed to improve the seismic performance of isolated bridges. However, previous studies have focused primarily on the control performance of NS-TMDs in simplified linear systems, without considering structural nonlinearities. To address this gap, this paper explores the effectiveness of using NS-TMDs for the seismic protection of bridges isolated with a FPS, and proposes a stability-based optimization strategy for NS-TMDs. In particular, the working mechanism and mechanical model of NS-TMDs are first introduced. The control devices are integrated into a FPS-isolated single-degree-of-freedom (SDOF) system. For this system, the nonlinear equilibrium equations are formulated, and a stochastic linearization analysis is performed. Subsequently, a stability-based optimization strategy is proposed for NS-TMDs and their control performance under stationary excitation is examined. Finally, a comprehensive analysis on the control effectiveness of NS-TMDs in the FPS-isolated bridge under non-stationary excitation is conducted. The results show that the optimized NS-TMDs could enhance the isolation efficiency of FPS while effectively constraining isolation deformation within a limited range under both far-field and near-fault earthquakes. In addition, NS-TMD I demonstrates greater effectiveness in reducing deck acceleration than deck displacement, whereas NS-TMD II exhibits the opposite trend. Overall, NS-TMDs provide an effective vibration control solution for improving the seismic performance of FPS-isolated bridges.
{"title":"Negative stiffness enhanced TMD for seismic response mitigation of bridges isolated with friction pendulum system (FPS)","authors":"Shaodong Jiang , Ruisheng Ma , Kaiming Bi , Huan Li , Xiuli Du","doi":"10.1016/j.engstruct.2025.119978","DOIUrl":"10.1016/j.engstruct.2025.119978","url":null,"abstract":"<div><div>Traditional seismic isolators, such as the friction pendulum system (FPS), exhibit high isolation efficiency during slight-to-moderate earthquakes, but their ability to constrain isolation deformations under severe earthquakes remains limited. The negative stiffness enhanced tuned mass dampers (NS-TMDs), which exist in two configurations (NS-TMD I and NS-TMD II), have been successfully employed to improve the seismic performance of isolated bridges. However, previous studies have focused primarily on the control performance of NS-TMDs in simplified linear systems, without considering structural nonlinearities. To address this gap, this paper explores the effectiveness of using NS-TMDs for the seismic protection of bridges isolated with a FPS, and proposes a stability-based optimization strategy for NS-TMDs. In particular, the working mechanism and mechanical model of NS-TMDs are first introduced. The control devices are integrated into a FPS-isolated single-degree-of-freedom (SDOF) system. For this system, the nonlinear equilibrium equations are formulated, and a stochastic linearization analysis is performed. Subsequently, a stability-based optimization strategy is proposed for NS-TMDs and their control performance under stationary excitation is examined. Finally, a comprehensive analysis on the control effectiveness of NS-TMDs in the FPS-isolated bridge under non-stationary excitation is conducted. The results show that the optimized NS-TMDs could enhance the isolation efficiency of FPS while effectively constraining isolation deformation within a limited range under both far-field and near-fault earthquakes. In addition, NS-TMD I demonstrates greater effectiveness in reducing deck acceleration than deck displacement, whereas NS-TMD II exhibits the opposite trend. Overall, NS-TMDs provide an effective vibration control solution for improving the seismic performance of FPS-isolated bridges.</div></div>","PeriodicalId":11763,"journal":{"name":"Engineering Structures","volume":"331 ","pages":"Article 119978"},"PeriodicalIF":5.6,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550427","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}