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}
Pub Date : 2025-03-03DOI: 10.1016/j.engstruct.2025.120009
Fenghao Qu , Shiping Yin , Huarui Liu
In the realm of masonry structures, walls—serving as the primary load-bearing components—exhibit significant susceptibility to damage during seismic events owing to their inherent brittleness. To enhance the shear performance of damaged walls, diagonal compression tests were performed on damaged specimens reinforced with textile reinforced concrete (TRC). This study meticulously examines various factors, including the extent of damage, reinforcement strategies, the number of textile layers, and the anchoring of the surface layer, while exploring the mechanisms through which TRC enhances the shear performance of damaged walls. The findings indicate that post-repair specimens predominantly exhibited diagonal tensile failures. Repairs utilizing a single-sided, two-layer textile demonstrated a degree of out-of-plane bending, whereas dual-sided reinforcement produced the most pronounced improvements in performance. Moreover, the shear strength, ductility, and energy dissipation exhibited significant enhancements within a specific range as the number of textile layers increased. Notably, improvements in mechanical performance parameters were modest in severely damaged specimens, whereas they remained comparable between slightly damaged and intact specimens. Anchoring effectively alleviated the out-of-plane bending associated with single-sided repairs, thereby enhancing shear performance. Ultimately, a comparative analysis of the experimental results against analytical models for reinforced walls demonstrated that the ACI 549.6R-20 calculation method aligns closely with the experimental data.
{"title":"In-plane shear behaviour by diagonal-compression testing of damaged masonry walls strengthened with carbon-glass hybrid textile reinforced concrete","authors":"Fenghao Qu , Shiping Yin , Huarui Liu","doi":"10.1016/j.engstruct.2025.120009","DOIUrl":"10.1016/j.engstruct.2025.120009","url":null,"abstract":"<div><div>In the realm of masonry structures, walls—serving as the primary load-bearing components—exhibit significant susceptibility to damage during seismic events owing to their inherent brittleness. To enhance the shear performance of damaged walls, diagonal compression tests were performed on damaged specimens reinforced with textile reinforced concrete (TRC). This study meticulously examines various factors, including the extent of damage, reinforcement strategies, the number of textile layers, and the anchoring of the surface layer, while exploring the mechanisms through which TRC enhances the shear performance of damaged walls. The findings indicate that post-repair specimens predominantly exhibited diagonal tensile failures. Repairs utilizing a single-sided, two-layer textile demonstrated a degree of out-of-plane bending, whereas dual-sided reinforcement produced the most pronounced improvements in performance. Moreover, the shear strength, ductility, and energy dissipation exhibited significant enhancements within a specific range as the number of textile layers increased. Notably, improvements in mechanical performance parameters were modest in severely damaged specimens, whereas they remained comparable between slightly damaged and intact specimens. Anchoring effectively alleviated the out-of-plane bending associated with single-sided repairs, thereby enhancing shear performance. Ultimately, a comparative analysis of the experimental results against analytical models for reinforced walls demonstrated that the ACI 549.6R-20 calculation method aligns closely with the experimental data.</div></div>","PeriodicalId":11763,"journal":{"name":"Engineering Structures","volume":"331 ","pages":"Article 120009"},"PeriodicalIF":5.6,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550323","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 : 2025-03-01DOI: 10.1016/j.engstruct.2025.119977
Zhi-Cheng Yang, Wei Li, Yu-Feng Cheng, Lin-Hai Han
This paper investigates the seismic performance of the grouted concrete-filled double skin steel tubular (CFDST) column base. Two column base specimens are tested under compression and lateral cyclic load, with analysis focused on investigating the failure modes, load-displacement relationship, strain distribution, deformation patterns, and the degradation of strength and stiffness. A finite element model is established, validated and employed for analysing the deformation and internal force. Three types of failure modes are identified, namely, the flexural failure at the CFDST column, the pullout failure of the grout, and the punching shear failure of the grout. These failure modes vary depending on parameters such as the embedment depth and the compressive strength of the grout. At shallow embedment depths, pullout failure at the grout becomes more prominent. Conversely, insufficient compressive strength of the grout enhances the risk of punching shear failure at the grout. A design method is proposed by parametric analysis, encompassing the flexural resistance calculation and structural detailing recommendations.
{"title":"Seismic performance of grouted CFDST column base: Investigation and design method","authors":"Zhi-Cheng Yang, Wei Li, Yu-Feng Cheng, Lin-Hai Han","doi":"10.1016/j.engstruct.2025.119977","DOIUrl":"10.1016/j.engstruct.2025.119977","url":null,"abstract":"<div><div>This paper investigates the seismic performance of the grouted concrete-filled double skin steel tubular (CFDST) column base. Two column base specimens are tested under compression and lateral cyclic load, with analysis focused on investigating the failure modes, load-displacement relationship, strain distribution, deformation patterns, and the degradation of strength and stiffness. A finite element model is established, validated and employed for analysing the deformation and internal force. Three types of failure modes are identified, namely, the flexural failure at the CFDST column, the pullout failure of the grout, and the punching shear failure of the grout. These failure modes vary depending on parameters such as the embedment depth and the compressive strength of the grout. At shallow embedment depths, pullout failure at the grout becomes more prominent. Conversely, insufficient compressive strength of the grout enhances the risk of punching shear failure at the grout. A design method is proposed by parametric analysis, encompassing the flexural resistance calculation and structural detailing recommendations.</div></div>","PeriodicalId":11763,"journal":{"name":"Engineering Structures","volume":"331 ","pages":"Article 119977"},"PeriodicalIF":5.6,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143527183","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 : 2025-03-01DOI: 10.1016/j.engstruct.2025.119995
Shiwen Han , Gang Xiao , Wei Tan , Peirong Mai , Ao Zhou , Jing Yu , Jinping Ou
Due to steel corrosion and shortage of freshwater and river sand for marine infrastructure, combing fiber-reinforced polymer (FRP) bars and seawater sea-sand concrete (SSC) has garnered increasing attention. Nevertheless, applying this combination in column is prevented by brittle failure and inferior compressive performance of FRP bars, and inferior confinement efficiency of conventional pultruded FRP stirrups. Here, a novel hybrid reinforcing system composed of longitudinal steel-FRP composite bars (SFCBs) and closed-type FRP stirrups was adopted for SSC column to obtain comparable mechanical behavior to steel bars reinforced concrete column. To overcome the inapplicability of existing design method, a simplified equivalent design method was explored and verified for hybrid-RC column. Results demonstrate that, in comparison with longitudinal steel bars, equal-stiffness longitudinal SFCBs offer comparable contribution for column under compression. Linear elastic properties and high strength of closed-type FRP stirrups result in excellent confinement, significantly enhancing the ductility by 58–163%. The desirable mechanical contribution of longitudinal SFCBs and the excellent confinement provided by FRP stirrups provide the foundation for establishing the equivalent design method. Equivalent-designed hybrid-RC column exhibits equivalent or even better compression behavior than steel-RC column. This equivalent method offers simple and safe design strategies for SSC column with hybrid reinforcing system.
{"title":"Simplified equivalent design for novel hybrid steel-FRP composite bars and closed-type FRP stirrups reinforced seawater sea-sand concrete columns","authors":"Shiwen Han , Gang Xiao , Wei Tan , Peirong Mai , Ao Zhou , Jing Yu , Jinping Ou","doi":"10.1016/j.engstruct.2025.119995","DOIUrl":"10.1016/j.engstruct.2025.119995","url":null,"abstract":"<div><div>Due to steel corrosion and shortage of freshwater and river sand for marine infrastructure, combing fiber-reinforced polymer (FRP) bars and seawater sea-sand concrete (SSC) has garnered increasing attention. Nevertheless, applying this combination in column is prevented by brittle failure and inferior compressive performance of FRP bars, and inferior confinement efficiency of conventional pultruded FRP stirrups. Here, a novel hybrid reinforcing system composed of longitudinal steel-FRP composite bars (SFCBs) and closed-type FRP stirrups was adopted for SSC column to obtain comparable mechanical behavior to steel bars reinforced concrete column. To overcome the inapplicability of existing design method, a simplified equivalent design method was explored and verified for hybrid-RC column. Results demonstrate that, in comparison with longitudinal steel bars, equal-stiffness longitudinal SFCBs offer comparable contribution for column under compression. Linear elastic properties and high strength of closed-type FRP stirrups result in excellent confinement, significantly enhancing the ductility by 58–163%. The desirable mechanical contribution of longitudinal SFCBs and the excellent confinement provided by FRP stirrups provide the foundation for establishing the equivalent design method. Equivalent-designed hybrid-RC column exhibits equivalent or even better compression behavior than steel-RC column. This equivalent method offers simple and safe design strategies for SSC column with hybrid reinforcing system.</div></div>","PeriodicalId":11763,"journal":{"name":"Engineering Structures","volume":"331 ","pages":"Article 119995"},"PeriodicalIF":5.6,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143521126","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 : 2025-03-01DOI: 10.1016/j.engstruct.2025.119975
Ernian Zhao , Qi Song , Xin Zhang , Shuming Li
Hybrid structures comprising steel and engineered wood or bamboo have attracted considerable attention from researchers and engineers worldwide. In this study, a novel inorganic-bonded bamboo (InorgBam) material was introduced, and the shear performance of steel-to-InorgBam composite (SBC) connections was investigated using double symmetric specimens. Bolt and welded grout stud shear connectors were considered. The impact of the slenderness ratio of shear connectors on the load-carrying capacity and shear stiffness of SBCs was discussed. The equations in EC 5 were used to evaluate the load-carrying capacity of the bolted connections. The rope effect in EC 5 was improved by considering the degree of plastic deformation of the bolts; in addition, an improved analytical model was proposed to evaluate the shear performance of the bolted connections. For SBC connections with welded stud connectors, load-carrying mechanisms were first discussed, which proved that the failure mode of welded stud connectors is like that of welded studs in steel-concrete composite structures. Consequently, equations to evaluate the shear capacity of steel-concrete composite structures have been adopted for SBC connections with welded stud connectors. The results indicate that the equations in AISC 360–16 are applicable to SBC connections with stud connectors embedded in grout pockets. These findings are beneficial for promoting the application of novel bamboo-based composites in SBC beams and floor systems.
{"title":"Shear performance of H-shaped steel to novel inorganic-bonded bamboo composite connections: Experimental tests and prediction models","authors":"Ernian Zhao , Qi Song , Xin Zhang , Shuming Li","doi":"10.1016/j.engstruct.2025.119975","DOIUrl":"10.1016/j.engstruct.2025.119975","url":null,"abstract":"<div><div>Hybrid structures comprising steel and engineered wood or bamboo have attracted considerable attention from researchers and engineers worldwide. In this study, a novel inorganic-bonded bamboo (<em>InorgBam</em>) material was introduced, and the shear performance of steel-to-<em>InorgBam</em> composite (SBC) connections was investigated using double symmetric specimens. Bolt and welded grout stud shear connectors were considered. The impact of the slenderness ratio of shear connectors on the load-carrying capacity and shear stiffness of SBCs was discussed. The equations in EC 5 were used to evaluate the load-carrying capacity of the bolted connections. The rope effect in EC 5 was improved by considering the degree of plastic deformation of the bolts; in addition, an improved analytical model was proposed to evaluate the shear performance of the bolted connections. For SBC connections with welded stud connectors, load-carrying mechanisms were first discussed, which proved that the failure mode of welded stud connectors is like that of welded studs in steel-concrete composite structures. Consequently, equations to evaluate the shear capacity of steel-concrete composite structures have been adopted for SBC connections with welded stud connectors. The results indicate that the equations in AISC 360–16 are applicable to SBC connections with stud connectors embedded in grout pockets. These findings are beneficial for promoting the application of novel bamboo-based composites in SBC beams and floor systems.</div></div>","PeriodicalId":11763,"journal":{"name":"Engineering Structures","volume":"331 ","pages":"Article 119975"},"PeriodicalIF":5.6,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143521183","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 : 2025-02-28DOI: 10.1016/j.engstruct.2025.119932
Freddie Theland , Geert Lombaert , Stijn François , Abbas Zangeneh , Fanny Deckner , Jean-Marc Battini
Ground-borne vibration from roads or railways is a growing concern in the planning of new buildings in urban environments. Vibration assessment is often based on initial measurements of the free field vibrations to estimate building vibrations by either empirical or numerical procedures. Dynamic interaction between the soil and the foundation has an important influence on the transmitted vibrations, especially for embedded foundations, and should therefore be properly accounted for. This paper presents the results from a series of full-scale field experiments that were performed to characterise the vibration response of an end-bearing pile group foundation in soft clay subjected to a dynamic load applied at the ground surface. Controlled dynamic excitation is applied vertically at the ground surface from 10 and 20 m horizontal distance using an electrodynamic inertial shaker. Accelerations are measured at different construction stages: prior to construction, after driving of the piles and after completion of the pile cap. Predictions from a numerical model and from a hybrid method utilising measurement data acquired in an earlier construction stage are both validated with the data from the field tests. The results indicate that the relationship between the amplitudes of the vertical foundation and free field responses are insensitive to source–receiver distance. It is also found that pile–soil–pile interaction has an important influence on the vertical response of the piles.
{"title":"Measurements and predictions of vibration response of end-bearing pile group in soft clay due to vertical ground surface load","authors":"Freddie Theland , Geert Lombaert , Stijn François , Abbas Zangeneh , Fanny Deckner , Jean-Marc Battini","doi":"10.1016/j.engstruct.2025.119932","DOIUrl":"10.1016/j.engstruct.2025.119932","url":null,"abstract":"<div><div>Ground-borne vibration from roads or railways is a growing concern in the planning of new buildings in urban environments. Vibration assessment is often based on initial measurements of the free field vibrations to estimate building vibrations by either empirical or numerical procedures. Dynamic interaction between the soil and the foundation has an important influence on the transmitted vibrations, especially for embedded foundations, and should therefore be properly accounted for. This paper presents the results from a series of full-scale field experiments that were performed to characterise the vibration response of an end-bearing pile group foundation in soft clay subjected to a dynamic load applied at the ground surface. Controlled dynamic excitation is applied vertically at the ground surface from 10 and 20 m horizontal distance using an electrodynamic inertial shaker. Accelerations are measured at different construction stages: prior to construction, after driving of the piles and after completion of the pile cap. Predictions from a numerical model and from a hybrid method utilising measurement data acquired in an earlier construction stage are both validated with the data from the field tests. The results indicate that the relationship between the amplitudes of the vertical foundation and free field responses are insensitive to source–receiver distance. It is also found that pile–soil–pile interaction has an important influence on the vertical response of the piles.</div></div>","PeriodicalId":11763,"journal":{"name":"Engineering Structures","volume":"331 ","pages":"Article 119932"},"PeriodicalIF":5.6,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143521181","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}
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