Pub Date : 2024-09-04DOI: 10.1016/j.istruc.2024.107184
Stefano Sorace, Nicola Bidoli, Gloria Terenzi
A wide stock of reinforced concrete (RC) gyms and sports halls was built in Italy from 1960s through 1990s with similar architectural characteristics, among which the two-level partition of façades, displaying continuous masonry infills full in contact with the frame structure on the lower level, and glazed ribbon windows on the upper level. A school gym built in 1976, well representative of this stock of edifices, is examined herein with the aim of assessing its seismic performance in current state and proposing a supplemental damping-based retrofit solution capable of providing adequate protection both to the structure and the non-structural elements. The assessment study is carried out via non-linear dynamic analysis, by modelling infills by means of equivalent diagonal struts, and RC members by plastic hinges. The response of the ribbon windows, not expressly simulated in the analysis, is checked in terms of relevant inter-level drift. The results show a significant inelastic response of the infill panels and the RC columns, and very high drifts on the glazed level, resulting in full collapse conditions of the ribbon windows, under a Basic Design Earthquake (BDE)-scaled seismic action. Consequently, a retrofit hypothesis is conceived, based on the installation of a dissipative bracing system incorporating pressurized fluid-viscous devices on the glazed level, and conventional braces on the infilled level. The location of the system implies no architectural intrusion in the interiors or interruption in the usage of the building. The analyses in post-intervention conditions highlight a remarkable response reduction both in terms of drifts and stress states, consistently with the target design objectives. This allows reaching a safe response of structural elements and ribbon windows, and an elastic response of infills, up to the BDE.
{"title":"Glazed-level dissipative brace incorporation in a gym building","authors":"Stefano Sorace, Nicola Bidoli, Gloria Terenzi","doi":"10.1016/j.istruc.2024.107184","DOIUrl":"https://doi.org/10.1016/j.istruc.2024.107184","url":null,"abstract":"A wide stock of reinforced concrete (RC) gyms and sports halls was built in Italy from 1960s through 1990s with similar architectural characteristics, among which the two-level partition of façades, displaying continuous masonry infills full in contact with the frame structure on the lower level, and glazed ribbon windows on the upper level. A school gym built in 1976, well representative of this stock of edifices, is examined herein with the aim of assessing its seismic performance in current state and proposing a supplemental damping-based retrofit solution capable of providing adequate protection both to the structure and the non-structural elements. The assessment study is carried out via non-linear dynamic analysis, by modelling infills by means of equivalent diagonal struts, and RC members by plastic hinges. The response of the ribbon windows, not expressly simulated in the analysis, is checked in terms of relevant inter-level drift. The results show a significant inelastic response of the infill panels and the RC columns, and very high drifts on the glazed level, resulting in full collapse conditions of the ribbon windows, under a Basic Design Earthquake (BDE)-scaled seismic action. Consequently, a retrofit hypothesis is conceived, based on the installation of a dissipative bracing system incorporating pressurized fluid-viscous devices on the glazed level, and conventional braces on the infilled level. The location of the system implies no architectural intrusion in the interiors or interruption in the usage of the building. The analyses in post-intervention conditions highlight a remarkable response reduction both in terms of drifts and stress states, consistently with the target design objectives. This allows reaching a safe response of structural elements and ribbon windows, and an elastic response of infills, up to the BDE.","PeriodicalId":48642,"journal":{"name":"Structures","volume":null,"pages":null},"PeriodicalIF":4.1,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142222189","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-04DOI: 10.1016/j.istruc.2024.107156
Tianyou Tao, Hao Wang, Xuehua Wen, Aksel Fenerci
Flutter is a significant concern in the safe design of long-span bridges, and its evaluation traditionally assumes a uniform wind field along the span. However, in the horizontal plane of a typhoon, the tangential wind speed exhibits non-uniformity as one moves further away from the typhoon's eye. Therefore, the assumption of a uniform wind field is not applicable to this specific wind hazard. To gain better insights into the flutter instability of long-span bridges, it is crucial to evaluate the structural flutter performance in a more realistic and non-uniform typhoon field. This paper presents a comprehensive flutter analysis of a long-span triple-tower suspension bridge (TTSB) under typhoon winds. In the parametric analysis, the effect of the radius of the typhoon eye and the relative position between the bridge and the typhoon is considered. Three typical bridge sections are employed for flutter analyses with a comparison to reveal the effect of aerodynamic shapes. The analytical results indicate that the flutter of a TTSB may potentially occur when the wind speed at limited sections of the span in non-uniform typhoon winds exceeds the critical wind speed observed under uniform wind conditions. This phenomenon is particularly significant when the bridge is situated within the typhoon eye and in close proximity to the eyewall. The spanwise variation rates of wind speed for comparable sections are approximately identical, which leads to an expedient determination of the spanwise distribution of non-uniform wind speeds for different sections in the preliminary design of bridge decks once the critical wind speed of the bridge under uniform winds is known. This could facilitate the development of more robust wind-resistant designs for TTSBs in regions prone to typhoons.
{"title":"Flutter analysis of a long-span triple-tower suspension bridge under typhoon winds with non-uniform spanwise profile","authors":"Tianyou Tao, Hao Wang, Xuehua Wen, Aksel Fenerci","doi":"10.1016/j.istruc.2024.107156","DOIUrl":"https://doi.org/10.1016/j.istruc.2024.107156","url":null,"abstract":"Flutter is a significant concern in the safe design of long-span bridges, and its evaluation traditionally assumes a uniform wind field along the span. However, in the horizontal plane of a typhoon, the tangential wind speed exhibits non-uniformity as one moves further away from the typhoon's eye. Therefore, the assumption of a uniform wind field is not applicable to this specific wind hazard. To gain better insights into the flutter instability of long-span bridges, it is crucial to evaluate the structural flutter performance in a more realistic and non-uniform typhoon field. This paper presents a comprehensive flutter analysis of a long-span triple-tower suspension bridge (TTSB) under typhoon winds. In the parametric analysis, the effect of the radius of the typhoon eye and the relative position between the bridge and the typhoon is considered. Three typical bridge sections are employed for flutter analyses with a comparison to reveal the effect of aerodynamic shapes. The analytical results indicate that the flutter of a TTSB may potentially occur when the wind speed at limited sections of the span in non-uniform typhoon winds exceeds the critical wind speed observed under uniform wind conditions. This phenomenon is particularly significant when the bridge is situated within the typhoon eye and in close proximity to the eyewall. The spanwise variation rates of wind speed for comparable sections are approximately identical, which leads to an expedient determination of the spanwise distribution of non-uniform wind speeds for different sections in the preliminary design of bridge decks once the critical wind speed of the bridge under uniform winds is known. This could facilitate the development of more robust wind-resistant designs for TTSBs in regions prone to typhoons.","PeriodicalId":48642,"journal":{"name":"Structures","volume":null,"pages":null},"PeriodicalIF":4.1,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142222174","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-03DOI: 10.1016/j.istruc.2024.107195
Jia-Ming Zhang, Chao-Qun Yu, Gen-Shu Tong, Ming Chen, Jing-Zhong Tong
Multi-celled corrugated-plate concrete-filled steel tubular (MC-CFST) walls are innovative steel-concrete composite walls comprising horizontally arranged corrugated steel plates, interval flat steel plates, and infilled concrete. Due to the significantly improved out-of-plane stiffness, the corrugated steel plate provides a considerable confinement effect on the infilled concrete, which enhances the structural efficiency and cost-effectiveness of MC-CFST walls. In this study, the stability performance of MC-CFST walls under combined axial and in-plane bending loads was investigated through extensive numerical simulations. A refined finite element (FE) model was established and validated using existing test results. Moreover, a formula for calculating the bending capacity of MC-CFST walls was also derived and validated against FE results. Additionally, parametric analyses were conducted to evaluate the effects of various factors such as the wall width, wall height, concrete strength, steel strength, and width of individual corrugated cells on the global stability performance. It was found that the stability performance was predominantly affected by the overall width of the wall rather than the width of the individual corrugated cells, with an increase in wall dimensions generally diminishing the stability performance. Furthermore, increasing the concrete strength improved the stability performance, while increasing the steel strength had a negative effect. Finally, a design formula was proposed for evaluating the bearing capacity and stability performance of MC-CFST walls under combined axial and in-plane bending loads. The formula demonstrated good agreement with the FE results, and it could provide a valuable reference for practical designs of MC-CFST walls.
{"title":"Stability design of multi-celled corrugated-plate CFST walls under combined axial and in-plane bending loads","authors":"Jia-Ming Zhang, Chao-Qun Yu, Gen-Shu Tong, Ming Chen, Jing-Zhong Tong","doi":"10.1016/j.istruc.2024.107195","DOIUrl":"https://doi.org/10.1016/j.istruc.2024.107195","url":null,"abstract":"Multi-celled corrugated-plate concrete-filled steel tubular (MC-CFST) walls are innovative steel-concrete composite walls comprising horizontally arranged corrugated steel plates, interval flat steel plates, and infilled concrete. Due to the significantly improved out-of-plane stiffness, the corrugated steel plate provides a considerable confinement effect on the infilled concrete, which enhances the structural efficiency and cost-effectiveness of MC-CFST walls. In this study, the stability performance of MC-CFST walls under combined axial and in-plane bending loads was investigated through extensive numerical simulations. A refined finite element (FE) model was established and validated using existing test results. Moreover, a formula for calculating the bending capacity of MC-CFST walls was also derived and validated against FE results. Additionally, parametric analyses were conducted to evaluate the effects of various factors such as the wall width, wall height, concrete strength, steel strength, and width of individual corrugated cells on the global stability performance. It was found that the stability performance was predominantly affected by the overall width of the wall rather than the width of the individual corrugated cells, with an increase in wall dimensions generally diminishing the stability performance. Furthermore, increasing the concrete strength improved the stability performance, while increasing the steel strength had a negative effect. Finally, a design formula was proposed for evaluating the bearing capacity and stability performance of MC-CFST walls under combined axial and in-plane bending loads. The formula demonstrated good agreement with the FE results, and it could provide a valuable reference for practical designs of MC-CFST walls.","PeriodicalId":48642,"journal":{"name":"Structures","volume":null,"pages":null},"PeriodicalIF":4.1,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142222197","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-03DOI: 10.1016/j.istruc.2024.107179
Yixin Zhang, Dahai Wang, Chao Sun, Xing Fu
Localized severe non-synoptic winds, such as downbursts and tornadoes, cause frequent structural failures of the electric transmission lines worldwide. This paper aims to develop an analytical approach to evaluate the extreme non-stationary dynamic response of transmission towers under downbursts in frequency domain. First, the empirical models of time-varying mean wind and non-stationary fluctuating wind of moving downbursts are introduced to deduce the transient wind loads on transmission towers in time domain. The closed-form frequency domain solutions of non-stationary fluctuating downburst wind-induced response of transmission towers are derived based on the pseudo excitation method. Furthermore, through the up-crossing extreme value theory, the probability distribution of the non-stationary extreme response is studied. Finally, the peak factors of the non-stationary and the equivalent stationary theoretical methods are compared based on the proposed equivalent stationary extreme value distribution for engineering application. The proposed theoretical framework is validated by stochastic sampling simulation and finite element analysis. It is found that the proposed theoretical framework can accurately assess the extreme value responses of transmission towers under non-stationary moving downbursts.
{"title":"Probabilistic study on non-stationary extreme response of transmission tower under moving downburst impact","authors":"Yixin Zhang, Dahai Wang, Chao Sun, Xing Fu","doi":"10.1016/j.istruc.2024.107179","DOIUrl":"https://doi.org/10.1016/j.istruc.2024.107179","url":null,"abstract":"Localized severe non-synoptic winds, such as downbursts and tornadoes, cause frequent structural failures of the electric transmission lines worldwide. This paper aims to develop an analytical approach to evaluate the extreme non-stationary dynamic response of transmission towers under downbursts in frequency domain. First, the empirical models of time-varying mean wind and non-stationary fluctuating wind of moving downbursts are introduced to deduce the transient wind loads on transmission towers in time domain. The closed-form frequency domain solutions of non-stationary fluctuating downburst wind-induced response of transmission towers are derived based on the pseudo excitation method. Furthermore, through the up-crossing extreme value theory, the probability distribution of the non-stationary extreme response is studied. Finally, the peak factors of the non-stationary and the equivalent stationary theoretical methods are compared based on the proposed equivalent stationary extreme value distribution for engineering application. The proposed theoretical framework is validated by stochastic sampling simulation and finite element analysis. It is found that the proposed theoretical framework can accurately assess the extreme value responses of transmission towers under non-stationary moving downbursts.","PeriodicalId":48642,"journal":{"name":"Structures","volume":null,"pages":null},"PeriodicalIF":4.1,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142222200","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-03DOI: 10.1016/j.istruc.2024.107161
Shen Wang, Chaoqi Zhang, Di Yao
Nuclear containment structures serve as the main line of defense to prevent escape of radioactive material during catastrophic events including the loss of coolant accident (LOCA), aircraft impact, explosions and earthquake. For more than half a century, structural types of nuclear containment remain essentially unchanged. With construction cost of recent nuclear projects increasing significantly, there is need to improve containment structures in order to achieve better cost efficiencies, schedule improvement and sustainability by utilizing the latest industry trends, technologies and innovations. Future novel containment may use Steel-Plate Composite (SC), Ultra High Performance Concrete (UHPC), 3D printing Concrete (3DPC), performance-based and risk-informed design method, and so on. With a lack of industry experience, however, specialists in aforementioned technical areas face additional challenges in spreading knowledge to nuclear containment designers so that the latter can be versed in applying those technologies. For these reasons, a comprehensive literature study on recent development trends on novel nuclear containment structures should be conducted. This article provides a comprehensive survey of current technological challenges and prospects for developing various novel containment types. Advantages and shortcomings of each technology, as well as their applicability in nuclear containments are evaluated and discussed. This state-of-the-art review is aimed at helping designers and researchers of future nuclear containments widen the use of relevant technologies and innovations. This review can serve as a starting point for developing future novel containment structures.
{"title":"Developing novel nuclear containment structures: Current status and future prospects","authors":"Shen Wang, Chaoqi Zhang, Di Yao","doi":"10.1016/j.istruc.2024.107161","DOIUrl":"https://doi.org/10.1016/j.istruc.2024.107161","url":null,"abstract":"Nuclear containment structures serve as the main line of defense to prevent escape of radioactive material during catastrophic events including the loss of coolant accident (LOCA), aircraft impact, explosions and earthquake. For more than half a century, structural types of nuclear containment remain essentially unchanged. With construction cost of recent nuclear projects increasing significantly, there is need to improve containment structures in order to achieve better cost efficiencies, schedule improvement and sustainability by utilizing the latest industry trends, technologies and innovations. Future novel containment may use Steel-Plate Composite (SC), Ultra High Performance Concrete (UHPC), 3D printing Concrete (3DPC), performance-based and risk-informed design method, and so on. With a lack of industry experience, however, specialists in aforementioned technical areas face additional challenges in spreading knowledge to nuclear containment designers so that the latter can be versed in applying those technologies. For these reasons, a comprehensive literature study on recent development trends on novel nuclear containment structures should be conducted. This article provides a comprehensive survey of current technological challenges and prospects for developing various novel containment types. Advantages and shortcomings of each technology, as well as their applicability in nuclear containments are evaluated and discussed. This state-of-the-art review is aimed at helping designers and researchers of future nuclear containments widen the use of relevant technologies and innovations. This review can serve as a starting point for developing future novel containment structures.","PeriodicalId":48642,"journal":{"name":"Structures","volume":null,"pages":null},"PeriodicalIF":4.1,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142222204","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}
The shear resistance of cold joint in concrete is influenced by various design parameters. Traditional mechanical models typically consider only a limited number of parameters to predict the shear strength of cold joints. This research aims to explore the complex nonlinear relationship between design parameters and cold joint shear strength using statistical method and machine learning technology. The goal is to develop a more accurate, reliable, and engineering applicable regression model for predicting shear strength. A dataset of 546 Z-shaped shear specimens characterizing cold joint in concrete was constructed, involving a total of 16 variables that may affect shear performance. Correlation analysis and recursive elimination were adopted to eliminate correlated and insignificant variables based on their importance. Multiple linear regression (MLR), random forest regression (RFR), and support vector machine regression (SVR) prediction models for cold joint shear strength were established based on rigorously screened variables and comprehensively evaluated using multiple methods. It was found that the most significant factors influencing the shear strength of cold joints are concrete strength, interface shear key, product of interface reinforcement strength and its reinforcement ratio, normal stress, fiber length of new concrete, casting method of the new concrete, and product of the fiber length and its tensile strength of old concrete. The MLR, SVR, and RFR models all exhibited superior performance relative to traditional mechanics-based models with regard to shear strength prediction of cold joints. The RFR model is recommended for predicting the shear strength of cold joints due to its superior evaluation indexes in comparison to the MLR and SVR models, and variable sensitivity analysis shows that it does not yield common-sense errors.
{"title":"Regression prediction model for shear strength of cold joint in concrete","authors":"Ziqin Zhong, Shixing Zhao, Jing Xia, Qirui Luo, Qiaoling Zhou, Shuheng Yang, Fei He, Yu Yao","doi":"10.1016/j.istruc.2024.107168","DOIUrl":"https://doi.org/10.1016/j.istruc.2024.107168","url":null,"abstract":"The shear resistance of cold joint in concrete is influenced by various design parameters. Traditional mechanical models typically consider only a limited number of parameters to predict the shear strength of cold joints. This research aims to explore the complex nonlinear relationship between design parameters and cold joint shear strength using statistical method and machine learning technology. The goal is to develop a more accurate, reliable, and engineering applicable regression model for predicting shear strength. A dataset of 546 Z-shaped shear specimens characterizing cold joint in concrete was constructed, involving a total of 16 variables that may affect shear performance. Correlation analysis and recursive elimination were adopted to eliminate correlated and insignificant variables based on their importance. Multiple linear regression (MLR), random forest regression (RFR), and support vector machine regression (SVR) prediction models for cold joint shear strength were established based on rigorously screened variables and comprehensively evaluated using multiple methods. It was found that the most significant factors influencing the shear strength of cold joints are concrete strength, interface shear key, product of interface reinforcement strength and its reinforcement ratio, normal stress, fiber length of new concrete, casting method of the new concrete, and product of the fiber length and its tensile strength of old concrete. The MLR, SVR, and RFR models all exhibited superior performance relative to traditional mechanics-based models with regard to shear strength prediction of cold joints. The RFR model is recommended for predicting the shear strength of cold joints due to its superior evaluation indexes in comparison to the MLR and SVR models, and variable sensitivity analysis shows that it does not yield common-sense errors.","PeriodicalId":48642,"journal":{"name":"Structures","volume":null,"pages":null},"PeriodicalIF":4.1,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142222202","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-03DOI: 10.1016/j.istruc.2024.107181
Yaojia Chen, Yubo Jiao, Hua Chen
This paper introduces a sustainable and environmentally friendly structural reinforcement method, which involves using fiber-reinforced polymer (FRP) steel composite tubes and sandwiched recycled aggregate concrete (RAC) to strengthen reinforced concrete (RC) columns. A total of fourteen specimens were designed to test under axial compression, including thirteen retrofitted columns and one original column. The effects of recycled coarse aggregate (RA) replacement ratio, external FRP layers, steel tube thickness, RAC strength grade, and confinement tube type on the structural performance of retrofitted columns were investigated. The research results demonstrated that FRP-steel composite tube composed of inner steel tube and external FRP showed efficient confinement ability and synergistic effects, which significantly improved the load-bearing capacity and stiffness of the original column. The bonding performance between sandwiched RAC and original concrete mainly depended on the confinement effect of inner steel tube. Waist bulge failure and shear failure were observed on the modified column, which can be divided into five characteristic points according to the stepwise failure behavior. Five existing strength models were reasonably modified by considering the strength contribution of each component material. Meanwhile, a prediction model was proposed based on the ultimate equilibrium theory to evaluate the load-bearing capacity of retrofitted columns. The findings of this study contribute to promoting the application of RAC in structural reinforcement, offering practical cases and references for low-carbon reinforcement strategies.
{"title":"Low-carbon repair of RC columns using sandwiched RAC and FRP-steel composite tube: Axial compression tests and design","authors":"Yaojia Chen, Yubo Jiao, Hua Chen","doi":"10.1016/j.istruc.2024.107181","DOIUrl":"https://doi.org/10.1016/j.istruc.2024.107181","url":null,"abstract":"This paper introduces a sustainable and environmentally friendly structural reinforcement method, which involves using fiber-reinforced polymer (FRP) steel composite tubes and sandwiched recycled aggregate concrete (RAC) to strengthen reinforced concrete (RC) columns. A total of fourteen specimens were designed to test under axial compression, including thirteen retrofitted columns and one original column. The effects of recycled coarse aggregate (RA) replacement ratio, external FRP layers, steel tube thickness, RAC strength grade, and confinement tube type on the structural performance of retrofitted columns were investigated. The research results demonstrated that FRP-steel composite tube composed of inner steel tube and external FRP showed efficient confinement ability and synergistic effects, which significantly improved the load-bearing capacity and stiffness of the original column. The bonding performance between sandwiched RAC and original concrete mainly depended on the confinement effect of inner steel tube. Waist bulge failure and shear failure were observed on the modified column, which can be divided into five characteristic points according to the stepwise failure behavior. Five existing strength models were reasonably modified by considering the strength contribution of each component material. Meanwhile, a prediction model was proposed based on the ultimate equilibrium theory to evaluate the load-bearing capacity of retrofitted columns. The findings of this study contribute to promoting the application of RAC in structural reinforcement, offering practical cases and references for low-carbon reinforcement strategies.","PeriodicalId":48642,"journal":{"name":"Structures","volume":null,"pages":null},"PeriodicalIF":4.1,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142222001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-03DOI: 10.1016/j.istruc.2024.107187
Wenshan Li, Zhao Liu, Suiwen Wu
Small- and medium-span simply supported bridges are widely used in highway bridges, which are vulnerable to pounding-induced damage under strong earthquake action. Thus, developing a precise and appropriate mechanical model is crucial for practitioners and researchers to investigate the pounding effect and damage mechanism of bridges under seismic excitations. This paper presents a non-smooth dynamic framework to address the pounding problem of simple span bridges under seismic excitations. Normal pounding force and corresponding transverse friction force are added to the fundamental dynamic equation using constrained Jacobian matrixes, and the motion equation for the system is created to portray the pounding behavior of the structure at the pounding locations. The shake table test results obtained by the author from the previous experiment were employed to validate the proposed method. The comparison shows that the proposed model can precisely predict the pounding scenario of simple span bridges under seismic excitations. Finally, the influence of the coefficient of friction (CoF), the coefficient of restitution (CoR), and the nonparallel pounding effect (NPE) on the peak girder rotation (PGR) are analyzed. It is found that simple span bridges can exhibit in-plane rotation if the CoF is more than 0.3 and the rotation is not significantly affected by an increase in CoF from 0.4 to 1.0.
{"title":"A non-smooth dynamic model for pounding analysis of simple span bridges under seismic excitations","authors":"Wenshan Li, Zhao Liu, Suiwen Wu","doi":"10.1016/j.istruc.2024.107187","DOIUrl":"https://doi.org/10.1016/j.istruc.2024.107187","url":null,"abstract":"Small- and medium-span simply supported bridges are widely used in highway bridges, which are vulnerable to pounding-induced damage under strong earthquake action. Thus, developing a precise and appropriate mechanical model is crucial for practitioners and researchers to investigate the pounding effect and damage mechanism of bridges under seismic excitations. This paper presents a non-smooth dynamic framework to address the pounding problem of simple span bridges under seismic excitations. Normal pounding force and corresponding transverse friction force are added to the fundamental dynamic equation using constrained Jacobian matrixes, and the motion equation for the system is created to portray the pounding behavior of the structure at the pounding locations. The shake table test results obtained by the author from the previous experiment were employed to validate the proposed method. The comparison shows that the proposed model can precisely predict the pounding scenario of simple span bridges under seismic excitations. Finally, the influence of the coefficient of friction (CoF), the coefficient of restitution (CoR), and the nonparallel pounding effect (NPE) on the peak girder rotation (PGR) are analyzed. It is found that simple span bridges can exhibit in-plane rotation if the CoF is more than 0.3 and the rotation is not significantly affected by an increase in CoF from 0.4 to 1.0.","PeriodicalId":48642,"journal":{"name":"Structures","volume":null,"pages":null},"PeriodicalIF":4.1,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142222198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-03DOI: 10.1016/j.istruc.2024.107199
Ligang Qi, Jie Bai, Hangzi Wu, Guowen Xu, Hao Xiong, Yan Yang
Existing engineering applications typically involve carbon fiber reinforced polymers (CFRP) cables with relatively small ultimate tensile forces (less than 10MN). This study presents the engineering application of China's first thousand-ton-grade CFRP cable-stayed bridge. The optimal steel and CFRP hybrid cable system was determined through a comparative analysis of structural behavior and life cycle cost. Thereafter, the CFRP cable, consisting of 121 strands of φ7 CFRP tendons, along with its anchoring system, was designed and manufactured with a theoretical ultimate tensile strength of 10,710 kN (). Subsequently, the mechanical properties of 7–121 CFRP cable were investigated and experimentally verified. The tensile test revealed a satisfied ultimate tensile bearing capacity of 10,805 kN. Furthermore, after two million fatigue cycles, the CFRP cables retained approximately 90 % of their theoretical ultimate force, highlighting their excellent fatigue resistance. Besides, no damage occurred with a maintained tension force of 0.45 at a temperature of 150 °C for a duration of at least 30 min, meeting the requirements of specification. Moreover, the key procedures of CFRP cable installation were also claimed. This study aims to further promote the application and development of CFRP cables in larger span and even super-long span bridges.
{"title":"The first engineering application of 10MN CFRP cables in cable-stayed bridge in China","authors":"Ligang Qi, Jie Bai, Hangzi Wu, Guowen Xu, Hao Xiong, Yan Yang","doi":"10.1016/j.istruc.2024.107199","DOIUrl":"https://doi.org/10.1016/j.istruc.2024.107199","url":null,"abstract":"Existing engineering applications typically involve carbon fiber reinforced polymers (CFRP) cables with relatively small ultimate tensile forces (less than 10MN). This study presents the engineering application of China's first thousand-ton-grade CFRP cable-stayed bridge. The optimal steel and CFRP hybrid cable system was determined through a comparative analysis of structural behavior and life cycle cost. Thereafter, the CFRP cable, consisting of 121 strands of φ7 CFRP tendons, along with its anchoring system, was designed and manufactured with a theoretical ultimate tensile strength of 10,710 kN (). Subsequently, the mechanical properties of 7–121 CFRP cable were investigated and experimentally verified. The tensile test revealed a satisfied ultimate tensile bearing capacity of 10,805 kN. Furthermore, after two million fatigue cycles, the CFRP cables retained approximately 90 % of their theoretical ultimate force, highlighting their excellent fatigue resistance. Besides, no damage occurred with a maintained tension force of 0.45 at a temperature of 150 °C for a duration of at least 30 min, meeting the requirements of specification. Moreover, the key procedures of CFRP cable installation were also claimed. This study aims to further promote the application and development of CFRP cables in larger span and even super-long span bridges.","PeriodicalId":48642,"journal":{"name":"Structures","volume":null,"pages":null},"PeriodicalIF":4.1,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142222195","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-03DOI: 10.1016/j.istruc.2024.107118
Martina Russo, Pio Lorenzo Cocco, Ilaria Giannetti
In the 20th century, the development of industrial buildings featured a strong relationship between form, conception, needs of production processes, and advanced structural solutions. The knowledge, safeguard, and valorization of the industrial heritage structures, of the 20th century, requires a multidisciplinary approach, including construction history, structural analysis, and advanced 3D modeling. In particular, the study of shape-resistant structures in reinforced concrete – such as thin shells – needs to consider the deeply intertwined aspects of form, construction, and structural conception. The main aim of the present paper is to set a methodological workflow based on the combination of archival research, Historic/Heritage Building Information Modeling (HBIM), and numerical structural analysis to support the knowledge, safeguard, and valorization of the thin shells in reinforced concrete. The effectiveness of the proposed methodology, scalable for the analysis of historical shell structures in reinforced concrete, is tested on the noteworthy case study of the so-called Silberkuhl shells. According to their convenience in terms of structural efficiency and economy of construction, this system stood out worldwide for industrial roofing in the second half of the 20th century, exploiting the possibility of both industrial production and on-site precast, adapting to different economic and technological backgrounds.
{"title":"Analysis of the form, construction, and structural conception of Silberkuhl shells through construction history and advanced HBIM","authors":"Martina Russo, Pio Lorenzo Cocco, Ilaria Giannetti","doi":"10.1016/j.istruc.2024.107118","DOIUrl":"https://doi.org/10.1016/j.istruc.2024.107118","url":null,"abstract":"In the 20th century, the development of industrial buildings featured a strong relationship between form, conception, needs of production processes, and advanced structural solutions. The knowledge, safeguard, and valorization of the industrial heritage structures, of the 20th century, requires a multidisciplinary approach, including construction history, structural analysis, and advanced 3D modeling. In particular, the study of shape-resistant structures in reinforced concrete – such as thin shells – needs to consider the deeply intertwined aspects of form, construction, and structural conception. The main aim of the present paper is to set a methodological workflow based on the combination of archival research, Historic/Heritage Building Information Modeling (HBIM), and numerical structural analysis to support the knowledge, safeguard, and valorization of the thin shells in reinforced concrete. The effectiveness of the proposed methodology, scalable for the analysis of historical shell structures in reinforced concrete, is tested on the noteworthy case study of the so-called Silberkuhl shells. According to their convenience in terms of structural efficiency and economy of construction, this system stood out worldwide for industrial roofing in the second half of the 20th century, exploiting the possibility of both industrial production and on-site precast, adapting to different economic and technological backgrounds.","PeriodicalId":48642,"journal":{"name":"Structures","volume":null,"pages":null},"PeriodicalIF":4.1,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142222003","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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