The Experts below are selected from a list of 8160 Experts worldwide ranked by ideXlab platform
Wenting Yuan - One of the best experts on this subject based on the ideXlab platform.
-
equivalent elastic modulus of reinforcement to consider bond slip effects of coastal Bridge Piers with non uniform corrosion
Engineering Structures, 2020Co-Authors: Wenting Yuan, Hui LiAbstract:Abstract Coastal Bridge Piers in marine environments are vulnerable to non-uniform corrosion due to wetting-drying cycles and high chloride concentration of seawater. This paper presents a methodology to analyze the seismic performance of coastal Bridges by modifying the elastic modulus of reinforcement, while considering the effects of bond-slip and non-uniform corrosion. Tensile stress-slip relationships of reinforcement with uniform and non-uniform corrosion are first derived. Then, a method to determine the equivalent elastic modulus of reinforcement with non-uniform corrosion is introduced. The proposed methodology is validated based on cyclic test results of Bridge pier specimens under uniaxial and biaxial loading actions. Through further numerical simulation, the effects of mass loss ratio and corrosion zone height on seismic performance of coastal Bridge Piers are examined. Compared to the method of using an interface element, the proposed method of using equivalent elastic modulus of reinforcement is simpler for the numerical simulation of bond-slip for coastal Bridge Piers. Results showed that the steel-to-concrete interfacial bond behavior slightly influences the peak strength of coastal Bridge Piers. However, it can significantly reduce the energy dissipation capacity and residual displacement of structural components.
-
experimental investigation on cyclic behavior of coastal Bridge Piers with non uniform corrosion under biaxial quasi static loads
Construction and Building Materials, 2018Co-Authors: Wenting Yuan, Wei Yuan, Hui LiAbstract:Abstract Corrosion-induced damage on coastal Bridge Piers reduces the seismic performance of structures. Biaxial earthquake excitation makes the degradation even worse. In this study, cyclic tests of four corroded Bridge Piers with different levels of non-uniform corrosion damage along the elevation were conducted under biaxial pseudo-static cyclic loads, while another corroded Bridge pier was applied with only a uniaxial load for comparison. First, the experimental program, including the specimen design, accelerated corrosion in laboratory, test facility, measurement instrument, and loading protocol, is introduced. Then, based on the test results, the experimental observations, hysteretic characteristics, strength, ductility, curvature distribution, and energy dissipation of the specimens are analyzed to investigate the effects of the corrosion degree and biaxial horizontal loading condition. The test results indicate that the seismic performance of Bridge Piers is strongly affected by biaxial horizontal loads, and the increase in local damage due to non-uniform corrosion makes the performance deterioration more severe.
-
shaking table tests of coastal Bridge Piers with different levels of corrosion damage caused by chloride penetration
Construction and Building Materials, 2018Co-Authors: Wei Yuan, Anxin Guo, Wenting YuanAbstract:Abstract Coastal Bridges in a marine environment are vulnerable to corrosion damage, which reduces the seismic capacity of the structures during a long-term service period. This paper presents the results of shaking table tests conducted for coastal Bridge Piers by considering the effect of a non-uniform corrosion. Four structural specimens with different degrees of corrosion at the designed splash and tidal zone are first fabricated by the electrochemical accelerated corrosion method. After subjecting the specimens to a series of gradually increasing ground motions, the natural period, damping ratio, displacement and acceleration responses, and average curvature distribution of the structures are analyzed. Based on the time-dependent constitutive models of the reinforcements, the finite element models of the aging columns are constructed. Four possible seismic failure modes are identified for the Bridge Piers through the evolution of the curvature distribution form during the entire service period. The results indicate that the structural seismic performance degrades continuously with the increase in the corrosion level. The significant performance difference between the atmospheric, splash and tidal, and submerged zones will probably result in the plastic hinge transfer phenomenon.
-
structural strength deterioration of coastal Bridge Piers considering non uniform corrosion in marine environments
Earthquake Engineering and Engineering Vibration, 2018Co-Authors: Wenting Yuan, Haitao Li, Hui LiAbstract:In the aggressive marine environment over a long-term service period, coastal Bridges inevitably sustain corrosion-induced damage due to high sea salt and humidity. This paper investigates the strength reduction of coastal Bridges, especially focusing on the effects of non-uniform corrosion along the height of Bridge Piers. First, the corrosion initiation time and the degradation of reinforcement and concrete are analyzed for Bridge Piers in marine environments. To investigate the various damage modes of the concrete cover, a discretization method with fiber cells is used for calculating time-dependent interaction diagrams of cross-sections of the Bridge Piers at the atmospheric zone and the splash and tidal zone under a combination of axial force and bending moment. Second, the shear strength of these aging structures is analyzed. Numerical simulation indicates that the strength of a concrete pier experiences dramatic reduction from corrosion initiation to the spalling of the concrete cover. Strength loss in the splash and tidal zone is more significant than in the atmospheric zone when structures’ service time is assumed to be the same.
Hui Li - One of the best experts on this subject based on the ideXlab platform.
-
equivalent elastic modulus of reinforcement to consider bond slip effects of coastal Bridge Piers with non uniform corrosion
Engineering Structures, 2020Co-Authors: Wenting Yuan, Hui LiAbstract:Abstract Coastal Bridge Piers in marine environments are vulnerable to non-uniform corrosion due to wetting-drying cycles and high chloride concentration of seawater. This paper presents a methodology to analyze the seismic performance of coastal Bridges by modifying the elastic modulus of reinforcement, while considering the effects of bond-slip and non-uniform corrosion. Tensile stress-slip relationships of reinforcement with uniform and non-uniform corrosion are first derived. Then, a method to determine the equivalent elastic modulus of reinforcement with non-uniform corrosion is introduced. The proposed methodology is validated based on cyclic test results of Bridge pier specimens under uniaxial and biaxial loading actions. Through further numerical simulation, the effects of mass loss ratio and corrosion zone height on seismic performance of coastal Bridge Piers are examined. Compared to the method of using an interface element, the proposed method of using equivalent elastic modulus of reinforcement is simpler for the numerical simulation of bond-slip for coastal Bridge Piers. Results showed that the steel-to-concrete interfacial bond behavior slightly influences the peak strength of coastal Bridge Piers. However, it can significantly reduce the energy dissipation capacity and residual displacement of structural components.
-
experimental investigation on cyclic behavior of coastal Bridge Piers with non uniform corrosion under biaxial quasi static loads
Construction and Building Materials, 2018Co-Authors: Wenting Yuan, Wei Yuan, Hui LiAbstract:Abstract Corrosion-induced damage on coastal Bridge Piers reduces the seismic performance of structures. Biaxial earthquake excitation makes the degradation even worse. In this study, cyclic tests of four corroded Bridge Piers with different levels of non-uniform corrosion damage along the elevation were conducted under biaxial pseudo-static cyclic loads, while another corroded Bridge pier was applied with only a uniaxial load for comparison. First, the experimental program, including the specimen design, accelerated corrosion in laboratory, test facility, measurement instrument, and loading protocol, is introduced. Then, based on the test results, the experimental observations, hysteretic characteristics, strength, ductility, curvature distribution, and energy dissipation of the specimens are analyzed to investigate the effects of the corrosion degree and biaxial horizontal loading condition. The test results indicate that the seismic performance of Bridge Piers is strongly affected by biaxial horizontal loads, and the increase in local damage due to non-uniform corrosion makes the performance deterioration more severe.
-
structural strength deterioration of coastal Bridge Piers considering non uniform corrosion in marine environments
Earthquake Engineering and Engineering Vibration, 2018Co-Authors: Wenting Yuan, Haitao Li, Hui LiAbstract:In the aggressive marine environment over a long-term service period, coastal Bridges inevitably sustain corrosion-induced damage due to high sea salt and humidity. This paper investigates the strength reduction of coastal Bridges, especially focusing on the effects of non-uniform corrosion along the height of Bridge Piers. First, the corrosion initiation time and the degradation of reinforcement and concrete are analyzed for Bridge Piers in marine environments. To investigate the various damage modes of the concrete cover, a discretization method with fiber cells is used for calculating time-dependent interaction diagrams of cross-sections of the Bridge Piers at the atmospheric zone and the splash and tidal zone under a combination of axial force and bending moment. Second, the shear strength of these aging structures is analyzed. Numerical simulation indicates that the strength of a concrete pier experiences dramatic reduction from corrosion initiation to the spalling of the concrete cover. Strength loss in the splash and tidal zone is more significant than in the atmospheric zone when structures’ service time is assumed to be the same.
-
experimental investigation on the cyclic behaviors of corroded coastal Bridge Piers with transfer of plastic hinge due to non uniform corrosion
Soil Dynamics and Earthquake Engineering, 2017Co-Authors: Wei Yuan, Hui LiAbstract:Abstract Coastal Bridge Piers exposed to marine environments always suffer from non-uniform corrosion along the elevation. Severe degradation in the splash and tidal zone would significantly affect the seismic performance of the structure with a specific phenomenon of the plastic hinge transferring from the column end to the splash and tidal zone. In a companion paper of the authors [1] , a theoretical method to identify the time-dependent failure mode and equivalent plastic hinge length of the aging Bridge Piers under seismic excitation in the whole life cycle was conducted. In this study, cyclic loading tests of six reinforced concrete circular Bridge Piers with different levels of corrosion are carried out to investigate the seismic performance of such types of structures and validate the proposed method. The test specimens and the experimental setup are first introduced. Based on the measured hysteretic curves, the experimental results of the curvature distributions, hysteretic characteristics, loading-resistance capacity, ductility, energy dissipation, equivalent viscous damping ratio and equivalent plastic hinge length are analyzed and discussed. The test results demonstrate the accuracy of the analysis results for the seismic failure modes presented in the companion paper. It is also indicated that the seismic performance of the non-uniformly corroded columns exhibited a small variation before the transfer of the plastic hinge location, while an obvious reduction was observed for moderately and severely corroded structures.
Wei Yuan - One of the best experts on this subject based on the ideXlab platform.
-
experimental investigation on cyclic behavior of coastal Bridge Piers with non uniform corrosion under biaxial quasi static loads
Construction and Building Materials, 2018Co-Authors: Wenting Yuan, Wei Yuan, Hui LiAbstract:Abstract Corrosion-induced damage on coastal Bridge Piers reduces the seismic performance of structures. Biaxial earthquake excitation makes the degradation even worse. In this study, cyclic tests of four corroded Bridge Piers with different levels of non-uniform corrosion damage along the elevation were conducted under biaxial pseudo-static cyclic loads, while another corroded Bridge pier was applied with only a uniaxial load for comparison. First, the experimental program, including the specimen design, accelerated corrosion in laboratory, test facility, measurement instrument, and loading protocol, is introduced. Then, based on the test results, the experimental observations, hysteretic characteristics, strength, ductility, curvature distribution, and energy dissipation of the specimens are analyzed to investigate the effects of the corrosion degree and biaxial horizontal loading condition. The test results indicate that the seismic performance of Bridge Piers is strongly affected by biaxial horizontal loads, and the increase in local damage due to non-uniform corrosion makes the performance deterioration more severe.
-
shaking table tests of coastal Bridge Piers with different levels of corrosion damage caused by chloride penetration
Construction and Building Materials, 2018Co-Authors: Wei Yuan, Anxin Guo, Wenting YuanAbstract:Abstract Coastal Bridges in a marine environment are vulnerable to corrosion damage, which reduces the seismic capacity of the structures during a long-term service period. This paper presents the results of shaking table tests conducted for coastal Bridge Piers by considering the effect of a non-uniform corrosion. Four structural specimens with different degrees of corrosion at the designed splash and tidal zone are first fabricated by the electrochemical accelerated corrosion method. After subjecting the specimens to a series of gradually increasing ground motions, the natural period, damping ratio, displacement and acceleration responses, and average curvature distribution of the structures are analyzed. Based on the time-dependent constitutive models of the reinforcements, the finite element models of the aging columns are constructed. Four possible seismic failure modes are identified for the Bridge Piers through the evolution of the curvature distribution form during the entire service period. The results indicate that the structural seismic performance degrades continuously with the increase in the corrosion level. The significant performance difference between the atmospheric, splash and tidal, and submerged zones will probably result in the plastic hinge transfer phenomenon.
-
experimental investigation on the cyclic behaviors of corroded coastal Bridge Piers with transfer of plastic hinge due to non uniform corrosion
Soil Dynamics and Earthquake Engineering, 2017Co-Authors: Wei Yuan, Hui LiAbstract:Abstract Coastal Bridge Piers exposed to marine environments always suffer from non-uniform corrosion along the elevation. Severe degradation in the splash and tidal zone would significantly affect the seismic performance of the structure with a specific phenomenon of the plastic hinge transferring from the column end to the splash and tidal zone. In a companion paper of the authors [1] , a theoretical method to identify the time-dependent failure mode and equivalent plastic hinge length of the aging Bridge Piers under seismic excitation in the whole life cycle was conducted. In this study, cyclic loading tests of six reinforced concrete circular Bridge Piers with different levels of corrosion are carried out to investigate the seismic performance of such types of structures and validate the proposed method. The test specimens and the experimental setup are first introduced. Based on the measured hysteretic curves, the experimental results of the curvature distributions, hysteretic characteristics, loading-resistance capacity, ductility, energy dissipation, equivalent viscous damping ratio and equivalent plastic hinge length are analyzed and discussed. The test results demonstrate the accuracy of the analysis results for the seismic failure modes presented in the companion paper. It is also indicated that the seismic performance of the non-uniformly corroded columns exhibited a small variation before the transfer of the plastic hinge location, while an obvious reduction was observed for moderately and severely corroded structures.
-
seismic failure mode of coastal Bridge Piers considering the effects of corrosion induced damage
Soil Dynamics and Earthquake Engineering, 2017Co-Authors: Wei Yuan, Anxin GuoAbstract:Abstract Coastal Bridges exposed to an aggressive environment are vulnerable to corrosion damage, which reduces the seismic resisting capacity of the structures. Focusing on the corrosion varying along the column height of the coastal Bridge Piers, this paper investigates the time-dependent failure mode and equivalent plastic hinge length of the aging Bridge Piers under seismic excitation in the whole life cycle. First, the possible seismic failure modes and the method to estimate the equivalent plastic hinge length are analyzed and discussed. Then, the corrosion initiation time and performance deterioration of the reinforcement are presented. After that, the finite element models of the sound and aging Bridge Piers are introduced based on the OpenSees software package and the time-dependent constitutive models of the reinforcement. According to the proposed flowchart of the computational procedure, a numerical simulation is conducted to investigate the plastic hinge evolution process of the coastal Bridge pier. The analysis results indicate that the seismic failure mode of the continuously corroded Bridge pier varies with the service time, and the plastic hinge has the possibility of transferring from the column end to the bottom of the splash and tidal zone.
Shahria M Alam - One of the best experts on this subject based on the ideXlab platform.
-
probabilistic seismic risk assessment of concrete Bridge Piers reinforced with different types of shape memory alloys
Engineering Structures, 2018Co-Authors: A Muntasir H M Billah, Shahria M AlamAbstract:Abstract Shape memory alloy (SMA) has emerged as an alternative to conventional steel reinforcement for improving the seismic performance of Bridges during an extreme earthquake. This paper presents the probabilistic seismic risk assessment of concrete Bridge Piers reinforced with different types of SMA (e.g. Ni-Ti, Cu-Al-Mn, and Fe-based) rebars. To achieve this objective, the Bridge Piers are designed following a performance-based approach. Ground motions with different probable earthquake hazard scenarios at the site of the Bridge Piers are considered. Probabilistic seismic demand models are generated using the response parameters obtained from incremental dynamic analysis. Considering maximum drift and residual drift as demand parameters, fragility curves are developed for five different SMA-RC Bridge Piers. Finally, seismic hazard curves are generated in order to compare the mean annual rate of exceedance of different damage states of different Bridge Piers. It is observed that all the Bridge Piers perform according to the design objective, and the performance of SMA-RC Piers is significantly affected by the type of SMA used. The results show that all the SMA-RC Piers have very low probability of collapse at maximum considered earthquake level. It is found that the Bridge pier reinforced with FeNCATB-SMA (SMA-3) performed better as compared to the other SMA-RC Piers.
-
performance based seismic design of shape memory alloy reinforced concrete Bridge Piers i development of performance based damage states
Journal of Structural Engineering-asce, 2016Co-Authors: A Muntasir H M Billah, Shahria M AlamAbstract:AbstractPerformance-based seismic design aims to dictate the structural performance in a predetermined fashion given the possible seismic hazard scenarios the structure is likely to experience. Identifying and assessing the probable performance is an integral part of performance-based design. Before implementation, accurate and practical definitions of different performance levels and corresponding limit states must be determined. This study aims to develop performance-based damage states for shape memory alloy (SMA)–reinforced concrete (RC) Bridge Piers considering different types of SMAs and seismic hazard scenarios. Using incremental dynamic analysis (IDA), this study develops quantitative damage states corresponding to different performance levels (cracking, yielding, and strength degradation) and specific probabilistic distributions for RC Bridge Piers reinforced with different types of SMAs. Based on an extensive numerical study, this study also proposes residual drift–based damage states for SMA-RC...
-
evaluating the seismic behavior of segmental unbounded posttensioned concrete Bridge Piers using factorial analysis
Journal of Bridge Engineering, 2016Co-Authors: Qi Zhang, Shahria M AlamAbstract:AbstractSegmental unbounded posttensioned concrete Bridge Piers can resist large lateral drifts and eliminate residual deformation during an earthquake. The seismic behavior of posttensioned Bridge Piers depends on several factors, including concrete strength, posttensioning (PT) force, aspect ratio, and axial-load ratio. This study investigated the effects of these factors and their interactions on the seismic behavior of such Piers, which are not adequately addressed in the existing literature. Here, finite-element models of unbounded posttensioned concrete Piers were generated to perform a parametric study. These models were first validated with experimental results and then used to predict the seismic behavior of unbounded posttensioned concrete Piers. At the initial stage, full factorial analysis was performed by considering the following three factors: PT level, PT ratio, and concrete strength. The results indicate that none of them in combination resulted negatively on pier yielding capacity and po...
Bimlesh Kumar - One of the best experts on this subject based on the ideXlab platform.
-
turbulent flow structures and scour hole characteristics around circular Bridge Piers over non uniform sand bed channels with downward seepage
Water, 2019Co-Authors: Rutuja Chavan, Paola Gualtieri, Bimlesh KumarAbstract:In alluvial rivers Bridge Piers often cause local scour, a complex phenomenon as a result of the interaction between turbulent flow and bed material. In this paper, the results of an experimental study on the scour hole characteristics around single vertical pier sets on a non-uniform sand bed, under no seepage, and with downward seepage conditions, are described. In case of downward seepage, turbulent statistics, such as Reynolds stress, higher order moments, TKE-flux, and consequently sediment transport, decrease upstream of the pier, while increasing on both sides of it, where the enhanced erosive capacity of the flow results in an increase in the scour hole width. Moreover, the scour hole length shifts downstream. Empirical equations for the evaluation of scour hole characteristics, such as the length, width, area, and volume, including the downward seepage parameter, are proposed and experimentally tested. Model predictions give reasonably good agreement with the experimental data.