• Computers and Concrete
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• v.14 no.4
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• pp.387-403
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• 2014

The aim of this study is to assess the structural performance of deteriorated reinforced concrete bridge piers, and to provide method for developing improved evaluation method. For a deteriorated bridge piers, once the cover spalls off and bond between the reinforcement and concrete has been lost, compressed reinforcements are likely to buckle. By using a sophisticated nonlinear finite element analysis program, the accuracy and objectivity of the assessment process can be enhanced. A computer program, RCAHEST (Reinforced Concrete Analysis in Higher Evaluation System Technology), is used to analyze reinforced concrete structures. Material nonlinearity is taken into account by comprising tensile, compressive and shear models of cracked concrete and a model of reinforcing steel. Advanced deteriorated material models are developed to predict behaviors of deteriorated reinforced concrete. The proposed numerical method for the structural performance assessment of deteriorated reinforced concrete bridge piers is verified by comparing it with reliable experimental results. Additionally, the studies and discussions presented in this investigation provide an insight into the key behavioral aspects of deteriorated reinforced concrete bridge piers.

• Structural Engineering and Mechanics
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• v.29 no.3
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• pp.259-278
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• 2008

This paper presents a nonlinear finite element procedure accounting for the effects of geometric as well as material nonlinearities for reinforced concrete bridge piers supported by laminated rubber bearings. Reinforced concrete bridge piers supported by laminated rubber bearings and carrying a cyclic load were analyzed by using a special purpose, nonlinear finite element program, RCAHEST. For reinforced concrete, the proposed robust nonlinear material model captures the salient response characteristics of the bridge piers under cyclic loading conditions and addresses with the influence of geometric nonlinearity on post-peak response of the bridge piers by transformations between local and global systems. Seismic isolator element to predict the behaviors of laminated rubber bearings is also developed. The seismic performance of reinforced concrete bridge piers supported by laminated rubber bearings is assessed analytically. The results show good correlation between the experimental findings and numerical predictions, and demonstrate the reliability and robustness of the proposed analytical model. Additionally, the studies and discussions presented in this investigation provide an insight into the key behavioral aspects of reinforced concrete bridge piers supported by laminated rubber bearings.

• Journal of the Korean Society of Safety
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• v.30 no.6
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• pp.70-77
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• 2015

In this study, the governing design factors of GFRP-reinforced concrete bridge deck are analyzed for typical bridges in Korea. The adopted bridge deck is a cast-in-situ concrete bridge deck for the prestressed concrete girder bridge with dimensions of 240 mm thickness and 2.75 m span length from center-to-center of supporting girders. The selected design variables are the diameters of GFRP rebar, spacings of GFRP rebars and concrete cover thicknesses, Considering the absence of the specification relating GFRP rebar in Korea, AASHTO specification is used to design the GFRP-reinforced concrete bridge deck. The GFRP-reinforced concrete bridge deck is proved to be governed by the criteria about serviceability, especially maximum crack width, while steel reinforced concrete bridge deck is governed by the criteria on ultimate limit state. In addition, GFRP rebars with diameter of 16 mm ~ 19 mm should be used for the main transverse direction of decks to assure appropriate rebar spacings.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2001.05a
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• pp.135-140
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• 2001

A post-tensioned reinforced concrete slab bridge is analyzed by specially orthotropic laminate theory. Symmetrically reinforced slab with tension and compression steel is considered for convenience of analysis. Each longitudinal and transverse steel layer is regarded as a lamina, and material constants of each lamina is calculated by the use of the rule of mixture. This bridge is under uniformly distributed vertical loads, and axial loads and end moments due to post-tensioning. In this paper, finite difference method is used for numerical analysis of this bridge. Theory and analysis method of specially orthotropic laminate plates used in this paper can be used for design of new bridges, and maintenance and repair of old bridges.

• Computers and Concrete
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• v.5 no.2
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• pp.135-154
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• 2008

This paper presents a nonlinear finite element analysis procedure for the seismic performance assessment of reinforced concrete bridge piers with unbonded reinforcing or prestressing bars. A computer program named RCAHEST (Reinforced Concrete Analysis in Higher Evaluation System Technology) is used to analyze reinforced concrete structures; this program was also used in our study. Tensile, compressive and shear models of cracked concrete and models of reinforcing and prestressing steel were used account for material nonlinearity of reinforced concrete. The smeared crack approach was incorporated. To represent the interaction between unbonded reinforcing or prestressing bar and concrete, an unbonded reinforcing or prestressing bar element based on the finite element method was developed in this study. The proposed numerical method for the seismic performance assessment of reinforced concrete bridge piers with unbonded reinforcing or prestressing bars is verified by comparison of its results with reliable experimental results.

• International Journal of Concrete Structures and Materials
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• v.6 no.3
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• pp.165-176
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• 2012

The aim of this study is to assess the seismic performance of hollow reinforced concrete and prestressed concrete bridge columns, and to provide data for developing improved seismic design criteria. By using a sophisticated nonlinear finite element analysis program, the accuracy and objectivity of the assessment process can be enhanced. A computer program, RCAHEST (Reinforced Concrete Analysis in Higher Evaluation System Technology), is used to analyze reinforced concrete and prestressed concrete structures. Tensile, compressive and shear models of cracked concrete and models of reinforcing and prestressing steel were used to account for the material nonlinearity of reinforced concrete and prestressed concrete. The smeared crack approach was incorporated. The proposed numerical method for the seismic performance assessment of hollow reinforced concrete and prestressed concrete bridge columns is verified by comparing it with the reliable experimental results. Additionally, the studies and discussions presented in this investigation provide an insight into the key behavioral aspects of hollow reinforced concrete and prestressed concrete bridge columns.

• Steel and Composite Structures
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• v.21 no.3
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• pp.661-677
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• 2016

The quasi static test of the steel reinforced concrete (SRC) bridge piers and rigid frame arch bridge structure with SRC piers was conducted in the laboratory, and the seismic performance of SRC piers was compared with that of reinforced concrete (RC) bridge piers. In the test, the failure process, the failure mechanism, hysteretic curves, skeleton curves, ductility coefficient, stiffness degradation curves and the energy dissipation curves were analyzed. According to the $M-{\Phi}$ relationship of fiber section, the three-wire type theoretical skeleton curve of the lateral force and the pier top displacement was proposed, and the theoretical skeleton curves are well consistent with the experimental curves. Based on the theoretical model, the effects of the concrete strength, axial compression ratio, slenderness ratio, reinforcement ratio, and the stiffness ratio of arch to pier on the skeleton curve were analyzed.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2002.09a
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• pp.197-204
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• 2002

The resent earthquakes in worldwide have caused extensive damage to highway reinforced concrete bridge piers. It has been observed in the Korean Peninsula that the number of minor or low earthquake motions have increased year by year. Since the concern about the earthquake hazards is increased, the objective of this research is to evaluate the damage of reinforced concrete bridge piers subjected to probable earthquake motions. Experimental investigation was conducted to study the seismic performance of the full-scale specimens in size D=1.2m H=4.8m, which were constructed with different longitudinal lap splice and loading pattern, through the quasi-static test and the pseudo-dynamic test. It is thought that this result could contribute to establish the retrofit decision-making and disaster planning of reinforced concrete bridge piers in earthquake regions. And it could be also possible to quantify the damage of reinforced concrete bridge piers under cyclic loading

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.2A
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• pp.351-361
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• 2006

In this study, nonlinear finite element analysis procedures are presented for the seismic performance assessment of circular reinforced concrete bridge piers with confinement steel. This paper defines a damage index based on the predicted hysteretic behavior of a circular reinforced concrete bridge pier. Damage indices aim to provide a means of quantifying numerically the damage in circular reinforced concrete bridge piers sustained under earthquake loading. The proposed numerical method is applied to circular reinforced concrete bridge piers with confinement steel tested by the authors. The proposed numerical method gives a realistic prediction of seismic performance throughout the loading cycles for several test specimens investigated.

• Computers and Concrete
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• v.18 no.1
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• pp.69-97
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• 2016

Performance-based remaining life assessment of reinforced concrete bridge girders, subject to chloride-induced corrosion of reinforcement, is addressed in this paper. Towards this, a methodology that takes into consideration the human judgmental aspects in expert decision making regarding condition state assessment is proposed. The condition of the bridge girder is specified by the assignment of a condition state from a set of predefined condition states, considering both serviceability- and ultimate- limit states, and, the performance of the bridge girder is described using performability measure. A non-homogeneous Markov chain is used for modelling the stochastic evolution of condition state of the bridge girder with time. The thinking process of the expert in condition state assessment is modelled within a probabilistic framework using Brunswikian theory and probabilistic mental models. The remaining life is determined as the time over which the performance of the girder is above the required performance level. The usefulness of the methodology is illustrated through the remaining life assessment of a reinforced concrete T-beam bridge girder.