• Earthquakes and Structures
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• v.17 no.3
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• pp.317-327
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• 2019

High-speed railway bridge piers in seismically active area may be subjected to multiple earthquakes and then produce cumulative residual deformation. To study the cumulative residual deformation of high-speed railway bridge piers under multiple earthquakes, a nonlinear numerical analytical model with multi-DOF (MDOF) system is presented and validated against two shaking table tests in this paper. Based on the presented model, a simple supported beam bridge pier model of high-speed railway is established and used to investigate the cumulative residual deformation of high-speed railway bridge pier under mainshock-aftershock sequences and swarm type seismic sequences. The results show that the cumulative residual deformation of the bridge pier increases with earthquake number, and the increasing rates are different under different earthquake number. The residual deformation of bridge pier subjected to multiple earthquakes is accumulated and may exceed the limit of code.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.4
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• pp.705-716
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• 2017

As many environmental pollution problems have arisen, various studies related to the environmental evaluation have been carried out in the construction industry. However, there is no methodology for estimating the environmental load quickly for design alternatives of civil facilities in the design phase. This study aim to establish criteria of works information and designed parts which can efficiently estimate environmental loads of PSC beam bridge based on standard quantity at the early design phase. For this purpose, a detailed environmental loads database was constructed by performing Life Cycle Assessment (LCA) based on detailed design data of 25 bridges. In addition, major work with high impact on environmental load were selected, and the analysis of characteristics of environmental load according to the required materials and 8 impact categories were conducted. As a result, the superstructure accounted for 42.91%. In the superstructure, remicon of the material base and PSC beam work occupied 53.13% and 31.25%. In the substructure, remicon, rebar, and cement, which are material base, accounted for more than 93%. It is expected that this major work and material information for each part of bridge can be utilized in the construction of the model, which can estimate the approximate environmental load, reflecting the characteristics of the structure in the design phase.

• Magazine of the Korea Concrete Institute
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• v.10 no.3
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• pp.53-61
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• 1998

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.315-319
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• 2000

This study is to analyze the effect of the cross beam in bridge design. The analysis on the cross beam using FEM method is to find the best location and numbers of the cross beam in bridges. These analysis will allow economical design and construction in the field.

• International Journal of Highway Engineering
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• v.15 no.1
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• pp.1-9
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• 2013

PURPOSES: The purpose of this study is to evaluate physical properties, durability, fatigue resistance, and long-term performance of poly-urethane concrete (PU) which can be possible application of thin layer on long-span orthotropic steel bridge and to check structural stability of bridge structure. METHODS : Various tests of physical properties, such as flexural strength, tensile strength, bond strength and coefficient of thermal expansion tests were conducted for physical property evaluation using two types of poly urethane concrete which have different curing time. Freezing and thawing test, accelerated weathering test and chloride ion penetration test were performed to evaluate the effect of exposed to marine environment. Beam fatigue test and small scale accelerated pavement test were performed to assess the resistance of PU against fatigue damage and long-term performance. Structural analysis were conducted to figure out structural stability of bridge structure and thin bridge deck pavement system. RESULTS: The property tests results showed that similar results were observed overall however the flexural strength of PUa was higher than those of PUb. It was also found that PU materials showed durability at marine environment. Beam fatigue test results showed that the resistances of the PUa against fatigue damage were two times higher than those of the PUb. It was found form small scale accelerated pavement test to evaluate long-term performance that there is no distress observed after 800,000 load applications. Structural analysis to figure out structural stability of bridge structure and thin bridge deck pavement system indicated that bridge structures were needed to increase thickness of steel deck plate or to improve longitudinal rib shape. CONCLUSIONS: It has been known that the use of PU can be positively considered to thin layer on long-span orthotropic steel bridge in terms of properties considered marine environment, resistance of fatigue damage and long-term performance.

• Steel and Composite Structures
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• v.35 no.1
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• pp.29-41
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• 2020

Cross-beams of modern through truss bridges are connected to truss chord at its nodes and between them. It results in variable rotational end restraint for cross-beams, thus variable bending moment distribution. This feature is captured in three-dimensional modelling of through truss bridge structure. However, for preliminary design or rapid assessment of service load effects such technique of analysis may not be available. So an analytical method of assessment of rotational end restraint for cross-beam of through truss bridges was worked out. Two cases - nodal cross-beam and inter-nodal cross-beam - were analyzed. Flexural and torsional stiffness of truss members, flexural stiffness of deck members and axial stiffness of wind bracing members in the vicinity of the analyzed cross-beam were taken into account. The provision for reduced stiffness of the X-type wind bracing was made. Finally, general formula for assessment of rotational end restraint was given. Rotational end restraints for cross-beams of three railway through truss bridges were assessed basing on the analytical method and the finite element method (three-dimensional beam-element modelling). Results of both methods show good agreement. The analytical method is able to reflect effects of some structural irregularities. On the basis of the obtained results the general values of rotational end restraint for nodal and inter-nodal cross-beams of railway through truss bridges were suggested.

• Structural Engineering and Mechanics
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• v.14 no.6
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• pp.733-738
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• 2002

A simplified rational method is developed to evaluate transverse earthquake-induced forces in continuous bridges. This method models the bridge as a beam on elastic foundation, and assumes a sinusoidal curve for both vibration mode shape and deflected shape in the transverse direction. The principle of minimum total potential is used to calculate the displacements and the earthquake-induced forces in the transverse direction. This method is concise and easy to apply, and hence, offers an attractive alternative to a lengthy and time consuming three dimensional modeling of the bridge as given by AASHTO under its Single Mode Spectral Analysis Method.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.6
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• pp.139-146
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• 2014

Recently, in field of bridge construction, modular technology has been studied to reduce construction period, traffic impact and environmental impact. This study is a part of research related to the modular bridges. The aim of the study is to analyze the structural behavior and evaluate a serviceability for transverse connection of modular slab bridge. A total of four specimens were fabricated. including a control beam for finding the maximum load by static test. And one control beam and two segmental beams were fabricated for cyclic loading test. As the test result, the beams that were introduced 100% of the design prestressing force showed a smaller maximum deflection, residual deflection and crack width than the control beam. The beam for serviceability evaluation was satisfied with structural serviceability limits of the deflection and crack.

• Magazine of the Korea Concrete Institute
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• v.10 no.4
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• pp.135-143
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• 1998

The wheel load distribution width for lane load is not specified in current Korea bridge design code(KD code), not like in current AASHTO and AASHTO LRFD specifications which specity it as twice of wheel load distribution width for wheel load. In this study, the wheel load distribution width in continuous reinforced concrete slab bridge is investigated. The major variables affecting the wheel load distribution of a reinforced concrete continuous slab bridge are the span length, bridge width, existence edge beam and boundary condition. From a series of comprehensive parametric study on each variable, the formula for wheel load distribution in continuous reinforced concrete slab bridge is proposed from the nonlinear regression analysis of finite element analysis results. The proposed formulas can be used efficiently in the accurate design of continuous reinforced concrete slab bridges.

• Journal of the Korean Society of Safety
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• v.13 no.3
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• pp.126-134
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• 1998

In this paper, the field test by truck load and the structural analysis were performed on a prestressed concrete beam bridge to investigate the load carrying capacity of the prestressed concrete beam bridges. From the results of the field test and the structural analysis, CAF (composite action factor), TIF(transformed impact factor), and $P_n$(load carrying capacity) of the prestressed concrete beam bridges were studied, and the load carrying capacity assessment of the prestressed concrete beam bridges were carried out using these factors.