• Journal of the Korea institute for structural maintenance and inspection
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• v.12 no.3
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• pp.127-134
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• 2008

The response of a bridge can be influenced by span length, bridge's surface condition, vehicle's weight, and vehicle's velocity. It is difficult to predict accurate behavior of a bridge. In the current standard of specifications, such dynamic effect is defined by impact factor and prescribed to consider live load as to increase design load by means of multiplying this value by live load. However, it is not well understood because the Impact factor method differs from every country. Dynamic, static and pseudo-staitic field loading tests on PSC-I girder bridges were carried out to find out the dynamic property of the bridge. This paper is aimed to figure out actual dynamic property of the bridge by using field loading test. An empirical method based on impact factor is widely used and also argued. Displacement and strain response measured from the tests was compared with one from the empirical method. The former seems to be reasonable since it can consider actual response of a bridge through field tests.

• Journal of the Korea institute for structural maintenance and inspection
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• v.17 no.6
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• pp.77-87
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• 2013

A present LSD (limited state design) code for temperature load in the domestic bridge design has applied a uniform standard for various bridge types. In this study, in order to calculate the effective temperature, a specimen of steel box girder bridge section with real size dimension was manufactured. For a year, the temperature data were measured at the 18 point in steel deck of steel box girder bridges specimen. Effective temperature within the cross section according to atmospheric temperature was calculated by this experiment data. The analyzed results were very similar correlation when compared with the effective temperature of the Euro Code. Therefore, the effective temperature which calculated based on the present data could be used as the basic data in order to present to the appropriate design criteria for the thermal loads on the domestic bridge design.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.06a
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• pp.31-42
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• 2002

The Design criteria are different from one another due to the different engineering properties of rock in the every nation. Most of the test results of the rock-socketed piers were loaded two times of the design load capacities because they would be used in the foundation of the bridge or the building. So we have much difficulties in study of the load capacities of the rock-socketed piers by the test result in Korea. When we design the rock-socket piers, every designer uses the different formula, and makes different results. Recently the demand of the large bridges and the huge buildings has been increased. The adequate design criterion of the rock-socketed pier is urgently needed to design them reasonable. In this paper we analyzed the various design criteria and proposed the adequate design criterion which is based on the test results of the rock-socked piers in Korea.

• Journal of Korean Society of Steel Construction
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• v.9 no.2 s.31
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• pp.159-169
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• 1997

Recently, due to the increasing overloaded heavy vehicles and traffic volumes fatigue failures of steel highway bridges frequently occur. Therefore, it is important to decide rational fatigue design procedure which can reflect lifetime cumulative fatigue damage reasonably. In this study, cumulative fatigue damages are simulated for various bridge systems and traffic conditions. The AASHTO LRFD fatigue design procedure is reviewed and the current fatigue design loading format, in which a single representative truck is loaded regardless of bridge width, is found to yield inconsistent safety level. Improved loading format with rational design load level for fatigue design is suggested.

• Steel and Composite Structures
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• v.24 no.5
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• pp.549-559
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• 2017

As few multi-tower single-box multi-cell cable-stayed bridges with corrugated steel webs have been built, analysis is mostly achieved by combining single-girder model, beam grillage model and solid model in support of the design. However, such analysis methods usually suffer from major limitations in terms of the engineering applications: single-girder model fails to account for spatial effect such as shear lag effect of the box girder and the relevant effective girder width and eccentric load coefficient; owing to the approximation in the principle equivalence, the plane grillage model cannot accurately capture shear stress distribution and local stress state in both top and bottom flange of composite box girder; and solid model is difficult to be practically combined with the overall calculation. The usual effective width method fails to provide a uniform and accurate "effective length" (and the codes fail to provide a unified design approach at those circumstance) considering different shear lag effects resulting from dead load, prestress and cable tension in the construction. Therefore, a novel spatial grid model has been developed to account for shear lag effect. The theoretical principle of the proposed spatial grid model has been elaborated along with the relevant illustrations of modeling parameters of composite box girder with corrugated steel webs. Then typical transverse and longitudinal shear lag coefficient distribution pattern at the side-span and mid-span key cross sections have been analyzed and summarized to provide reference for similar bridges. The effectiveness and accuracy of spatial grid analysis methods has been finally validated through a practical cable-stayed bridge.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1555-1561
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• 2011

The dynamic behavior of a bridge under moving loads has been investigated over many years. Especially, with the introduction of High Speed Railway, numerous theoretical studies on the interaction problem between bridges and trains are carried out. In the present study, advanced bridge/train interaction analyses are performed and compared with field tests of a simply-supported 40m long PSC box girder bridge of Kyung-Bu High Speed Railway. Vertical displacements and vertical accelerations of a bridge with increasing speeds are analyzed. In addition, wheel load reduction rates and accelerations of a car-body of the train are investigated for a study of appropriateness of traffic safety criteria of bridge design specification.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2001.05a
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• pp.141-146
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• 2001

A post-tensioned steel plate girder bridge with cross-beams is analyzed by specially orthotropic laminate theory. The cross-sections of both girders and cross-beams are WF types. The result is compared with that of the beam theory. This bridge with simple support is under uniformly distributed vertical load, and axial loads and moment due to post-tension. In this paper, finite difference method for numerical analysis of simple supported bridge is developed. Relatively exact solution is obtained even with small number of meshes. Theory and analysis method of specially orthotropic laminate plates used in this paper can be used in design of new bridges, and maintenance and repair of old bridges.

• Journal of the Korea Institute of Military Science and Technology
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• v.12 no.2
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• pp.236-247
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• 2009

In Korea, the driving system restriction criteria is strictly applied(gross weight 400kN, axial load 100kN). Especially after the Seoungsu Bridge accident, safety factor has been strictly applied. The Safety factor is applied to the cumulative results for each steps like design, construction, maintenance of the Bridge. Because of it, the bridge is undervalued compared to its capacity. So, this generates loss for both private and military sector(eg. logistical delays, structural damage, etc.). But analyzing data from many existing researches we have confirmed that the military heavy vehicle may pass through the first class bridges. In consequence, this study have focused on determining whether HETS vehicles can pass over the first class bridge, without safety issues, using MIDAS structural analysis program. The results have confirmed that the military heavy vehicle may pass over the bridge.

• Steel and Composite Structures
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• v.27 no.3
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• pp.285-295
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• 2018

In this paper, the bearing capacity of a non-eccentric and eccentric tubular, concrete-filled, steel bridge pier was studied through the finite element method. Firstly, to verify the validity of the numerical analysis, the finite element analysis of four steel tube columns with concrete in-fill was carried out under eccentric loading and horizontal cyclic loading. The analytical results were compared with experimental data. Secondly, the effects of the eccentricity of the vertical loading on the seismic performance of these eccentrically loaded steel tubular bridge piers were considered. According to the simulated results, with increasing eccentricity ratio, the bearing capacity on the eccentric side of a steel tubular bridge pier (with concrete in-fill) is greatly reduced, while the capacity on the opposite side is improved. Moreover, an empirical formula was proposed to describe the bearing capacity of such bridge piers under non-eccentric and eccentric load. This will provide theoretical evidence for the seismic design of the eccentrically loaded steel tubular bridge piers with concrete in-fill.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2003.04a
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• pp.119-126
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• 2003

In the conventional reinforced-concrete bridge deck, concrete and steels are likely to be deteriorated and corroded under the influence of noxious environment. To cope with these problems caused in the conventional reinforced-concrete bridge deck, pultruded composite bridge deck having light weight, high strength, corrosion resistence and durability is developed. Based on the previous study, Pultruded composite bridge deck is designed. For the DB24 truck load finite element analysis is performed to verify whether it meets both strength and serviceability design criteria. For the fabricated and assembled deck panel, structural testings are conducted. This paper present structural details and field application and testing results of composite bridge deck are presented. of composite bridge deck.