• Journal of Korean Society of Steel Construction
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• v.14 no.3
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• pp.395-402
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• 2002

This study proposed a muti-objective optimum design method for rational optimizing of orthotropic steel deck bridges. This multi-objective optimum design method was found to be effective in optimizing multi-objective problems, considering cost and deflection functions. It may ve difficult to optimize orthotropic steel deck bridges using a conventional optimization, since the bridges have several parts and show complex structural behaviors. Therefore, the Pareto curve can be obtained by performing the multi-objective optimization for real orthotropic steel deck bridges, using the multi-level technique with excellent efficiency. A reasonable and economical design can be attained using the Parato curve in the cost and deflection functions of the bridge. Thus, more reasonable design values can be determined based on a comparison with those using a conventional design procedure.

• 한국도로학회지:도로
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• v.2 no.1
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• pp.30-39
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• 2000

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.3A
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• pp.391-399
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• 2008

Because of relatively high temperature, over $240^{\circ}C$, of asphalt for steel deck bridge during pavement procedure, the temperature of deck could rise over $100^{\circ}C$ and undesirable excessive displacement and thermal stress could occur. In this study, in order to estimate the thermal effect of pavement process and to find the optimal pavement process, a new thermal analysis technique with Equivalent Heat Source (EHS) is proposed and its applicability to the practical pavement of steel bridge is studied. EHS is developed to simulate the high temperature pavement materials and its thermal effect such as conduction and convection which cannot be explain easily in general structural analysis program for bridge design. To verify the applicability of new analysis technique with EHS, thermal analyses of steel deck bridge with uplift and curved bridge with various pavement procedures are presented.

• Journal of Korean Society of Steel Construction
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• v.13 no.4
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• pp.337-349
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• 2001

This study present an optimum deck and girder system design for minimizing the life-cycle cost (LCC) of orthotropic steel deck bridges. The problem of optimum LCC design of orthotropic steel deck bridges is formulated as that of minimization of the expected total LCC that consists of initial cost, maintenance cost, expected retrofit costs for strength, deflection, and fatigue. To demonstrate the effect of LCC optimum design of orthotropic steel deck bridges, the proposed optimum LCC design is compared with the conventional method for orthotropic steel deck bridges design. From the numerical investigations, it may be positively stated that the proposed optimum design procedure for orthotropic steel deck bridges based on the LCC will lead to more rational, economical and safer design.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1998.04a
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• pp.77-84
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• 1998

The finite strip method is presented for the analysis of steel deck bridges. Like the Pelikan-Esslinger design method for the steel deck bridges, steel deck is treated as an equivalent orthotropic plate. In the presented method, the deck is discretised by finite strips in the longitudinal direction and the effect of main girder or floor beam deflection can also be accounted for. In this method, the terms of harmonic series at elastically support such as transverse floor or diaphragm in steel deck become coupled. Solutions of this method are compared with other available analytical and numerical solution, and good agreement is observed.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.6
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• pp.100-109
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• 2011

Recently, the concrete-steel hybrid extradosed bridge has been proposed as alternative bridge type at long span site. The hybrid extradosed bridge adopts light orthogonal deck girder instead of heavy concrete deck girder at the center span of bridge, and it enables to construct long-span bridge. And also, for this bridge type the decrease of self-weight of girder enables to reduce girder depth and side span length of extradosed bridge, so its type has more efficient structural behavior and makes it possible to perform optimal bridge design. Therefore, it is very important to set up the procedure and parameters of optimal design for concrete-steel hybrid extradosed bridge. In this study, the effects of design parameters (the variation of pylon height, bridge deck depth and orthogonal deck girder length) are discussed. And numerical analysis and sensitivity analysis are carried out according to these parameters. And design weight values about these parameters are quantitatively suggested to reflect characteristics of concrete-steel hybrid bridge.

• Journal of the Korea institute for structural maintenance and inspection
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• v.10 no.4
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• pp.127-135
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• 2006

In this study, steel deck bridges are chosen as analytic model to show the structural behaviors generated by high temperature of pavement and to formulate the simplified approximate analysis of thermal effects. In general, the thermal effect is changed by the material property of pavements and environmental temperature as well as shape, size and boundary conditions of bridge. Specially, this effect is the representative initial stress problem dependent on time. The thermal effect, however, does not depend on time and thermal effect is regarded as initial load in this study. After these thermal loading is modelled as moving loads, influence lines of reactions of shoes are calculated and the successive pavement steps with arbitrary segments are determined to minimize the thermal effect of shoes by influence line.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.4
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• pp.99-106
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• 2014

In order to study the reasonable design thermal loads, the steel box girder bridge specimen which have no concrete slab was manufactured with the real size dimension. The temperature data were measured for 5 month at the 18 thermo gauges which were attached according to height. The temperature differences between the top and bottom flange in steel box girder specimen were calculated and the temperature gradient models were proposed by the probabilistic method. This proposed model showed a correlation of approximately 97% when compared with the similar model of Euro Code. Thus, the temperature gradient models which were suggested in this study may be used as the basis data in calculating the design load temperature.