• Wind and Structures
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• v.35 no.4
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• pp.243-253
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• 2022

The conformal mapping method (CMM) has been broadly exploited in the study of fluid flows over airfoils and other research areas, yet it's hard to find relevant research in bridge engineering. This paper explores the feasibility of CMM in streamlined box girder bridges. Firstly, the mapping function transforming a unit circle to the streamlined box girder was solved by CMM. Subsequently, the potential flow solution of aerostatic pressure on the streamlined box girder was obtained and was compared with numerical simulation results. Finally, the aerostatic pressure attained by CMM was utilized to estimate the aerostatic coefficient and flutter performance of the streamlined box girder. The results indicate that the solution of the aerostatic pressure by CMM on the windward side is satisfactory within a small angle of attack. Considering the windward aerostatic pressure and coefficient of correction, CMM can be employed to estimate the rate of change of the lift and moment coefficients with angle of attack and the influence of the geometric shape of the streamlined box girder on flutter performance.

• Structural Engineering and Mechanics
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• v.51 no.1
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• pp.67-88
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• 2014

It is shown that topology optimization is a valuable tool for the design of bridge girders. This paper is a follow-up to (Kuty${\l}$owski and Rasiak 2014) and it includes an analysis of truss members' outer dimensions dictated by the standards. Moreover, a frame bridge girder mapped from a selected topology is compared with a typical frame girder on the basis of (Kuty${\l}$owski and Rasiak 2014). The analysis shows that topology optimization by means of the proposed algorithm yields a topology from which one can map a frame bridge girder requiring less material for its construction than the typical frame girder currently used in bridge construction.

• Journal of the Korea Safety Management & Science
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• v.16 no.4
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• pp.391-396
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• 2014

For the purpose of finding out the acoustical characteristics of exterior materials in bridge, analytical studies are performed with boundary elements method by using the commercial program SYSNOISE. Before analysis, to figure out material property, it was conducted experiments of absorption coefficient for absorptive material. And prediction of pressure were conducted I GIRDER type (before & after installation of absorption panel ) and BOX GIRDER type (before & after installation of absorption panel) The results show that when the absorption panel is installed, environment around bridge can help reduce traffic noise. It was proved to be the effective noise reduction counter-plan for a traffic noise in the bridges.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.1326-1331
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• 2006

The precast concrete deck is one of suitable solutions for replacement and new construction in urban area. However, the precast concrete deck could be a weak point of the steel plate girder bridges structurally due to the connections between precast panels in the longitudinal direction. Thereafter, it is necessary for improvement of durability and load carrying capacity to introduce the prestress force in the longitudinal direction Some cracks of connections at the precast concrete deck may be occurred due to live loads, the difference of temperature and long-term effects. The shrinkage and creep of concrete may significantly affect long-term behaviors which occur tensile stresses at the precast concrete deck of steel plate girder bridges. In this study, the time-dependant analysis program has been developed to determine the initial prestress force in the longitudinal direction considering loss of stress at the precast concrete deck. Also it has been estimated the initial prestress force by construction stages and shapes of girder.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.77-80
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• 2004

In bridge deck systems, deflections and cracking can be controlled by longitudinal and transverse prestressing, There are some benefits, longitudinal cracking control, the thickness reduction of deck slab, the widening of deck width and the reduction of the cross section area, in transversely post-tensioned concrete box girder bridges. However, it has been not sufficient to study the structural behaviors of transversely post-tensioned concrete box girder. Therefore, It is needed to predict the structural behaviors by prestressing and static loading. In this study, the analytical and experimental load tests are carried out to study the effect of transverse prestressing on concrete box girder. For these objectives, four test specimens are fabricated with various tendon spacing and steel ratio of top slab. The analytical and experimental studies are performed to estimate effects of the prestressing and failure tests.

• Steel and Composite Structures
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• v.5 no.4
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• pp.259-269
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• 2005

Many slab-on-girder bridges around the world are being assessed because they are approaching the end of their anticipated design lives or codes are permitting higher allowable loads. Current analytical techniques assume that the concrete and steel components act independently, typically requiring full-scale load testing to more accurately predict the remaining strength or endurance of the structure. However, many of the load tests carried out on these types of bridges would be unnecessary if the degree of interaction resulting from friction at the steel-concrete interface could be adequately modeled. Experimental testing confirmed that interface friction has a negligible effect on the flexural capacity of a slab-on-girder beam however, it also showed that interface friction is significant under serviceability loading. This has led to the development of an improved analytical technique which is presented in this paper and referred to as the slab-on-girder mixed analysis service load assessment approach.

• Proceedings of the KSR Conference
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• 2003.10b
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• pp.596-601
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• 2003

After the development of practical technology for tilting system, tilting trains are operated on conventional lines of KORAIL. As the running speed of trains is increased, it is very important to investigate the dynamic characteristics of plate girder bridges with direct track fixation. Therefore, this paper reviews the dynamic interactions between tilting train and welded plate girder bridges designed by L-22, a standard load type of KORAIL. The span lengths of plate girder analyzed here are 6.6m, 9.7m, 12.9m, 16.0m, 19.2m, 22.3m, 25.4m and 31.1m. Using 2-D dynamic analysis, the critical velocity of tilting train, vertical deflection ratios of plate girder and maximum accelerations of car body are calculated. And the analytical results are compared with those of design criteria.

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.463-464
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• 2010

Pre-tension Girder using Precast Concrete bed System have advantage of simplifying construction process, reducing prestress-loss and cost compared with post-tension Girder. That is because it is possible to produce pre-tension Girder by prefabricated concrete bed in site not factory. This paper present pre-tension girder method using precast concrete bed system and field application.

• Journal of Ship and Ocean Technology
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• v.8 no.4
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• pp.17-25
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• 2004

Hull girder stress monitoring system for container ship uses four long-base-strain-gages at mid-ship to monitor the resultant stresses and the applied moment components of horizontal, vertical and torsional moments. The bending moments are estimated by using the conventional strain-moment relations, however, the torsional moment related to the warping strain requires the assumption of the shape of torsional moments over the hull girder. Though this shape could be a sine function with an adequate period, it largely depends upon certain empirical formulas. This paper introduces additional four long-base-strain-gages at mid-ship to derive the longitudinal slope of the warping strain because this slope is directly related to the torsional moment by Bi-moment concept. An open-channel-type cantilever beam has been selected as a simplified model for container ship and the result has proved that the suggested concepts can estimate the torsional component accurately. Finally this method can become reliable technique to derive all external moments in hull girder stress monitoring system for container ships.

• Proceedings of the KSR Conference
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• 2002.10b
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• pp.1047-1052
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• 2002

KTX is going to directly operate on the existing plate girder bridges before the complete construction of new high-speed line. Also the speed and traffic volume is increased after electrification of conventional line. Then, it is necessary to check the dynamic behaviors of these bridges. Therefore, this paper reviews the dynamic behaviors of welded plate girder bridges designed by L-22, a standard load type of KNR. The span lengths of plate girder analyzed here are 6.6m, 9.7m, 12.9m, 16.0m, 19.2m, 22.3m, 25.4m and 31.1m. Using 2-D dynamic analysis, vertical deflection ratios of plate girder and maximum accelerations of car body are calculated. And the analytical results are compared with those of design criteria.