• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.4A
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• pp.735-742
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• 2006

In this study, the ultimate shear strength behavior of transversely stiffened curved web panels was investigated through nonlinear finite element analysis. It was found that if the transverse stiffener has a sufficient rigidity, then curved web panels used in practical designs are able to develop the postbuckling strength that is equivalent to that of straight girder web panels having the same dimensional and material properties. The nonlinear analysis results indicate that in order for curved web panels to develop the potential postbuckling strength. The rigidity of the transverse stiffener needs to be increased several times the value obtained from the Guide Specifications (AASHTO, 2003). However, in the case of thick web panels where the shear design is governed by shear yielding, the stiffener rigidity does not have to be increased. From the analysis results, a simple design formula is suggested for the rigidity of transverse stiffener under strength limit state.

• Journal of Korean Society of Steel Construction
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• v.21 no.3
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• pp.321-330
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• 2009

This paper presents numerical analysis results for the lateral-torsional buckling (LTB) strength of steel I-girder bridges. Current Korean and AASHTO design specifications for LTB consider the buckling strength of a single girder with both its ends constrained. The I-girder bridges are composed of more than one girder, and the girders are interconnected with intermediate cross-beams or cross-frames. Therefore, it should be required to evaluate the effects of cross-beam stiffness and the interactionof girders on LTB strength. It is also necessary to consider the effects of transverse web stiffeners on LTB strength. By considering these parameters, a series of four-girder systemswere numerically modeled using 3D shell elements to estimate the LTB strength while considering initial imperfections and residual stresses.

• Journal of the Korean Geosynthetics Society
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• v.10 no.3
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• pp.43-51
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• 2011

This paper describes the results of pullout tests in the laboratory, which are conducted to assess the pullout performance of recently developed geosynthetic strip reinforcement with rounded band anchor. The geosynthetic strip can be used as reinforcements in reinforced soil wall with concrete block facing. The pullout resistance of the geosynthetic strip with rounded band anchor is mobilized by the combination of the interface friction between soil-reinforcement surface and the passive soil resistance caused by the rounded band anchor. Therefore, both the friction resistance and the passive resistance have to be considered in design. From the pullout test results, when the rounded band anchor are formed in the end part of the geosynthetic strip, pullout strength increases about from 10% to 65%. The passive resistance can be evaluated based on the pullout test results.

• Journal of Korean Society of Steel Construction
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• v.16 no.1 s.68
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• pp.1-10
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• 2004

A study on the evaluation of proper spacing and required flexural rigidity of cross beams in composite two I-section steel girder bridges without a lateral and sway bracing system was performed. Specifically, a 2-lane, 40-m simple span bridge and a 3-span continuous (40+50+10m) bridge were designed, and structural analyses under dead load before and after composite, live, wind, and seismic loads were performed using spacing and flexural rigidity or cross beams as parameters. Through parametric analysis, the effect on the stresses due to the combination of loads and live load distribution was investigated. In addition. material and geometric nonlinear analyses under dead load before composite were performed to evaluate the lateral buckling strength of the steel girders and cross beam. Based on the results or such analyses, the proper spacing and flexural rigidity of cross beams at intermediate points and supports were proposed.

• Journal of Korean Society of Steel Construction
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• v.14 no.6
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• pp.691-699
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• 2002

A study on the evaluationof the proper spacing and required bending rigidity of cross beams in composite multiple I-girder bridge without lateral and sway bracing system was performed. For the purpose, a two-lane 40m simple span and 40+50+40m continuous sample bridge with four girders was designed. For the sample bridges, structural analysis under the design loads including dead load before and after composite, live load, and seismic loads has been performed. The material and geometric nonlinear analysis under dead load before composite has also been performed to evaluate lateral buckling strength of the steel-girder-cross beam grillage. Based on the two phase anlayses, proper spacing and bending righidity of cross beams were proposed.