• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.1A
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• pp.1-9
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• 2006

An analysis of the annual frequency of collapse(AF) is performed for each bridge pier exposed to ship collision. From this analysis, the impact lateral resistance can be determined for each pier. The bridge pier impact resistance is selected using a probability-based analysis procedure in which the predicted annual frequency of bridge collapse, AF, from the ship collision risk assessment is compared to an acceptance criterion. The analysis procedure is an iterative process in which a trial impact resistance is selected for a bridge component and a computed AF is compared to the acceptance criterion, and revisions to the analysis variables are made as necessary to achieve compliance. The distribution of the AF acceptance criterion among the exposed piers is generally based on the designer's judgment. In this study, the acceptance criterion is allocated to each pier using allocation weights based on the previous predictions. To determine the design impact lateral resistance of bridge components such pylon and pier, the numerical analysis is performed iteratively with the analysis variable of impact resistance ratio of pylon to pier. The design impact lateral resistance can vary greatly among the components of the same bridge, depending upon the waterway geometry, available water depth, bridge geometry, and vessel traffic characteristics. More researches on the allocation model of AF and the determination of impact resistance are required.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.4
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• pp.1327-1336
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• 2013

In this study, the effects of corrugated webs on the ultimate behavior of horizontally curved I-shaped girders are investigated. Because of the geometric characteristics of corrugated plates, corrugated webs can be used for enhancing torsional and warping stiffness of plate girders. Many researches have been conducted to study the effects of corrugated webs on the ultimate behavior of straight girders. But, the studies of the ultimate behavior of horizontally curved girders with corrugated webs, which generally show out-of plane behavior manly, have been rarely performed so far. By performing inelastic-nonlinear analysis, the ultimate behavior of curved girders with corrugated webs is studied in this paper. Laterally unsupported length and subtended angle of girders, and length of height of corrugation of webs are considered as the geometric parameters which would be expected to affect the ultimate behavior. By this analytical study with considering the geometric parameters, the changes of ultimate behavior and load carrying capacity of curved girders with corrugated webs are investigated. Also, the effects of corrugated webs on the increase of load carrying capacity for curved girders are studied with comparing to the capacity of general curved girders with flat webs. According to the analytical results, corrugated webs can be used to increase the ultimate load carrying capacity of curved girders, because of their high torsional and warping stiffness. But, it is also indicated that they may decrease the load carrying capacity of curved girders which have relatively small subtended angle or initial curvature, because of an accordion effect.

• Journal of the Korea institute for structural maintenance and inspection
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• v.9 no.4
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• pp.169-176
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• 2005

An analysis of the annual frequency of collapse(AF) is performed for each bridge pier exposed to ship collision. From this analysis, the impact lateral resistance can be determined for each pier. The bridge pier impact resistance is selected using a probability-based analysis procedure in which the predicted annual frequency of bridge collapse, AF, from the ship collision risk assessment is compared to an acceptance criterion. The analysis procedure is an iterative process in which a trial impact resistance is selected for a bridge component and a computed AF is compared to the acceptance criterion, and revisions to the analysis variables are made as necessary to achieve compliance. The distribution of the AF acceptance criterion among the exposed piers is generally based on the designer's judgment. In this study, the acceptance criterion is allocated to each pier using allocation weights based on the previous predictions.

• Journal of the Korea Concrete Institute
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• v.20 no.6
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• pp.747-754
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• 2008

In this study, high strength concrete corbels reinforced with steel fibers and polypropylene fibers, and subjected to the vertical and horizontal loads were constructed and tested. The results showed that performance in terms of load carrying capacities, stiffness, ductility, crack width, and number of cracks was improved, as the steel fibers and polypropylene fibers were added. The polypropylene fiber reinforced concrete corbels resulted in higher ductility in presence of horizontal loads, but showed larger crack width than the steel fiber reinforced concrete corbels. And, the heads of the headed bars provided excellent end anchorage of the main tension tie reinforcement. Experimental results presented in this paper are also compared with various prediction models proposed by codes and researchers. The refined strut-and-tie model showed more accurate and conservative predictions in presence of horizontal loads, and the truss model proposed by Fattuhi provides fairly good predictions for fiber reinforced concrete corbels.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.9
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• pp.6385-6390
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• 2015

With bending moment, torsional moment due to geometric properties as "Initial curvature" acts in horizontally curved I-girder. These behavior causes the secondary effect of bending in minor-axis because of interaction between bending and torsion. The bending and torsion interaction cause a loss of load bearing capacity by induced the early inelastic or plasticity condition in curved girder. Also eccentric load by movements of traffic can increase torsion. However, Equation of interaction between bending and torsion for straight girder, not deal with characteristics of curved girder behavior in previous studies, can be overestimated for ultimate strength in horizontally curved I-girder acting vertical force. Therefore, using more rational, obvious suggestion is required when design curved girder. In this study, we identified the bending-torsional moment interaction for the horizontally curved I-girder of the eccentric load acting by FEM analysis.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.13-16
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• 2008

Corbels are short cantilevers that project from the faces of a column and are a type of stress disturbed member, resisting both the ultimate shear force applied to them by the beam, and the ultimate horizontal force caused by shrinkage, temperature changes, and creep of the supported elements. Recently, as there have been an increase in the use of high-strength concrete and the concern about corrosion problems, lots of researches about hybrid reinforcing technique, applying strategically high performance reinforcements to the concrete elements, are performed. In this study, fiber reinforced high strength concrete corbels were constructed and tested for applying hybrid reinforcing technique to the corbels using steel fibers and headed bars. The results showed that the performance in terms of load carrying capacities, stiffness, ductility, and crack width was improved, as the steel fibers were added and the percentage of steel fibers was increased. In addition, the corbel specimens used headed bars as main tension ties showed superior load carrying capacities, stiffness, and ductility to the corbel specimens anchored main tension ties by welding to the transverse bars.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.434-438
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• 2001

Military facilities with masonry construction have a great portion in the whole military facilities. But lots of them have been used for more than 20 years, the degree of deterioration of the facilities are very serious. Futhermore, as small budget for the facilities maintenance and poor maintenance, the performance of the aged masonry facilities have continually decreased. We suggest a structural performance assesment criteria for the military facility through literature review, interview with experts and questionnaire. The assesment of structural performance includes the inclining and sinking degree of the facilities, durability of materials and resisting force of the structural members.

• Journal of Korean Society of Steel Construction
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• v.18 no.2
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• pp.137-146
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• 2006

In this paper, a numerical study on the evaluation of the redundancy according to the dimension and spacing of cross beams in the composite twin steel plate girder bridges that are generally recognized as a non-redundant load path structures, has been performed. Specifically, a two-lane three-span continuous (40+50+40m) bridge with I-section cross beams which serve as cross bracing, and without a lateral bracing were considered. The material and geometric nonlinear analyses were conducted to evaluate the ultimate loading capacity of the intact and damaged bridge in which one of the two girders is seriously fractured. Through the numerical analyses, it was recognized that there is little difference in redundancy according to the variation of the dimension and spacing of the cross beams for both intact and damaged bridges.

• Journal of the Korea institute for structural maintenance and inspection
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• v.10 no.3
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• pp.123-134
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• 2006

In this study ship collision risk analysis is performed to determine the design vessel for collision impact analysis of the maritime bridge. Method II which is a probability based analysis procedure is used to select the design vessel for collision impact from the risk analysis results. The analysis procedure, an iterative process in which a computed annual frequency of collapse(AF) is compared to the acceptance criterion, includes allocation method of acceptance criterion of annual frequency of bridge component collapse. The AF allocation by weights seems to be more reasonable than the pylon concentration allocation method because this AF allocation takes the design parameter characteristics quantitatively into consideration although the pylon concentration allocation method brings more economical results when the overestimated design collision strength of piers compared to the strength of pylon is moderately modified. From the assessment of ship collision risk for each bridge pier exposed to ship collision, a representative design vessel for all bridge components is selected. The design vessel size varies much from each other in the same bridge structure depending upon the vessel traffic characteristics.

• Journal of the Korea Concrete Institute
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• v.16 no.4 s.82
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• pp.467-476
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• 2004

Because of crack control by steel bars after cracking the material models for reinforced concrete(RC) differ from those for plain concrete(PL). The nonlinear behavior of columns subjected to lateral load was simulated with reasonable accuracy in 3D analysis by applying distinct material models for RC and PL zone subdivided properly on the section. The shear strain is confirmed to develope unstably with ununiform distribution in out-of-plane direction. And this tendency becomes stronger as the thickness of column member increases in out-of-plane direction. If this ununiformity in strain distribution is not taken into consideration the capacity and the deformability of columns in shear dominant failure are overestimated excessively in two dimensional analysis. By introducing equivalent softening model a behavior of columns can be predicted too in two dimensional analysis.