• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.659-662
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• 2004

An analysis of the 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 AF, from the ship collision risk assessment is compared to an acceptance criterion. 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.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.11a
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• pp.168-187
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• 2002

Scour is the physical or chemical attack of flowing water which excavates and carries away material from stream beds and banks. Especially, hydraulic structures such as bridge piers and abutments placed in the channel causes the changes of the flow pattern like acceleration, the formation of vortices, and scour around the structures. Channel scour, especially bridge pier scour is the leading cause of bridge failures. It is very important to apply appropriate methods for both of scour analysis and protection. In this paper, several methods world-widely used for bridge scour analysis and protection are introduced and compared.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2005.04a
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• pp.564-571
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• 2005

Two-plate girder bridge and narrow steel box girder bridge are suggested for the steel wheel AGT system. For these bridge system, rail-bridge interaction analysis was carried out and dynamic behavior of these bridges was investigated. The result shows that all the estimated parameters satisfy the criteria concerned. As a result these two suggested bridge systems have enough performance to be competitive for the LRT elevated structures.

• Proceedings of the Korean Geotechical Society Conference
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• 2004.03b
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• pp.517-524
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• 2004

The leading cause of bridge failures is scouring bed material from around bridge foundations. Many advanced countries such as U.S.A., U.K., the Netherlands and New Zealand have developed and revised their own bridge scour manuals fit for their field conditions. In Korea, researches for reducing bridge failures during floods have concentrated on analysis, laboratory test and countermeasure of bridge scour during the last ten years. however no comprehensive manual for evaluating bridge scour and for identifying the conditions of bridge foundations has been provided yet. In this study, a new bridge scour manual is developed for the accurate evaluation of bridge scour, which reflects domestic field conditions with various streambed materials. The SRICOS method and the Erodibility Index Method are suggested for fine-grained soils and weathered rocks, respectively. In addition, bridge scour analysis algorithms are developed for field engineers to estimate bridge scour depth and to evaluate the susceptibility of bridge scour with ease.

• Journal of the Earthquake Engineering Society of Korea
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• v.24 no.4
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• pp.157-167
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• 2020

In this study, a field bridge test was conducted to find the dynamic properties of cable supported bridges with resilient-friction base isolation systems (R-FBI). Various ambient vibration tests were performed to estimate dynamic properties of a test bridge using trucks in a non-transportation state before opening of the bridge and by ordinary traffic loadings about one year later after opening of the bridge. The dynamic properties found from the results of the tests were compared with an analysis model. From the result of the ambient vibration tests of the cable supported bridge with R-FBI, it was confirmed that the dynamic properties were sensitive to the stiffness of the R-FBI in the bridge, and the seismic analysis model of the test bridge using the effective stiffness of the R-FBI was insufficient for reflecting the dynamic behavior of the bridge. In the case of cable supported bridges, the seismic design must follow the "Korean Highway Bridge Design Code (Limit State Design) for Cable supported bridges." Therefore, in order to reflect the actual behavior characteristics of the R-FBI installed on cable-supported bridges, an improved seismic design procedure should be proposed.

• 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.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2008.04a
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• pp.490-494
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• 2008

U-Channel Bridge is effective bridge type, because its edge beam performs role of barrier and enables to reduce additional dead loads. Although it is effective to reduce additional dead loads, there is possibility of bridge collapse under impact load due to car crash. Also, edge beam must have ability to induce safe driving and prevent falling accidents. Therefore, it requires behavior analysis and property investigation through the vehicle impact crashing edge beam. This study presents method of structural analysis of U-channel bridge and investigates design specifications for the effect of the edge beam under the vehicle impact. Also, it carries out stability investigation of behavior of edge beam and slab, based on Korean Highway Bridge Design Specifications and AASHTO LRFD Bridge Design Specification.

• Steel and Composite Structures
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• v.11 no.5
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• pp.423-434
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• 2011

Tongwamen Bridge is a critical link between Dongmen Island and the land in Shipu town, Zhejiang province, China. It is a 238 m span, half-through, concrete-filled steel tubular (CFST) X-type arch bridge. The width of the deck is only 10 m, yielding a width-to-span ratio of 1/23.8. The plane truss type section rib was adopted, which made of two CFST chords and web member system. The lateral stability is the key issue to this bridge. However, the existing researches on Tongwamen Bridge's lateral stability are all the deterministic structural analysis. In this paper, a new strategy for positioning sampling points of the response surface method (RSM), based on the composite method combining RSM with geometric method for structural reliability analysis, is employed to obtain the reliability index of lateral stability. In addition the correlated parameters were discussed in detail to find the major factors. According to the analysis results, increasing the stiff of lateral braces between the arch ribs and setting the proper inward-incline degree of the arch rib can enhance obviously the reliability of lateral stability. Moreover, the deck action of non-orienting force is less than the two factors above. The calculated results indicate that the arch ribs are safe enough to keep excellent stability, and it provides the foundation that the plane truss rib would be a competitive solution for a long-span, narrow, CFST arch bridge.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.13 no.2
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• pp.165-178
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• 2000

The simplified model for 3-dimensional analysis of vehicle-bridge interactions is presented in this study. By using the analysis model which includes the eccentricity of axle loads and the effect of the torsional forces acting on the bridge, the more accurate analysis results of the behavior of the bridge can be obtained. The equations of kinetic energy, potential energy and damping energy are expressed by degrees of freedom of the vehicle and the bridge. And then by applying Lagrange's equations of motion, the equations of motion of the vehicle and the bridge are obtained. By deriving the equations of forces acting on the bridge considering the vehicle-bridge vertical interactions and also by identifying the position of vehicle as time goes by, mass matrix, stiffness matrix, damping matrix and load vector of vehicle-bridge system are constructed in accordance with the position of vehicles. Then using Newmark's β-method(average acceleration), the equations of motion for the total vehicle bridge system are solved.

• Structural Engineering and Mechanics
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• v.64 no.2
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• pp.225-232
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• 2017

Leaning-type arch bridge is a new spatial structural system composed of two vertical arches and two leaning arches. So far there has been no contrast analysis of leaning type arch bridge with different systems. This paper focus on a parametric study of leaning type arch bridge with different systems to find the influential rules on structural forces and stability and to provide some reference for practical designs. The parametric analysis is conducted with different rise-to-span ratios and bending rigidities of arch ribs by comparing internal forces. The internal forces decline obviously with the increase of the rise-to-span ratio. The bending moments at the centers of the main arches and the leaning arches are sensitive to the bending rigidities of arch ribs. Parametric studies are also carried out with different structural systems and leaning angles of the leaning arch by comparing the static stability. The lateral stiffness of leaning-type arch bridge is less than the in-plan stiffness. Compared with the leaning-type arch bridge without thrust, the leaning-type arch bridge with thrust has a lower stability safety coefficient. The stability safety coefficient rises gradually with the increase of inclining angle of the leaning arch. This study shows that the rise-to-span ratio, bending rigidities of arch ribs, structural system and leaning angles of the leaning arch are all critical design parameters. Therefore, these parameters in unreasonable range should be avoided.