• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.143-144
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• 2009

This study is a development of new PSC girder overcomes weakness of the existing PSC girder and has advantage of construction mark, economical efficiency and maintenance. The gole of this study is reducing dead-load and long-span as HWPC girder has same section through hole and multi-prestressing.

• The Journal of the Korea Contents Association
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• v.14 no.7
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• pp.511-517
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• 2014

The superstructure type of the railway bridge in our country, is mainly classified into the box girder and the I-type girder. The box girder is widely used in the high speed railway bridge because of the safety due to dynamic behavior. The I-type girder is used in the conventional railway bridge, and is also divided into the general type and the composite type, and the newly modified types have been developed. According to the current railway bridge design code, the girder design by the span length in various railway bridge types are performed in this study. The suitable girder height by the span length are analyzed, and the comparative analysis of the structural efficiency and the economical efficiency is carried out. From this study, the composite type girder is appeared the good result in respect of the structural efficiency. However, in the economical aspect, the general I-type girder is required less cost than the other types.

• Journal of the Korea Concrete Institute
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• v.26 no.3
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• pp.267-275
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• 2014

Recently, the construction of curved bridge has increased, thus researchers perform the analytic studies on PSC curved bridge. However, the grid analysis method that are mostly used in the construction industry is not adequate to acquire the precise behavior evaluation of curved PSC briges. Therefore, the precise finite element analysis considering the effective variables were performed to establish the basis for the design method of curved PSC bridge by using 3D elements and bar element. The evaluated variables in this analysis were the number of girders, loading point, section figure, change of prestressing force. The results show the load carrying capacity of the 3 girder type bridge is 200% of that of the 2 girder type, and that applying load on outer girder makes the load resistance capacity and the deflection deviation of 2 girders smaller. The structural capacity of the bridge is improved when the section size is increased, but the efficiency of it is not sufficient enough compare to that of the change of prestressing forces. The change of prestressing forces shows that the camber and the load carrying capacity are linearly increased as PS force is increased. Moreover, when the PS force applied on outer girder is increased than that of inner girder, the deviation of deflection the girders decreases, thereby the stability of the bridge is enhanced.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.245-248
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• 2008

Recently, much research has been conducted on FRP composite to replace steel. However, the concept of FRP girder filled with concrete has not been fully attempted. This study focuses on the analytical behavior of FRP girders filled with concrete. FRP girders usually have large deflection due to relatively low elastic modulus compared to steel members. However, in the previous experimental investigation on small sized modular beams, it has been verified that the displacement of FRP-girder filled with concrete is reduced and the strength is increased considerably. In this research, analytical investigations have conducted to verify the analytical method by comparing the results with tests. In addition, analyses on large girders assembled with small modules have been carried out to predict the feasibility before tests. The analytical results showed that the assembled FRP girders can be used as substitutes for steel girders.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.5
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• pp.569-576
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• 2019

PSC-Edge Rahmen Bridge makes low thickness and long span by introducing prestressed force to the edge girder and reducing positive moment. In the bridge, diagonal tension cracks occurred in the direction of $45^{\circ}$ to outer side of the girder after the temporary bent supported on the lower part of the upper slab and the secondary strand is tensioned on the girder. Researches on stress distribution and burst crack behavior of pre-stress anchorage has been conducted, it is difficult to analyze an obvious cause due to difference between actual shape and boundary condition. This study performed 3D frame analysis with additional boundary condition of temporary bent, the maximum compression stress occurred in the girder and there was a limit to identify the cause. It performed 3D Solid analysis with LUSAS 16.1 and the maximum principal tensile stress occurred at the boundary between the girder and the slab. As analyzing required reinforcement quantity at obtuse angle of the girder with the maximum principal tensile stress and directional cosine, reinforcement quantity was insufficient. Additional bridges have increased reinforcement quantity and extended area and crack was not occurred. It is expected that cracks on the girder during construction could be controlled by applying the proposed method to PSC-Edge Rahmen Bridge.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.1
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• pp.271-280
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• 2011

This study intends to analytically evaluate the vibration serviceability of the bridges for each long-span type having the same span length and road width using the Meister vibration sensation curve. With MIDAS, a structural analysis program, bridges were modeled using the girders as the frame element and slabs as the plate element. The transient analysis was performed using the moving loads of the design vehicles. This study presents the analytical process of reviewing the vibration serviceability during the design of long-span bridges. It involves the comparison of the vibration serviceability of different bridge types by applying the lagging-behind and acceleration amplitude from transient analysis to Meister curve. The result confirms that the process is appropriate.

• Journal of the Korean Society for Railway
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• v.11 no.5
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• pp.471-476
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• 2008

The superstructure type of the railway bridge in our country, is mainly classified into the box girder and the I-type girder. The box girder is widely used in the high speed railway bridge because of the safety due to dynamic behavior. The I-type girder is used in the conventional railway bridge, and is also divided into the general type and the composite type, and the newly modified types have been developed. According to the current railway bridge design code, the girder design by the span length in various types of railway bridge is performed in is study. The suitable girder height and the construction cost by the span length are analyzed, and the comparative analysis of the structural efficiency and the economical efficiency is carried out. From this study, the composite type girder is appeared the good result in respect of the structural efficiency. However, in the economical aspect, the general I-type girder is required less cost than the other types.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.39 no.2
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• pp.287-296
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• 2019

In recent years, a number of long span cable-stayed pedestrian bridges have been constructed to the advantages of relatively low cost construction and the many tourists visiting. However, most of the pedestrian bridges are located in parks or sightseeing areas, so they are conducted without proper review and design process. It is necessary to review the aerodynamic stability of the long span cable-stayed pedestrian bridge, and it should be designed in detail from various points of view rather than the road bridge. In this study, we investigated the wind characteristics of the cable-stayed pedestrian bridge, and the empirical equations for the relationship between the main span length and the fundamental natural frequencies are presented for future use. In addition, the flutter wind speed limit of the flat plate deck pedestrian bridge calculated using the Selberg's equation is also presented. The final aerodynamic bridge section which satisfied the aerodynamic stability was found from open grating method. The proposed method can be used for long span cable-stayed pedestrian bridge in the future.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.405-408
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• 2008

The most effective factors that improve sections and elongate spans of the prestressed concrete girders are shapes of sections and strengths of concretes, and the concrete strength is more influenced to enhance the allowable tensile strength on top and bottom fibers than increasing of flexural strength of girders. In this study, 60 MPa high-strength prestressed concretes were constructed at the Wonsoo Bridge where in the 1st section of expanding constructions of the Nonsan to Junjoo Expressway, the high-strength concrete was placed on the eight- 35 meters simple span IPC girders of four lanes of Nonsan direction. During casting of girder concretes, quality controls were carried out with continuing controls of surface moistures and corrections of the unit water using the air-meter methods right after batching. It was confirmed that compressive strengths of girder concretes ensure the target strength and the heat of hydrations of girder concrete were measured. Though using same materials and constructing methods, there're a wide range of strengths of each girder, so, when high-strength concretes cast in the place hereafter, a countermove should be prepared.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.39-40
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• 2009

This study is for development the anchorage that for development and practicality a holed precast prestressed concrete girder for forming an I-type Prestressed concrete girder bridge, in which at least one hole is formed in a body portion of the I-type Prestressed concrete girder.