• Proceedings of the KSR Conference
• /
• 2006.11b
• /
• pp.359-364
• /
• 2006

경부고속철도 교량은 대부분 콘크리트교량으로 2@40m와 3@25m의 박스거더교량의 대표적인 형식이다. 일부구간에서 단경간 또는 2경간 연속 50 m 2주형을 갖는 강합성교량이 건설되었다. 연행하는 차륜이 반복해서 통과하는 철도교량은 주기적인 동적하중에 의하여 공진이 발생할 수 있으며, 특히 고속전철이 통과하는 교량은 저속차량이 통과하는 일반철도보다 공진의 발생가능성이 클 뿐 아니라 고속으로 주행하는 열차의 주행안정성 확보를 위해서 엄격한 제한조건을 만족시켜야 하는 엄밀한 동적설계 조건을 갖게 된다. 그러한 조건 중에서 가속도의 제한 규정은 UIC에서 제안된 기준치로서 도상을 갖는 경우에 0.35g이하를 만족시키도록 요구하고 있다. 현재 KTX가 주행하는 교량에서는 일부구간 및 시점에서 규정치를 초과하는 값을 보이고 있는 것으로 계측되었으며, 그 원인 및 대책마련을 위한 연구를 수행하고 있다. 본 연구에서는 그러한 과도한 가속도의 원인 규명을 위한 각종 매개변수 연구와 그 해결책 마련을 위한 연구를 수행하였으며, 경제적이면서도 효과적인 진동저감 방안을 제시하고 있다.

• Journal of Korean Society of Steel Construction
• /
• v.15 no.3
• /
• pp.321-329
• /
• 2003

To effectively use the cross section of concrete decks, analytical and experimental studies on prestressed steel-box-girder bridges were performed in this study. The method of applying prestress was determined in the analytical study and the longitudinal behavior of the prestressed steel-box-girder bridge was considered in the experimental study. The object model for these studies was a two-span continuous bridge. The method of applying prestress determined herein was divided into two parts: one is that apply prestress to the concrete deck at its intermediate support, and the other is that apply prestress to the lower flange of the steel-box-girder bridge at its end support. The prototype bridge for the experiment was simulated based on the rule of similitude and was fabricated according to construction steps to apply prestress effectively. From the results of the experimental study, it has demonstrated that the prestressed steel-box-girder bridge provides better performance than the general steel-box-girder bridge in view of the increase of the design live load, the reduction of the tensile stress of the concrete deck at intermediate support, and the reduction of the displacement.

• Proceedings of the Korean Institute of Industrial Safety Conference
• /
• 2003.10a
• /
• pp.391-396
• /
• 2003

최근 차량하중의 대형화에 의해 교량구조물은 사용년수가 증가함에 따라 노후손상에 의해 당초의 설계능력을 발휘하지 못하는 경우가 종종 있으며, 이에 대해 교량구조물의 내하력을 증강시키기 위하여 여러 가지 보수 보강 공법들이 사용되고 있다. 특히 재료의 내부식성, 친환경성 등을 고려하여 GFRP(Glass Fiber Reinforced Plastic)에 의한 보강이 점차 증가하는 추세에 있으나, 아직까지 기존 철근콘크리트 부재와 보강되는 GFRP 부재의 합성에 의한 해석기술에 대한 연구가 많지 않은 실정이다.(중략)

• Journal of the Korea Concrete Institute
• /
• v.25 no.5
• /
• pp.517-528
• /
• 2013

The modular technology has been already applied in automotive industry, plant and shipbuilding industry. Recently, the modular technology was applied in bridge construction. The modular bridge is different from the existing precast bridges in terms of standardized design that the detailed design of members is omitted by using the standard modules; the design of the modular bridge is completed by only assembling the standard modules without design in member level. The girder-type precast modular bridge has been developed as a simply supported bridge. The girder-type precast modular bridge could be applied to the multi-span bridges through the continuity method. The continuity of the girder-type precast modular bridge is achieved by using the link slab which is easy to construction and appropriate to the rapid construction. The link slabs have been used as the type of reinforced concrete structure in US from the 1950's. In 2000's, the link slab using the engineered cementitious concrete (ECC link slab) has been developed. In this study, the RC type link slab which is more reproducible and economic relative to the ECC link slab was used for the continuity of the girder-type precast modular bridges, and the construction detail of RC type link slab was modified. In addition, the modified iterative design method of RC type link slab was proposed in this study. To verify the proposed design method, the flexural tests were conducted using the RC type link slab specimens. Also, the fatigue test using the mock-up specimen was conducted with cyclic loading condition up to two million cycles.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.13 no.4
• /
• pp.1-13
• /
• 1993

In design of prestressed concrete structures, structural analysis is performed normally several times for selection of adequate sectional dimension and tendon amount. Especially for precast segmental multi-span bridges. time consuming structural analysis process due to time dependent material properties and structural system change could be effectively reduced by use of a reduced-span bridge model. 5-span and 3-span bridges are selected as reduced-span models for the 10-span full bridge to investigate the acceptability in practical design. The analytical results of deflection, total moment, statical moment, and ultimate moment of the reduced span-models are compared with those of the 10-span full bridge. Application of the load factors to structural analysis for ultimate moment calculation in prestressed concrete is reviewed and a rational method is proposed.

• Journal of the Korea Concrete Institute
• /
• v.19 no.4
• /
• pp.393-399
• /
• 2007

Concrete bridge decks are directly exposed to the severe environmental conditions such as rain water and deicing chemicals resulting in the freeze-thaw action and the rebar corrosion during their service lift. These deteriorations of bridge decks shorten the service lift and consequently they are the major concerns of the maintenance. The high performance concrete (HPC) deck is proposed as the alternative to minimize the deterioration problems. To develop more durable concrete deck, the performance characteristic tests of HPC mixtures were carried out. In this study, 4 different concrete mixtures were used varying the mineral admixtures as the cement replacement; ordinary portland cement (OPC), 20% fly ash (FA),20% fly ash with 4% silica fume (FS), and 40% ground granulated blast-furnace slag (BS). The design compressive strengths of HPC specimens were 27 MPa and 35 MPa, respectively. The results showed that the compressive strength of concrete did not much affect the durability of concrete. HPC with fly ash and silica lune (FS) were turned out to have the good durability and crack resistance.

• Magazine of the Korea Concrete Institute
• /
• v.19 no.4
• /
• pp.66-72
• /
• 2007

• Magazine of the Korea Concrete Institute
• /
• v.16 no.1 s.78
• /
• pp.80-85
• /
• 2004

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.24 no.5
• /
• pp.531-542
• /
• 2011

The time-dependent temperature distribution across the section in bridges is determined on the basis of the three-dimensional finite element analyses and numerical time integration in this study. The material properties which change with time and thermal stress of concrete are taken into account to effectively trace the early-age structural responses. Since the temperature distribution is nonlinear and depends upon many material constants such as the thermal conductivity, specific heat, hydration heat of concrete, heat transfer coefficients and solar radiation, three representative influencing factors of the construction season, wind velocity and bridge pavement are considered at the parametric studies. The validity of the introduced numerical model is established by comparing the analytical predictions with results from previous analytical studies. On the basis of parametric studies for four different bridge sections, it is found that the creep deformation in concrete bridges must be considered to reach more reasonable design results and the temperature distribution proposed in the Korean bridge design specification need to be improved.

• 한국방재학회:학술대회논문집
• /
• 2010.02a
• /
• pp.83.1-83.1
• /
• 2010

본 연구는 고강도 강재를 적용한 연속교 형식의 강교량에 대하여 연구를 수행하였다. 교량에 사용되는 주구조의 고강도화에 따로 연속교의 교각 부근 부모멘트부에는 정모멘트부에 비하여 큰 모멘트가 작용하게 된다. 또한 정모멘트 구간과 달리 상부플랜지에 인장력이 작용하게 되어 완공 후에도 극한 하중 상태에서 콘크리트 데크가 응력을 부담할 수 없게 된다. 이에 따라 하부 플랜지에 불안정 파괴가 발생할 가능성이 있으며 비합성 단면과 같은 방법으로 설계하게 된다. 또한 모멘트 재분배를 고려한 설계를 하기 위해서는 부모멘트부에 충분한 휨 연성이 필요하다. 고강도 강재를 적용한 교량은 일반강재를 적용한 교량에 비하여 휨연성이 감소하게 되므로 휨연성 확보를 위한 보강방안이 필요하다. 본 연구는 부모멘트부의 휨연성 향상을 휘하여 가로보의 부등 배치를 제안하였으며, 유한요소해석 결과 휨연성이 향상되었다.