• International Journal of Highway Engineering
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• v.13 no.2
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• pp.147-157
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• 2011

As a background study to apply the reliability-based resistance factors to the domestic concrete bridge design code, a comparative study is conducted for the design results and the reliability indexes obtained by adopting different resistance factor formats to yield the design strength of concrete structures. The design results which are calculated by applying the section resistance factors of the current domestic design code and the material resistance factors of Eurocode are compared for the concrete beam bridge. The reliability index is calculated by considering the uncertainties involved in material, dimension and strength equation during the design procedure to get the strength of concrete structure. Also, the sensitivity analysis is performed to figure out which design variables have great impact on the reliability index. The resistance factors of the current domestic bridge design code, AASHTO LRFD and Eurocode are applied to the bridge design for flexure and shear strength and the results show that the resistance factors of the domestic code give the largest reliability indexes. It is observed that the probabilistic distribution of the live load makes difference for the reliability index and the yield strength of reinforcing steel and the live load have great impact on the reliability of both flexural and shear strength of concrete beam through the sensitivity analysis.

• Journal of the Korea institute for structural maintenance and inspection
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• v.17 no.6
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• pp.50-60
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• 2013

Dynamic response of steel plate girder bridges by KL-510 design truck in KHBDC considering the road surface roughness of bridges and bridge-vehicle interaction is investigated. Simply supported steel plate girder bridges with span length of 20m, 30m, and 40m from "Standard Highway Bridge Superstructure" published by the Korean Ministry of Construction are used for a bridge model, and ten sets of the road surface roughness of bridge deck are generated from power spectral density (PSD) function by assuming the roadway as "Average Road". A three dimensionally modeled 5-axle tractor-trailer with its gross weight, which is the same as that of KL-510 design truck, is used for dynamic analysis. For the finite element modeling of superstructure, beam element for the main girder, shell element for the concrete deck, and rigid link between main girder and concrete deck are used. Impact factor and DLA of steel plate girder bridges for different span are calculated by the proposed numerical analysis model and compared with those specified by several bridge codes.

• International Journal of Highway Engineering
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• v.13 no.4
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• pp.123-132
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• 2011

The purpose of this study is to calculate and propose rational multi-lane loading factors for bridge design considering the probability of simultaneous truck passing in adjacent lanes and real truck weights. The probability of simultaneous truck passing is calculated by analyzing video image taken at various locations in highways and national roads. Weigh-In-Motion system data at two locations are used, which is combined with the probability of multiple presence to calculate the multi-lane loading factors for typical 2 lane and 5 lane bridges. Statistical properties of multi-lane loading factors are also calculated assuming that locations for video images and WIM data represent the overall traffic condition in the country. Results are compared with various design codes in the world and they show that the values are between the current Korea Bridge Design Code and AASHTO LRFD specification or Eurocode and are similar to Canadian Code.

• Journal of Korean Society of Steel Construction
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• v.12 no.5 s.48
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• pp.475-485
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• 2000

In this study, an automated optimum design program for steel box girder bridges has been developed for the optimum design of composite steel box girder bridges. The design constraints required for the optimum design of steel box girder bridges are based on the Korean standard bridge specification. Considering characteristics of steel box girder bridges, several approximation techniques, such as artificial constraint deletion, variable linking and stress reanalysis technique etc. are also introduced to enhance the efficiency of optimization. The developed program is mainly composed of major sub-system modules including structural analysis module using commercial structural analysis program such as RM-SPACEFRAME, optimum design module, pre-process module for friendly user input, and post-processor module for office automation. In addition, in order to demonstrate the efficiency and applicability of the developed optimum design program for steel box girder bridges, a few numerical examples are applied. Based on the results of the application, it may be stated that the automatic optimum design program developed in this study can be a prototype model for the developement of optimum design program for other type of bridge.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.5
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• pp.510-519
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• 2019

In this study, the structural analysis was conducted to the comparison of reaction force and contact pressure on the design truck load (DB-24 and KL-510) of slab bridge supported by MSEW abutment. As a result of the structural analysis, the reaction force acting on the abutment at the continuous bridge was reduced rather than the simple span bridge. The reaction force due to the dead load was estimated to be about twice as large as that of the live load, and the influence of the live load on the total reaction force was relatively small. The contact pressure of the MSEW abutment was estimated to be the largest in the simple span bridge. The influence of contact pressure on the type of live load was relatively small. Therefore, it is considered to be more advantageous to apply the MSEW abutment to the continuous bridge than to the simple span bridge because the contact pressure acting on the abutment on the continuous bridge is estimated to be small. Since the reaction force and the load sharing ratio acting on the MSEW abutment depending on various conditions, it is necessary to examine the contact pressure in various types of bridges and specifications.

• 한국방재학회:학술대회논문집
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• 2011.02a
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• pp.214-214
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• 2011

최근 국내 연안역에는 관광의 활성화 등의 목적으로 잔교가 많이 가설되고 있다. 그러나 잔교의 설계에 대한 규정이 없어 현재는 항만 및 어항설계기준을 준용하여 설계하고 있는 실정이며, 또한 지역적 특성을 반영하지 못하고 건설되어 과다한 단면을 사용하는 경우가 많고, 경제성이나 경관성을 갖추지 못한 경우가 많은 실정이다. 본 연구에서는 합리적인 잔교용 설계기준을 마련하기 위한 기초적인 연구로써 지반조건을 고려한 잔교의 거동특성을 분석하고자 하였다. 이를 위하여 해석모델을 개발하고, 다양한 해석조건에 대한 해석을 수행하여 그 특성을 정리하고자 하였다. 이를 통하여 잔교의 합리적인 구조시스템을 개발하고, 설계기준을 정리하는데 이바지 하고자 한다. 이 연구에서는 서해안의 연약지반을 고려하기 위해 지반스프링을 이용한 해석모델을 개발하고, 다양한 해석조건에 대한 해석을 수행하여 그 특성을 파악하고자 하였다. 조립식 잔교는 Capbeam, Wood Deck, ㄱ형강, Pile로 네 가지의 구성으로 이루어지고, 이 네 가지 요소의 재료는 강재로 사용하였으며, 하중에 대해서는 항만 및 어항설계기준을 준용하여 군중하중 $5kN/m^2$, 월파력 $20.1kN/m^2$을 사용하였고, 풍하중은 도로교 설계기준을 이용하여 산정한 $3.309kN/m^2$을 사용하였다. 재하하중 및 하중에 대한 최적단면에 대한 연구를 활용하여 본 연구에서는 지반조건의 영향, Capbeam과 Pile의 크기변화, 사항 등의 영향을 고려하였을 때 각 구성요소에서 발생하는 단면력의 변화와 축력, 접합부 모멘트 등의 외력과 내력을 정리하여 잔교의 거동특성을 파악하고자 하였다. 다양한 변수해석을 수행하기 위하여 지반조건을 고려한 2D 해석모델을 개발하였으며, 본 연구에서 고려한 군중하중, 풍하중, 월파력의 설계하중 중에서는 월파력이 지배적인 것을 알 수 있었다. Pier의 지름이 증가 하면 작용하는 월파력이 커지고 따라서 단면력이 증가하는 것을 알 수 있었다. 그러므로 합리적인 Pier의 크기 결정이 경제적이고 경관이 우수한 잔교 건설에 중요 요인임을 알 수 있다. 본 연구는 잔교의 설계기준 정립에 기초자료로 활용할 수 있을 것으로 판단되나, 보다 합리적인 잔교의 설계와 시공을 위해서는 지속적인 연구가 필요한 것으로 판단된다.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.29 no.2
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• pp.187-192
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• 2016

While structures are designed within elastic range by other designs, plastic behavior of structures should be verified and controlled in order to prevent structural collapse by the earthquake resistant design. No Collapse Requirement for typical bridges is to avoid falling down of superstructure by way of plastic behavior of certain structural elements and to operate emergency vehicles after earthquake. Such plastic behavior is restricted to connections or pier columns and appropriate measures are required for each case. Earthquake Resistant Design part of Roadway Bridge Design Code provides design processes for Ductile Collapse Mechanism by forming plastic hinges at pier columns. Also for bridges with reinforced concrete piers ductility-based design processes are provided as an appendix constructing Brittle Collapse Mechanism with connection yielding. In this study, a typical bridge with steel bearing connections and reinforced concrete piers is selected and No Collapse Design procedure considering both Ductile and Brittle Collapse Mechanism is proposed together with revisions required for the Earthquake Resistant Design part.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.3
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• pp.375-384
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• 2016

In the current Korea highway bridge design code (KHBDC), the criteria of concrete bridge decks are mainly based on short span decks of steel plate girder bridge, there are very little the specific criteria of long span decks in the twin steel plate girder bridge. Therefore, to put more rational and practical design criteria of the long span decks on the code, the complements of the related criteria are required in the current design code. This paper proposed the design bending moments of decks with 6.0~12.0m span for KL-510 load in direction to bridge (longitudinal direction) and perpendicular direction to bridge (transverse direction). The effects of orthotropic concrete decks, stiffness of steel girders and multiple lane loading factors (MLLF) were reflected in the design bending moments. The proposed design bending moments were compared to the design bending moments with DB-24 load.

• Journal of the Korea institute for structural maintenance and inspection
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• v.17 no.5
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• pp.49-58
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• 2013

Eight small scale circular reinforced concrete columns were tested under cyclic lateral load with constant axial load. Test specimens were designed with 4.5 aspect ratio. The selected test variables are longitudinal steel ratio, transverse steel ratio, yielding strength of longitudinal steel and axial load ratio. The test results of columns with different longitudinal steel ratio, transverse steel ratio and axial load ratio showed different seismic performance such as equivalent damping ratio, residual displacement and effective stiffness. It was found that the column with low strength of longitudinal steel showed significantly reduced seismic performance, especially for equivalent damping ratio and residual displacement. The regulation of flexural over-strength is adopted by Korea Bridge Design Specifications (Limited state design, 2012). The test results are compared with nominal strength, result of nonlinear moment-curvature analysis and the design specifications such as AASHTO LRFD and Korea Bridge Design Specifications (Limited state design).

• Journal of the Korea institute for structural maintenance and inspection
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• v.12 no.1
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• pp.135-142
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• 2008

This study is concerned with the optimum design of LB-Deck plate girder bridge. The optimizing problems of the composite bridge are formulated with objective functions and constraints. The objective functions are formulated as the total cost of the concrete deck and steel girder construction and the constraints are derived by criteria with respect to the Korean Highway bridge design. The optimizing algorithm using SUMT for optimum design of the Simple span, 2-Span, 3-span LB-deck plate and general RC-steel composite girder bridges (L=60m) which act live load(DB24). And their optimum numerical results are compares and analyzed to examine the possibility of optimization, the application and convergency of this optimizing algorithm.