• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2010년도 춘계 학술대회 제22권1호
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• pp.451-452
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• 2010

PSC I 거더교는 시공성, 경제성, 사용성, 안전성 등 모든 면에서 성능이 매우 우수하여 지금까지 가장 많이 건설되어 온 교량형식이다. 그러나, 국내의 경우에는 표준거더의 형고가 높게 설계되어 장지간화에는 제한적이었다. 따라서, 본 논문에서는 가로보 정착구조를 적용하고 다단계 인장기술을 이용한 연속화 PSC거더의 기술을 개발하는데 그 목적을 두었다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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• pp.417-420
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• 2004

The Prestressed concrete girder bridges(PSC girder bridges), consisting of prestressed concrete girders and cast-in-place deck slabs, are sensitive to creep and shrinkage of concrete. Shrinkage and creep produce additional internal forces md deformations in PSC girder bridges. The long-term behavior of the PSC girder bridges depends on time-dependent properties of materials, amount of prestressing, methods and sequences of construction and age at loading. The purpose of this study is to predict the long-term behavior of PSC girder bridge. For this purpose, Computer program for Time-dependent analysis of PSC girder bridge has been developed. thereafter, Time-dependent analysis using developed computer program was carried out about 3-span continuous PSC girder bridges. Various construction timing sequences were used for parametric study.

• Structural Engineering and Mechanics
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• 제17권6호
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• pp.879-898
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• 2004

A method of making simply supported girders continuous is described for bridges with spans of 30-45 m. The splicing method takes advantage of an induced secondary moment to transform the self-weight stresses in the precast simply supported girders into values representative of a continuous girder. The secondary moment results from prestressing of continuity tendons and detensioning of temporary tendons in the girders. Preliminary sections are selected for spliced U-girder bridges with a range of span lengths. Use of the proposed technique results in girder depth reductions of 500-800 mm when compared to standard simply supported I-girder bridges. The flexural behavior of an example bridge with 40-m spans is examined to illustrate the necessary considerations for determining the optimum sequence of splicing operations.

• 한국해양공학회지
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• 제20권5호
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• pp.63-69
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• 2006

An isolated bridge using a laminated rubber bearing provides an elastic support of continuous span and prevents the transmission of excessive seismic force from the substructure of the bridge, which uses a metal bearing, as this permits a relative displacement between the super-and substructure. Hawever, this kind of bridge is caused long periodic, as a result of enlargingtotal thickness of the rubber, since it corresponds to temperature change and increases the horizontal displacement of the superstructure. This paper uses a numerical study to describe the pounding problem between adjacent decks when subjected to a strong earthquake. Furthermore, numerical results are clarified for the buffer rubber used to mitigate the pounding force between adjacent decks.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2004년도 가을 학술발표회 논문집
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• pp.195-202
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• 2004

After the 1990's, Guss asphalt has chosen in Korea for using in pavement of a steel deck bridge because of it's distinguish ability about water proof and so on. But on the other hand it may cause server stress and displacement on the bridge as it is treated using very high temperature ranging from 220℃ to 260℃. Therefore it is critical to estimate the thermal effect of Guss asphalt on the steel deck bridge before the width and pattern of the unit portion are decided to minimize impact. In this study, a serious of numerical tests of the some steel box bridges were idealized were conducted to verify the feasibility of numerical value analysis. The parametric study was performed to present design proposal about the Box section dimensions and the diaphragm spacing.

• International Journal of Safety
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• 제9권1호
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• pp.12-20
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• 2010

In this study, a series of random field test and dynamic analysis in the time domain were carried out in order to find in the reason of fatigue damage of the main and the secondary members in the 3-span continuous steel plate girder railway bridge being under in service over 60 years. From the measured and the analyzed results, the stress distribution patterns were investigated for the members with fatigue damage. In addition, global and local numerical stress analysis was performed for the members damaged severely by corrosion, to estimate variation of the distribution by corrosion. Finally, a reasonable cut-off ratio in the steel plate railway bridge will be proposed by analyzing the equivalent stress ranges according the ratio.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2011년도 정기 학술대회
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• pp.57-60
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• 2011

Updating model parameters are required in order to simulate the actual behavior of the dynamic structure. A new strategy, mean-iterative neural networks (MINNs) has been proposed in this paper for model parameter updating of a steel box girder bridge. With new strategy for structural dynamic model updating, it offers many advantages such as potential savings of computational effort, more consistent in reaching convergence. The dynamic response obtained from the experimental test on a two span continuous bridge is used as the target for model updating. And the presented algorithm is applied to update the model parameters. These results show a good possible of using MINNs in practice for dynamic model updating.

• International Journal of Safety
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• 제10권1호
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• pp.22-31
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• 2011

Seismic response control method of the bridge structures with semi-active control device, i.e., magneto-rheological (MR) damper, is studied in this paper. Design of various kinds of clipped optimal controller and fuzzy controller are suggested as a semi-active control algorithm. For determining the control force of MR damper, clipped optimal control method adopts bi-state approach, but the fuzzy control method continuously quantifies input currents through fuzzy inference mechanism to finely modulate the damper force. To investigate the performances of the suggested control techniques, numerical simulations of a multi-span continuous bridge system subjected to various earthquakes are performed, and their performances are compared with each other. From the comparison of results, it is shown that the fuzzy control system can provide well-balanced control force between girder and pier in the view point of structural safety and stability and be quite effective in reducing both girder and pier displacements over the existing control method.

• Earthquakes and Structures
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• 제13권4호
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• pp.353-363
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• 2017

The present study considers a multi-span continuous bridge, isolated by lead rubber bearing (LRB). Dynamic soilstructure interaction (SSI) is modelled with the help of a simplified, sway-rocking model for different types of soil. It is well understood from the literature that SSI influences the structural responses and the isolator performance. However, the abovementioned effect of SSI also depends on the earthquake ground motion properties. It is very important to understand how the interaction between soil and structure varies with the earthquake ground motion characteristics but, as far as the knowledge of the authors go, no study has been carried out to investigate this effect. Therefore, the objectives of the present study are to investigate the influence of earthquake ground motion characteristics on: (a) the responses of a multi span bridge (isolated and non-isolated), (b) the performance of the isolator and, most importantly, (c) the soil-structure interaction. Statistical analyses are conducted by considering 14 earthquakes which are selected in such a way that they can be categorized into three frequency content groups according to their peak ground acceleration to peak ground velocity (PGA/PGV) ratio. Lumped mass model of the bridge is developed and time history analyses are carried out by solving the governing equations of motion in the state space form. The performance of the isolator is studied by comparing the responses of the bridge with those of the corresponding uncontrolled bridge (i.e., non-isolated bridge). On studying the effect of earthquake motions, it is observed that the earthquake ground motion characteristics affect the interaction between soil and structure in such a way that the responses decrease with increase in frequency content of the earthquake for all the types of soil considered. The reverse phenomenon is observed in case of the isolator performance where the control efficiencies increase with frequency content of earthquake.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1999년도 학회창립 10주년 기념 1999년도 가을 학술발표회 논문집
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• pp.869-881
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• 1999

Inchon International Airport Elevated Road Way is located between the Passenger Terminal Building and Transportaion Center which are Inchon International Airport core construction projects. The deck of the bridge is consists of 5-span or 6-span continuous pre-stressed concrete slab. Steel form has been used to enhance the quality of texture on concrete slab. Steel form has been used to enhance the quality of texture on concrete surface, lower surface of deck slab with the two way arch has been manufactured by highly professional manner in order to get an beautiful exterior architectural looks. The prestressed concrete deck slab is mass concrete structures with a high-specified concrete strength and a varying section in the range of 0.95-2.8m thickness. Therefore high risks of thermal cracking occurrence by heat of hydration highly are expected. To resolve such problem, we adopted type 1 cement and pipe cooking method at construction site through mass concrete specimen test and 3-dimensional analysis. For Pipe cooling we used 25mm diameter stainless pipes with wrinkles. Cooling pipe with spacing 50-60cm has been installed. And continuous pipe cooling with cooling water of 15$^{\circ}C$ was conducted for 2days. In present 8 span of all 29 spans construction has been completed. No thermal cracking heat hydration has been observed yet.