• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.3D
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• pp.421-431
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• 2011

In this paper, actual bridges constructed with SMA (Stone Mastic Asphalt) deck pavement and virtual bridges substituted the deck pavement with polymer concrete under the same conditions were statically analyzed to investigate applicability of the thin polymer concrete bridge deck pavements. PSC (prestressed Concrete) girder bridge, steel box girder bridge, PSC box girder bridge, and RC (Reinforced Concrete) rahmen bridge constructed with the SMA deck pavement were analyzed and compared to evaluate various types of the bridge. The bridge deck and pavement were assumed to be fully bonded and the stress and deformation during the construction were ignored while those due to pavement weight and vehicle loading were analyzed. According to the analysis results, the stress and deformation of the bridges using the polymer concrete due to the pavement weight were smaller than those using the SMA because of smaller self weight due to lighter unit weight and thinner thickness of the pavement. The stress and deformation of the bridges using the polymer concrete due to the vehicle loading were larger than those using the SMA because of the smaller area moment of inertia due to the thinner pavement thickness. In case that the pavement weight and vehicle loading applied simultaneously, the stress and deformation of the bridges using the polymer concrete were smaller because effect of self weight reduction was more dominant. Investigation of performance of the bridge deck pavement and analysis of economical efficiency are warranted.

• Proceedings of the KSR Conference
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• 1998.05a
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• pp.564-571
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• 1998

The function of diaphragms at abutments and piers of prestressed concrete (PSC) box girder train bridge is to transfer forces from the superstructure onto bearings or column and to stiffen the superstructure cross-section against in-plane deformation. Due to large stress disturbance at diaphragm, the design for the diaphragm using conventional design method is relatively irrational than designs for other structual members. And, due to contribution to boundary condition of deck slab by the diaphragm, the behavior of deck slab near the diaphragm is different from behavior of the deck slab obtained from two dimensional analysis of the bridge, which is basis far the design of deck slab. In this paper, three dimensional behavior of deck slab near diaphragm of PSC box girder train bridge constructed by the precast span method are analyzed by using three dimensional finite element modeling. Then, strut-and-tie model is applied to design the diaphragm of PSC box girder train bridge. The modeling techniques in this paper can be applied effectively to examine the causes of cracks at deck slab near diaphragm and to design diaphragm rationally.

• Journal of the Korean Society of Safety
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• v.27 no.6
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• pp.84-92
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• 2012

Anchorage zone in prestressed concrete cable stayed bridges is very important area due to the more accurate analysis is needed to estimate the behavior. In the study, since the cable anchorage zone in the prestressed concrete cable-stayed bridge is subject to a large amount of concentrated tendon forces, it shows very complicated stress distributions and causes a serious local cracks. Accordingly, It is necessary to investigate the parameters of affecting the stress properties, such as the cable inclination, the position of anchor plate, the modeling method and the three dimensional effect. The tensile stress distribution of anchorage zone is compared to the actual design condition by varing the stiffness of spring element in the local modeling and an appropriate position of anchor plate is determined. These results would be elementary data to the stress state of anchorage zone and more efficient design.

• International Journal of Concrete Structures and Materials
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• v.8 no.1
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• pp.43-59
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• 2014

Many bridges are subject to lateral damage for their girders due to impact by over-height vehicles collision. In this study, the optimum configurations of carbon fiber reinforced polymers (CFRP) laminates were investigated to repair the laterally damaged prestressed concrete (PS) bridge girders. Experimental and analytical investigations were conducted to study the flexural behavior of 13 half-scale AASHTO type II PS girders under both static and fatigue loading. Lateral impact damage due to vehicle collision was simulated by sawing through the concrete of the bottom flange and slicing through one of the prestressing strands. The damaged concrete was repaired and CFRP systems (longitudinal soffit laminates and evenly spaced transverse U-wraps) were applied to restore the original flexural capacity and mitigate debonding of soffit CFRP longitudinal laminates. In addition to the static load tests for ten girders, three more girders were tested under fatigue loading cycles to investigate the behavior under simulated traffic conditions. Measurements of the applied load, the deflection at five different locations, strains along the cross-section height at mid-span, and multiple strains longitudinally along the bottom soffit were recorded. The study investigated and recommended the proper CFRP repair design in terms of the CFRP longitudinal layers and U-wrapping spacing to obtain flexural capacity improvement and desired failure modes for the repaired girders. Test results showed that with proper detailing, CFRP systems can be designed to restore the lost flexural capacity, sustain the fatigue load cycles, and maintain the desired failure mode.

• Journal of the Korea Concrete Institute
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• v.23 no.5
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• pp.667-674
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• 2011

This paper discusses the analysis method of prestressed concrete girder integral abutment bridges for a 75-year bridge life and the development of prediction models for abutment displacements under thermal loading due to annual temperature fluctuation and time-dependent loading. The developed nonlinear numerical modeling methodologies considered soil-structure interaction between supporting piles and surrounding soils and between abutment and backfills. Material nonlinearity was also considered to simulate differential rotation in construction joints between abutment and backwall. Based on the numerical modeling methodologies, a parametric study of 243 analysis cases, considering five parameters: (1) thermal expansion coefficient, (2) bridge length, (3) backfill height, (4) backfill stiffness, and (5) pile soil stiffness, was performed to established prediction models for abutment displacements over a bridge life. The parametric study results revealed that thermal expansion coefficient, bridge length, and pile-soil stiffness significantly influenced the abutment displacement. Bridge length parameter significantly influenced the abutment top displacement at the centroid of the superstructure, which is similar to the free expansion analysis results. Developed prediction model can be used for a preliminary design of integral abutment bridges.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05a
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• pp.538-541
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• 2006

PSC(Prestressed Concrete) box girder bridges have been widely applied in Korea. A number of these bridges have been built by the segmental construction method in the longitudinal direction and(or) vertically along the cross-sectional depth with MSS(Moving Scaffolding System). An actual 2-span continuous PSC box girder bridge of Kyeongbu high speed railway was selected and instrumented with 96 vibrating wire embedded type strain gauges and 2 thermocouples. The long-term behavior of the bridge was monitored through two major points located at mid-span of the first span and at the internal support. Data collection started just after the casting of the first segment (U section). Concrete strain and temperature data were gathered regularly by a data logger (CR10) during 600 days under and after construction. According to this measurement, the parabolic longitudinal strain distribution in the top slab at mid-span is shown. And also, the same distribution at the interior support is shown. The compressive strains at the cantilever region are larger than at the web position and the internal part in the top slab. Strain difference largely happened during the early construction period.

• Journal of the Korean Society for Railway
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• v.9 no.1 s.32
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• pp.102-109
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• 2006

The PSC girders which currently used at highway bridge have the standard cross sections about 25m, 30m and 35m span. Thus, in case of highway bridge design, the bridge designer can choose the adequate standard cross section according to constructional condition. However, in railway bridge design, there are limitations on reasonable bridge design considering circumstances of a construction site and conditions of location etc, because the PSC girders used at railway bridge have the cross section about only 25m span length. In this study, the optimum design for the PSC girder railway bridge with 30m span length has been performed. Also, in order to investigate the dynamic stability of railway bridge using the optimum section of PSC girder, dynamic analysis has been carried out. From the results of analysis, it is suggested to denote the optimum section which satisfied the structural safety, dynamic stability and economical efficiency all together.

• Journal of the Korea Concrete Institute
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• v.18 no.2 s.92
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• pp.169-176
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• 2006

Prestressed composite girder with concrete infilled steel tubes(PSC-CFT girder) is new type of bridge girder which enhances the resisting capacities due to the double composite action of PSC composite girder and concrete infilled tube. The flexural behaviors of PSC-CFT girder in the negative moment regions are investigated based on the experimental observations recently performed on two of 3.6m long specimens. The mechanical and structural roles and failure mechanism of the composite action are discussed through comparing the test results with those numerically predicted by the three methods of one and three-dimensional nonlinear finite element analysis, and section analysis method.

• Journal of the Korea Concrete Institute
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• v.18 no.3 s.93
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• pp.313-320
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• 2006

Prestressed composite girder with concrete infilled steel tubes(PSC-CFT girder) is new type of bridge girder which enhances the resisting capacities due to the double composite action of PSC composite girder and concrete infilled tube. The flexural behaviors of PSC-CFT girder in the positive moment regions are investigated based on the experimental observations recently performed on two of 4.4m long specimens. The mechanical and structural roles and failure mechanism of the composite action are discussed through comparing the test results with those numerically predicted by the three methods of one- and three-dimensional nonlinear finite element analyses, and section analysis method.

• Structural Engineering and Mechanics
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• v.69 no.3
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• pp.347-359
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• 2019

This paper aims to evaluate the behavior of Dorim-Goh bridge in Seoul, Korea, under static and dynamic loads effects by ambient trucks. The prestressed concrete (PSC) girders and reinforcement concrete (RC) slab of the bridge are evaluated and assessed. A short period monitoring system is designed which comprises displacement, strain and accelerometer sensors to measure the bridge performance under static and dynamic trucks loads. The statistical analysis is used to assess the static behavior of the bridge and the wavelet analysis and probabilistic using Weibull distribution are used to evaluate the frequency and reliability of the dynamic behavior of the bridge. The results show that the bridge is safe under static and dynamic loading cases. In the static evaluation, the measured neutral axis position of the girders is deviated within 5% from its theoretical position. The dynamic amplification factor of the bridge girder and slab are lower than the design value of that factor. The Weibull shape parameters are decreased, it which means that the bridge performance decreases under dynamic loads effect. The bridge girder and slab's frequencies are higher than the design values and constant under different truck speeds.