• Journal of the Earthquake Engineering Society of Korea
• /
• v.3 no.2
• /
• pp.55-66
• /
• 1999

Eight RC bridge plers have been made on a 1/3.4 scale model and have been tested in a quasi-static cyclic load so as to investigate their seismic performance. The ultimate objective of this experimental study is to investigate the hysteretic behavior of reinforced concrete plers, which have been widely used for urban transportation facilities in Korea. Improtant test parameters are hoop ratio, axial load, load pattern, and etc. And noninear behaviors of test columns have been evaluated through their yield and ultimate strength, energy dissipation, ductility and load-deflection characteristics under quasi-static cyclic loads. From the quasi-static tests on 8 bridge piers, it is concluded that energy dissipation, ultimate strength and curvature for a given displacement factor ${\mu}={\Delta}/{\Delta}_y$ are higher for the seismically designed columns than for the nonseismically designed columns.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.26 no.6
• /
• pp.102-111
• /
• 2022

The aim of this study is to assess the seismic performance of octagonal hollow cross section reinforced concrete bridge pier, and to investigate the effect of longitudinal reinforcement ratios on the failure behavior. Four octagonal hollow section RC bridge columns of small scale model were tested under a quasi-static cyclically reversed horizontal load with constant axial load. The volumetric ratio of transverse spiral hoop of all specimens was maintained constant(0.206%), the ratios of longitudinal reinforcement were varied(2.36 ~ 4.71%). Failure behavior and seismic performance were investigated. Three specimens with the exception of lap spliced specimen showed flexure-shear failure at final stage. The test results with the exception of lap spliced specimen showed that the displacement ductility factor and accumulated energy dissipation decreased in inverse proportion to the ratio of longitudinal steel.

• Structural Monitoring and Maintenance
• /
• v.7 no.4
• /
• pp.367-392
• /
• 2020

The specific characteristics of near-field earthquake records can lead to different dynamic responses of bridges compared to far-field records. However, the effect of near-field strong ground motion has often been neglected in the seismic performance assessment of the bridges. Furthermore, damage to horizontally curved multi-frame RC box-girder bridges in the past earthquakes has intensified the potential of seismic vulnerability of these structures due to their distinctive dynamic behavior. Based on the nonlinear time history analyses in OpenSEES, this article, assesses the effects of near-field versus far-field earthquakes on the seismic performance of horizontally curved multi-frame RC box-girder bridges by accounting the vertical component of the earthquake records. Analytical seismic fragility curves have been derived thru considering uncertainties in the earthquake records, material and geometric properties of bridges. The findings indicate that near-field effects reasonably increase the seismic vulnerability in this bridge sub-class. The results pave the way for future regional risk assessments regarding the importance of either including or excluding near-field effects on the seismic performance of horizontally curved bridges.

• Proceedings of the Earthquake Engineering Society of Korea Conference
• /
• 2003.09a
• /
• pp.368-375
• /
• 2003

The objectives of this study were to provide experimental data on the behavior of interlocking spiral columns under cyclic loading, to compare the performance of columns with interlocking spirals to columns with U-type hoops with hook, to study the flexural detailing of interlocking spirals and other transverse steel configurations as the transverse reinforcement The oblong columns with interlocking spirals and with hooked U-type hoops and cross-ties better seismic performance than the rectangular columns with rectangular hoops and cross-ties. The oblong columns with hooked U-type hoops and cross-ties showed better seismic performance than the rectangular columns with rectangular hoops and cross-ties. And this research were to make recommendations for the design of bridge columns incorporating interlocking spirals and U-type hoops with hook as the transverse reinforcement.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2006.11a
• /
• pp.349-352
• /
• 2006

According to current bridge design code cable supported bridges are designed generally against 1000-year-return-period earthquake. Considering its importance, however, it may be desirable to design against 2400-year-return-period earthquake. But the seismic behavior of cable supported bridges under higher seismicity is not investigated fully. In this study, several cable supported bridges were analyzed under higher seismicity and then the response forces in prime members were compared with those analyzed under current design earthquake.

• Proceedings of the Earthquake Engineering Society of Korea Conference
• /
• 2003.09a
• /
• pp.255-262
• /
• 2003

In present Korea Highway Bridge Standards the lap splice of longitudinal bars in a potential plastic hinge region is allowed so that large amount of transverse rebar specified in high seismicity regions Is required to prevent brittle bond failure If the brittle failure effects can be completely removed from the conventional designed piers, the amount of transverse rebar will be reduced drastically. In this study scaled models with solid and hollow rectangular sections were tested to investigate the seismic behavior of RC piers with 50％ of lap-spliced longitudinal bars in plastic hinge regions. In the tests the typical flexural failure conducting a ductile behavior were observed in both models. It is shown that the 50％ of lap-spliced bars can be considered as a good alternative of seismic detailing for longitudinal bars.

• Proceedings of the Earthquake Engineering Society of Korea Conference
• /
• 2003.03a
• /
• pp.385-392
• /
• 2003

Experimental investigation was conducted into the flexure/shear-critical behavior of earthquake-damaged reinforced concrete columns with lap splicing of longitudinal reinforcement in the plastic hinge region. Six test specimens in the aspect ratio of 2.5 were made with test parameters: confinement ratios, lap splices, and retrofitting FRP materials. They were damaged under series of artificial earthquakes that could be compatible in Korean peninsula. Directly after the pseudo-dynamic test, damaged columns were retested under inelastic reversal cyclic loading simultaneously under a constant axial load, P = 0.1 $f_{ck}$ $A_{g}$. Residual seismic performance of damaged columns was evaluated and compared to that of the corresponding original columns. Test results show that RC bridge piers with lap-spliced longitudinal steels in the plastic hinge region appeared to fail at low ductility. This was due to the debonding of the lap splice, which resulted from insufficient development of the longitudinal steels. The specimens externally wrapped with composite FRP straps in the potential plastic hinge region indicated significant improvement both in flexural strength and displacement ductility.y.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2003.05a
• /
• pp.943-948
• /
• 2003

The experimental study for oblong section was carried out by the column test in weak axis. The column specimens had 3 types of transverse steel configurations, such as interlocking spirals, interlocking circular hoop ties and rectangular ties. The oblong columns with interlocking spirals and with interlocking circular hoop ties showed better seismic performance than the rectangular columns with rectangular hoops and cross-ties. The objectives of this study were to provide experimental data on the behavior of interlocking spiral columns under cyclic loading, to compare the performance of columns with interlocking spirals to columns with various transverse steel configurations, to study the flexural detailing of interlocking spirals, interlocking circular hoops, and other transverse steel configurations as the transverse reinforcement, and to make recommendations for the design of bridge columns incorporating interlocking spirals, circular hoops as the transverse reinforcement.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2009.05a
• /
• pp.69-70
• /
• 2009

This paper investigates the seismic behavior of prefabricated piers which are made by onsite connection of precast composite column segments to accelerate bridge construction. Quasi-static cyclic loading tests on the piers show better overall seismic capacity compared to RC piers with seismic details..

• Journal of the Korea Concrete Institute
• /
• v.17 no.1 s.85
• /
• pp.27-34
• /
• 2005

The purpose of this study is to investigate the structural behavior of RC Piers using high strength concrete and high strength rebars. The high strength concrete offers many advantages such as enhanced mechanical performance and durability, in addition to member size reduction. The high strength rebars are used here to reduce the amount of rebars, which facilitates the placement of concrete and labor works. Five RC piers were tested under a constant axial load and a cyclically reversed horizontal load. The seismic design of piers were implemented, according to the current Korean Bridge Design Code. The test variables include concrete compressive strength, steel strength, and steel ratio. The test results indicate that RC piers using the high strength concrete and high strength rebars exhibit ductile behavior and appropriate seismic performance, in compliance with the design code. The present study allows more realistic application of high strength rebars and concrete to RC piers, which will provide enhanced durability as well as more economy.