• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.485-488
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• 2004

Steel encased composite columns have been used for buildings and piers of bridges. Since column section for pier is relatively larger than that of building columns, economical steel ratio need to be investigated for the required performance. Composite action between concrete and embedded steel sections can be obtained by bonding and friction. However, the behavior. of the column depends on the load introduction mechanism. Compression can be applied to concrete section, steel section and composite section. In this paper, experiments on shear strength of the steel encased composite column were performed to study the effect of confinement by transverse reinforcements, mechanical interlock by holes, and shear connectors. Shear strength obtained from the tests showed considerably higher than the design value. Confinement, mechanical interlock and stud connectors increased the shear strength and these values can be used effectively to obtain composite action of SRC columns.

• Journal of the Korea Concrete Institute
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• v.17 no.5 s.89
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• pp.775-784
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• 2005

In this research, major design factors have been evaluated for the establishment of the rational seismic design code of circular RC(reinforced concrete) bridge pier Previous experimental researches have drawn a conclusion that transverse confinement reinforcements have been excessively used for RC bridge piers in Korea. Thus, the objective of this study is to propose a rational design equation for transverse reinforcements of RC bridge piers in Korea which would be classified as a low or moderate seismic region. Newly proposed equation further considers the effect of the axial force ratio and the longitudinal steel ratio. Minimum transverse confinement steel ratio is also proposed to avoid probable buckling of the longitudinal reinforcing steels subjected to relatively low axial force. It is thought that these new codes seem to alleviate the rebar congestion in the plastic hinge region of RC bridge piers which contribute to the enhancement of constructibility and economization for RC bridge construction.

• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.6
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• pp.1-12
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• 2023

This paper assesses the suitability of existing standards for plastic material models and performance level evaluation methods in seismic performance evaluations of concrete dam piers during Maximum Credible Earthquakes (MCE). Dynamic plastic analysis was conducted to examine the applicability of the plastic material model under various conditions. As a result reveal that when the minimum reinforcement ratio is not met, the average stress-average strain method recommended in current dam seismic performance evaluation guidelines tends to underestimate pier responses compared to the predicted outcomes of dynamic elastic analysis. Consequently, the paper proposes an improvement plan that treats dam piers with an insufficient minimum reinforcement ratio as unreinforced and integrates fracture energy into concrete tensile behavior characteristics for performance level evaluation. Implementing these improvements can lead to more conservative evaluation outcomes compared to current seismic performance evaluation methods.

• Journal of the Korea institute for structural maintenance and inspection
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• v.17 no.1
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• pp.94-105
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• 2013

Recently, the construction industry has been changed in such a way that the cost for bridge construction should be optimized or reduced. Therefore, bridges are required be cost-effective in terms of initial construction as well as in the maintenance during service stage. In order to reduce the cost for bridge construction, the Rahmen typed structure, in which the bridge components from superstructure to substructure are integral, has many advantages to reduce the size of structural members including girders, since the loadings from superstructure may be transferred to substructure through the connecting rebars such as stud, etc. This paper studied on the continuous Up and Down Prestressed Concrete (UD PSC) girder bridge in which the reinforced concrete pier cap is integral with the part of girders in superstructure. In previous studies, it is known that the structural behavior of continuous UD PSC girder bridge is quite different compared to the one of the bridges with conventional bearings or shoes to support the loading from girders. Nevertheless, it has hardly been studied about the structural behavior of bridge with UD PSC girder. Therefore, in this study, various dynamic behaviors of continuous UD PSC girder bridge with integral pier cap have been analyzed using numerical method. Furthermore, an equation to evaluate the impact factor is suggested for the UD PSC girder bridge which has two to three continuous spans.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.692-695
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• 2004

Seismic performance of reinforced concrete(RC) column bent piers to bidirectional seismic loadings was investigated experimentally. RC column bent piers represent one of the most popular forms of piers used in highway bridges. Further to series of previous experimental researches for the performance of single bridge columns subjected to seismic loadings, four column bent piers were constructed in 400 mm diameter and 2,000 mm height. Each pier has two circular supporting columns. These piers were tested under lateral load reversals with axial load of $0.1f_{ck}A_g$. Bidirectional lateral loadings were applied. The test parameters included: different transverse reinforcement contents and lap-spliced longitudinal reinforcing steels. Test results indicate that lap-splices of longitudinal reinforcing steels have significantly influence on hysteretic response of column bent piers. Column capacity changed with the level of transverse confinement, and bidirectional repeated loadings induced more strength and stiffness degradation than unidirectional repeated loading.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.177-178
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• 2009

This study is based on the precast concrete bridge which recently became important field of bridge construction. to develop the connecting technology of pier and footing, the purpose of this study is to verify applicability through the result of nonlinear analysis.

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.165-166
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• 2010

Collision scenario was 12 cases considering gate location, water level and lateral location of collision etc. And then, analysis result of trunnion by collision loads (reservoir side gate). Compressive fracture may not occur because the maximum compressive stress of concrete is below the allowable compressive strength. but, it is possible to appear some local crack because the maximum tensile stress exceed the tensile strength.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.712-717
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• 2005

When the weight if a concrete member makes problems, or when the cost of the concrete is relatively high, it may be economical to use a hollow concrete member. But a hollow R.C column may have poor ductility because of the brittle failure at the inner face of the hollow R.C column. This brittle failure results from the absence of the confinement at the inner face of the hollow R.C column. To avoid this brittle failure an internally confined hollow R.C column by a steel tube was developed before. In this study, a hollow R.C column is internally confined by a corrugated steel tube instead of a general flat steel tube. And a column ductility is performed. Test results show that the energy ductility ratio of a internally confined hollow R.C column by a by a corrugated steel tube corresponds to $80\%$ of the energy ductility ratio of a general solid R.C column.

• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.464-469
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• 2003

The traditional and still most widely used, test methods for concrete structures are destructive method, such as coring, drilling or otherwise removing part of the structure to permit visual inspection of the interior. While these methods are highly reliable, they are also time consuming and expensive, and the defects they leave behind often become focal point for deterioration. In this study, tomography by theoretical inversion method in case of elastic wave using impact-echo method among concrete non-destruction test method was made. Taken model experiments are theoretical inversion method and time domain and frequency domain test on pier test model at laboratory level. Also experiment concerning frequency domain on 3 kinds of tunnel model with I-dimension form was carried out.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2008.05a
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• pp.31-34
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• 2008

Construction of buildings downtown is increasing as much as ever with a strong demand. A Top-Down Method is suitable for its advantage in minimizing its disturbance to the neighborhood. In general, the Pre-founded Column, one of the most important aspects of the Top-Down Method, has been made with an H-Shape Steel Column. However, due to its structural and economical benefits, the usage of CFT(Concrete Filled Tube) columns in the place of Pre-founded Columns is increasing. To promote their applications, we analyze the merits of CFT columns by comparing them with I-Shape columns and propose further research.