• Earthquakes and Structures
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• v.15 no.6
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• pp.701-713
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• 2018

Many bridges in Algeria were constructed without taking into account the seismic effect in the design. The implantation of a new regulation code RPOA-2008 requires a higher reinforcement ratio than with the seismic coefficient method, which is a common feature of the existing bridges. For better perception of the performance bridge piers and evaluation of the risk assessment of existing bridges, fragility analysis is an interesting tool to assess the vulnerability study of these structures. This paper presents a comparative performance of bridge piers designed with the seismic coefficient method and the new RPOA-2008. The performances of the designed bridge piers are assessed using thirty ground motion records and incremental dynamic analysis. Fragility curves for the bridge piers are plotted using probabilistic seismic demand model to perform the seismic vulnerability analysis. The impact of changing the reinforcement strength on the seismic behavior of the designed bridge piers is checked by fragility analysis. The fragility results reveal that the probability of damage with the RPOA-2008 is less and perform well comparing to the conventional design pier.

• Journal of the Korea Concrete Institute
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• v.28 no.6
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• pp.713-722
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• 2016

The goal of this study was to assess the seismic performance of hollow cast-in-place and precast reinforced concrete bridge columns with triangular reinforcement details. The developed material quantity reduction details are economically feasible and rational, and facilitate shorter construction periods. By using a sophisticated nonlinear finite element analysis program, the accuracy and objectivity of the assessment process can be enhanced. The used numerical method gives a realistic prediction of seismic performance throughout the input ground motions for several hollow column specimens investigated. As a result, triangular reinforcement details were designed to be superior to the existing reinforcement details in terms of required seismic performance.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.6
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• pp.138-147
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• 2018

With the recent series of damage caused by earthquakes in Korea, such as Gyeongju and Pohang, we know that Korea is no longer a safe zone for earthquakes and that we need to be prepared for them. In addition, bridges built prior to the introduction of seismic design concepts remain without adequate seismic reinforcement measures, and earthquake reinforcement should be performed efficiently considering economic and structural safety. Preliminary assessment of seismic performance of existing bridges is divided into four seismic groups, taking into account seismicity, vulnerability and Impact, considering the magnitude of the existing bridge's seismic, and prioritization for further evaluation of seismic performance. In this study, unlike the existing anti-seismic reinforcement priority method, scores are calculated based on the seismic design criteria applied to bridges, importance coefficient of the bridge including the zone coefficient and the Importance, vulnerability index of the bridge including the soil condition and the elapsed years, detail coefficient of the bridge including the superstructure form, the span length, the width, the height, the design load, and the daily traffic volume. The calculated score items will be weighted and grouped according to the results. Using this, a simpler and more efficient algorithm was proposed to determine the priority of seismic reinforcement on a bridge.

• Structural Engineering and Mechanics
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• v.83 no.6
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• pp.745-756
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• 2022

This study aims to determine the cause of the load resistance loss in storage racks that can be attributed to external forces such as earthquakes and to improve safety by developing reinforcement systems that can prevent load resistance loss. To this end, a static cyclic loading test was performed on pallet racks commonly used in logistics warehouses. The test results indicated that a pallet rack exposed to an external force loses more than 50% of its load resistance owing to the damage caused to column-beam joints. Three reinforcement systems were developed for preventing load resistance loss in storage racks exposed to an external force and for performing differentiated target functions: column reinforcement device, seismic damper, and viscoelastic damper. Shake table testing was performed to evaluate the earthquake response and verify the performance of these reinforcement systems. The results confirmed that, the maximum displacement, which causes the loss of load resistance and the permanent deformation of racks under external force, is reduced using the developed reinforcement devices. Thus, the appropriate selection of the developed reinforcement devices by users can help secure the safety of the storage racks.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2000.04a
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• pp.319-326
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• 2000

The purpose of this study is to evaluate seismic performance of reinforced concrete pier columns in Seohae Ground Bridge. Since the bridge was designed before preparing the seismic design specification the bridge columns of hollow hexagonal section were designed and constructed with insufficient seismic reinforcement details such as longitudinal and transverse reinforcement lap-splices. In order to take the necessary measures to improve its seismic performance experimental study was performed by small-scale test for the bridge columns, From the quasi-static test for small-scale column specimens the lap-splices were not critical for overall behavior of the column if sufficient lap-splice-length was provided. The test results of failure mode effective stiffness ductility and equivalent viscous damping ratio are presented.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.553-558
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• 2001

Recent destructive seismic events demonstrated the importance of mitigating human casualties and serious property damages in design and construction of structures. The Korean Bridge Design Specifications (1992) adopted seismic design requirements based on the AASHTO specification, and minor modification was made in 2000. The longitudinal steel connection of reinforced concrete bridge column is sometimes practically unavoidable. The longitudinal reinforcement details affect seismic performance such as flexural failure and shear failure. This research aims to develop longitudinal steel connection details with confinement steel by experimental study for seismic performance of reinforced concrete bridge columns. Quasi-static test under three different axial load levels was conducted for 12 spiral column specimens. All the column specimens had the same aspect ratio of 3.5. The column specimens were transversely reinforced with spiral and with five different longitudinal steel connection. The final objective of this study is to suggest appropriate longitudinal reinforcement connection details for the limited ductility design concept and improve construction quality.

• KCI Concrete Journal
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• v.14 no.3
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• pp.130-137
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• 2002

It is known that lap splice in the longitudinal reinforcement of reinforced concrete(RC) bridge columns is not desirable for seismic performance, but it is sometimes unavoidable. Lap splices were practically located in the potential plastic hinge region of most bridge columns that were constructed before the adoption of the seismic design provision of Korea Bridge Design Specification on 1992. The objective of this research is to evaluate the seismic performance of reinforced concrete(RC) bridge piers with lap splicing of longitudinal reinforcement in the plastic hinge region, to develop the enhancement scheme of their seismic capacity by retrofitting with glassfiber sheets, and to develop appropriate limited ductility design concept in low or moderate seismicity region. Nine test specimens in the aspect ratio of 4 were made with three confinement ratios and three types of lap splice. Quasi-static test was conducted in a displacement-controlled way under three different axial load levels. A significant reduction of displacement ductility ratios was observed for test columns with lap splices of longitudinal steels.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.11a
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• pp.97-100
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• 2005

It has been known that lab splices of the longitudinal reinforcement steel in bridge columns are not desirable for seismic performance, but it is sometimes unavoidable. Lap splices were usually be located in the plastic hinge region of most bridge columns that were constructed before the adoption of the seismic design provision of Korea Bridge Design Specification on 1992. This research is to evaluate the seismic performance of reinforced concrete bridge piers with lap splicing of longitudinal reinforcement in the plastic hinge region, and to develop the enhancement scheme of their seismic capacity by retrofitting with steel bands. It was observed that RC bridge specimens with lap-spliced longitudinal steels appeared to fail at low curvature and displacement ductility, but significant improvement was appeared in the ductility of RC specimens with steel bands retrofitted around the plastic hinge region.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2001.09a
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• pp.179-186
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• 2001

It has been known that lap splicing in the longitudinal reinforcement of bridge columns is not desirable for seismic performance, but it is sometimes unavoidable. Lap splices were usually be located in the plastic hinge region of most bridge columns that were constructed before the adoption of the seismic design provision of Korea Bridge Design Specification on 1992. This research is to evacuate the seismic performance of reinforced concrete bridge piers with lap splicing of longitudinal reinforcement in the plastic hinge region, and to develop the enhancement scheme of their seismic capacity by retrofitting with glassfiber sheets and to develop appropriate limited ductility design concept in low or moderate seismicity region. Nine test specimens in the aspect ratio of 4.0 were made with three confinement ratios and three types of lap splicing. Quasi-static tests under three different axial load levees were conducted. It has been observed that displacement ductility ratios of test columns with lap splicing were significantly reduced.

• Journal of the Korea Concrete Institute
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• v.25 no.3
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• pp.271-281
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• 2013

The current seismic design code prescribes that a structural wall should be designed as a special shear wall when the building height is more than 60 m and its seismic design category is classified as D. However, the use of a special shear wall has a negative effect on constructability and economic efficiency. In the present study, the seismic performance of a special shear wall and a special shear wall with relaxed reinforcement detail was evaluated through a cyclic reversal loading test. The specimens were constructed to measure the results of the experimental variable regarding the reinforcement details of the special boundary element. Next, the seismic performances of a special shear wall structural system and that of a special shear wall structural system with relaxed reinforcement detail was evaluated by methods proposed in the FEMA P695. The cyclic reversal loading test results of this study showed that the performance of the shear wall with relaxed reinforcement detail was almost similar to the performance of a special shear wall and has the performance which requested from standard. The results of the seismic evaluation showed that all special shear walls with relaxed reinforcement detail are satisfied with the design code and seismic performance.