• Computers and Concrete
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• v.13 no.4
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• pp.501-516
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• 2014

The purpose of this study was to investigate the performance of precast concrete pier cap system. The proposed precast pier cap provides an alternative to current cast-in-place systems, particularly for projects in which a reduced construction time is desired. Five large-scale pier cap specimens were constructed and tested under quasistatic monotonic loading. The computer program, RCAHEST (Reinforced Concrete Analysis in Higher Evaluation System Technology) was used for the analysis of reinforced concrete structures. A bonded tendon element is used based on the finite element method, and can represent the interaction between the tendon and concrete of a prestressed concrete member. A joint element is used in order to predict the inelastic behaviors of segmental joints with a shear key. This study documents the testing of the precast concrete pier cap system under monotonic loading and presents conclusions and design recommendations based on the experimental and analytical findings. Additional full-scale experimental research is needed to refine and confirm design details, especially for actual detailing employed in the field.

• Journal of the Korea Concrete Institute
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• v.27 no.1
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• pp.55-63
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• 2015

Prefabrication technologies are making bridge construction safer and less disruptive to the environment and traveling public, making bridge designs more constructible and, improving the quality and durability by shifting site work to a more controllable environment. Modular bridge substructures with concrete-filled steel tube (CFT) piers and composite pier caps were suggested to realize accelerated bridge construction. The precast segmental pier cap consists of a composite pier table and precast prestressed segments on the table. The pier table has embedded steel section to mitigate stress concentration at the connection by small tubes. Each bridge pier has four or six CFT columns which connect to the pier cap. Shear strength of the pier cap was obtained by extending vertical reinforcing bars from the table to the precast segment. Transverse prestressing was introduced to control tensile stresses by service loadings. Structural performance of the proposed modular system was evaluated by static tests. Design requirements of the composite pier cap were satisfied by continuous reinforcing bars and prestressing tendons. Standardized modular substructures can be effectively utilized for the fast replacement or construction of bridges.

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.81-82
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• 2010

As a part of rapid construction technology of bridge pier caps, controversial issues for design and construction of precast pier caps were discussed. Three kinds of approaches of rapid bridge pier cap construction were proposed and discussed. Especially for an approach of precast shell type structures, experimental studies were performed to evaluate structural performance and compared with conventionally constructed reinforced concrete pier cap.

• Journal of the Earthquake Engineering Society of Korea
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• v.20 no.3
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• pp.135-143
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• 2016

In this paper, a design concept of post-tensioned precast bridge piers was proposed to improve seismic behavior of the bridge pier. Mild reinforcing bars are placed continuously along the height of the column. Prestressing tendons are also provided to obtain re-centering capability for seismic events. Arrangement of the axial steels to prevent buckling of rebars at plastic hinge region was suggested and enhanced seismic performance was verified by experiments. Moment-curvature analyses were performed to evaluate the effect of effective prestress on seismic behavior after verifying the calculation method by cyclic tests of the precast columns. A real bridge pier was designed to investigate the seismic performance according to different level of effective prestress. Level of effective prestress showed obvious effect on crushing displacement but negligible effect on lateral displacement at fracture of tendons and reinforcements.

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.153-154
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• 2010

For completing an fully optimized and prefabricated substructure system of bridge, developing pier of precast segment PSC which equip the connection structure of shear resistance and precast foundation are conducted previously. Specimens of coping of bridge were developed and customized, and experiments were performed. The result of the experiment through the result from a reliable non-linear analysis program (RCAHEST) were compared and analyzed and evaluated the stability and ultimate behavior of coping of precast pier.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.121-124
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• 2008

Fast construction of bridge substructures is a new trend of bridge design. A precast pier system with bonded prestressing bars was proposed. In this paper, quasi-static tests on precast prestressed piers were conducted to evaluate the seismic behavior of the precast piers with bonded prestressing bars. In order to strengthen the shear strength of the joints between column segments, steel tubes filled with mortar were used. Displacement ductility and energy dissipation capacity of the precast piers were evaluated. The suggested precast pier system showed better seismic performance than the required ductility. Based on the research results, an example bridge pier for light-railway lines was designed and design considerations were discussed.

• Journal of KIBIM
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• v.8 no.1
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• pp.15-23
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• 2018

Geometry control of precast members is the most important technology for modular construction. In this paper, image-based modeling and rendering (IBMR) technology was adopted for 3D modeling of precast elements. It is necessary to use match-casting method for precast post-tensioned column assembly. Preassembly using 3D models created by image processing can minimize construction error. Augmented reality devices are used to check the geometry of the segment. Laboratory-scale tests were performed. The proposed process has been applied to the real precast bridge pier segments.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.253-258
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• 2000

Recently, the area of design optimization, especially structural optimization, has been and to be a continuous active area of research. And the design optimizations of port facilities have been achieved by many other civil engineers. But the design optimization of port facilities were limited to the design optimization of the breasting dolphin. This paper invested the design optimization of mooring pier and the foundations of mooring pier was suggested considering the convenience of repair and reinforcement work. The mooring pier devised with prestressed precast concrete panel and rigid frame welded wide flange beam to steel pipe pile. To accomplish the design optimization of mooring pier, the Augmented Lagrangian Multiplier Method(ALM) of ADS(Garret N. Vanderplaats) optimization routine, BFGS method as optimizer and Golden Section Method as one dimensional search were utilized. As a result, thirty percent of material cost for construction was reduced by design optimization. The tensile stress of concrete panel and bottom flage was critical constraints under service load. So, using high strength concrete and steel will be economical. And lots of initial values must be invested to accomplish the design optimization in design procedures.

• Earthquakes and Structures
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• v.25 no.2
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• pp.89-97
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• 2023

In order to obtain the impact of socket connection interface forms and socket gap sizes on the seismic performance of reinforced concrete (RC) socket prefabricated bridge piers, quasi-static tests for three socket prefabricated piers with different column-foundation connection interface forms and reserved socket gap sizes, as well as to the corresponding cast-in-situ reinforced concrete piers, were carried out. The influence of socket connection structure on various seismic performance indexes of socket prefabricated piers was studied by comparing and analyzing the hysteresis curve and skeleton curve obtained through the experiment. Results showed that the ultimate failure mode of the socket prefabricated pier with circumferential corrugated treatment at the connection interface was the closest to that of the monolithic pier, the maximum bearing capacity was slightly less than that of the cast-in-situ pier but larger than that of the socket pier with roughened connection interface, and the displacement ductility and accumulated energy consumption capacity were smaller than those of socket piers with roughened connection interface. The connection interface treatment form had less influence on the residual deformation of socket prefabricated bridge piers. With the increase in the reserved socket gap size between the precast pier column and the precast foundation, the bearing capacity of the prefabricated socket bridge pier component, as well as the ductility and residual displacement of the component, would be reduced and had unfavorable effect on the energy dissipation property of the bridge pier component.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.237-240
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• 2008

Today, some bridges or highways are becoming superannuated in Korea. Also, in this section, rehabilitation, replacement and expansion are necessary to increasing traffic volumes these days. Bridge reconstruction is major problem because it has relation to civil application, economical loss and loss of vehicles made a detour while this work. Many precast components and methods of construction are developed for this issue. Many research of various precast components and new materials are being performed owing to apply to prefabrication bridges. The present paper represents experimental studies on the performance of precast CFFT pier model. Also, stay-in-place RC pier and stay-in-place CFFT pier are made an experiment on due to comparing test results. Hysteretic responses of all columns are obtained through the test. Compared with the displacement ductility factors, conclusions of seismic performances can be made.