• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.1
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• pp.148-155
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• 2010

The purpose of this study is to propose and evaluate the continuous joint constructed with MRS system which is utilized for floor system in the parking structures or commercial retail buildings. Four specimens were fabricated and tested to examine the structural performance of the continuous joint with different joint detailing. Structural test for the specimens was undertaken to simulate the actual stress condition of the negative moment resisting connection in the prestressed precast concrete parking structures with 8m span. Based on the experimental results, the MRS system could be designed as the ductile continuous joint governed by flexural behavior. Therefore the MRS system developed in this study would provide a superior joint behavior to conventional double-tee system when constructing monolithic joint composed of simply supported precast members.

• Journal of the Korea Concrete Institute
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• v.22 no.2
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• pp.247-254
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• 2010

The purpose of study is to investigate the load resistance mechanism of MRS continuous joint designed with different details. Six full-scale specimens, which could simulate the negative moment region of the 8 m long MRS system, were prepared to evaluate the structural performance of the continuous joint. According to the experimental results, all specimens which include the specimen with dapped ends designed by loads at the construction stage were failed in a flexural manner and showed the load carrying capacity over the nominal flexural strength. Therefore it is recommended that the dapped ends for MRS continuous joints be designed for the loads of the construction stage. And the shear key, which was installed on the top of rib for MRS slab, helps the enhancement of strength and especially deformation capacity.

• Journal of the Earthquake Engineering Society of Korea
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• v.3 no.2
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• pp.29-40
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• 1999

This study presents a simplifled calculation method for required ductility of coupling beams in precast coupled shear walls at preliminary seismic design stages. Deflection of precast coupled shear walls based on a continuum approach is combined with inelastic gap opening of horizontal connection of panels to provide a relationship between the system-level ductility and the element-level ductility in a precast coupled shear wall. The equation proposed herein for ductility requirement for coupling beams shows that higher stiffness and lower strength of coupling beams result in high ductility reuqirement. The equation also shows that the ductility requirement is proportional to the degree of gap opening of the story in question. However, the coupling beam ductility in higher stories are not affected by gap openings of horizontal connections of panel.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.6
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• pp.166-174
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• 2011

The object of this study is to evaluate the structural shear capacity of the PC girder-PC beam joint. The dapped end of PC beam and the ledger of PC girder are usually designed to design load. If the end of PC beam can be designed with continuous end, the dapped end of PC beam and the ledger of PC girder do not need to resist to all loads except dead load and construction load. The experimental program was carried out with 7 specimens containing the variable factors as the anchored method of the hanger bar, design load, be or not exist of ledger bars. As a result, the continuity of the dapped end and the ledger were ensured their safety although the design load was only the dead load and the construction load. The shear critical section was expanded toward the effective depth d, the distance from the supported position of the beam. If the ledger is designed according to PCI Design Handbook, the structural system of the ledger is as to the cantilever slab system. But the ledger of this study is as to the 3 side fixed slab system. Therefore the design of the ledger by PCI Design Handbook will lead to highly conservative results.