• Proceedings of the Korea Concrete Institute Conference
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• 2006.05a
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• pp.26-29
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• 2006

A flat plate-column connection is susceptible to brittle punching shear failure, which may result in the necessity of shear reinforcement. In present study, experimental tests were performed to study the capacity of slab-column connections strengthened with lattice, stud rail, shear band and stirrup under gravity and cyclic lateral load. Among them, the capacity of the specimens with lattice are superior to the others due to the truss action of the lattice bars and dowel action of the longitudinal bars as well as the shear resistance of the web re-bar. On the other hand, the strengths of the specimens with stud rail, shear band and stirrup are lower than the estimated strength by the ACI, therefore design formulas of the ACI are needed to revise.

• Computational Structural Engineering
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• v.3 no.4
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• pp.123-132
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• 1990

In current practice of earthquake resistant design the equivalent lateral force procedure is widely used because of its simplicity and convenience. But the equivalent lateral force procedure is derived based on the assumptions that the dynamic behavior of the structure is governed primarily by the fundamental vibration mode and the effect of higher modes is included in an approximate manner. Therefore the prediction of dynamic responses of structures using the equivalent lateral force procedure is not reliable when the effect of higher vibration modes on the dynamic behavior is significant. In this study, design seismic load which can reflect the effect of higher vibration modes is proposed from the point of view of proper assessment of story shears which have the major influence on the design moment of beams and columns. To evaluate the effect of higher modes, differences between the story force based on the equivalent lateral force procedure specified in current earthquake resistance building code and the one based on modal analysis using design spectrum analysis are examined. From these results an improved design seismic load for the equivalent lateral force procedure which can reflect the effect of higher vibration modes are proposed.

• Structural Engineering and Mechanics
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• v.51 no.2
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• pp.267-276
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• 2014

Wharfs are essential to shipping and support very large gravity loads on both a short-term and long-term basis which cause quite large seismic internal forces. Therefore, these structures are vulnerable to seismic activities. As they are supported on vertical and/or batter piles, soil-pile interaction effects under earthquake events have a great importance in seismic resistance which is not yet fully understood. Seismic design codes have become more stringent and suggest the use of new design methods, such as Performance Based Design principles. According to Turkish Code for Coastal and Port Structures (TCCS 2008), the interaction between soil and pile should somehow be considered in the nonlinear analysis in an accurate manner. This study aims to explore the lateral load carrying capacity of recently designed wharf structures considering soil-pile interaction effects for different soil conditions. For this purpose, nonlinear structure analysis according to TCCS (2008) has been performed comparing simplified and detailed modeling results.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.5
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• pp.139-145
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• 2018

An outrigger system is used widely to increase the lateral stiffness of high-rise buildings, resulting in reduced dynamic responses to seismic or wind loads. Because the dynamic characteristics of earthquake or wind loads are quite different, a smart vibration control system associated with an outrigger system can be used effectively for both seismic and wind excitation. In this study, an adaptive smart structural control system based on an outrigger damper system was investigated for the response reduction of multi-hazards, including seismic and wind loads. A MR damper was employed to develop the smart outrigger damper system. Three cities in the U.S., L.A., Charleston, and Anchorage, were used to generate multi-hazard earthquake and wind loads. Parametric studies on the MR damper capacity were performed to investigate the optimal design of the smart outrigger damper system. A smart control algorithm was developed using a fuzzy controller optimized by a genetic algorithm. The analytical results showed that an adaptive smart structural control system based on an outrigger damper system can provide good control performance for multi-hazards of earthquake and wind loads.

• Journal of the Korea Concrete Institute
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• v.26 no.2
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• pp.135-142
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• 2014

In paper after the strong earthquake of recently the Korea neighborhood, the Korean government survey show that the 86% of school buildings in Korea are in potential damage risk and only 14% of them are designed as earthquake-resistance buildings. Earthquake Reinforcing projects of school have been a leading by the ministry of education, however their reinforcing methods done by not proved a engineering by experiment which results in uneconomical and uneffective rehabilitation for the future earthquake. An experimental and analytical study have been conducted for the shear reinforcing method of RC beam by axis and horizontal axis load using attaching composite beam. Based on the previous research, in this study, design examples are given to show the performance evaluation for the column reinforcing of old school buildings using nonlinear analysis is going to be conducted and strengthening method is going to be on the market after their performance is proved by the test.

• Journal of the Korea Institute of Building Construction
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• v.23 no.4
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• pp.405-416
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• 2023

Recent seismic activities in countries like China and Turkey have underscored the widespread and severe damages that earthquakes can inflict globally. Being situated in a seismically active zone, South Korea can no longer regard itself as immune to earthquake hazards, necessitating the urgent adoption of proactive measures against such threats. The government has been proactive in evaluating, formulating processes, and methods for the seismic retrofitting of public buildings lacking in earthquake resistance. However, enforcement mechanisms for privately-owned apartment complexes are absent, and in the face of insufficient previous research and guidelines, preemptive measures for public safety remain alarmingly inadequate. With over 48% of residential structures in Korea aged over 30 years, and apartment complexes constituting more than 80% of these, the gravity of the situation is undeniable. This study deduces key factors for seismic retrofitting of apartment buildings like earthquake zones, soil type, building significance, aging degree, vulnerability, etc., based on building seismic design codes. It further proposes an algorithm for a more succinct and efficient determination of the priority of seismic reinforcements for apartment buildings.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.10 no.1
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• pp.9-16
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• 1990

The safety of concrete nuclear containment structures should be secured against all kinds of loading due to various natural disasters or extraordinary accidental loads. The current design criteria of concrete containment structures are not based on the reliabillty-based design concept but rely on the conventional design concept. In this paper, a probabillty-based reliability analysis were proposed based on a FEM-based random vibration analysis and serviceability limit state of structures. The limit state model defined for the study is a serviceability limit state in terms of the more realistic crack failure that might cause the emission of radioactive materials, and the results are compared with those of the strength limit state. More accurate reliability analyses under various dynamic loads such as earthquake loads were made possible by incorporation the FEM and random vibration theory, which is different from the conventional reliability analysis method. The uncertainties in loads and resistance available in Korea and the refernces were adapted to the situation of Korea, and especially in the case of earthquake, the design earthquake was assessed based on the available re ports on probabilistic description of earthquake ground acceleration in the Korea peninsula.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.593-596
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• 2008

The reed switch position transmitter (RSPT) is used as a position indicator for the control rod in commercial nuclear power plants made by ABB-CE. But this position indicator has some problems when directly adopting it to the integral reactor. The Control Element Drive Mechanism (CEDM) for the integral reactor is designed to raise and lower the control rod in steps of 2mm in order to satisfy the design features of the integral reactor which are the soluble boron free operation and the use of a nuclear heating for the reactor start-up. Therefore the resolution of the position indicator for the integral reactor should be achieved to sense the position of the control rod more precisely than that of the RSPT of the ABB-CE. This paper adopts seismic resistance reed switches to the position indicator in order to reduce the damages or impacts during the handling of the position indicator and earthquake.

• Computers and Concrete
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• v.21 no.6
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• pp.637-647
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• 2018

Numerical approach using finite element method has been used to evaluate the behaviour of reinforced concrete frame structure subjected to fire. The structure is previously designed in accordance with Eurocode standards for the design of structures for earthquake resistance, for the ductility class M. Thermal and structural response are obtained using a commercially available software ANSYS. Temperature-dependent nonlinear thermal and mechanical properties are adopted according to Eurocode standards, with the application of constitutive model for the triaxial behaviour of concrete with a smeared crack approach. Discrete modelling of concrete and reinforcement has enabled monitoring of the behaviour at a global, as well as at a local level, providing information on the level of damage occurring during fire. Critical regions in frame structures are identified and assessed, based on temperatures, displacements, variations of internal forces magnitudes and achieved plastic deformations of main reinforcement bars. Parametric analyses are conducted for different fire scenarios and different types of concrete aggregate to determine their effect on global deformations of frame structures. According to analyses results, the three-dimensional finite element model can be used to evaluate the insulation and mechanical resistance criteria of reinforced concrete frame structures subjected to nominal fire curves.

• International Journal of High-Rise Buildings
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• v.12 no.3
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• pp.251-262
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• 2023

In response to China's "Regulations on the Management of Earthquake Resistance of Building Constructions" on the provision of eight types of important buildings to maintain functional after fortified earthquakes occur, "Guidelines for Seismic Design of post-quake functional buildings (Draft for Review)" distinguishes Class I and Class II buildings, and gives the performance objectives and seismic verification requirements for design earthquakes and severe earthquakes respectively. In this paper, a hospital and a school building are selected as examples to design according to the requirements of fortification of Intensity 8 and 7 respectively. Two design strategies, the seismic isolation scheme and energy dissipation scheme, are considered which are evaluated through elastic-plastic dynamic time-history analysis to meet the requirement of post-quake functional buildings. The results show that the seismic isolation design can meet the requirements in the above cases, and the energy dissipation scheme is difficult to meet the requirements of the "Guidelines" on floor acceleration in some cases, for which the scheme shall be made valid through the seismic resilience assessment. The research in this paper can provide a reference for designers to choose schemes for post-quake functional buildings.