• Structural Engineering and Mechanics
• /
• v.62 no.2
• /
• pp.197-208
• /
• 2017

Among various retrofitting strategies, use of semi-active control for retrofitting a building structure has gained momentum in recent years. One of the techniques for such retrofitting is to connect a weaker building to an adjacent stronger building by semi-active devices, so that performances of a weaker building are significantly improved for seismic forces. In this paper, a ten storey weaker building is connected to an adjacent stronger building using magneto-rheological (MR) dampers, for primarily improving the performance of the weaker building in terms of displacement, drift and base shear. For this, a fuzzy logic controller is specifically developed by fuzzyfying the responses of the coupled system. The performance of the control strategy is compared with the passive-on and passive-off controls. Pounding Mitigation between the two buildings is also investigated using all three control strategies. The results show that there exists a fundamental frequency ratio between the two buildings for which maximum control of the weaker building response takes place with no penalty on the stronger building. There exists also a fundamental frequency ratio where control of the weaker building response is achieved at the expense of the amplification of the stronger building. However, coupling strategy always improves the possibility of pounding mitigation.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2019.11a
• /
• pp.4-5
• /
• 2019

With recent advances in computer technology, the ratio of free-form building designs to those of the past is increasing gradually. However, the current technology of free-form structure is very low. The core technology for free-form building implementation is the manufacturing technology of FCP (Free-form Concrete Panel), which indicates an unformed outside, and through the development of FCP manufacturing technology, the construction technology of free-form architecture can be enhanced. The inside and outside of an free-form building should be represented by the designer's intended curvature, and the panel's thickness by segment should be constant. For this reason, the technology that keeps the thickness of panels constant during the FCP production process is a key technology that can improve the quality of FCP. In this study, a basic study on ways to maintain a constant thickness of FCP is conducted.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2022.04a
• /
• pp.135-136
• /
• 2022

As a recent technology, it is possible to partially grasp the occurrence of displacement of the entire building through artificial intelligence technology for big data through scanning. However, scanning and data processing take a lot of time, so there is a limit to constant monitoring, so constant monitoring technology of building behavior that combines wireless remote sensors and 3D shape scanning is required. Therefore, in this study, artificial intelligence program coding technology is linked. In addition, a technology capable of real-time wireless remote measurement of structure displacement will be developed through technology development in response to safety management that combines existing building technologies such as sensors. Through this, it is possible to establish an integrated management system for safety inspection and diagnosis.

• Journal of the Korean Society of Safety
• /
• v.35 no.4
• /
• pp.32-39
• /
• 2020

The fire compartments with fire-resistant construction are installed in the principal structural parts of a building in order to reduce damage in the event of a building fire. As a fire may spread through a crack in the fire compartment, the firestop with secured performance is used according to the procedure, methods, and standards specified in the detailed operation guideline. According to the current detailed operation guideline, vertical members (wall penetration) and horizontal members (floor penetration) are classified into different categories respective to each other for the classification of the firestop. Therefore, an accreditation applicant must apply for the performance test for each structure even if the wall and the floor have the same structure. Also, Grade T is used for the firestop that penetrates the fire compartment. However, in the case of foreign countries, the use of Grade F for the firestop is allowed even if it penetrates the fire compartment. The result of the precedent studies also showed that there was a significantly low possibility of fire to spread even if Grade F was applied for a metallic duct that penetrated the fire compartment. In this study, the improved scheme for the classification and performance standard of firestops was presented by analyzing the results of precedent studies regarding the firestop and domestic and overseas firestop qualification systems.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.8 no.1
• /
• pp.17-25
• /
• 2020

In this study, non-flammable mineral foam board using waste glass that can be produced to standardized specifications were developed and evaluated for the performance. In addition to the physical and mechanical performance, the environmental properties such as insulation, non-combustibility, gas hazard, sound absorption, etc. were tested to verify the use as interior and exterior building materials. Through the structural review, the validity was verified for the application of the office and restaurant building.

• Smart Structures and Systems
• /
• v.25 no.5
• /
• pp.531-541
• /
• 2020

This paper demonstrates the possibility of evaluating the safety of a building right after an earthquake using consumer-grade surveillance cameras installed in the building. Two cameras are used in each story to extract the time history of interstory drift during the earthquake based on camera calibration, stereo triangulation, and image template matching techniques. The interstory drift of several markers on the rigid floor are used to estimate the motion of the geometric center using the least square approach, then the horizontal interstory drift of any location on the floor can be estimated. A shaking table collapse test of a steel building was conducted to verify the proposed approach. The results indicate that the accuracy of the interstory drift measured by the cameras is high enough to estimate the damage state of the building based on the fragility curve of the interstory drift ratio. On the other hand, the interstory drift measured by an accelerometer tends to underestimate the damage state when residual interstory drift occurs because the low frequency content of the displacement signal is eliminated when high-pass filtering is employed for baseline correction.

• Wind and Structures
• /
• v.11 no.6
• /
• pp.427-440
• /
• 2008

Estimates of wind-induced wind effects on tall buildings are based largely on 1980s technology. Such estimates can vary significantly depending upon the wind engineering laboratory producing them. We describe an efficient database-assisted design (DAD) procedure allowing the realistic estimation of wind-induced internal forces with any mean recurrence interval in any individual member. The procedure makes use of (a) time series of directional aerodynamic pressures recorded simultaneously at typically hundreds of ports on the building surface, (b) directional wind climatological data, (c) micrometeorological modeling of ratios between wind speeds in open exposure and mean wind speeds at the top of the building, (d) a physically and probabilistically realistic aerodynamic/climatological interfacing model, and (e) modern computational resources for calculating internal forces and demand-to-capacity ratios for each member being designed. The procedure is applicable to tall buildings not susceptible to aeroelastic effects, and with sufficiently large dimensions to allow placement of the requisite pressure measurement tubes. The paper then addresses the issue of accounting explicitly for uncertainties in the factors that determine wind effects. Unlike for routine structures, for which simplifications inherent in standard provisions are acceptable, for tall buildings these uncertainties need to be considered with care, since over-simplified reliability estimates could defeat the purpose of ad-hoc wind tunnel tests.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.20 no.4
• /
• pp.252-259
• /
• 2008

The purpose of this study is to estimate the movement of microbial contaminant caused by bio-attack using bio-agent such as bacillus anthracis for preventing contaminant diffusion. multizone simulation was carried out in the case of three types of bio-attack scenario in the government building. Simulation results show that severe contaminant diffusion is brought about in all cases of bio-attack scenario in one hour, though pollution boundaries have different mode according to bio-attack scenarios. Simulation results also show that immune building technology such as filter and UVGI technology gives us powerful alternatives to meet the emergent situation caused by unexpected bio-attack.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.24 no.4
• /
• pp.343-350
• /
• 2012

The major goal of building energy management is to minimize the energy consumption while maintaining the comfortable environment condition. Nowadays building energy management to save HVAC energy and so on is the most critical issue for existing building service branch with high efficiency equipments and their optimal operation. The effects on the building energy savings of the building equipment retrofit and the improvement of its operation method, especially in the field of HVAC system, were analyzed in this study for domestic small and/or medium sized buildings. Over 8.8% of energy saving was achieved compared withe total energy consumption in commercial building. These results could be used for reasonable maintenance and efficient management of the various building service equipments and related systems.

• Journal of the Korea Institute of Building Construction
• /
• v.23 no.1
• /
• pp.69-79
• /
• 2023

In this study, an experimental study was conducted on the development of crack monitoring technology in buildings using a mechanochromic sensor. After attaching a mechanochromic sensor to the cracks induced in the concrete specimen, the color variation image of the sensor according to the progress of the cracks was taken. In addition, a method of analyzing a sensor color variation image was proposed, and an equation for deriving a crack's width from the relationship between the analysis result and the crack width was also proposed. In addition, the possibility of using an mechanochromic sensor for monitoring cracks in buildings was confirmed through the verification of crack width monitoring technology.