• Earthquakes and Structures
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• v.13 no.4
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• pp.377-386
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• 2017

Earthquake-induced pounding damages to building structures were repeatedly observed in many previous major earthquakes. Extensive researches have been carried out in this field. Previous studies mainly focused on the regular shaped buildings and each building was normally simplified as a single-degree-of-freedom (SDOF) system or a multi-degree-of-freedom (MDOF) system by assuming the masses of the building lumped at the floor levels. The researches on the pounding responses between irregular asymmetric buildings are rare. For the asymmetric buildings subjected to earthquake loading, torsional vibration modes of the structures are excited, which in turn may significantly change the structural responses. Moreover, contact element was normally used to consider the pounding phenomenon in previous studies, which may result in inaccurate estimations of the structural responses since this method is based on the point-to-point pounding assumption with the predetermined pounding locations. In reality, poundings may take place between any locations. In other words, the pounding locations cannot be predefined. To more realistically consider the arbitrary poundings between asymmetric structures, detailed three-dimensional (3D) finite element models (FEM) and arbitrary pounding algorithm are necessary. This paper carries out numerical simulations on the pounding responses between a symmetric rectangular-shaped building and an asymmetric L-shaped building by using the explicit finite element code LS-DYNA. The detailed 3D FEMs are developed and arbitrary 3D pounding locations between these two buildings under bi-directional earthquake ground motions are investigated. Special attention is paid to the relative locations of two adjacent buildings. The influences of the left-and-right, fore-and-aft relative locations and separation gap between the two buildings on the pounding responses are systematically investigated.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.06a
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• pp.222-223
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• 2020

Recently, as the era of economic cooperation on the Korean Peninsula approaches, the role of the building sector, such as humanitarian reorganization of North Korean housing, is increasing. The purpose of this study is to find out the current location of North Korean housing standards through the North Korean Housing Survey. For the survey, a survey was conducted through 79 North Korean defectors. The main construction methods of North Korean housing are reinforced concrete, steel framed, wooden framed, masonry, and reinforced concrete walled and prefabricated. The residential environment satisfaction items consist of durability, waterproof, heating, ventilation, heat insulation, air tightness, mining, soundproofing, disaster safety, fire safety, and crime prevention. The result is as follows. The housing construction method in North Korea, which lived at that time, consisted of 21 people (30.88%) of reinforced concrete frames, 18 people (26.47%) of wooden frames, 17 people (25%) of masonry walls, 5 people of prefabricated structures (7.35%), and reinforced concrete. Two people (2.94%) were walled. Among these, the wooden frame type had the lowest satisfaction level for each item, and the reinforced concrete had a high level of dissatisfaction in the items of heating, confidentiality, and disaster safety, and the other item had a high level of satisfaction. The masonry wall type has a relatively high satisfaction level in terms of insulation, confidentiality, mining, and disaster safety.

• Fire Science and Engineering
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• v.30 no.1
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• pp.63-73
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• 2016

This study examined the effects of the wind conditions, such as wind velocity and wind directions, on the performance of the mechanical smoke exhaust systems for high-rise building fires. A scaled model design and CFD simulations were used to verify the effects both quantitatively and qualitatively. The results showed that the smoke exhaust velocity of the mechanical exhaust system can be reduced by up to 17% at a wind velocity of 5 m/s (equivalent to an outdoor wind speed of 16 m/s) and a wind direction of ${\theta}=5^{\circ}$. In addition, the angle of the outdoor wind direction below ${\theta}=25^{\circ}$ had a significantly influence on the smoke exhaust flow rate and reduced exhaust performance of the smoke exhaust system in a fire.

• Journal of the Korea Institute of Building Construction
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• v.23 no.6
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• pp.683-692
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• 2023

This research assesses the mechanical properties of concrete, utilizing both normal and lightweight aggregates, through measurements of compressive strength and ultrasonic pulse velocity. The study observed that concrete with normal aggregates exhibited higher compressive strength in its initial stages, whereas concrete with lightweight aggregates showed increased strength over time, likely attributed to the higher water absorption rate of lightweight aggregates. Ultrasonic pulse velocity generally registered higher in normal aggregate concrete, barring a specific duration, presumably due to variations in the internal pore structure of the aggregates. The correlation coefficient(R²) for the strength prediction equation, derived from the relationship between compressive strength and ultrasonic pulse velocity, exceeds 0.95. This high correlation suggests that the predictive equation based on these experimental findings is a reliable method for estimating concrete strength.

• Proceedings of the Safety Management and Science Conference
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• 2011.04a
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• pp.433-444
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• 2011

In this study, the war has caused a huge scandal at home and abroad caused a fire in the agora, theoretical considerations and issues through case studies to identify and consequent evacuation plan is to undertake. Many a rally in a swarm of fire in the agora can cause a big disaster, focusing on the multi complex building for the evacuation area with a logical review of current and upcoming taller industrial society to cope with future activities, the nature of the fire prevention activities is to ensure the safety of the lives.

• Journal of the Society of Disaster Information
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• v.12 no.3
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• pp.210-218
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• 2016

In this study, the fire analysis program FDS and Pathfinder was used to analysis a simulated accidental fire of a narrow dwelling space as a test bed. The results showed that the evacuation time of the H form internal building structure was the fastest at 285 seconds. In addition, when the automatic sprinkler system functioned with the entrances closed, the temperature distribution was lower and the visible smoke density was reduced.

• Proceedings of the Safety Management and Science Conference
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• 2012.04a
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• pp.325-336
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• 2012

• Journal of the Korean Association of Geographic Information Studies
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• v.19 no.1
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• pp.180-196
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• 2016

To minimize the damage from disasters, various aspects of prevention, preparation, and response, etc. are being managed. Even though prevention and preparation are well conducted, irresistible calamities such as natural disasters may cause unexpected damage. Therefore, a system that can share the identical disaster information based on prompt disaster management and prediction must be developed and constructed for integrated disaster management. Especially, for a prompt disaster response, the same information needs to be shared between the related organization and the disaster prevention personnel such as on-site officials. Recent disaster management systems use high-capacity geographic information or other various factors for accurate disaster predictions. In case of using a recently constructed or researched 3D GIS, the system may not be used in some cases due to conflicts with hardware, etc. Thus, even though response information is secured using prediction simulation in advance, it is essentially difficult in some cases to share the common information when the system cannot be utilized or the extension of the corresponding data cannot be read. Therefore, this study aims to construct a system for dealing with disasters that shares the same prompt and accurate information in compliance with common data formats. The system is expected to reduce the existing disaster response time and minimize human and physical damage by assisting decision making through prompt responses.

• Journal of Korean Society of Forest Science
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• v.101 no.4
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• pp.656-662
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• 2012

This study has been undertaken to research the characteristics of growth of Pinus thunbergii Parl., which were planted in Uljin-gun, Gyeongbuk, Coast Disaster Prevention Forest. The total amount of 3600 trees of 9 sand dune stabilizing hedges were monitored in the past 4 years. The relationship between tree growth with environmental factors such as wind speed, soil conditions and sand-accumulation fences has been compared and investigated. To increase the growth increment of coastal disaster prevention forests, the development of sand-accumulating fences is the most important factor in controlling wind speed effectively. The monitoring for the maximizing wind-break effect of the sand-accumulating fences should be investigated when building coastal disaster prevention forests.

• Ocean and Polar Research
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• v.31 no.4
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• pp.361-368
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• 2009

An operational oceanographic system needs to be established for the preservation and management of marine environments and resources, and also to secure the safety and efficiency of marine operations in Korea. One of the major roles of operational oceanography is to deliver ocean science products which can meet the requirements of users such as marine industries, the general public, government agencies, and scientific research communities. Technical issues in relation to development of an effective operational oceanographic system in Korea are identified and discussed. Among others, cooperation among the agencies in ocean, meteorology, hydrology and environment, and also among those of neighboring countries is important for the development of an effective operational oceanographic system. The strategy for building a system that meets the demands of users, with consideration to potential problems, are explored.