• Journal of the Korean Solar Energy Society
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• v.27 no.4
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• pp.77-85
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• 2007

With the increase in the demand for sustainable and environment-friendly development all over the world, it becomes an urgent issue for Korea to reduce $CO_2$ emission. Since building industry accounts for about 40% of international energy and resource consumption and $30{\sim}40%$ of $CO_2$ emission, it is essential to prepare for energy-efficient building. This study aims to seek for improvement direction for a domestic Building Energy Efficiency Rating System through the comparison with foreign systems. Two foreign building energy rating systems which have the similar application scope with domestic one, HERS(Home Energy Rating System) and SAP(Standard Assessment Procedure)2005 were selected. As compared with foreign systems, we intended to suggest improvement direction for effective application of Building Energy Efficiency Rating System in Korea.

• Journal of Korean Tunnelling and Underground Space Association
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• v.11 no.4
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• pp.437-447
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• 2009

It is easily found by several references of NATM that the cracks on the lining concrete of NATM are more developed than those of the conventional tunnel methods. Based on the results of research, the new method is proposed to control and protect the axial cracks on the tunnel linings. Also, the efficiency of proposed method is evaluated using the Distinct Element Method.

• Journal of Korean Tunnelling and Underground Space Association
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• v.14 no.3
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• pp.159-181
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• 2012

The segment lining which consists of segments and joints are main component of shield tunnel. There are a number of methods that are being used in design which compute the sectional forces of a ring of segment lining. The traditional design methods which do not consider the effect of joints have been commonly used for design procedure without a specific verification of structural analysis. This paper presents the result of a comparative study for analytical and numerical models of the shield tunnel segment lining. For the traditional methods, the elastic equation method and the Duddeck & Erdmann method were considered. The ring-beam and the continuum analysis model were also considered as the numerical model.

• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.4
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• pp.68-76
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• 2016

The present study proposes the definition of service life and the end-of-life criterion for bridge maintenance. Bridges begin to deteriorate as soon as they are put into service. Effective bridge maintenance requires sound understanding of the deterioration mechanism as well as the expected service life. In order to determine the expected service life of a bridge for effective bridge maintenance, it is necessary to have a clear definition of service life and end-of-life. However, service life can be viewed from several perspectives based on literature review. The end of a bridge's life can be also defined by more than one perspective or performance measure. This study presents definition of service life which can be used for bridge maintenance and the end-of life criterion using the performance measure such as a damage score. The regression model can predict an average service life of bridges using the proposed end-of-life criterion.

• Journal of Korean Tunnelling and Underground Space Association
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• v.25 no.3
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• pp.245-259
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• 2023

The purpose of this paper is to examine the most recent tunnel scanning systems to obtain insights for the development of non-contact mobile inspection system. Tunnel scanning systems are mostly being developed by adapting two main technologies, namely laser scanning and image scanning systems. Laser scanning system has the advantage of accurately recreating the geometric characteristics of tunnel linings from point cloud. On the other hand, image scanning system employs computer vision to effortlessly identify damage, such as fine cracks and leaks on the tunnel lining surface. The analysis suggests that image scanning system is more suitable for detecting damage on tunnel linings. A camera-based tunnel scanning system under development should include components such as lighting, data storage, power supply, and image-capturing controller synchronized with vehicle speed.

• Journal of the Society of Disaster Information
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• v.19 no.4
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• pp.984-992
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• 2023

Purpose: The core problem of this study is that there are no specific noise regulation standards for domestic blasting work. Currently, the domestic blasting work noise regulation standard has not been established separately, and the noise regulation standard of 80 decibels is corrected by 10 decibels to 70 decibels, which is the daily living noise standard. In contrast, many foreign countries have separate noise regulation standards specifically tailored to blasting work. Accordingly, it is intended to present international reasonable blasting noise standards by comparing domestic and foreign blasting work noise regulation standards. Mmethod: This study can be inferred as a comparative analysis of domestic and foreign noise regulation standards. Data on the current noise regulation standards during domestic blasting and noise regulation standards during blasting operations in the United States, the United Kingdom, Australia, Japan, and China are collected and analyzed. Results: According to the study, the noise regulation value during blasting work at domestic construction sites was not separately established, so it was not properly tailored to the specific and characteristics of blasting noise. In the case of overseas, a realistic noise regulation value was established so that a safer, more efficient and eco-friendly blasting method could be applied to the noise regulation value uniformly during blasting work. Conclusion: In this study, it is hoped that noise regulations will be established during reasonable blasting work, as shown in domestic and international comparative studies, and will be widely adopted without interfering with the introduction of efficient, economical, and eco-friendly blasting methods by complying well with blasting safety standards.

• Journal of the Society of Disaster Information
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• v.9 no.4
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• pp.429-438
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• 2013

In this study, compare and analyze for high-rise evacuation safety design criteria improvement about internal high-rise building egress safety rule. To the result, high-rise evacuation safety design criteria improvement data can be summarized as follows. First, should compute the evacuation capacity about the number of persons and when more than 2 exits are requested, over 50% of evacuation capacity must be satisfied even approaching to 1 exit is unable. Second, 2 ways of evacuation can be made smoothly by the stair or exit separation-distance standard regulation. Third, regulate the length limitation of dead-end corridor or passageway and it should give grades in limitation of whether the spring-cooler has been installed. Fourth, must secure the evacuation way and do the evacuee guidance when it's safety area and elevator or stair. Also needs to provide extra safety area to secure horizontal direction Escape Safety except fire escaping floor.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.3
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• pp.28-39
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• 2014

This paper reviews past literatures relevant to fire-resistance properties of high strength concrete and investigates spalling mechanism of high strength concrete in fire. First, literatures were reviewed on spalling occurrence and fire-resistance methods. Second, a chemical change of concrete components in an elevated temperature was presented. Finally, the mechanism of the spalling occurrence and spalling resistance were examined in terms of hybrid fiber content. The focus of the experimental study as part of this research is to investigate the effects of fire on the variation of thermal properties of high strength concrete, which tends to be used in super tall buildings. This experimental study was devised to investigate the fire-resistance performance of high strength concrete containing hybrid fibers. A total of 48 test specimens were exposed to high temperature ranging from $100^{\circ}C$ to $700^{\circ}C$, including room temperature (${\sim}20^{\circ}C$). Test results provide valuable information regarding fire-resistance properties of strength concrete with 100 MPa or greater.

• Journal of the Korea institute for structural maintenance and inspection
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• v.7 no.3
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• pp.251-262
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• 2003

LCP(Life Cycle Profiles) of bridge structures are indispensable for the LCC(Life Cycle Cost) evaluations of bridge system. The bridge under considerations may be newly-designed one or one in service. Thus, a systematic study of LCP is essential for both reliable LCC evaluation and strategic bridge management. LCP is mainly influenced by the structural environment in nature. However, in Korea, LCC evaluation has been performed with the LCP of foreign research results or only with the pieces of professional engineers' opinion. Therefore, to alleviate the drawbacks of foreign LCP and to enhance the reliability of current LCP, LCP should be established using the available data in bridge management system(BMS). In this study, LCP along with a subset of the BMS data was investigated and several mathematical expressions were proposed and evaluated. The condition ratings of a bridge were trasformed into the numerical indices through fuzzy logics with real field data. From the numerical results, it is concluded that the mathematical LCP model of $y=\sqrt{y^2_0-at}$ is shown to be the fittest one (R=0.815) to express the condition rating varied with the age. This has been drawn from the case study of slab bridges under the similar conditions.

• Journal of Korean Tunnelling and Underground Space Association
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• v.3 no.3
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• pp.31-43
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• 2001

In this study, we carried out investigation and analysis on damages in tunnels on order to provide the basic information for the safety assessment of tunnels and to minimize the potential damage of the same kind as investigated. The frequencies of occurrence in terms of 4 items, i.e., service life interval, type of the damage, cause of the damage, and geological condition, were examined and summarized based on 44 foreign and domestic cases of tunnel damages. Also, we carried out a survey research of which the content included 28 questions on the tunnel safety assessment. The answers collected from domestic experts in tunneling suggested that the most probable cause of the tunnel damages was cracking in tunnels at 42~58%. They also suggested that the poor constrution work strongly caused the damages. Therefore, to ensure tunnel safety, high quality of constrution should be maintained as examined. The types of damage and their extent of influence on the overall tunnel safety are of practical importance to be used in the artficial intelligent system for tunnel safety assessment.