• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 춘계 학술발표회 논문집
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• pp.423-430
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• 2005

Fire accidents in underground space may bring much loss of lives as well as properties and result in catastrophic disasters. This study aimed to manufacture the high-temperature furnace capable of simulating fire scenarios (RABT and RWS) and carry out the preliminary fire tests to evaluate fire-induced damage in underground structures. Specimens used in the fire tests were the concrete segments generally used in shield TBM tunnels. The simulated fire scenario was set to the RABT curve that is the most representative fire scenario in underground space. From the fire tests, the spalling was estimated to reach approximately 20cm from the surface exposed to fire. In addition, from the observation of core specimens obtained after fire tests, the deteriorated zone of unspalled specimens amounted to approximately 10cm from the surface of spalling.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2018년도 춘계 학술논문 발표대회
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• pp.339-340
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• 2018

Contemporary concrete structures make use of underground spaces as parking lots and other comfort facilities for efficiency purposes. As underground environmental conditions are in constant exposure to degradation factors from the environment such as groundwater, hydraulic and soil pressure, structural movement and settlement, structural defects in the form of leakage occur. Current maintenance regulations and regimes are unable to respond to this field, as degradation mechanisms in underground environments are still unclear. In this regard, this study proposes the utilization of integrated information sharing system that can provide various technical information for construction designs to prevent leakages in underground concrete structures.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2002년도 봄 학술발표회 논문집
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• pp.665-672
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• 2002

In this paper, the utilization of waste foundry sand produced in the molding process is studied as a backfill material for underground electric utility systems such as concrete box structures and pipe lines for power supply. The physical, chemical and thermal properties for waste foundry sand are investigated for mechanical stability, environmental hazard and power transmission capacity. Also its properties are compared with the natural river sand. The test results show that waste foundry sand can be utilized for underground concrete box structures as a backfill material; however, it can not be applied to underground pipe lines due to high thermal resistivity or low power transmission capacity.

• 콘크리트학회지
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• 제19권5호
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• pp.35-38
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• 2007

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 봄 학술발표회 논문집
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• pp.880-887
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• 2000

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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• pp.397-402
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• 2001

Due to the recent economic growth and the subsequent increase in demand of electricity, the construction of underground transmission line is also on the rise. Especially, in the metropolitan area, we have much obstruction in laying the line to the central district because of difficulties in procurement of construction land and the increase in the construction cost. Therefore, the necessity of increasing the capacity of transmission line has been suggested. In order to increase the capacity, the electric voltage and current intensity in size-limited lines should be also increased. But, eventually, it leads to the generation of unnecessary heat and the heat radiates through insulation cables and backfill concrete. So we need to develop the material that has good heat radiation characteristics. In this study, we developed and tested backfill concrete that can be a substitute for previously used backfill sand.

• 한국농공학회지
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• 제45권6호
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• pp.136-143
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• 2003

This study is performed to evaluate performance of the developed pipe when using for underground drainage in fm land, the efficiency of the pipe is examined such as quantity of drainage, water temperature and other field performance in all weather condition. Results of this study, the higher permeability through wall of the pipe is achieved by making various size pores using open-graded aggregate. And in all weather conditions, permeable polymer concrete pipe perform much better than conventional perforated pipes. During rice farming period, quantity of drainage the permeable polymer concrete pipe is 1.25 time greater than conventional perforated pipes. Therefore, use of the permeable polymer concrete pipe is greater advantages when considering collecting and draining capacity compared with conventional perforated pipes.

• 자연, 터널 그리고 지하공간
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• 제1권1호
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• pp.81-87
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• 1999

Effects of blasting vibrations on curing concrete have not been well studied. As a result, unrealistic and costly blasting vibration constraints have been placed on blasting when it occurs in the vicinity of curing concrete. To study the effects of blasting, concrete blocks of $30\times20\times20cm$ were molded and placed on the quarry Different sets of concrete blocks were subjected to peak vibrations of 0.25, 0.5, 1.0, 5.0, and 10cm/sec. The impulses of blasting vibrations were applied at thirty minutes intervals . Along with unvibrated concrete blocks, the vibrated concrete samples with 60.3mm in diameters were measured for elastic moduli, sonic velocity and uniaxial compressive strength. Test results can be summarized as follows : 1) The blasting vibrations between 6 and 8 hours after pour generally have exerted bad influences on the uniaxial compressive strength of the concrete 2) Under low vibration of 0.25cm/sec variations of the uniaxial compressive strength were not shown. As the magnitudes of blasting vibration increased, compressive strength of concrete decreased. But under the vibrations between 5 and 10cm/sec decreases in strength were almost same. 3) Physical properties of the p-wave velocity, Young's modulus, and Poisson's ratio appeared to decrease for the concrete blocks subjected to vibration for 6 to 8 hours.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 추계학술대회 논문집
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• pp.1184-1189
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• 2005

Durability of concrete has been currently issued in the engineering societies and a large number of studies on the concrete corrosion in salty environment have been performed. The reinforcement corrosion, which is the primary reason of deterioration of the concrete structure exposed to chloride environment. is caused by the chloride ions infiltration owing to underground water seeping into the concrete. In this study. the endurance periods using the diffusion equation of the concrete specification have been evaluated on the concrete structures with different addictives for the brand new R/C subway structure exposed to seashore underground water. Furthermore. the guidance for proper use of the addictives and the reasonable thickness of concrete cover are derived for concrete mixing. From the result of the evaluation corresponding to salt damage for Inchon subway line I, the endurance periods of the ordinary Portlandcement concretes are represented as $42\~75$ years and fail to achieve the objective period of 100 years. However, the lower water-cement ratio expands the endurance periods and the blast furnace slag concrete with small quantity of the silica fume, which shows the best performance of corrosion resistance in this study, represents more than 170 years of the endurance period. Moreover, the case of use of blast furnace slag and fly ash together shows the endurance period of $134\~171$ years and it means that the result very satisfies the objective endurance period.

• 한국터널지하공간학회 논문집
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• 제7권4호
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• pp.323-333
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• 2005

최근 세계적으로 터널 및 지하구조물에 대형화재가 발생하고 있으며 이로 인해 경제 사회적으로 심각한 손실이 발생하고 있는 실정이다. 이처럼 폐쇄된 공간인 터널 및 지하구조물내 화재 발생 시 구조체의 강도저하로 인한 붕괴 및 인명피해 뿐만 아니라 사회기반시설인 교통망을 장시간 끊어놓게 되는 등 큰 문제를 야기한다. 이에 본 연구에서는 터널에 화재 발생시 구조물 안정성에 대한 한국도로공사 관련 시방 규정을 도출하기 위한 기초 자료를 구축하는 것으로서 콘크리트의 폭열 방지에 효과적인 것으로 알려져 있는 폴리프로필렌 섬유를 혼입한 폴리프로필렌 섬유보강 콘크리트를 이용하여 터널내 화재시 터널 콘크리트 라이닝의 폭열 현상에 대한 방지를 위한 실험을 실시하였다. 본 연구결과 폴리프로필렌 섬유의 혼입률에 따른 모르타르의 내화시험결과를 토대로 폭열이 일어나지 않는 폴리프로필렌 섬유 혼입률을 0.2%~0.25% 인 것으로 분석되었다.