• 한국터널지하공간학회 논문집
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• 제3권3호
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• pp.31-43
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• 2001

본 연구에서는 안전진단에 관한 기본적 정보를 제공하고 유사한 변상의 발생을 최소화하기 위한 목적으로 터널의 변상사례들에 대한 조사와 분석을 수행하였다. 국내외 터널의 44개 변상사례에 대하여 4개 항목 즉, 내용수명, 변상유형 및 원인, 지질상태 등에 관한 빈도 수를 분석하였다. 이와 더불어 국내 터널분야의 전문가들로부터 안전진단 평가에 관련하여 총 28개 항목에 대한 설문조사를 수행하였다. 본 연구의 결과는 터널의 변상항목 중에는 균열에 의한 변상이 42~58% 정도로 가장 높은 비율을 나타났다. 변상 원인으로는 시공불량에 의한 영향이 높은 비율을 나타내고 있으므로 시공품질의 확보가 중요한 요인으로 사료된다. 설문조사 결과로부터 경직된 평가기준의 완화를 지적하였다. 그리고 각 항목별 중요도를 제시함으로써 인공지능기법 등을 안전진단분야에 적용하기 위한 기초자료로 활용될 수 있을 것이다.

• Clinical Pain
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• 제18권2호
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• pp.70-75
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• 2019

Objective: The purpose of this study is to evaluate the usefulness of infrared thermography in patients with carpal tunnel syndrome by comparing with electrodiagnostic and ultrasonographic findings. Method: From January 2014 to October 2017, electrodiagnosis, ultrasound, and digital infrared thermal image (DITI) of unilateral carpal tunnel syndrome diagnosed in a single hospital were retrospectively analyzed. The subjects with bilateral symptoms of carpal tunnel syndrome, peripheral vascular disease, diabetes, thyroid disease, fibromyalgia, rheumatic disease, systemic infection, inflammation, malignant tumor, and other musculoskeletal disorders such as finger osteoarthritis, peripheral neuropathy, cervical radiculopathy, and the previous history of surgery were excluded. Results: Of 53 patients diagnosed with carpal tunnel syndrome, 11 were male and 42 were female. The visual analogue scale was 4.9 ± 1.9, and the duration of symptom was 11.8 ± 12.5 months. There was no statistically significant difference in the body surface temperature between the unaffected and affected sides. The severity of symptoms, electrodiagnostic findings, and cross-sectional area of the median nerve significantly correlates to each other. The temperature difference between the second fingers of the affected and unaffected sides showed a weak correlation with the amplitude of sensory nerve action potential and onset latency of compound muscle action potential, when there was no significant correlation with the other parameters. Conclusion: The difference in temperature on the surface of the body, which can be confirmed by DITI, is little diagnostic value when DITI is performed in unilateral carpal tunnel syndrome patients, especially when compared with ultrasonography.

• 한국신뢰성학회지:신뢰성응용연구
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• 제9권4호
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• pp.275-290
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• 2009

This paper considers accelerated thermal degradation tests which are performed for rubber seal materials used for undersea tunnels constructed by immersion method. Three types of rubber seals are tested; rubber expansion seal, omega seal, and shock absorber hose. Main ingredient of rubber expansion seal is EPDM(Ethylene Propylene Diene Monomer) and that of both omega seal and shock absorber hose is SBR(Styrene Butadiene Rubber). The accelerated stress is temperature and an Arrhenius model is introduced to describe the relationship between the lifetime and the stress. From the accelerated degradation tests, dominant failure mode of the rubber seals is found to be the loss of elongation. The lifetime distribution and the service life of the rubber seals at use condition are estimated from the test results. The acceleration factor for three types of rubber seals are also investigated.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.1378-1387
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• 2011

Seoul Metropolitan Rapid Transit Corporation - which is operating the subway lines No. 5, 6, 7 and 8 of Seoul's subway - has been operating a variety of motor cars and rail inspection vehicles to transport workers and materials into the tunnel at night after the daily revenue service for the maintenance of tunnel structure and track. However, the air quality in tunnels has been contaminated due to the operation of diesel engine cars, and rail inspection vehicles are now having higher chances of risks since the lightweight vehicles made with aluminum bogie became too obsolete. In this study, MRT type eco-friendly electric multi-inspection car has been elaborated for the purpose of improvement of tunnel environment and replacement of motor cars and rail inspection vehicles.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.341-344
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• 2005

High-speed trains with maximum speed of 300km/h, named KTX, have started revenue services since April 2004. Because of the geographical features of Korea a large portion of the 'Kyung-Bu' line is comprised of tunnels, which may cause excessive noise in a vehicle. The KTX interior noise follows in tunnel structure and the place where the quality appears different, the quality against hereupon from the commerce vehicle from the research which it sees it executes and comparison to analyze.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 추계학술대회 논문집(II)
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• pp.265-270
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• 2003

Though the probability of tunnel fire accident is very low, but critical fatalities are expected when it occurred. In this study the effect of critical safety parameters on tunnel fire accident are examined using probabilistic technique. Fire detection time, smoke spread velocity, passenger escape velocity, flash-over time, and emergency service arrival time are considered. In order to estimate the uncertainties of input parameters Monte Carlo simulation are used, and fatalities for each assumed accident scenarios are obtained as results. For the efficiency of iterative calculation PRA(Probabilistic Risk Analysis) code is developed in this study. As a result fire detection have large effect.

• Smart Structures and Systems
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• 제21권5호
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• pp.623-635
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• 2018

In order to study the mechanical behavior of shield tunnel segments during assembly stage, the in-situ tests and FDM numerical simulation were conducted based on the Foguan Shiziyang Tunnel with large cross-section. Analysis for the load state of the assembling segments in different assembly steps as well as the investigation for the changing of inner forces and longitudinal stress of segments with assembling steps were carried out in this paper. By comparing the tested results with the simulated results, the conclusions and suggestions could be drawn as follows: (1) It is the most significant for the effects on axial force and bending moment caused by the assembly of adjacent segment, followed by the insertion of key segment while the effects in the other assembly steps are relative smaller. With the increasing value of axial force, the negative bending moment turns into positive and remains increasing in most monitored sections, while the bending moment of segment B1and B6 are negative and keeping increasing; (2) The closer the monitored section to the adjacent segments or the key segment, the more significant the internal forces response, and the monitored effects of key segment insertion are more obvious than that of calculation; (3) The axial forces are all in compression during assembling and the monitored values are about 1.5~1.75 times larger than the calculated values, and the monitored values of bending moment are about 2 times the numerical calculation. The bending moment is more sensitive to the segments assembly process compared with axial force, and it will result in the large bending moment of segments during assembling when the construction parameters are not suitable or the assembly error is too large. However, the internal forces in assembly stage are less than those in normal service stage; (4) The distribution of longitudinal stress has strong influence on the changing of the internal forces. The segment side surface and intrados in the middle of two adjacent jacks are the crack-sensitive positions in the early assembly stage, and subsequently segment corners far away from the jacks become the crack-sensitive parts either.

• 한국산학기술학회논문지
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• 제12권4호
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• pp.1796-1802
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• 2011

본 논문에서는 지하 터널환경에서 전파의 경로 손실 특성을 예측할 수 있는 시뮬레이터를 개발하였다. 전파의 경로를 정확히 분석하기 위하여 image theory 방법을 이용하였으며, 직선 터널 구간뿐만 아니라 곡선 터널 구간에서도 전파 손실을 예측할 수 있도록 구현하였다. 시뮬레이터는 다양한 변수들을 입력받아 실시간으로 전파 경로를 도식화하여 결과를 보여줄 수 있으며, 송신부와 수신부의 위치를 변경하며 결과를 예측할 수도 있다. 개발된 시뮬레이터의 결과는 충훈 터널에서 실측한 전파 경로 손실 데이터와 비교 분석하여 타당성을 확인하였다.

• 한국화재소방학회논문지
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• 제31권5호
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• pp.107-116
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• 2017

터널화재는 국제적인 관심사이며, 매년 중대 터널화재는 발생하고 있다. 교통밀도가 증가하면서 장대터널은 물론, 더 많은 수의 터널이 건설되고 있어서, 앞으로 터널화재의 잠재위험성이 더 나빠질 수 있으므로 더욱더 심각한 문제이다. 도로터널 화재발생시 소방대원이 효과적인 소방활동 전략을 수립하도록 하는 것이 본 연구의 궁극적 목적이다. 과거 화재 사례로부터 어떠한 사고가 발생하였고, 어떠한 소방활동이 행해졌는지 알아보기 위하여 국내외 73건의 터널화재사고사례를 조사하여 4가지 사고유형으로 분류하였다. 소방활동의 전략수립을 위해 개입시간과 열방출율의 관계로 6가지 화재시나리오 곡선을 도출하였다. 이것은 두 가지 기준 즉, 반응한계와 최대 도착시간에 따라 소방활동의 전략을 수비적, 공격적 전략 중 선택할 수 있도록 하였다. 도로터널 분류 모델은 각 소방기관이 관할 터널의 화재 위험 정도를 화재 진압의 관점에서 평가하고 예방조치를 수립하는데 사용될 수 있다.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2006년도 PARALLEL CFD 2006
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• pp.203-206
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• 2006