• 설비공학논문집
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• 제14권7호
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• pp.567-574
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• 2002

In the present study, ventilation flow rates and pressure rises through a road tunnel are simulated numerically using CFD with the various conditions such as roughness height, swirl angle of jet fan, entrance and exit effect and hub to tip ratio. By using a modified wall function, friction factor can be predicted under 10％ of error with respect to the Moody chart for the circular pipe flow and 15％, for the present tunnel. For more precise design, the effects of the swirl angle and hub to tip ratio of jet fan, which is not included in the theoretical equation of pressure rise by jet fan are necessary to be considered.

• 한국터널지하공간학회 논문집
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• 제2권3호
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• pp.13-24
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• 2000

본 논문에서는 고속도로터널의 붕락형태와 원인분석, 보강방법에 대하여 다루었다. 고속도로터널의 붕락형태를 분석해 보면 3가지 유형으로 분류된다. 지반풍화로 인해 터널붕락이 지표면까지 함몰된 경우 35%, 불리한 암반절리로 인한 터널내 국부적인 쐐기형 암반블럭 붕락의 경우 50%, 터널굴진방향과 미끄럼면의 교차로 인해 터널내 침하가 발생한 경우 15%의 비율로 조사되었고 터널붕락이 발생된 위치는 입출구 40m 이내와 입출구와 인접한 계곡부에서 85%, 비상주차대과 본선접속부에서 15% 발생되었다. 고속도로터널에서 발생한 붕락을 파괴개념으로 분석하면 활동파괴가 83%이상을 차지하는 것으로 분석되었다.

• 한국터널지하공간학회 논문집
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• 제13권5호
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• pp.385-393
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• 2011

경제성장의 달성과 직선도로의 증가에 따라 터널은 전보다 더 많이 만들어졌다. 이러한 터널들의 입구 조명은 안전하고 편안한 운전을 위해 중요하다. 대부분의 터널 조명은 인공조명으로 많은 에너지를 사용한다. 본 연구에서는 터널의 조명 개선과 에너지 절약으로 반사거울 시스템을 적용하여 평가하였다. 반사거울 시스템을 적용하면 주광을 유입하여 터널 조명 환경을 개선할 수 있으며, 본 연구는 터널 인공조명 에너지의 절약을 위한 선행연구의 일환으로 진행되었다.

• 대한기계학회논문집
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• 제19권8호
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• pp.1972-1981
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• 1995

As a railway train enters a tunnel at high speed, a compression wave is formed in front of the train and propagates along the tunnel. The compression wave subsequently emerges from the exit of the tunnel, which causes an impulsive noise. The impulsive noise is closely related to the pressure gradient of the compression wave propagating the tunnel. In order to investigate the characteristics of the compression waves, in the present study an experiment was made using a shock tube. The results show that the strength of a compression wave decreases with the distance from the tunnel entrance and the nonlinear effect of compression wave appears to be significant if strength of the initial compression wave is greater than 7 kPa. Furthermore if the wave pattern is known, attenuation of the compression wave propagating in a tunnel can be reasonably predicted by a theoretical equation considering viscous action and heat transfer in boundary layer.

• 한국터널지하공간학회 논문집
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• 제14권6호
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• pp.607-616
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• 2012

지속적인 터널 건설의 증가는 터널 내 대기질 관리에 대한 필요성을 점증시키고 있어 측정 및 모델 모사를 통한 터널 내 대기질 거동에 대한 연구를 수행하였다. 남산1호 터널 입구와 출구의 $CO_2$ 농도차는 250 ppm~400 ppm으로 출구쪽이 높았으며 환기를 안 하는 차량 내부의 농도는 외부에 비해 200 ppm~300 ppm 낮게 측정되었다. 교통량이 적을 시 터널 내 유속은 빨라지며 일정한 농도 구배를 나타내고, 교통량이 증가하면 일정치 않은 농도 구배를 나타내는 것으로 나타났다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2002년도 봄 학술발표회 논문집
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• pp.229-236
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• 2002

In this paper, a new novel technique of seismic survey is introduced to estimate the continuity of inclined pits filled with water, It was assumed that the pits would be connected to an abandoned railway tunnel that might be constructed in the past. Thus, detection of pit end was needed for the design of a new highway tunnel(Yukshimreong tunnel) that was likely to be met with a pit. In the beginning of exploration, no reliable, cost effective method was available. Hence, focus of interest moved toward the high impedance contrast(reflection coefficient k∼0.8) between water and rock. In this special model of sequence rock-water-rock, total reflection occurs and the seismic energy, when it is generated in the pit water, is nearly confined to the pit so that seismic waves can propagate much further within the pit. As a matter of convenience, this is called“tunnel channel wave”. With these considerations in mind, seismic detonator(2g) was used as a source at the entrance of pit, whereas hydrophone chain(hydrophone interval=1m) was placed on the bottom of pit. With this appropriate source-receiver arrangement, desirable down-going and up-going waves could be observed that will help conform the continuity of pits. After about one year, it was ascertained that the inclined pit of interest was just nearby crossed with the newly excavated tunnel, as it was predicted.

• 한국터널지하공간학회 논문집
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• 제13권5호
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• pp.371-383
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• 2011

터널은 밝기가 급변하는 공간으로 운전자의 안전을 위해 조도의 확보가 중요하고, 터널의 조명설비는 주간과 야간에 모두 운영되고 있어 많은 전기 에너지가 소비되고 있다. 따라서 본 연구는 주간에 터널의 자연채광을 효율적으로 이용하여 에너지를 절약할 수 있는 방안으로 RADIANCE 시뮬레이션 프로그램을 사용하여 자연채광 반사거울 시스템의 채광 성능을 평가해 보았다. 프로그램을 사용하여 바(bar)형식과 폴(pole)형식으로 구분하여 벽면과 바닥면으로 주광을 유입한 결과 터널입구부로부터 20 m에서 바형식의 형태가 터널내부의 높은 조도를 확보하는 것으로 나타났다.

• 대한기계학회논문집B
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• 제33권3호
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• pp.156-163
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• 2009

In this study, comparative analysis on the back-layer phenomena in the tunnel-fire driven flow is performed using numerical simulation with LES and RANS. FDS(Fire Dynamics Simulator) code is employed to calculate the fire-driven turbulent flow for LES and Smartfire code is used for RANS. Hwang and Wargo's data of scaling tunnel fire experiment are employed to compare with the present numerical simulation. The modeled tunnel is 5.4m(L) ${\times}$ 0.4m(W) ${\times}$ 0.3m(H). Heat Release Rate (HRR) of fire is 3.3kW and ventilation-velocity is 0.33m/s in the main stream. The various grid-distributions are systematically tested with FDS code to analyze the effects of grid size. The LES method with FDS provides an improved back-layer flow behavior in comparison with the RANS (${\kappa}-{\epsilon}$) method by Smartfire. The FDS solvers, however, overpredict the velocity in the center region of flow which is caused by the defects in the tunnel-entrance turbulence strength and in the near-wall turbulent flow in FDS code.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.869-875
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• 2009

Safety is a big issue in the construction sites. For safe and secure management, tracking locations of construction resources such as labors, materials, machineries, vehicles and so on is important. The materials, machineries and vehicles could be controlled by computer, whereas the movement of labors does not have fixed pattern. So, the location and movement of labors need to be monitored continuously for safety. In general, Global Positioning System(GPS) is an opt solution to obtain the location information in outside environments. But it cannot be used for indoor locations as it requires a clear Line-Of-Sight(LOS) to satellites Therefore, indoor location monitoring system could be a convenient alternative for environments such as tunnel and indoor building construction sites. This paper presents a case study to investigate feasibility of Wi-Fi based indoor location monitoring system in construction site. The system is developed by using fingerprint map of gathering Received Signal Strength Indication(RSSI) from each Access Point(AP). The signal information is gathered by Radio Frequency Identification (RFID) tags, which are attached on a helmet of labors to track their locations, and is sent to server computer. Experiments were conducted in a shield tunnel construction site at Guangzhou, China. This study consists of three phases as follows: First, we have a tracking test in entrance area of tunnel construction site. This experiment was performed to find the effective geometry of APs installation. The geometry of APs installation was changed for finding effective locations, and the experiment was performed using one and more tags. Second, APs were separated into two groups, and they were connected with LAN cable in tunnel construction site. The purpose of this experiment was to check the validity of group separating strategy. One group was installed around the entrance and the other one was installed inside the tunnel. Finally, we installed the system inner area of tunnel, boring machine area, and checked the performance with varying conditions (the presence of obstacles such as train, worker, and so on). Accuracy of this study was calculated from the data, which was collected at some known points. Experimental results showed that WiFi-based indoor location system has a level of accuracy of a few meters in tunnel construction site. From the results, it is inferred that the location tracking system can track the approximate location of labors in the construction site. It is able to alert the labors when they are closer to dangerous zones like poisonous region or cave-in..

• 한국소음진동공학회논문집
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• 제16권1호
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• pp.19-26
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• 2006

The test blasts were carried out by detonating some single blastholes at two upper sites of the underground storage cavern for the crude oil. One was performed at the entrance site of the construction tunnel and the other at the middle area of the underground storage cavern. Based on the blast-induced nitration measured by the test blasts, we suggested the propagation equations of blasting vibration that were capable of estimating the peak particle velocity. In addition, in order to assess the stability of the adjacent ground storage tank, we did the frequency analysis and the response spectrum analysis with the particle velocity-time history and the particle acceleration-time history that were measured by the test blast carried out on the entrance site of the construction tunnel. In result, it was predicted that the displacement on the highest part of the tank shell was less than the allowable displacement.