• Geomechanics and Engineering
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• 제15권2호
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• pp.721-728
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• 2018

The surrounding rock mass contains cracks and joints which are distributed randomly around tunnels, and in the process of tunnel blasting excavation, radial cracks could also be induced in the surrounding rock mass. In order to clearly understand the impact of radial cracks on tunnel stability, tunnel model tests and finite element numerical analysis were implemented in this paper. Two kinds of materials: cement mortar and sandstone, were used to make tunnel models, which were loaded vertically and confined horizontally. The tunnel failure pattern was simulated by using RFPA2D code, and the Tresca stresses and the stress intensity factors were calculated by using ABAQUS code, which were applied to the analysis of tunnel model test results. The numerical results generally agree with the model test results, and the mode II stress intensity factors calculated by ABAQUS code can well explain the model test results. It can be seen that for tunnels with a radial crack emanating from three points on tunnel edge, i.e., the middle point between tunnel spandrel and its top with a dip angle $45^{\circ}$, the tunnel foot with a dip angle $127^{\circ}$, and the tunnel spandrel with $135^{\circ}$ with tunnel wall, the tunnel model strength is about a half of the regular tunnel model strength, and the corresponding tunnel stability decreases largely.

• 한국지하수토양환경학회지:지하수토양환경
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• 제13권5호
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• pp.88-95
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• 2008

본 연구에서는 터널 굴착으로 인한 지하수 영향 등 지반 환경 문제 해결을 위한 합리적인 평가 방법을 정립하고 이를 국민적 초미의 관심사 중 하나인 호남고속철도 계룡산 터널 구간에 적용하므로써, 계룡산 구간을 통과하는 터널 구간에 대한 환경문제(지하수/토양)를 사전에 연구하여 최적의 대안을 도출코자 한다. 지하수 유동모델링 결과 터널 굴착에 따른 지하수의 유출 및 지하수위 강하가 발생하며 터널굴착 완료 후에 지하수위가 회복되는 양상을 보인다. 따라서 구간에 분포하는 연약구간에 대해서는 특수 그라우팅이 필요할 것으로 사료된다.

• 한국산학기술학회논문지
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• 제17권5호
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• pp.637-644
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• 2016

본 논문은 터널 환경 측정 시스템 개발 및 측정 I [1], II [2]의 후속논문이다. 본 연구의 대상이 되는 터널인 솔안터널은 백두대간을 관통하는 연장 16.7 km의 루프식 단선 터널로 산악지형에 위치하며 화물열차와 승객열차가 혼용인 일반철도 터널이다. 본 논문에서는 솔안터널의 환경 측정을 위하여 터널 내부에 3개의 위치에 설치된 환경 측정 장치에서 약 1년간 측정된 온도 및 습도를 분석하였다. 선행의 연구에서는 도심지 및 도심지 인근에 위치한 터널 내부에서 측정 결과 결과에 대하여 분석하였지만, 본 논문에서는 산악지형에 위치한 터널 내부에서 측정한 온도 및 습도 등을 외부에서의 기상 측정 결과와 비교한 것으로 선행 연구와 차별성을 지닌다. 솔안터널 내부에 측정된 온도 및 습도를 월별로 지역에서의 기상 측정 결과와 비교하였으며, 여름과 겨울을 대표하는 대표적인 일자에 대해서 철도터널에서의 시간별 온도 및 습도의 변화도 분석하였다. 또한 터널 내 측정 위치에 따른 환경 특성도 분석하였다. 본 연구에서 제시한 철도터널의 환경측정 분석 결과는 터널의 환기 및 화재 시뮬레이션 등 터널의 기류의 컴퓨터 해석 및 터널의 공기질 및 온열환경과 관련된 연구에 폭넓게 사용될 수 있다.

• 제어로봇시스템학회논문지
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• 제10권1호
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• pp.66-72
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• 2004

To assess tunnel safety, cracks in tunnel lining are measured by inspectors, who observe cracks with their naked eyes and record them. But manual inspection is slow, and measured crack data is subjective. Therefore, this study proposes inspection system fur measuring cracks in tunnel lining and providing objective crack data to be used in safety assessment. The system consists of On-vehicle system and Laboratory system. On-Vehicle system acquires image data with line CCD camera on scanning along the tunnel lining. Laboratory system extracts crack information from the acquired image using image processing. Measured crack information is crack thickness, length and orientation. To improve accuracy of crack recognition, the geometric properties and patterns of cracks in concrete structure were applied to image processing. The proposed system was verified with experiments in both laboratory environment and field environment such as subway tunnel.

• 한국터널공학회:학술대회논문집
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• 한국터널공학회 2005년도 학술발표회 논문집
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• pp.270-281
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• 2005

An especial attention for old tunnel safety is required on increasing of The various tunnel recently. Specially, the lining investigation method of the old tunnel will be able to presume condition of concrete lining indirectly. Because it is many restriction thought of environment and ground condition investigation method of tunnel lining rear. This study carried out section & convergence measurement of part which was deformed in tunnel lining. It had been observed for the change of tunnel behavior with a continuous measurement. It has been analyzed for a cause of tunnel deformation and inspected for the effect after a repair-reinforcement to tunnel compared with the effect before those by structure analysis. By establishing automatic measurement system after repair-reinforcement to tunnel, it would be accomplished to convergence measurement continually. As a result, it was observed that deflection and deformation of tunnel was convergent. but it should be followed to a continuous maintenance because of unstable ground condition, cause of inner tunnel, environment. The railroad tunnel which was executed a reinforcement of the tunnel lining must investigate the close condition of reinforcement lining and concrete lining.

• 한국산학기술학회논문지
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• 제17권4호
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• pp.758-765
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• 2016

본 논문은 터널 환경 측정 시스템 개발 및 측정 I -개발 시스템 및 지하철터널 측정- [1]의 후속논문이다. 일반적인 철도터널 형태를 보이는 20.3 km 연장의 고속철도 복선터널인 금정터널에 환경측정장치를 설치하여 약 1년간 환경 측정한 결과에 대하여 논하였다. 월별 터널 내의 온도 및 상대습도에 대하여 측정한 결과를 분석하였으며, 겨울과 여름의 특정 일을 선택하여 측정결과를 분석하였다. 월별 온도의 경우, 터널 내부의 온도가 여름에는 외기의 온도와 거의 유사하였으나, 겨울에는 현저하게 높았다. 지중 온도가 연중 일정한 상황에서 여름에는 터널이 외기의 영향을 많이 받아 외기와 유사한 온도를 나타냈으나, 겨울에는 지열과 열차에서 발생하는 열 등에 의해 온도가 더 높은 것으로 보인다. 또한 측정장치의 설치 위치별 환경 특성에 대하여 분석하였다. 터널 내부에서는 외기와 바로 연결되어 있는 수직구와 사갱이 본선에 비하여 온도와 상대습도의 변화가 심하게 나타났는데, 이는 수직구와 사갱이 외기와 바로 연결되어 있어 외기의 영향을 더 많이 받기 때문이다. 이러한 분석 결과는 터널의 환기나 공기질 개선, 온열환경 개선 등의 연구에 폭넓게 사용될 수 있을 것으로 기대된다.

• Geomechanics and Engineering
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• 제18권4호
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• pp.373-389
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• 2019

It is important to study the problem of durability for tunnel structures. As a main influence on the durability of tunnel structures, carbonation-induced corrosion is studied. For the complicated environment of tunnel structures, based on the data samples from real engineering examples, the intelligent method (genetic programming) is used to construct the service life prediction model of tunnel structures. Based on the model, the prediction of service life for tunnel structures in carbonation environments is studied. Using the data samples from some tunnel engineering examples in China under carbonation environment, the proposed method is verified. In addition, the performance of the proposed prediction model is compared with that of the artificial neural network method. Finally, the effect of two main controlling parameters, the population size and sample size, on the performance of the prediction model by genetic programming is analyzed in detail.

• 설비공학논문집
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• 제9권4호
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• pp.504-516
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• 1997

Recently scientists and engineers are developing a system to get waste heat of low-temperature level with advanced heat pump, which have not been used up to now. As the reason, it is necessary to examine capability of using waste heat which is raised up in the tunnel of subway out of widely distributed low-temperature waste heat in large cities. Therefore we surveyed thermal environment of the tunnel of subway in $S\check{o}my\check{o}n$, downtown of Pusan, from November 1995 to December 1996 and developed a program to predict the thermal environment of subway on the basis of experimental data and the geometries of tunnels. This paper has proved availability of waste heat of subway when the measured results obtained in subway in the winter time and the simulated results of thermal environment prediction program are compared, as well as has reported results of estimating reliability of the simulation program. As the result, the charateristics of thermal environment in the tunnel of subway in $S\check{o}my\check{o}n$ station in the winter time are to be followed; 1) temperature in the tunnel is about $10^{\circ}C$ higher than outside air temperature, 2) temperature change in the tunnel is less than that in the platform so that we may obtain stable heat source, 3) and when the measured results obtained in subway in the winter time and the simulated results of thermal environment prodiction program is compared, both results show similar tendency. Therefore, we confirm estimating reliability of the simulation program.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2002년도 추계학술발표회
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• pp.327-330
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• 2002

In this study, analyses of contaminant transport are peformed to evaluate the diffusion effect of A sewage tunnel. First, Crank's analytical method is used to measure the concentration change of contaminant with time and space. Two dimensional numerical analysis is performed to measure concentration distribution of contaminant. Both methods show that the diffusion effect is little even after 500 years. This means that when flow converges into the tunnel, the environmental effect of contaminant in tunnel is not serious because there is no advection occurs.

• Geomechanics and Engineering
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• 제21권2호
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• pp.171-178
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• 2020

Mountainous areas cover more than 70% of Korea. With the rapid increase in tunnel construction, tunnel-collapse incidents and excessive deformation are occurring more frequently. In addition, longer tunnel structures are being constructed, and geologically weaker ground conditions are increasingly being encountered during the construction process. Tunnels constructed under weak ground conditions exhibit long-term deformation behavior that leads to tunnel instability. This study analyzes the behavior of the bottom region of tunnels under geological conditions of long-term deformation. Long-term deformation causes various types of damage, such as cracks and ridges in the packing part of tunnels, as well as cracks and upheavals in the pavement of tunnels. We observed rapid tunnel over-displacement due to the squeezing of a fault rupture zone after the inflow of a large amount of groundwater. Excessive increments in the support member strength resulted in damage to the support and tunnel bottom. In addition, upward infiltration pressure on the tunnel road was found to cause severe pavement damage. Furthermore, smectite (a highly expandable mineral), chlorite, illite, and hematite, were also observed. Soil samples and rock samples containing clay minerals were found to have greater expansibility than general soil samples. Considering these findings, countermeasures against the deformation of tunnel bottoms are required.