• 대한기계학회:학술대회논문집
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• 대한기계학회 2002년도 학술대회지
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• pp.253-254
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• 2002

The determination of thrust is very important in hypersonic air-breathing propulsion design and evaluation. Because of the short flow-residence time in the combustor, the evaluation of engine performance is strongly influenced upon the engine thrust. Conventional methods to determine the thrust is using thrust stand or force measurement system. However, these methods cannot be applied to the case where thrust stands are impractical, such as free jet testing of engines, and model combustor. With this reason, the thrust determination method from measured pilot pressure is considered and evaluated.

• 한국터널지하공간학회 논문집
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• 제9권3호
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• pp.229-240
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• 2007

터널 및 지하공간 시공 중 일상계측에서의 계측관리 효율성 및 고급의 내공변위 분석을 위해 3차원 광파기, 선단앵커정착형 타겟부착장치, 절대변위 계측관리 프로그램으로 구성된 3차원 절대변위 계측시스템을 구축하였다. 본 연구를 통해 3차원 절대변위 계측에 필요한 광파기의 종류와 사양을 제시하였고, 기존 타겟부착장치의 문제점을 개선한 선단앵커정착형 타겟부착장치에 대한 성능시험을 수행하여 우수한 시준거리와 측정정밀도를 확인하였다. 또한 절대변위 계측관리 프로그램에 대한 현장성능시험을 수행하여 얻어진 경향선/영향선 등 다양한 분석방법을 활용하여 막장전방의 연약대 존재 예측이 가능하였고, TSP탐사결과와 비교하여 정확성을 확인하였다.

• 한국터널지하공간학회 논문집
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• 제26권5호
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• pp.463-476
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• 2024

쉴드 TBM 공법은 소음·진동 등의 환경위해요소를 배재할 수 있어 친환경적이며 연약한 지반조건에서도 안전한 터널건설이 가능하지만 기존 NATM 공법에 비해 고가의 공사비로 인해 적용에 많은 제약이 있다. 따라서 쉴드 TBM 공법의 적용성을 높이기 위해서는 공사비 절감을 통한 경제성 확보가 필요하며 이중 쉴드 TBM 터널 공사비의 약 35~40%로 가장 큰 비중을 차지하고 있는 세그먼트 공사비 절감이 매우 중요하다. 그 일환으로 본 논문에서는 쉴드 TBM 시공경험이 풍부한 일본의 쉴드 TBM 장기계측 데이터 분석을 통하여 터널 시공 및 운용 중 세그먼트 응력, 터널외부하중 조건 등의 변화추이를 고찰하고 설계단계의 예상치와 운용 중 계측값의 차이를 비교분석하였다. 이를 통하여 쉴드 TBM 설계단계에서 세그먼트 경제성 확보를 위한 개선사항을 연구하고자 한다.

• 터널과지하공간
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• 제25권3호
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• pp.244-254
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• 2015

모래와 자갈이 암반 위에 퇴적된 지층에서 터널의 윗부분이 지하수가 많은 모래자갈층을 통과하는 상황에서 터널을 시공하였다. 지상의 일부 곡선구간에 빌딩들도 있는 저심도 터널을 안전하게 시공하기 위하여 강도가 작고 지하수가 많은 터널천정부의 모래자갈이 터널 내로 낙하하는 유사현상(sand flow)을 예방해야 하였다. 이를 위하여 대구경강관다단그라우팅이나 제트그라우팅으로 터널주변 충적층을 굴착 전에 미리 보강한 후 터널을 시공하였다. 이와 같이 터널을 보강한 효과와 지상빌딩의 안전을 시공 중 계측을 통하여 확인하였다.

• Journal of Mechanical Science and Technology
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• 제20권4호
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• pp.482-493
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• 2006

The carbody structure of a high speed train passing through a tunnel is subjected to pressure fluctuation. Fatigue strength of the carbody structure against the fluctuating pressure loading should be proved in the design stage for safety. In this study, to get the useful information on the pressure fluctuation in the tunnel, measurement has been conducted during test running of KHST on the high speed line for two years. The measured results were analyzed and arranged to be used for carbody design. A prediction method for the magnitude and frequency of pressure change was proposed and the propagating characteristics of pressure wave was investigated. By statistical analysis for the measured results, a pressure loading spectrum for the high speed train was given. The proposed method can also be used to estimate the pressure loading spectrum for new high speed line at design stage combined with the results of train performance simulation.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2006년도 춘계학술발표회 논문집
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• pp.507-512
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• 2006

There are many risks in constructing tunnel-structure. To prevent these risks from occurring and secure safety, the precise and rapid survey of inside displacement of the tunnel is required. But nowadays the measurement of the crown settlement, convergency, and surface settlement depends on general kinds of method which use total station or level. In the way to provide data about maintaining structure according to recent improvement and progress of measuring technology, 3D laser scanning is used. It solves the problem of reliability in measuring displacement of existing structure, provides material that enables to estimate shape change of structure visually, and makes it possible to deliberate speedy countermeasure. By this three dimensioning it is possible to make efficient use of structure maintenance and field measurement

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.92-96
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• 2007

Microphone array beamforming method has been recognized as an important aeroacoustic research field and become a standard technique in localizing sound sources. This method also used in flight acoustic measurement, and especially, it is very useful when measure sounds inside the wind tunnel. In measuring sound which is inside the wind tunnel by traditional beamforming method, there are some errors caused by airstream. The speed and the propagation path of the sound changes as it travel through the airstream. This makes the error which the position of sound is changed a little bit to the down stream direction. In this paper, validation test has made about the correction equation for this wind effects of previous researches. And beamforming including shear layer correction was performed about a sound source in the anechoic open-jet windtunnel.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 춘계 학술발표회
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• pp.1376-1381
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• 2010

In this study, we dealt with an analysis and development of measurement systems for tunnel and slope structures under a high velocity. Deterioration of tunnel and slope structures becomes a critical issue in regard to both safety and economic concerns. Deterioration itself is inevitable, but condition assessment technology and nondestructive evaluation techniques could provide solutions to ensure public safety by means of detecting damage before serious and expensive degradation consequences occur. We reviewed the existing monitoring and maintenance systems of slopes and tunnels and more advanced directions, especially for highways under high-speed vehicles.

• 전기학회논문지
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• 제61권11호
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• pp.1732-1736
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• 2012

To increase speed up of train, in the field of catenary system, it is necessary to develop of new monitoring methods for dynamic interaction between pantograph and contact wire. Also, there is a need to develop technologies that constantly measure are from various railway structure such as uplift of contact wire, vibration of catenary, dynamic strain of contact line in tunnel. In this paper condition monitoring systems for dynamic performance of catenary systems in tunnel were proposed. An advanced method and results of field tests using high speed camera for monitoring of vertical upward movement of the grooved contact wire due to the force produced from the pantograph were presented. The proposed uplift measurement system of contact wire is expected to enhance precision of current collection quality performance assessment methods at high-speed lines.

• 터널과지하공간
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• 제5권4호
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• pp.347-362
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• 1995

The purpose of this study was that manage effectively the excavation process of the transport tunnel in DONGHAE mine area by investigating the variationof the surface and groundwater flow system around the tunnel and neighbouring villages. Thus, the effect of excavation and water-prrofing process on the water system has been studied through the naked eye survey of the tunnel and the surface outcrop, joint survey, core drilling, the measurement of the surface water quantity, evapotranspiration and precipitation analysis, rock hydraulics approach, the pressure test of boreholes, the variation of the water level, and finally the numerical analysis. From above approachs, we derived the conclusion that the exhaustion of the surface water was not caused by the tunnel excavation on the groundwater system was minimized by effective water proofing process.