• 한국지진공학회논문집
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• 제6권1호
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• pp.7-11
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• 2002

본 연구에서는 다단계방법(multi-step method)을 사용하여, 지진시 지반과 지하구조물 경계가 가장 미끄러지기 쉬운 상태일 수 있는 지반 공진시에 대하여 지하구조물 축방향 동지반강성계수와 미끄러지기 쉬운 조건들을 구하였다. 상재하중에 의한 지반과 지하구조물 경계에서의 전단저항력과 지진시 발생되는 미끄러짐 부분의 전단력을 비교함으로써 미끄러짐 조건을 결정하였다. 그리고 매개변수 해석을 통하여 지하구조물의 크기와 위치, 지반조건, 표층지반의 형상 및 경계마찰계수에 대하여 미끄러지기 쉬운 조건을 구하였다.

• 산업기술연구
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• 제22권A호
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• pp.107-117
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• 2002

The blast works for open cuts and underground constructions near urban areas have recently increased complaint of ground vibration, air blast and fly rock. In order to reduce these problems, it is necessary to develop more cautious blasting, or non-blast excavation methods by mechanical power. For these breaker workings instead of blast are sometimes adopted. To compare the characteristics of blast vibration with breaker vibration, the level, range of frequency and spectrum amplifications of each vibration were studied.

• 한국안전학회지
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• 제14권4호
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• pp.71-77
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• 1999

Exposed gas pipeline in underground, especially subway construction site, has been continuously vibrated by vehicle above ground. Because this vibration can cause unexpected damages to pipeline, we had measured and analyzed the vibration. This paper presents results of the vibration analysis of exposed gas pipeline and the results are as follows. The major vertical vibration frequency of pipeline was about 13 Hz and the other frequency components disappeared when the vibration transmitted to I-beam and wire rope. Existence of wooden casement had not affect vibration of exposed gas pipeline. The results of modal analysis by experimental and analytical methods have good agreement and it is also shown that exposed pipeline has possibility of resonance at second mode.

• 터널과지하공간
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• 제12권3호
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• pp.210-219
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• 2002

구조물 발파해체시 발생하는 지반진동은 발파진동과 붕괴되는 구조물의 낙하에 의한 충격진동으로 구별되어 나타난다. 본 연구에서는 모형 구조물에 장전층을 달리하여 붕괴시켰다. 이때 발생하는 지반진동을 발파진동과 충격진동으로 구별하여 각 방향별 파형 및 주주파수를 분석하고 장전층의 변화에 따른 진동의 특성을 비교하였다.

• 화약ㆍ발파
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• 제35권2호
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• pp.1-8
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• 2017

본 연구에서는 증기압을 이용한 새로운 파암공법의 특징을 간략하게 소개하였다. 이 파암공법은 지하암반굴착에서 지반진동을 저감시키려는 목적으로 개발된 것이다. 한 터널굴착 현장에서 대상공법에 대한 검증시험을 실시하였다. 지반진동은 시험현장 부근에서 측정하였다. 측정된 진동자료는 일본의 한 기업이 제안한 진동 추정식으로 예측한 결과와 서로 비교하였다. 공법의 경제성을 입증해 보이기 위해 간단한 비용분석 결과도 제시하였다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1997년도 춘계학술대회논문집; 경주코오롱호텔; 22-23 May 1997
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• pp.229-234
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• 1997

The dynamic behavior of underground structures is complex due to the effects of vibrational characteristics of the structure and the rock. In this study, dynamic displacement responses at the structure surface by the elastic stress waves are considered as the vibrational characteristics, and evaluated by the form of the frequency spectrum. The variation of the vibrational characteristic is simulated by numerical analysis at the case of the structure has internal defections. The results reveals the possibility of the experimental detection of void existence and size. Furthermore, the verification of the dynamic response can be used for rating the stability of a tunnel.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 춘계학술대회논문집
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• pp.821-826
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• 2003

Leaks in underground pipelines can cause social, environmental and economical problems. One of a good contermeasures of leaks Is to find and repair of leak points of pipes. Leak noise is a good source to identify the location of leak points of pipelines. Although there have been several methods to detect the leak location with leak noise, such as listening rods, hydrophones or ground microphones, they were not so efficient tools beca. In this paper, two accelermeters are used to detect leak locations which could provide an easier and efficient method. The filtering, signal processing and algorithm is described for the detection of leak location. A 120m-long pipeline system for experiment is installed and the results with the system show that the algorithm with the two accelerometers gives very accurate pinpointing of leaks. Theoretical analysis of sound wave propagation speed in underground pipes is also described.

• 화약ㆍ발파
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• 제23권4호
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• pp.1-18
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• 2005

고준위폐기물 처분시스템의 거동 실증을 위해 한국원자력연구소내에 추진되고 있는 지하처분연구시설은 고성능 폭약을 이용한 발파 기법에 의해 지하 화강암반내에 건설된다. $6m{\times}6m$ 크기의 터널을 굴착하기 위한 발파에 의한 진동 및 소음이 인접한 연구시설 및 하나로 원자로에 영향을 예측하기 위한 시험 발파가 실시되었다. 시험발파를 통해 얻어진 발파진동식을 이용한 원자력연구소내 주요시설에 대한 발파영향을 평가결과 설계기준에 비해 훨씬 낮은 것으로 파악되었다. 굴착 진행에 따른 소음, 진동값을 측정하였으며 진동값의 경우 발파진동식으로 추정한 값보다 더 낮게 나타났다. 따라서 원자력연구소내 지하에 280m 규모의 처분연구시설을 건설하기 위한 발파작업으로 연구소내 주요 시설에 미칠 영향은 미미할 것으로 판단된다.

• Steel and Composite Structures
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• 제22권5호
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• pp.1039-1054
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• 2016

This paper presents the dynamic characteristics analysis of the purlin-sheet roofs by the random vibration theories. Results show that the natural vibration frequency of the purlin-sheet roof is low, while the frequencies and mode distributions are very intensive. The random vibration theory should be used for the dynamic characteristics of the roof structures due to complex vibration response. Among the first 20th vibration modes, the first vibration mode is mainly the deformations of purlins, while the rest modes are the overall deformations of the roof. In the following 30th modes, it mainly performs unilateral local deformations of the roof. The frequency distribution of the first 20th modes varies significantly while those of the following 30th modes are relatively sensitive. For different parts, the contributions of vibration modes on the vibration response are different. For the part far from the roof ridge, only considering the first 5th modes can reflect the wind-induced vibration response. For the part near the ridge, at least the first 12 modes should be considered, due to complex vibration response. The wind vibration coefficients of the upwind side are slightly higher than that of the leeward side. Finally, the corresponding wind vibration coefficient for the purlin-sheet roof is proposed.

• 한국전산유체공학회지
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• 제17권1호
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• pp.36-43
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• 2012

When a high-speed train passes an underground station, large pressure waves are generated due to the piston effect. These pressure waves can cause the problems of vibration and noise as well as the ear discomfort of passengers at the underground station. This work numerically analyzed the pressure wave generation and propagation in an high-speed railway underground station, and the optimal location for vent shafts was studied to improve the passenger comfort by reducing the magnitude of the pressure wave and its rate of change. The evolution of pressure field in the underground station was calculated using a CFD(Computational Fluid Dynamics) software(Fluent), where the axis-symmetric two-dimensional model verified by Wu was used. And this study is applied to modelling of the underground station and the tunnel from Daegok station A-line of GTX(Great Train Express). From the result, we can have a conclusion that the role of vent shafts respectively were different according to the position in and out the underground station. Also Vent shaft in the underground station widely reduced pressure magnitude. And vent shaft out underground station reduced initial pressure peak value. Double vent shafts installed at tunnel toward station entrance and inside of the tunnel are the most efficient to reduce pressure. and pressure reduction increases according to the number of vent shaft.