• 제목/요약/키워드: Ground-test simulation

검색결과 337건 처리시간 0.029초

Evaluation of artificial ground freezing behavior considering the effect of pore water salinity

  • Gyu-Hyun Go;Dinh-Viet Le;Jangguen Lee
    • Geomechanics and Engineering
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    • 제39권1호
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    • pp.73-85
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    • 2024
  • There is growing interest in introducing artificial ground freezing (AGF) as a method to temporarily secure unstable ground during tunnel construction. In order to efficiently operate an artificial ground freezing system, basic modeling research is needed on the changes in freezing behavior according to various soil environmental conditions as well as design conditions. In this study, a thermal-hydraulic coupled analysis was performed to simulate the artificial ground freezing process of ground containing salt water. The effect of major variables, including pore water salinity, on artificial ground freezing test performance was investigated. Additionally, an artificial neural network-based prediction model was proposed to estimate the time required to achieve the desired arch thickness. The artificial neural network model demonstrated reliable accuracy (R2 = 0.9942) in predicting the time it would take to reach the desired arch thickness. Among the major input variables considered, pore water salinity appeared to be the most influential input variable, and initial soil temperature showed the least importance.

선로변 시설물 차상제어를 위한 차상중심 열차제어시스템의 통신 연속성 시험 (Communication Consecutive Test of Train Oriented Control System for Wayside Equipment Control)

  • 백종현
    • 전기학회논문지
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    • 제63권5호
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    • pp.703-712
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    • 2014
  • To improve the efficiency and safety of railway systems, the train control system has been considerably evolved from the ground-equipment-based control system (e.g. track circuit, interlocking system, etc.) into the on-board-equipment-based control system. In addition, this train control system enables the rolling stock to intelligently control the trackside facilities by introducing the information and communication technologies (ICT). Accordingly, since the ICT-based train control system makes the railway system be simplified (i.e. the heavy ground-equipment can be removed), the efficient and cost-effective railway system can be realized. In this paper, we perform the feasibility test of the ICT-based train control system via a simulation. To this end, we have developed the prototypes of the on-board controller and wayside object control units which control the point and crossing gate and performed the integrated operation simulation in a testbed. In this paper, before the field test of the on-board-controller-based train control system, we perform the Consecutive operation test for prototypes of the on-board controller, wayside object control units and local control computer.

PSD선도를 이용한 국내노면의 상관성 분석에 관한 연구 (The Study on Interrelationship Analysis of Domestic Road Using PSD)

  • 김찬중;권성진;이봉현;김현철;배철용
    • 한국소음진동공학회논문집
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    • 제16권8호
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    • pp.806-813
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    • 2006
  • An important factor of vibration test using MAST(multi axial simulation table) system is the reliance of input excitation source. Generally the generation of input excitation source is obtained by the measured data on special road in proving ground. The measured data on special road have more exciting energy than the data of real fields, therefore the time and expense for test can be reduced. But the magnitude of input excitation source must be defined by comparison with the excited energy on real field. The object of this paper makes the data base of domestic roads for the definition of input excitation source which is obtained by the measured data on special road in proving ground. These real field data on domestic roads are analyzed by the power spectral density and interrelationship index.

RTS test study and numerical simulation of mechanical properties of HDR bearings

  • Peng, Tianbo;Wu, Yicheng
    • Earthquakes and Structures
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    • 제13권3호
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    • pp.299-307
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    • 2017
  • High Damping Rubber bearings (HDR bearings) have been used in the seismic design of bridge structures widely in China. In earthquakes, structural natural periods will be extended, seismic energy will be dissipated by this kind of bearing. Previously, cyclic loading method was used mainly for test studies on mechanical properties of HDR bearings, which cannot simulate real seismic responses. In this paper, Real-Time Substructure (RTS) test study on mechanical properties of HDR bearings was conducted and it was found that the loading rate effect was not negligible. Then the influence of peak acceleration of ground motion was studied. At last test results were compared with a numerical simulation in the OpenSees software framework with the Kikuchi model. It is found that the Kikuchi model can simulate real mechanical properties of HDR bearings in earthquakes accurately.

잔교식 구조물의 응답스펙트럼 해석법 개선사항 도출 연구: 고유주기 및 입력지반가속도를 중점으로 (Study on Improvement of Response Spectrum Analysis of Pile-supported Structure: Focusing on the Natural Periods and Input Ground Acceleration)

  • 윤정원;한진태;김종관
    • 한국지반공학회논문집
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    • 제36권6호
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    • pp.17-34
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    • 2020
  • 일반적으로 잔교식 구조물의 내진설계를 위한 응답스펙트럼 해석 시 기준서들에서는 지진응답해석을 통해 증폭된 가속도를 입력가속도 활용하도록 제시하고 있으나, 기준서에 따라 방법이 상이하여 설계 시 혼란을 야기할 수 있다. 이에, 본 연구에서는 동적원심모형실험을 통해 지반 내 다양한 깊이에서 지반 가속도를 산정하였으며, 산정된 지반가 속도를 활용하여 응답스펙트럼 해석을 수행하였다. 이후 실험 및 해석을 통해 도출된 잔교식 안벽 구조물의 모멘트 결과를 비교하였으며, 응답스펙트럼 해석 시 적절한 입력지반가속도를 결정하기 위한 방법을 제시하고자 하였다. 실험 및 해석을 비교한 결과, 탄성 지반 스프링을 적용하는 경우 구조물의 고유주기를 가장 적절하게 모사하는 것으로 나타났으며, 상부 지표면에서 증폭된 지진파를 입력가속도로 활용하는 것이 사질토 지반에 관입된 구조물 응답을 가장 합리적으로 모사하는 것으로 나타났다.

이중충격파형 충격시험장비를 이용한 충격시험 결과 및 분석 (The Shock-Test Result and Analysis Using Dual-Pulse Shock Testing Machine)

  • 배종수
    • 한국군사과학기술학회지
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    • 제21권3호
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    • pp.342-348
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    • 2018
  • The important issue of equipment installed in maritime weapon system is shock survivability against underwater explosion(UNDEX). If the shock survivability of equipment should not be guaranteed, the successful mission also could not be achieved. For that reason, the shock-resistance of each equipment under UNDEX environment should be demonstrated before deployment at combat field. However, the actual UNDEX test on the ocean is too expensive to conduct. Also, it has diverse dangerous factors. The main characteristic of UNDEX is a dual-pulse shock. The vertical shock test machine able to simulate dual pulse shock signal on the ground will be introduced in this paper. The dual-pulse shock signal presented in certain shock standard was achieved with this shock-test machine on the ground. The analytical procedure to set a test condition was verified by comparing simulation result with experiment result.

축소 모의된 22.9 kV-Y 배전선로의 유도 전압에 대한 신뢰성 검증 (Verification of Reliability by the Induced Voltage of a Downscaled and Simulated 22.9kV-Y Distribution Line)

  • 김점식;최충석
    • 한국안전학회지
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    • 제30권4호
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    • pp.26-31
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    • 2015
  • The purpose of this paper is to measure the induced voltage of the downscaled and simulated overhead ground wire of a 22.9kV-Y distribution line. This study performed a test of the downscaled and simulated distribution line according to whether it is grounded or not and the value of the ground resistance. In order to verify the reliability of the data measured by the test, the data was analyzed using the Minitab 17 program. It was found that the induced voltage of the downscaled and simulated distribution line is influenced by the value of the ground resistance. It was also found that the ground resistance obtained at a certain point is closely related to whether electric poles are grounded or not. The analysis results of the measured test data with a statistical method showed that the Anderson Darling (AD) was analyzed to be the smallest as 0.188 when the ground resistance of the electric poles had been maintained at $10{\Omega}$. In addition, the P value analyzed to be 0.894 which is in the proximity of the theoretical value of 1 and verified the reliability of the test data. It could be seen that the data measured by the downscaled simulation test forms a linear graph. It is thought that if a distribution line is installed in the same manner as the downscaled, simulated distribution line, the mean induced voltage will be reduced and reliability will be increased.

구조체 접지의 전위상승에 대한 반구형 수조에 의한 측정값과 계산값의 비교 (Comparison of Theoretical Resu Its and Measured Data Using Hemispherical Water Tank Model for Potential Rise of Structure Grounding)

  • 길형준;최충석;김향곤;한운기;이복희
    • 한국조명전기설비학회:학술대회논문집
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    • 한국조명전기설비학회 2005년도 학술대회 논문집
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    • pp.111-114
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    • 2005
  • This paper presents a comparison of experimental value by hemispherical grounding simulation system and calculated value by CDEGS program for ground potential rise of structure. When a test current flowed through structure grounding electrodes, ground potential rise was measured and analyzed for types of structure using the hemispherical grounding simulation system in real time, and was computed by means of CDEGS program. The model structures were designed and fabricated with two types on a scale of one-one hundred sixty. When the experimental data were compared with the theoretical values, the similar profile was shown. Therefore, the confidence of measurement was obtained. The distributions of ground surface potential are dependent on the resistivity and absorption percentage in concrete attached to structure.

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수평 직선형 지중 열교환기 설계 방안 제안 (Suggestions of Design Method for a Horizontal Straight Ground Heat Exchanger)

  • 김민준;이승래;윤석;전준서
    • 한국지열·수열에너지학회논문집
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    • 제12권4호
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    • pp.1-7
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    • 2016
  • This paper presents a design method for the horizontal straight ground heat exchanger (GHE) based on the Kavanaugh design method. In order to examine suitability of the suggested design method, a horizontal line type GHE was installed in a steel box of which the size was $5m{\times}1m{\times}1m$ filled with dried Joomunjin standard, and a thermal response test (TRT) was conducted for 21 hours. A numerical analysis was performed for a simulation of a peak month operation and for its verification by finite element method (FEM). According to the simulation results, it was concluded that the suggested design method for a horizontal straight GHE is reliable for the estimation of a design length.