• 제목/요약/키워드: Civil Movement

검색결과 583건 처리시간 0.025초

유한 요소법을 이용한 중소하천 유역에서의 이동호우에 대한 유출특성 분석

  • 조현경;이영화;최윤영
    • 한국환경과학회지
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    • 제7권4호
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    • pp.415-424
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    • 1998
  • In the rainfalll-runoff relation, consideration of the spatial movement of storms is very unportant in designing a hydraulic structure or evaluating an environmental influence for land usage. Because of thins reason, this study has suggested the finite element model which consider the spatial movement of a storm and it was applied on a small river basin(Wi stream basin). In the application of the model, the basin was treated as a pivot point and the storms are simulated 10 movement in each directions. As a result, It shows that the storms moving from north to south have higher peak discharge and faster peak time than the storms moving in other directions. So these characteristics have to be considered In the designation of a hydraulic structure or evaluation of an environmental influence.

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Numerical investigation of floating breakwater movement using SPH method

  • Najafi-Jilani, A.;Rezaie-Mazyak, A.
    • International Journal of Naval Architecture and Ocean Engineering
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    • 제3권2호
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    • pp.122-125
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    • 2011
  • In this work, the movement pattern of a floating breakwater is numerically analyzed using Smoothed Particle Hydrodynamic (SPH) method as a Lagrangian scheme. At the seaside, the regular incident waves with varying height and period were considered as the dynamic free surface boundary conditions. The smooth and impermeable beach slope was defined as the bottom boundary condition. The effects of various boundary conditions such as incident wave characteristics, beach slope, and water depth on the movement of the floating body were studied. The numerical results are in good agreement with the available experimental data in the literature The results of the movement of the floating body were used to determine the transmitted wave height at the corresponding boundary conditions.

변형연화모델을 이용한 미고결 지반의 터널변형 (Tunnel Deformation in Shallow Unconsolidated Ground by Using Strain-Softening Model)

  • 서인식;김병탁
    • 한국산업융합학회 논문집
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    • 제10권2호
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    • pp.81-88
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    • 2007
  • In case of an urban tunnel, the displacement of ground base controls the tunnel design because it is built on shallow and unconsolidated ground many times. There are more insufficiency to describe the ground movement which coincides in the measured result of the situ because the design of an urban tunnel is dependent on the method of numerical analysis used to the existing elastic and elasto-plastic models. We studied about the prediction for the ground movement of a shallow tunnel in unconsolidated ground, mechanism of collapse, and settlement. Also this paper shows comparison with the existing elastic and elasto-plastic model using the unlinear analysis of the strain-softening model. We can model the real ground movement as the increasement of ground surface inclination or occurrence of shear band by using strain-softening model for the result of ground movement of an urban NATM tunnel.

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Shrinkage movement analysis of reinforced concrete floors constructed in stages

  • Kwan, A.K.H.;Ng, P.L.
    • Computers and Concrete
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    • 제6권2호
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    • pp.167-185
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    • 2009
  • Reinforced concrete floors constructed between movement restraints often crack seriously due to shrinkage after completion. One common mitigation measure is to construct the concrete floors in stages to allow part of the shrinkage movement to take place before completion. However, shrinkage movement analysis of concrete floors constructed in stages is quite cumbersome, as the structural configuration changes during construction, thus necessitating reanalysis of the partially completed structure at each stage. Herein, a finite element method for shrinkage movement analysis of concrete floors constructed in stages is developed. It analyses the whole structure, including the completed and uncompleted portions, at all stages. The same mesh is used all the time and therefore re-meshing and location matching are no longer necessary. This is achieved by giving negligibly small stiffness to the uncompleted portions, which in reality do not exist yet. In the analysis, the locked-in strains due to increase in elastic modulus as the concrete hardens and the creep of the hardened concrete are taken into account. Most important of all, this method would enable fully automatic shrinkage movement analysis for the purpose of construction control.

액상화된 지반의 점성 유체 특성과 그 흐름이 말뚝의 거동에 미치는 영향 분석 (Viscous fluid characteristics of liquefied soils and behavior of pile subjected to flow of liquefied soils)

  • 황재익;김창엽;정충기;김명모
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2004년도 춘계학술발표회
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    • pp.722-729
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    • 2004
  • The horizontal movement of sloping ground due to flow liquefaction has caused many pile foundations to fail, especially those in ports and harbor structures. In this study, a virtual case is assumed in which flow liquefaction is induced by earthquake loads in a fully saturated infinite sand slope with a single pile installation. Under the assumption that the movement of liquefied ground is viscous fluid flow, the influence of ground movement due to flow liquefaction on the pile behavior was analyzed. Since the liquefied soil is assumed as a viscous fluid, its viscosity must be evaluated, and the viscosity was estimated by the dropping ball method ,md the pulling bar method. Finally, the influence of the flow of liquefied soil on a single pile installed in an infinite slope was analyzed by a numerical method.

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First Results of GPS Measurements Along the Lai Chau - Dien Bien Fault in North-West Vietnam

  • DUONG Chi Cong;YUN Hong-Sic;CHO Jae-Myong;LEE Dong-Ha
    • Korean Journal of Geomatics
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    • 제5권1호
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    • pp.51-58
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    • 2005
  • GPS measurements from Feb. 2002 through Mar. 2004 were used to estimate recent crustal movement across the Lai Chau - Dien Bien fault system in North-West Vietnam. Four GPS campaign data were processed and combined with appropriate constraints using automatic GAMIT/GLOBK run in order to estimate ITRF2000 coordinates, local horizontal velocity and extensive/compressive strain rates. ITRF2000 velocities are consistent with east-southeastward movement of Sundaland i.e. Indochina. Local velocities show not much left-lateral strike-slip of the fault system and derived strain rates are insignificant from zero at $95\%$ confidence.

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Static and dynamic responses of a tied-arch railway bridge under train load

  • Gou, Hongye;Yang, Biao;Guo, Wei;Bao, Yi
    • Structural Engineering and Mechanics
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    • 제71권1호
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    • pp.13-22
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    • 2019
  • In this paper, the static and dynamic responses of a tied-arch railway bridge under train load were studied through field tests. The deflection and stresses of the bridge were measured in different static loading scenarios. The dynamic load test of the bridge was carried out under the excitation of running train at different speeds. The dynamic properties of the bridge were investigated in terms of the free vibration characteristics, dynamic coefficients, accelerations, displacements and derailment coefficients. The results indicate that the tie of the measuring point has a significant effect on the vertical movement of the test section. The dynamic responses of arch bridge are insensitive to the number of trains. The derailment coefficients of locomotive and carriage increase with the train speed and symmetrically distributed double-line loads reduce the train derailment probability.

매립지반 지하공동구의 수평이동원인에 대한 수치해석적 분석 (Numerical Analysis of Utility Tunnel Movement under Reclamation Ground)

  • 윤우현;황철성
    • 한국안전학회지
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    • 제28권5호
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    • pp.35-40
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    • 2013
  • Recently reclamation land is largely developed to utilize the land according to economic growth. The soil of landfill is soft, low shear strength, which makes it difficult to use the equipment. A large movement is occurred on the utility tunnel under construction. The inclined land with high water level and underground facilities are widely distributed and the excess pore water pressure may occur under construction similarly to this study. Some different conditions are made to design result, such as 4m of soil piling near the construction area, heavy rainfall during 2nd excavation that may cause flow liquefaction. To analyze the cause of transverse lateral movement, Three dimensional analysis are performed to four load cases, which is original design condition, flow liquefaction by heavy rainfall, unsymmetric lateral soil pressure, and both of them simultaneously. Ten steps of full construction stage, 1st excavation for utility tunnel, construction of utility tunnel, 1st refill, piling soil from 1m to 4 m, 2nd excavation for drainage culvert, liquefaction around the utility tunnel, construction of drainage culvert and 2nd refill, are take into account to investigate the cause of movement.

수치모형을 이용한 하상변동 연구 (A Study on the Sediment Movement Using Numerical Models)

  • 임창수;손광익;이재준;윤세의
    • 한국수자원학회논문집
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    • 제32권2호
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    • pp.131-142
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    • 1999
  • 본 연구에서는 금강 부여취수구를 중심으로 한 금강본류의 상하류에 대한 수리적 특성 및 유사론적 특성을 파악하기 위하여 1차원 및 준2차원 수치해석적 유사모의 분석을 실시하였다. 1차원 유사이동 수치모형 모의분석은 HEC-6를 사용하였으며 준2차원 유사이동 수치모형 모의분석은 GSTARS를 이용하여 1988년부터 1996년까지에 대한 유사이동 수치모형 모의분석을 실시하여 프로그램의 현장 적용가능성을 분석한 후 1988년부터 2001년까지에 대한 예측을 통하여 금강 부여취수탑 주변에 대한 유사이동 현황분석을 실시하였다. 1988년 실측된 하상 실측 자료를 초기 하상자료로 하여 13년 후인 2001년의 장기하상변동을 예측한 결과 전체적으로는 금강본류를 따라 퇴적 및 침식이 반복되는 현황을 보이고 있고 금강 부여취수구 주변 및 취수구 하류부근에서는 최심하상고가 높아져 계속 퇴적되는 추세를 보여주고 있었다.

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모래지반에서 측방변형을 받는 무리말뚝의 실험적 연구 (The Study of Group Piles under Lateral Soil Movement in Sand by Model test)

  • 배종순;김성호;권민재
    • 한국지반공학회논문집
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    • 제22권10호
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    • pp.165-172
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    • 2006
  • 본 연구에서는 합천사에 매설되어 측방변형을 받는 무리말뚝의 거동특성을 분석하였다. 무리말뚝의 위치, 말뚝의 간격과 말뚝배열이 미치는 무리말뚝의 영향을 알고자 하였다. 실험결과는 다음과 같다. 무리말뚝에서는 모멘트 형상은 단독말뚝과 유사하나 최대 휨모멘트의 발생깊이가 깊어지고, 그 크기는 감소하였다. 말뚝의 중심간격이 증가할수록 최대휨모멘트비$(R_M)$와 수평력분담비$(R_F)$는 증가하였다. 지반변형에 따른 $R_M$은 열방향에서는 후열, 전열, 중간열의 순으로 크게 나타났고 줄방향에서는 내측보다 외측이보다 크게 나타났다.