• 제목/요약/키워드: horizontal stability

검색결과 647건 처리시간 0.025초

해안 구조물에 작용하는 부유체의 충격력에 관한 연구(I) - 연직원주에 작용하는 수평력 - (A study on the Impact force of floating body which acts on near shore structures - On the horizontal force acts on the vertical circular piles -)

  • 양윤모;김병욱;김도삼
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 1982년도 제24회 수공학 연구발표회 논문초록집
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    • pp.105-120
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    • 1982
  • The circular cylindrical piles are extensively used in near shore structures. For the purpose of analysing stability of vertical pile, we must consider the horizontal force, the lift force, and the traverse force etc. In this paper author studied horizontal force acts on the vertical circular pile and investigated the relation between the floating body coefficients C$$ and U$$T/D.

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HARMONIC MORPHISMS AND STABLE MINIMAL SUBMANIFOLDS

  • Choi, Gundon;Yun, Gabjin
    • Korean Journal of Mathematics
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    • 제14권1호
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    • pp.13-33
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    • 2006
  • In this article, we study the relations of horizontally conformal maps and harmonic morphisms with the stability of minimal fibers. Let ${\varphi}:(M^n,g){\rightarrow}(N^m,h)$ be a horizontally conformal submersion. There is a tensor T measuring minimality or totally geodesics of fibers of ${\varphi}$. We prove that if T is parallel and the horizontal distribution is integrable, then any minimal fiber of ${\varphi}$ is volume-stable. As a corollary, we obtain that any fiber of a submersive harmonic morphism whose fibers are totally geodesics and the horizontal distribution is integrable is volume-stable. As a consequence, we obtain if ${\varphi}:(M^n,g){\rightarrow}(N^2,h)$ is a submersive harmonic morphism of minimal fibers from a compact Riemannian manifold M into a surface N, T is parallel and the horizontal distribution is integrable, then ${\varphi}$ is energy-stable.

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실내 진동대 실험을 통한 하구둑 구조물의 내진 안정성에 관한 연구 (A Study on Stability of Earthquake in Estuary Barrage through Shaking Table Test)

  • 신은철;강현회;류병현
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2010년도 추계 학술발표회 2차
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    • pp.38-44
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    • 2010
  • Shaking table tests were performed to reproduce the dynamic behavior of estuary barrage and its subbase soil which can be potentially damaged during earthquake loading. For understanding the vibration effect to the ground during earthquake, the model was formulated with 1/300 scale of prototype estuary barrage and subbase soil. Scott and Iai(1989) proposed the law of the similarity for similar experimental conditions. The laboratory model shaking table test was conducted under the vibration condition of simulated earthquake of 0.154g. The horizontal displacement on the structure was measured during the shaking table test. The pore water pressure was also monitored for the underground layers of soil. The field horizontal displacement and the pore water pressure can be predicted by using the results of the laboratory shaking table test.

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이중 아웃리거 구조 시스템의 한계 세장비에 대한 연구 (Study on the Limit Slenderness of a Double Outrigger System)

  • 양재광;강호근;박성수
    • 대한건축학회논문집:구조계
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    • 제34권3호
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    • pp.11-18
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    • 2018
  • Due to the recent overpopulation of urban cities, land shortage and soaring land prices have caused an increase in the demand for high-rise buildings. To build buildings on a limited land, the size of the building is important. Displacement control by horizontal loads in a skyscraper is critical to securing stability and usability of structures. Several systems have been proposed for efficient horizontal displacement control, and so far the study continues. Among them, the Outrigger System is a representative of the typical horizontal load resistance system. Although studies have been conducted so far to locate the optimal position of the outrigger, studies of the slenderness ratio of the buildings are still insufficient. Based on the Outrigger-Optimized Position equation, this study induces the calculation of the displacement of the outrigger installation building according to the slenderness ratio.

Three-dimensional stability assessment of slopes with spatially varying undrained shear strength

  • Shi, Yunwei;Luo, Xianqi;Wang, Pingfan
    • Geomechanics and Engineering
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    • 제31권4호
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    • pp.375-384
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    • 2022
  • The variation of the undrained shear strength (cu) is an important consideration for assessing slope stability in engineering practice. Previous studies focused on the three-dimensional (3D) stability of slopes in normally consolidated clays generally assume the undrained shear strength increases linearly with depth but does not vary in the horizontal direction. To assess the 3D stability of slopes with spatially varying undrained shear strength, the kinematic approach of limit analysis was adopted to obtain the upper bound solution to the stability number based on a modified failure mechanism. Three types failure mechanism: the toe failure, face failure and below-toe failure were considered. A serious of charts was then presented to illustrate the effect of key parameters on the slope stability and failure geometry. It was found that the stability and failure geometry of slopes are significantly influenced by the gradient of cu in the depth direction. The influence of cu profile inclination on the slope stability was found to be pronounced when the increasing gradient of cu in the depth direction is large. Slopes with larger width-to-height ratio B/H are more sensitive to the variation of cu profile inclination.

실험계획법과 최적화알고리듬을 이용한 터널지보의 파손하중 예측 (Failure Load Prediction of Tunnel Support using DOE and Optimization Algorithm)

  • 이동우;조석수
    • 한국산학기술학회논문지
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    • 제13권4호
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    • pp.1480-1487
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    • 2012
  • 최근, 국내 탄광의 안전성이 향상되고 있으나 사고는 꾸준히 발생하고 있다. 대부분의 터널 지보는 I빔과 I빔을 연결하는 이음판 부분에서 지압을 견디지 못하고 파손이 발생한다. XX 탄광의 경우, 터널지보의 아치부가 일반적인 굽힘 거동이 아닌, 위쪽 방향으로 굽힘이 발생하고 있다. 이러한 경우는 터널지보에 수직하중 이외에 수평하중이 과대하게 작용하는 경우로 볼 수 있으며 이러한 수평하중은 지하암반의 급격한 변화에 의한 암반의 이완범위의 증가나 지하수의 누출 등으로 인한 수리학적인 요인 등의 복합적인 문제가 작용하여 나타난다. 따라서 본 연구에서는 위쪽 방향으로 굽힘을 일으키는 수평하중의 크기를 추정하기 위하여 실험계획법과 최적화 알고리듬을 적용하여 터널지보의 굽힘거동을 규명하였다.

연약지반상 고성토 교대구간의 지반거동 특성 (Characteristics of Ground Movement in High Filling Abutment on Soft Ground)

  • 허열;송석철;안광국;오승탁;서상구
    • 한국지반환경공학회 논문집
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    • 제9권7호
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    • pp.13-23
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    • 2008
  • 본 연구에서는 모래다짐말뚝으로 개량된 점성토 지반에 고성토시 발생될 수 있는 측방유동과 교대의 안정성을 파악하기 위하여 원심모형실험과 수치해석을 수행하였다. 원심모형실험과 수치해석은 교대 배면구간을 EPS로 성토한 경우(Case 1)와 토사로 성토한 경우(Case 2)에 대하여 수행하였으며, 모형실험시 교대와 성토체에 potentiometer를 설치하여 교대상부의 수직변위와 수평변위 및 성토체의 수직변위를 측정하였다. 원심모형실험결과 Case 1에서 교대의 수평변위는 1.4cm 정도로 해석결과와 거의 일치하며, 허용기준을 만족하는 것으로 나타났다. 반면, Case 2에서 교대의 수평변위는 12cm 정도로 해석결과에 비해 18% 정도 크게 평가되었으며, 허용기준을 초과하는 것으로 나타났다. 해석결과 Case 1에서 말뚝의 최대수평변위는 1.26cm로 허용 수평변위 기준(1.5cm)을 만족하는 것으로 나타난 반면, Case 2에서 말뚝의 최대 수평변위는 1.005m로 허용기준을 크게 초과하는 것으로 나타났다.

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연약지반 개량후 교대구간 수평지반반력계수 적용 사례 (Application of Horizontal Subgrade Reaction Modulus to Bridge Abutment Design after Soil Improvement)

  • 김경태;박시범;김창현;이종범;윤여원
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2006년도 춘계 학술발표회 논문집
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    • pp.1228-1236
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    • 2006
  • In soft ground, There are many case that Bridge Abutment is constructed after soil improvement in order to reduce the Negative Friction and prevent from Lateral Soil movements of Bridge Abutment. That section of Horizontal Subgrade Reaction $Modulus(K_h)$ derivation has much important mean due to Horizontal Stability of Abutment. It is come from behavior of Pile and Soil within depth of $1/\beta$. After Soil Improvement, however, If Bridge Abutment was construction, It's not impossible to carry out Field Investigation After Ground of Improved at design stage. Therefore, It's not able to derivate Horizontal Subgrade Reaction $Modulus(K_h)$. Therefore, in this case of study compare with Field Construction Test Data in order to derivation of Horizontal Subgrade Reaction $Modulus(K_h)$ and Reliability in terms of ground of Bridge Abutment by Sand Compaction Pile(SCP) during design of The 2nd Bridge Connection Road of Incheon International Airport. In this paper determine, Soil Property(The rate of strength increase, $c_u$ so on) and Horizontal Subgrade Reaction $Modulus(K_h)$ after soil improvement at design stage.

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종곡선/평면곡선 경합여부에 따른 최적평면선형조건 및 승차감 비교 분석 (Comparative Study on Ride Comfort and Optimum Horizontal Curve Conditions for Superimposition of Vertical and Horizontal Curve)

  • 엄주환;최일윤;양신추;이일화;김만철
    • 한국철도학회논문집
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    • 제13권6호
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    • pp.589-594
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    • 2010
  • 철도에서 평면곡선과 종곡선의 경합은 승차감 및 열차의 주행안전성을 저해시키는 원인이 되며, 유지보수비용에도 큰 영향을 미친다. 그러나 철도노선 계획 시 지형조건 및 예기치 않은 환경적 요인에 의해 선형경합이 필요하게 될 경우가 발생된다. 본 연구에서는 종곡선과 평면곡선의 경합이 곡선부에서의 승차감 및 평면곡선의 최적선형조건에 미치는 영향을 파악하고자 하였다. 이를 위해 평면곡선과 종곡선이 경합하였을 경우와 경합하지 않고 평면선형만 있을 경우에 대한 최적캔트량 및 승차감을 비교분석 하였으며, 고속영역에서 선형 경합이 곡선선형조건과 승차감에 미치는 영향을 검토하였다. 그 결과 경합한 경우라도 보정캔트를 부설한다면 승차감 측면에서 평면선형만 부설한 경우와 유사한 조건이 될 수 있음을 알 수 있었다.

건축 구조체를 이용한 개량 역타공법 적용시 흙막이 벽체의 거동 연구 (A Study on the Behavior of the Retaining Walls with the Improved Top-Down Support System using the Building Structure)

  • 천병식;노배영;도종남;유우현
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2008년도 추계 학술발표회
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    • pp.1666-1672
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    • 2008
  • In this study, it collected and analyzed a construction case of the improved top-down support system application field on a case by case retaining wall method. The behavior of horizontal displacement was analyzed according to retaining wall type after reviewing a design stage and estimated horizontal displacement under the construction. The study results showed that it is judged stable until excavation termination irrelevant to a retaining wall method at the improved top-down support system application. It is judged that the settlement of behind ground can minimize because the retaining wall head displacement also behave stably. It was compared the predicted horizontal displacement in design and the measured horizontal displacement acquired through a measurement by using Elasto-Plastic analysis program. The comparison results showed that a similar horizontal displacement was predicted within stability standard irrelevant to a retaining wall method. So, it is decided that the advanced prediction is reasonable by Elasto-Plastic analysis in design applied the improved top-down support system. In the case of the ground anchor method application under a same condition, it is decided that a horizontal displacement will more increase than the improved top-down support system is applied. If a section condition is same, it was decided that to apply top-down support system is more stable than that.

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