• 제목/요약/키워드: Lateral stability

검색결과 835건 처리시간 0.026초

지하공동의 형상과 규모가 공동의 안정성에 미치는 영향 연구 (A Study on the Shape and Size Effects on the Stability of Underground Openings)

  • 박상찬;문현구
    • 한국지반공학회지:지반
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    • 제14권1호
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    • pp.93-108
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    • 1998
  • 본 연구에서는 지하공동의 형상과 규모가 공동의 안정성에 미치는 영향을 이론적 해석법과 수치 해석법을 이용하여 평가하였다. 지하 공동의 안정성에 영향을 미치는 제반요소들 중에서 암질, 초기응력의 크기 및 방향 그리고 측압계수가 공동주위에 발생하는 변위, 응력집중 그리고 소성영역의 크기와 범위에 미치는 영향을 중심으로 안정성을 평가하였다. 이론적 해석법을 이용하여 공동 벽면의 형상변화에 따른 응력집중계수의 변화를 분석하였으며 공동 벽면에서의 응력집중계수는 벽면의 곡률반경에 반비례하여 나타났다. 수치 해석법을 이용한 매개변수연구를 통하여 공동의 형상과 크기 변화에 따라서 제반요소들이 나타내는 특징들을 비교 평가하였다. 위 제반요소들이 나타내는 특징들을 지하비축공동 형상으로 널리 사용되고 있는 마제형 공동에 적용하여 측압계수와 공동단면의 비가 공동주위에 발생하는 최대변위의 변화 및 소성영역의 발달 양상에 미치는 영향을 평가하였다. 본 연구를 통하여 현재 건설되고 있는 국내 지하저장공동의 공동단면의 비는 공동이 위치할 현장의 측압계수조건에 따라서 안정성의 커다란 문제 없이도 공동의 높이 증가에 의한 공동의 단면적 증가가 경제적으로 가능함을 알수 있었다.

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젊은 성인 여성의 휴대 가방 위치가 보행 후 정적 균형 변화에 미치는 영향 (The Effect of Changes in Young Women's Static Balance after Performing Walking Task with Different Carrying Bag Positions)

  • 김진섭;김경;전덕훈
    • 대한물리의학회지
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    • 제6권1호
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    • pp.51-58
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    • 2011
  • Purpose : This study was designed to identify the effects of carrying bag positions (None, left hand, right hand, left shoulder, right shoulder) on static balance. Methods : Fourteen healthy adult females participated in the this study. The exclusion criteria were orthopedic or neurologic disease, predominant left side. Measurements were performed initial effects. Results were evaluated by OSI, APSI, and MLSI in the biodex stability system. Results : There are among the three assessments (overall stability index(OSI), antero-posterior stability index (APSI), medio-lateral stability index(MLSI) significants difference for the carrying bags positions (None bag, left hand, right hand, left shoulder, right shoulder)(p<.05). The post-hoc test revealed a significant difference between none bag and both left hand and left shoulder in the OSI, APSI, MLSI (p<.05). Also, comparing the carrying positions significant difference between right hand and both left hand and left shoulder in the MLSI (p<.05). Conclusion : The results suggest that none dominant side with carrying bag improve more imbalance than none bag and right hand of dominant with carrying bag improve more balance than non dominant side. When comparing the four carrying bag conditions, right hand was more effective than another conditions in static balance.

Effects of Kinesio Taping and Massage Application to Calf Muscle on Ankle Stability

  • Kim, Chan-Woo;Roh, Hyo-Lyun
    • 대한물리의학회지
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    • 제13권4호
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    • pp.35-42
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    • 2018
  • PURPOSE: This study was conducted to investigate the effects of Kinesio taping and massage application to the calf muscles on ankle stability. METHODS: The study subjects were 66 healthy adults (male: 32, female: 34) who had no instability in their ankles. Subjects were randomly assigned to a Kinesio taping group or a massage group. The research tool used the Y-balance test to measure instability of the ankle. The distance between the right and left foot was measured from the center in the anterior, posterior-medial, and posterior-lateral directions. Massage was applied to the calf muscles three times over two weeks and Kinesio tape was attached to the calf muscle and tibialis anterior for 10 hours twice during the experimental period. RESULTS: The results showed that application of Kinesio taping resulted in increases in the distance between the feet increased in some directions. After the massage, the distance extended from the anterior and posterior-lateral directions was prolonged, and the ankle stability on the right and left sides was partially improved by massage application. CONCLUSION: Kinesio taping and massage applied to the calf muscles are appropriate interventions for the improvement of ankle stability. Based on the application times of massage, Kinesio taping appears to work more effectively for ankle stability.

Improved refined plastic hinge analysis accounting for local buckling and lateral-torsional buckling

  • Thai, Huu-Tai;Kim, Seung-Eock;Kim, Jongmin
    • Steel and Composite Structures
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    • 제24권3호
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    • pp.339-349
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    • 2017
  • In this paper, a conventional refined plastic hinge analysis is improved to account for the effects of local buckling and lateral-torsional buckling. The degradation of flexural strength caused by these effects is implicitly considered using practical LRFD equation. The second-order effect is captured using stability functions to minimize modeling and solution time. An incremental-iterative scheme based on the generalized displacement control method is employed to solve the nonlinear equilibrium equations. A computer program is developed to predict the second-order inelastic behavior of space steel frames. To verify the accuracy and efficiency of the proposed program, the obtained results are compared with the existing results and those generated using the commercial finite element package ABAQUS. It can be concluded that the proposed program proves to be a reliable and effective tool for daily use in engineering design.

사이드 비어러 가 있는 보기 의 安定性 및 커브 走行性能 (Stability and Curving Performance of Bogies Having Side Bearer)

  • 임진수
    • 대한기계학회논문집
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    • 제8권6호
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    • pp.526-535
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    • 1984
  • 본 연구에서는 개인용 컴퓨터 정도를 사용하여서도 각 성능을 계산할 수 있고 또 실제 상황이 비교적 잘 반영될 수 있는 모델을 채택하였다. 한편으로 이 모델의 적합성 여부도 검토하여 해석 결과의 적용한계를 추측하고져 하였다.

장대레일궤도의 온도좌굴에 영향을 미치는 매개변수 연구 (Parametric Study on Thermal Buckling of CWR Tracks)

  • 최동호;김호배
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2001년도 춘계학술대회 논문집
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    • pp.295-302
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    • 2001
  • The lateral stability of curved continuous welded rail (CWR) is studied fur buckling prevention. This study includes the influences of vehicle induced loads on the thermal buckling behavior of straight and curved CWR tracks. quasi-static loads model is assumed to determine the uplift region, which occurs due to the vertical track deformation induced by wheel loads of vehicle. Parametric numerical analyses are performed to calculate the upper and lower critical buckling temperatures of CWR tracks. The parameters include track lateral resistance, track curvature, longitudinal stiffness, tie-ballast friction coefficient, axle load, truck center spacing, and the ratio of lateral to vertical vehicle load. This study provides a guideline for the improvement or stability for dynamic buckling in on tracks.

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측방유동 연약지반상 교대의 안정성 (Stability of Bridge Abutments on Soft Ground Undergoing Lateral Flow)

  • 홍원표;송영석;신도순;손규만
    • 한국지반공학회논문집
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    • 제17권4호
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    • pp.199-208
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    • 2001
  • 본 연구의 목적은 교대가 설치된 지반의 사면안전율과 교대측방변위의 관계를 분석하여 교대의 측방이동 판정기준을 마련하고자 함에 있다. 이를 위하여 국내의 연약지반에 설치된 30개 교대의 측방이동사례를 조사하고, SLOPILE (Ver 2.0)프로그램을 이용하여 교대의 측방변위와 교대기초말뚝의 사면안정효과를 고려한 사면안정해석을 실시한다. 해석결과 교대기초말뚝의 실측측방변위를 고려할 경우 1.8이상 되어야 한다. 또한, 교대기초말뚝의 허용측방변위량에 따른 사면안정 해석결과, 교대의 허용측방변위가 작게 규정될수록 사면안정성에 기여하는 말뚝의 효과는 감소하고 있음을 알 수 있다.

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타워크레인 로프가잉 안정성 검토에 관한 연구 (A Study on the Stability of Rope Guying of Tower Cranes.)

  • 이원석;호종관;김선국
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2009년도 추계 학술논문 발표대회
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    • pp.247-252
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    • 2009
  • With the increasing use of tower cranes higher than free standing height, the importance of lateral support is also growing. Since the fall of 43 tower cranes hit by the last typhoon 'Mami' in 2003, regulations and concerns about safety of construction equipment have increased and construction laws regarding lateral support have been strengthened. In Korea, where there are many large-scale apartment housing construction works with the development of new towns, Rope Guying is a more economical construction method than Wall Brace which fixes building structure like building wall and slab. The safety of this Rope Guying is not verified and many construction works are still carried out based on the experience of site managers. There has been no case of construction work where frame and measurements are applied. The objective of this study is to examine the safety of Rope Guying method and ensure the effective implementation of equipment and prevention of disasters.

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Effects of Relief Shelves on Stability of Retaining Walls

  • Ahn, Taebong
    • 한국지반환경공학회 논문집
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    • 제23권9호
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    • pp.25-31
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    • 2022
  • Attaching shelf to retaining structure leads to a decrease in the total lateral earth pressure. This decrease enables the retaining structures to become more stable, to have small displacement, and to exhibit lower bending moments, the relief shelves effects are analyzed using FEM in order to understand how they stabilize cantilever wall in this study. Several models are varied by changing location and width of shelves to realize earth pressure and displacements of retaining wall. The displacement is getting smaller because earth pressure acting on shelf increases as shelves locations are lower and width is longer. The ground settlement variation effects caused by relief shelves are studied also. The ground settlement increases abruptly where shelf location is between of 0.5H and 0.625H, and settlement decreases suddenly where shelf width is between b/h=0.375 and b/h=0.500. The shelf significantly reduces earth pressure and movement of the wall. This decrease in the lateral pressure increases the retaining structure stability.

도상직업에 의한 도상 횡저항력 변화 (Variation of Lateral Ballast Resistance due to Ballast Work)

  • 임남형;황성호;이지하;양신추
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2004년도 춘계학술대회 논문집
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    • pp.961-966
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    • 2004
  • Lateral ballast resistance is one of track components that causes much effects in track buckling. Ballast work or tie renewal if is done the ballast original lateral resistance lose. Reduction of lateral ballast resistance may significantly reduce the stability of track. Lateral ballast resistance that is decreased by these work increases slowly according to the increase of train passing tonnage. We measured the ballast lateral resistance in Okchon station neighborhood in Seoul-Busan line to grasp fluctuation phenomenon of ballast resistance by ballast class-2 work. The rate of decrease of ballast lateral resistance shortly after ballast work and the rate of increase by increase of train passing tonnage were investigated.

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