• 제목/요약/키워드: Lateral pressure

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옹벽 상단 교통하중의 분포에 따른 옹벽의 수평 토압 분석 (Analysis of Lateral Earth Pressures on Retaining Wall from Traffic Load Distribution)

  • 이기철;김동욱;정문경
    • 한국지반신소재학회논문집
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    • 제16권4호
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    • pp.43-55
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    • 2017
  • 본 연구에서는 교통시설 하부구조인 옹벽(중력식 옹벽)에 가해지는 수평토압의 크기에 교통하중이 미치는 영향을 파악하였다. 교통시설 하부구조인 옹벽에서 상부 교통하중이 옹벽 안전성에 미치는 영향에 관한 연구가 부족한 실정이다. 교통하중으로 인해 옹벽에 유발되는 수평토압은 도로의 차선 수, 차량 하중의 크기 및 옹벽으로부터 떨어진 거리 등의 영향을 받을 것이다. 따라서 이들 변수를 대상으로 수치해석한 결과, 차량하중 이격거리가 옹벽 높이보다 클 경우 수평토압의 변화는 미미하였다. 따라서 상부에 교통하중을 받는 도로옹벽 설계 시 옹벽내측으로부터 교통하중까지의 이격거리가 옹벽의 높이 내의 교통하중만을 고려하는 것이 실용적이고 합리적이다.

흡착식 소켓을 착용한 일측 대퇴절단환자의 소켓내부압력분포 (Socket Pressure Distribution of the Uni-Lateral Trans-Femoral Amputee with a Suction Socket)

  • 장윤희;양길태;임송학;문무성;김영호
    • 대한의용생체공학회:의공학회지
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    • 제19권4호
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    • pp.417-422
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    • 1998
  • 본 연구는 대퇴의족착용자의 정적중립상태 및 자유보행시에 단단부와 소케의 경계에 작용하는 압력 분포를 측정하였다. 정적중립상태에서는 단단부의 외측과 내측면과 후면에서 압력집중현상이 나타나고, 자유보행시는 이러한 압력집중이 보행중에 일정한 형태로 이동함을 알 수 있었다. 최대 소켓압력은 중간입각기나 발뒤축들림기에 외측, 내측 앞쪽, 후면에서 나타나고 있고, 소켓과 단단부 사이의 상태를 확인하는 방법중 하나로 소켓 압력 측정을 사용할 수가 있다.

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횡하중을 고려한 선체보강판넬의 압축 붕괴거동에 관한 연구 (Axial Collapse Behaviour of Ship's Stiffened Panels considering Lateral Pressure Load)

  • 고재용;박주신
    • 한국항해항만학회지
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    • 제31권3호
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    • pp.235-245
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    • 2007
  • 선체의 갑판부와 선저부 그리고 해양구조물의 기본적인 구조는 보강판이다. 보강판넬은 한쪽방향으로 위치한 보강재 혹은 종/횡 방향으로 복잡하게 위치한 구조를 이루고 있으며, 후자의 모델을 그릴리지 구조라고 부른다 선체구조설계 단계에서 선박의 종강도 평가는 가장 중요한 항목이다. 일반적으로, 극심한 해상상태에 놓인 선박의 선저부에는 호깅조건에 의해 발생되는 횡모멘트에 기인하여 압축하중이 작용하게 되며, 이와 동시에 수압하중 작용으로 인한 국부휭모멘트가 작용된다. 본 논문에서는, 구조해석 결과의 검증을 위해서 여러 가지 해석프로그램 및 현재 사용되고 있는 선급룰과의 비교를 하여 횡하중의 영향에 따른 압축최종강도에 대해 분석하고, 여러 가지 설계변수를 변화하여, 각각의 영향을 검토하고, 최종적으로 조합하중 조건에서의 횡하중의 영향에 대해서 분석하였다. 본 연구에서 얻어진 결과들은 최종한계상태설계법에 기반을 두고, 조합하중이 작용하는 선체보강판의 구조강도 거동에 대해서 하중성분에 대한 관계를 고찰하였다.

조합 하중을 받은 샌드위치 패널의 최종강도 설계식 개발 (Analytical Solution for the Ultimate Strength of Sandwich Panels under In-plane Compression and Lateral Pressure)

  • 김봉주
    • 한국해양공학회지
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    • 제33권6호
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    • pp.535-546
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    • 2019
  • The paper presents a closed-form analytical solution for the ultimate strength of sandwich panels with metal faces and an elastic isotropic core during combined in-plane compression and lateral pressure under clamped boundary condition. By using the principle of minimum potential energy, the stress distribution in the faces during uni-axial edge compression and constant lateral pressure was obtained. Then, the ultimate edge compression was derived on the basis that collapse occurs when yield has spread from the mid-length of the sides of the face plates to the center of the convex face plates. The results were validated by nonlinear finite element analysis. Because the solution is analytical and closed-form, it is rapid and efficient and is well-suited for use in practical structural design methods, including repetitive use in structural optimization. The solution applies for any elastic isotropic core material, but the application that stimulated this study was an elastomer-cored steel sandwich panel that had excellent energy absorbing and protective properties against fire, collisions, ballistic projectiles, and explosions.

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.

인접 구조물의 터파기로 인한 흙막이 벽체의 거동 분석 (Behavior Analysis of Earth Retaining Walls on the Excavation for Contact Structure)

  • 김영묵;정영수;홍창표;신윤섭
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2005년도 춘계 학술발표회 논문집
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    • pp.1496-1503
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    • 2005
  • The study on the lateral earth pressure is briskly preformed for various conditions such as type of retaining walls, ground condition, and type of supporting systems. It is not simple to determine the distribution of lateral earth pressure accurately, however, because the lateral earth pressure is affected by various factors. This study is performed to analyze the behavior of earth retaining walls for new excavation contacting with existing excavation by comparing with the site measuring values before and after new excavation. On the base of observation, the distribution of strut axial forces is similar to that of ganeral earth retaining walls, but strut axial forces is increased by removal of existing earth anchors. When new excavation is performed contacting with existing excavation, the axial force of strut is decreased because of soil exclusion in the behind walls, but that force is increased after new exeavation. The analysis result show that the installation of strut in middle part makes a effect to not only 1 adjacent strut, but 3-5 adjacent struts. Also during new excavation strut axial forces is decreased by relaxation of total earth retaining wall system.

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면내조합하중과 횡압 하의 선박 이중판 설계시스템 구축 (Development of Doubler Plate Design System for Ship Structure Subjected to In-plane Combined Loads and Lateral Pressure)

  • 함주혁
    • 한국해양공학회지
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    • 제33권2호
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    • pp.146-152
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    • 2019
  • A design system was developed for the doubler plate of a ship structure simultaneously subjected to in-plane loads and lateral pressure based on general dimensions and those of a representative ship structure. An equivalent design equation that considers various structural design parameters was derived by introducing the equivalent plate thickness theory, and the design of the doubler plate reinforcement of the ship structure was developed. A hybrid structural design system was established for a doubler plate simultaneously subjected to in-plane loads and lateral pressure consisting of two modules: an optimized design module and a double plate strength & design review module. The practical application of this design system was illustrated to show its usability. It was found that the design safety of the doubler plate was ensured, and this system could be used as an initial design guide to review the double plate reinforcement for a dent or corrosion of the ship plate members. Using the developed design system would make it possible to obtain a more reasonable doubler plate structure that considers the rational reinforcement of plate members of ship structures. In addition, a more reliable structural analysis using a strength evaluation process can be performed to verify the efficiency of the optimum structural design for the doubler plate structure.

뇌졸중 후 편마비 환자의 보행능력 향상에 따른 질량중심 좌우이동의 변화 (The Change of Lateral Shift of Center of Pressure according to the Gait Improvement in Post-Stroke Hemiplegic Patients)

  • 이일석;박기언;홍해진;성강경;이상관
    • 대한한방내과학회지
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    • 제35권4호
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    • pp.448-454
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    • 2014
  • Objectives: The aim of this study was to analyze the change of lateral shift of Center of Pressure (CoP) according to the gait improvement in post-stroke hemiplegic patients and to investigate relationship between the change of motor grade and lateral shift of CoP. Methods: We measured the lateral shift of CoP and motor grade of eight post-stroke hemiplegic patients at the beginning of dependent gait and independent gait. Results: We found that CoP tended to be shifted to the non-affected side when patients started to walk independently. Furthermore, there was no relationship between the change of motor grade and lateral shift of CoP. Conclusions: This result may suggest it is more important to control the non-affected side than the affected side, at least until the beginning independent gait.

과팽창 노즐 유동에서 발생하는 측력변동에 관한 연구 (A Study of Lateral Force Fluctuations in Over-Expanded Nozzle Flow)

  • 이종성;차용수;;김희동
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2009년도 제33회 추계학술대회논문집
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    • pp.253-256
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    • 2009
  • 과팽창 상태 추력 노즐 내부의 측력(Lateral Force)발생에 대한 기초적 연구 분석을 실험적, 수치 해석적 방법으로 수행하였다. 엔진 정지 과정시 추력 노즐 내에 발생하는 압력진동을 조사하였다. 구동 압력비 변화에 따른 벽 압력 분포를 측정 및 쉴리렌 가시화를 수행하였다. RSS(Restricted Shock Separation)에서 FSS(Free Shock Separation)로 천이하는 순간 벽 압력 피크값이 발생하였다.

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Effects of Combined Wedge on Angle and Moment of Ankle and Knee Joint During Gait in Patients With Genu Varus

  • Yang, Hae Sun;Choi, Houng Sik
    • 국제물리치료학회지
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    • 제7권2호
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    • pp.1025-1030
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    • 2016
  • The purpose of this study was to investigate the effects of combined wedge on the range of motion in ankle and knee joint, ankle eversion moment and knee adduction moment, and center of pressure excursion of foot for genu varus among adult men during gait. This study was carried out with 10 adult men for genu varus in a motion analysis laboratory in J university. The subjects of the experiment were measured above 5cm width between the knees on contact of both medial malleolus of ankle while standing. The width of their knees in neutral position was measured without the inversion or eversion of the subtalar joint by the investigator. The subjects of the experiment were ten who were conducted randomly for standard insole, insole with $10^{\circ}$ lateral on rear foot wedge, insole at $10^{\circ}$lateral on rear foot and $5^{\circ}$ medial on fore foot wedge. Before and after intervention, changes on the range of motion in ankle and knee joint, ankle eversion moment and knee adduction moment, and center of pressure excursion were measured. In order to compare analyses among groups; repeated one-way ANOVA and $Scheff{\acute{e}}$ post hoc test were used. As a result, combined wedge group was significantly decreased compared to control wedge group in terms of knee varus angle in mid-stance(p<.05). Combined wedge group was significantly decreased compared to lateral wedge group in terms of ankle eversion moment in whole stance(p<.05). Combined wedge group was significantly decreased compared to lateral wedge group in terms of knee adduction moment in whole stance(p<.05). Combined wedge group was significantly decreased compared to lateral wedge in terms of center of pressure excursion in whole stance(p<.05). The results of this study suggest that combined wedge for genu varus decreased ankle eversion moment and knee adduction moment upon center of pressure excursion. We hypothesize that combined wedge may also be effective in the protection excessive ankle pronation.