• Title/Summary/Keyword: arch effect

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The Immediate Effects of External Kinesio-tape Wrapping for Inner Arch Support on the Lower Leg EMG for Gait in Stiletto Heels

  • Yi, Kyungock
    • 한국운동역학회지
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    • 제26권1호
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    • pp.127-133
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    • 2016
  • Purpose: The purpose of this study was to analyze the effects of using external kinesio-tape wrapping for inner arch support on the lower extremity EMG for gait in stiletto heels. Methods: Subjects for this study were two female college students who had been wearing stiletto heels almost every day of the week for more than three years. The independent variable was the presence or absence of kinesio-tape wrap for inner arch support. Dependent variables were EMG readings for the four muscle groups: the medial and lateral gastrocnemius, the tibialis anterior, and the peroneus longus. EMG readings were taken using the NORAXON (USA). The Paired t-test within the subject repeated measure design for the presence and absence of inner arch support (p<0.05) was used via SPSS 18.0. Results: With kinesio-tape wrap for inner arch support, there was a statistically significant decrease in the muscle force mean values for the peroneus longus and the medial and lateral gastrocnemius, in the maximum muscle forces of the peroneus longus and the lateral gastrocnemius. Conclusion: External kinesio-tape wrapping for inner arch support in stiletto heels could have an effect to reduce peroneus longus, and medial/lateral gastrocnemius activities that could result in decreased fatigue and discomfort.

Investigation of water length effects on the modal behavior of a prototype arch dam using operational and analytical modal analyses

  • Sevim, Baris;Bayraktar, Alemdar;Altunisik, Ahmet Can
    • Structural Engineering and Mechanics
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    • 제37권6호
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    • pp.593-615
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    • 2011
  • This study determines the water length effects on the modal behavior of a prototype arch dam using Operational and Analytical Modal Analyses. Achievement of this purpose involves construction of a prototype arch dam-reservoir-foundation model under laboratory conditions. In the model, reservoir length was taken to be as much as three times the dam height. To determine the experimental dynamic characteristics of the arch dam using Operational Modal Analysis, ambient vibration tests were implemented for empty reservoir and three different reservoir water lengths. In the ambient vibration tests, the dam was vibrated by natural excitations provided from small impact effects and the response signals were measured using sensitive accelerometers. Operational Modal Analysis software process signals collected from the ambient vibration tests, and Enhanced Frequency Domain Decomposition and Stochastic Subspace Identification techniques estimated modal parameters of the dams. To validate the experimental results, 3D finite element model of the prototype arch dam was modeled by ANSYS software for empty reservoir and three different reservoir water lengths, and dynamic characteristics of each model were determined analytically. At the end of the study, experimentally and analytically identified dynamic characteristics compared to each other. Also, changes on the natural frequencies along to water length are plotted as graphs. Results suggest that reservoir water complicates the modal behavior of the arch dam significantly.

라이즈비를 고려한 닐센아치교의 형상 거동에 관한 연구 (The Study on Shape Behavior of Nielsen Arch Bridge Considering Rise Ratio)

  • 박순응;박문호;김진규;노우혁;조성욱;류지영
    • 한국산업융합학회 논문집
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    • 제13권3호
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    • pp.161-168
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    • 2010
  • Recently, bridges have been momenttous as not only regarding function but also concerning aesthetics. However, when beauty is considered in the bridge, it is also essential that stability and economics be considered. Besides, when considering stability, an arch bridge is one of the most stable structures. The most important element is a rise ratio when regarding beauty and economics of arch bridges. The effect of dead load and DB24 load have been considered to decide proper rise ratio. Therefore, in this study, examined the value of moment, displacement and member forces, in the variation of the rise ratio of arch bridges. The most optimum shape of Nielsen arch bridges has determined by analyzing member forces, moments and displacement with parameters of rise ratio and angle of vertical members. By comparison between values, the hanger types have been also considered to derive the optimum shape of Nielsen arch bridge.

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The proper width of the intermittent trough for tunnel enlarging

  • Tan, Yi-Zhong;Liu, Yuan-Xue;Li, Zhong-You
    • Geomechanics and Engineering
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    • 제6권5호
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    • pp.455-467
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    • 2014
  • As the traffic increased, the original capacity of the tunnel has been unable to meet the needs, so it must be expanded. Based on the features of tunnel, the intermittent trough method must be supposed for tunnel enlarging. Under the situation on the buried deep of the tunnel, it could be used the reasonable arch axis model to descript the past covered rock pressure for mechanism calculating of self-bearing arch. Then establish the three-arch combination effectible model for the analysis which is relied on the tunneling enlarging to Chongqing Yu-Zhou tunnel. It has determined the proper width for the intermittent trough in shallow buried tunnel enlarging.

The supporting effect of pipe wing rib designed to achieve early contact between ground and steel arch tunnel support

  • Kinoshita Yasunori;Shinji Masato;Nakagawa Koji;Yamamoto Minoru
    • 한국지구물리탐사학회:학술대회논문집
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    • 한국지구물리탐사학회 2003년도 Proceedings of the international symposium on the fusion technology
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    • pp.103-108
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    • 2003
  • In the construction of mountain tunnels, reaction forces of the legs of steel arch supports against the ground are often expected to support the ground being excavated. In these cases, a stress concentration occurs in the ground directly under the support legs. If the bearing capacity of the ground is insufficient or displacement is not effectively constrained, the local failure of the ground under the support legs or settlement of the tunnel supports due to large deformation could result. It is therefore necessary to reinforce the support legs to reduce settlement. As a means of reducing settlement, wing-ribbed steel arch supports are well used. In this study, with the aim of finding a way to quickly reduce the settlement of steel arch support legs, effectiveness of a new type of wing ribs to reinforce steel arch supports was investigated through laboratory testing.

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호선에 부여한 loop와 교정용 고무가 치궁만곡도 개선에 미치는 영향에 관한 광탄성학적 연구 (A PHOTOELASTIC STUDY OF THE EFFECT OF LOOPS IN ARCH WIRE AND ORTHODONTIC ELASTICS IN RELIEF OF CURVE OF SPEE)

  • 이병태
    • 대한치과교정학회지
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    • 제23권4호
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    • pp.485-492
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    • 1993
  • Multiloop Edgewise Archwire(MEAW) is effective in relief the Curve of Spee in mandibular arch but up Sl down orthodontic elastics must be used with it. The purpose of this study was to analyse the effect of orthodontic elastics, like as up & down elastics, Class II elastics, and Class III elastics, and the effect of L loop in Multioop Edgewise Archwire. 1. Intrusive force of MEAW in anterior teeth was reduced and uprighting force in premolars was increased by up & down elastics. 2. Uprighting force was significintly increased with Class III elastics in multiple L loop arch wire. 3. The force of Class II elastics made molars tip mesially and Curve of Spee deep.

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사질토지반에서 2 Arch 터널의 거동 (Behavior of 2 Arch Tunnel in Sand)

  • 이상덕;전은숙
    • 한국터널지하공간학회 논문집
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    • 제6권2호
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    • pp.171-182
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    • 2004
  • 사질토지반에서 2 Arch 터널을 굴착할 때에 중앙터널의 굴착규모와 인버트 폐합에 따른 중앙필러 및 터널 주변지반의 거동특성을 규명하기 위하여 모형실험을 수행하였다. 3개로 분리되어 수직이동이 가능한 가동판 위에 중앙필러와 모형라이닝을 설치하고 모형지반 조성 후에 가동판을 강하시켜서 중앙터널굴착을 표현하였고, 중앙터널굴착 후에 좌 우측 터널을 굴착하였으며 굴착이 완료된 2 Arch 터널 전체에 대한 가동판을 움직여서 2 Arch 터널굴착에 따른 하중전이 및 지반이완 형태는 물론 중앙필러에 작용하는 하중의 변화를 관찰하였다. 실험중에 가동판, 중앙필러 및 바닥판에 작용하는 이완하중 및 전이하중을 측정하였고, 모형터널의 내부와 지중 및 지표에 변위계를 설치하여 모형터널의 내공변위 및 지반의 변위를 측정하였다. 본 연구결과 시공순서와 라이닝의 기초부 구속조건에 따라 중앙필러가 부담하게 되는 하중의 변화를 확인하였고 2 Arch 터널굴착에 따른 하중전이 및 지반이완형태를 확인하였다.

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Seismic analysis of half-through steel truss arch bridge considering superstructure

  • Li, Ruiqi;Yuan, Xinzhe;Yuan, Wancheng;Dang, Xinzhi;Shen, Guoyu
    • Structural Engineering and Mechanics
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    • 제59권3호
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    • pp.387-401
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    • 2016
  • This paper takes a half-through steel truss arch bridge as an example. A seismic analysis is conducted with nonlinear finite element method. Contrast models are established to discuss the effect of simplified method for main girder on the accuracy of the result. The influence of seismic wave direction and wave-passage on seismic behaviors are analysed as well as the superstructure and arch ring interaction which is mostly related with the supported bearings and wind resistant springs. In the end, the application of cable-sliding aseismic devices is discussed to put forward a layout principle. The main conclusions include: (1) The seismic response isn't too distinctive with the simplified method of main girder. Generally speaking, the grillage method is recommended. (2) Under seismic input from different directions, arch foot is usually the mostly dangerous section. (3) Vertical wave input and horizontal wave-passage greatly influence the seismic responses of arch ring, significantly increasing that of midspan. (4) The superstructure interaction has an obvious impact on the seismic performance. Half-through arch bridges with long spandrel columns fixed has a less response than those with short ones fixed. And a large stiffness of wind resistant spring makes the the seismic responses of arch ring larger. (5) A good isolation effectiveness for half-through arch bridge can be achieved by a reasonable arrangement of CSFABs.

변단면 변화곡율 캔틸레버 아치의 자유진동 (Free Vibrations of Tapered Cantilever Arches with Variable Curvature)

  • 이병구;이용수;오상진
    • 소음진동
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    • 제10권2호
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    • pp.353-360
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    • 2000
  • Numerical methods are developed for calculating the natural frequencies and mode shapes of the tapered cantilever arches with variable curvature. The differential equations governing the free vibrations of such arches are derived and solved numerically, in which the effect of rotatory inertia is included. The parabolic shape is chosen as the arch with variable curvature while both the prime and quadratic arched members are considered as the tapered arch with variable curvature while both the prime and quadratic arched members are considered as the tapered arch. Comparisons the natural jfrequencies between this study and finite element method SAP 90 seve to validate the numerical method developed herein. The lowest four natural frequencies are reported as a function of four non-dimensional system parameters. The effects of both the rotatory inertia and cross-sectional shape are reported. Also, the typical mode shapes of stress resultants as well as the displacements are reported.

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Assessment of masonry arch bridges retrofitted by sprayed concrete under in-plane cyclic loading

  • Mahdi Yazdani;Mehrdad Zirakbash
    • Structural Monitoring and Maintenance
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    • 제11권1호
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    • pp.57-70
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    • 2024
  • Masonry arch bridges as a vital infrastructure were not designed for seismic loads. Given that masonry arch bridges are made up of various components, their contribution under the seismic actions can be very undetermined and each of these structural components can play a different role in energy dissipation. Iran is known as a high-risk area in terms of seismic excitations and according to the seismic hazard zoning classification of Iran, most of these railway infrastructures are placed in the high and very high seismicity zones or constructed near the major faults. Besides, these ageing structures are deteriorated and thus in recent years, some of these bridges using various retrofitting approaches, including sprayed concrete technique are strengthened. Therefore, investigating the behavior of these restored structures with new characteristics is very significant. The aim of this study is to investigate the cyclic in-plane performance of masonry arch bridges retrofitted by sprayed concrete technique through the finite element simulation. So, by considering the fill-arch interaction, the nonlinear behavior of a bridge has been investigated. Finally, by extracting the hysteresis and enveloping curves of the retrofitted and non-retrofitted bridge, the effect of strengthening on energy absorption and degradation of material has been investigated.