• 제목/요약/키워드: the earth

검색결과 15,200건 처리시간 0.056초

수조모델 실험에 의한 접지저항 추정 (presumption of Earth Resistance by Water Tank Model)

  • 고희석;최종규;김주찬;이충식
    • 한국조명전기설비학회:학술대회논문집
    • /
    • 한국조명전기설비학회 2002년도 학술대회논문집
    • /
    • pp.125-131
    • /
    • 2002
  • It is very important to assume potential distribution to be generated in electrode environs and grounding resistance by current beforehand, when incoming at grounding electrode to plan efficient grounding facilities In this paper, we analyzed grounding resistance through a simulation experiment by a water tank scaled model electrode of the rectangular earth plate, a theoretical Calculation result of the rectangular earth plate and measurement of grounding resistance buried rectangular earth plate analysing earth surface potential.

  • PDF

Experimental study on effect of underground excavation distance on the behavior of retaining wall

  • Lee, Seok-Won
    • Geomechanics and Engineering
    • /
    • 제17권5호
    • /
    • pp.413-420
    • /
    • 2019
  • The changes in earth pressure and ground settlement due to underground excavation near an existing retaining wall were studied experimentally according to the separation distance between the underground excavation and the retaining wall. In addition, this study attempted to experimentally prove that the arching phenomenon occurred during the construction of the underground space. A model tank having 120 cm in length, 160 cm in height, and 40 cm in width was manufactured to simulate underground excavation through the use of five separated base wall bodies. The variation of earth pressure on the retaining wall was measured according to the underground excavation phase through the use of 10 separated right wall bodies. The results showed that the earth pressure on the retaining wall was changed by the lowering of the first base bottom wall; however, the earth pressure was not changed significantly by the lowering of the third base bottom wall, since the third base wall had sufficient separation distance from the retaining wall. Lowering of the first base wall induced a decrease in the earth pressure in the lower part of the retaining wall; in contrast, lowering of the first base wall induced an increase in the earth pressure in the middle part of the retaining wall, proving the arching effect experimentally. It is necessary to consider the changes in earth pressure on the retaining wall in designing earth retaining structures for sections where the arching effect occurs.

Effects of partially earth-anchored cable system on dynamic wind response of cable-stayed bridges

  • Won, Jeong-Hun;Yoon, Ji-Hyun;Park, Se-Jun;Kim, Sang-Hyo
    • Wind and Structures
    • /
    • 제11권6호
    • /
    • pp.441-453
    • /
    • 2008
  • In this study, a partially earth-anchored cable system is studied in order to reduce the dynamic wind response of cable-stayed bridges. The employment of earth-anchored cables changes the dynamic characteristics of cable-stayed bridges under wind loads. In order to estimate the changes in the member forces, the spectral analysis for wind buffeting loads are performed and the peak responses are evaluated using 3-D finite element models of the three-span cable-stayed bridges with the partially earth-anchored cable system and with the self-anchored cable system, respectively. Comparing the results for the two different models, it is found that the earth-anchored cables affect longitudinal and vertical modes of the bridge. The changes of the natural frequencies for the longitudinal modes remarkably decrease the peak bending moment in the pylon and the movements at the expansion joints. The small changes of the natural frequencies for the vertical modes slightly increase bending moments and deflections in the girder. The original effects of the partially earth-anchored cable system are also shown under wind loads; the decrement of girder axial forces and bearing uplifting forces, and the increment of cable forces in the earth-anchored cables.