• 제목/요약/키워드: single column/shaft

검색결과 7건 처리시간 0.02초

지반의 비선형거동을 고려한 단일현장타설말뚝의 의사정적해석 (Pseudostatic Analysis of Single Column/Shafts Considering Nonlinear Soil Behavior)

  • 이준규;김병철;정상섬;송성욱
    • 대한토목학회논문집
    • /
    • 제28권1C호
    • /
    • pp.31-40
    • /
    • 2008
  • 본 연구에서는 지진하중을 받는 Single Column/Shaft의 내진해석으로 의사정적해석법을 적용하였으며 해석상에서 지반의 비선형 거동특성을 나타내는 다양한 수평방향 하중전이특성(p-y 곡선, Bi-linear 곡선)를 이용하여 지반-말뚝의 상호작용을 고려하였다. 비선형 지반모델을 적용한 해석은 지반-말뚝 시스템의 지진거동을 간편히 예측할 수 있었으며 동일한 해석조건에서 응답변위법에 의한 Single Column/Shaft의 수평거동이 진도법에 근거하여 산정한 해석결과보다 크게 예측되었다. 두부경계조건과 상대강성이 Single Column/Shaft의 단면력에 미치는 영향을 분석하기 위해 다양한 지반모델에 대한 변수연구를 수행한 결과, 두부경계가 고정이고 말뚝강성이 감소할수록 수평변위가 작은 것으로 나타났으며, JRA의 Bi-linear 지반모델을 적용한 해석은 Single Column/Shaft의 수평거동을 비교적 정확히 예측하였다.

반복수평재하시험을 통한 단일형현장타설말뚝의 거동분석 (Analysis of Horizontal Behavior of a Single Column/Shaft by Horizontal Two-way Pile Load Test)

  • 정상섬;송성욱;김병철
    • 한국지반공학회:학술대회논문집
    • /
    • 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
    • /
    • pp.1132-1143
    • /
    • 2008
  • A single Column/Shaft which extended the pile to the column of the bridge with same diameter has better safety and economical profit, but it usually has larger lateral displacement due to lateral loads such as wind, earthquake, wave, etc. A series of horizontal pile load testing were performed to study the lateral behavior of single column/shaft with varying different free lengths and embedded pile lengths. Eight instrumented test piles were cast-in-placed by bonding strain gauges at certain locations on both faces of the pile to measure bending moment, from two-way loadings. Linear variable differential transformers(LVDTs) were installed to measure the lateral pile displacement. Based on this, it is found that the test single column/shaft with different free lengths shows different failure modes. If the test pile has a longer free length, the failure occurs at the near the ground surface, but the shorter one's failure occurs at the below the ground surface.

  • PDF

단주 구조 송전탑 기초의 횡방향 거동에 관한 연구 (Laterally Loaded Behavior of Short Drilled Shaft Foundation for Single-Pole Structures)

  • 최호영;김영훈;이승래;김대학;김대홍
    • 한국지반공학회:학술대회논문집
    • /
    • 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
    • /
    • pp.1106-1116
    • /
    • 2008
  • Single-pole transmission structures which are supported by drilled shaft foundations are usually subjected to large overturning moments with modest vertical and lateral loads. To analyze the behavior of the drilled shaft under such loading conditions, an analytical model was developed based on beam-column and subgrade reaction methods. Field model tests were performed to calibrate the developed analytical model in which additional subgrade spring models were adopted. The field test results estimated from the calibrated analytical model were compared with those calculated by one spring model and other commercial program. According to the comparison study, the developed analytical model was proven to be a useful tool to analyze the laterally loaded behavior of foundations for single-pole structures.

  • PDF

단일 현장타설말뚝 기초의 설계 및 시공 (Design and consturction of single drilled shaft foundation)

  • 전경수;김경석;김정열
    • 기술발표회
    • /
    • 통권2006호
    • /
    • pp.86-100
    • /
    • 2006
  • The single drilled shaft foundation has been used in the other countries, but has not used in South Korea at all This foundation is very effective and economic method in South Korea which is easy to meet a good rock mass within 50m depth from the ground We have many experiences to construct 1.52 5m drilled shaft foundations and ability to construct 30m drilled shaft foundation without special efforts The soil behavior is nonlinear, but it can be proposed in linear in practical purpose on bridges. The elastic modulus of soil can be rationally obtained by the method of Road Bridge Design Manual in South Korea using the Schmertmann(1970)'s proposal, and the elastic modulus of rock can be obtained by the field test. In seismic design the column and drilled shaft must be restricted to the elastic design because the behavior of this foundation is flexible and the arrangement of the rebars makes the various defect In this paper the design criteria is compared with FHWA design criteria, and the design criteria is proposed in consistent with Road Bridge Design Manual in South Korea. The single drilled shaft foundation of a test bridge was constructed in the Iksan-Jangsoo highway, and we checked its stability, workability and economy

  • PDF

Wind-induced fatigue loading of tubular steel lighting columns

  • Robertson, A.P.;Hoxey, R.P.;Short, J.L.;Burgess, L.R.;Smith, B.W.;Ko, R.H.Y.
    • Wind and Structures
    • /
    • 제4권2호
    • /
    • pp.163-176
    • /
    • 2001
  • Two 12 m high tubular steel lighting columns have been instrumented to determine the wind-induced fatigue loading experienced by such columns. Each column supported a single luminaire mounted on a 0.5 m long bracket. One column was planted in soil, and the other bolted through a welded baseplate to a substantial concrete base. The columns were strain gauged just above the shoulder weld which connected the main shaft to the larger base tube. Forced vibration tests were undertaken to determine the natural frequencies and damping of the columns. Extensive recordings were made of response to winds with speeds from 4 m/s to 17 m/s. Selected records were analysed to obtain stress cycle counts and fatigue lives. Mean drag coefficients were also derived from the strain data to investigate experimentally the effect of Reynolds Number.

파이프 골조 온실의 구조 및 유지관리실태 조사분석 (A Field Survey on the Structure and Maintenance Status of Pipe Framed Greenhouses)

  • 남상운
    • 한국농공학회지
    • /
    • 제42권4호
    • /
    • pp.106-114
    • /
    • 2000
  • An investigation was conducted to get the basic data for establishing maintenance strategy of pipe framed greenhouses. The contents of the investigation consisted of actual state of structures, maintenance status, meteorological disaster, and corrosion characteristics of pipe framework in greenhouses. the number of greenhouses investigated was 108 in total. Most multi-span greenhouses had narrower width and lower height than the standared 1-2W greenhouse, and most of single-span greenhouses were tunnel type. In multi-span greenhouses, the size and interval of frameworks such as rafter, purline, column , and cross beam were mostly suitable, but frameworks of single-span greenhouses were mostly insufficient. After about 7 years in grounds, 8 years in joints, 10 years in bending parts. and 13 years in columns. pipe surface was mostly rusted. Most weak parts in corrosion were pipes in contact with the ground, joints, roll-up shaft pipes, and pipes close to the gutter. Almost all of the greenhouse farmers didn't pay any attention to maintenance affair in a regular interval for pipe framed grenhouses. Many greenhouses have experienced the meteorologicla diaster such as uplift of foundation, partial or complete failure by the hyphoon and/or high winds.

  • PDF

단열식 회전연료 노즐의 오리피스 직경에 따른 분무특성 연구 (A Study of Spray Characteristic with Orifice Diameter for Single Column Rotating Fuel Nozzle)

  • 장성호;최성만
    • 한국추진공학회:학술대회논문집
    • /
    • 한국추진공학회 2009년도 춘계학술대회 논문집
    • /
    • pp.253-256
    • /
    • 2009
  • 350Kw급 이하의 초소형 터보제트엔진에서 연료 미립화 특성을 만족하는 분사시스템을 개발하는 것은 매우 어려운 일이다. 그러나 회전 연료 분사시스템은 복잡한 고압연료펌프 시스템 없이도 엔진축의 원심력만을 이용함으로써 좋은 미립화를 할 수 있다. 이러한 이유로, 직경 40 mm의 매우 작은 회전식 연료 인젝터를 제작하였으며, 여러 가지 크기의 분사 오리피스에 대한 실험을 수행하였다. PDPA 측정 시스템을 사용하여 입자의 크기와 속도, 분무분포를 측정하였다. 실험 결과, 분사 오리피스로부터 분출된 단일 액주의 길이는 회전속도에 의해 제어되며, SMD는 회전수가 증가함에 따라 감소하고, 오리피스의 직경과 오리피스 내부에 생성되는 액막두께에 큰 영향을 받는다.

  • PDF