• Title/Summary/Keyword: 극한하중

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Load-carrying Capacity of Thermal Prestressed Steel Beam with Eccentric Bracket (편심 브라켓 설치 온도프리스트레싱 강재보의 하중저항 성능)

  • Kim, Sang-Hyo;Jung, Chi-Young;Choi, Kyu-Tae;Ahn, Jin-Hee
    • Journal of Korean Society of Steel Construction
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    • v.22 no.6
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    • pp.563-572
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    • 2010
  • This study evaluates the load-carrying capacity of a thermal prestressed steel beam with an eccentric bracket. The steel beam that is proposed in this study has an eccentrically installed cover plate through application of the eccentric bracket. The eccentric bracket helps the steel beam achieve greater sectional stiffness and more efficiently induces prestress. A material non-linear characteristic applied finite element analysis was also conducted to check the validity of the experiments. The results of this study showed that the structural stiffness, yield load, and ultimate strength of the TPSM-applied steel beam with the eccentric bracket increased due to the eccentricity of the cover plate.

말뚝기초의 연적 방향 극한하중

  • 김명모
    • Proceedings of the Korean Geotechical Society Conference
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    • 2002.11a
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    • pp.209-236
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    • 2002
  • Ultimate pile capacity - Point resistance - Frictional resistance - Determination of point and frictional resistances from field tests - Summary of recommendations from design Group effects Settlement analysis.

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Centrifuge Model Tests on Sliding Behavior of Cantilever Retaining Wall due to Surcharges (과재하중에 의한 역T형 옹벽의 활동거동에 관한 원심모형실험)

  • 유남재;유건선;이명욱;이종호
    • Journal of the Korean Geotechnical Society
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    • v.16 no.6
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    • pp.153-160
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    • 2000
  • 본 연구는 과제하중의 재하폭과 재하위치를 매개변수로 변화시켜 옹벽의 뒤채움재 상부 지표면에서 제한폭의 과재하중작용시 그의 활동거동에 관한 실험적, 수치적 해석적 연구이다. 중력 수준을 1g, 20g,40g로 변화시켜 수행한 원심모형실험을 통해 구한 기초의 극한지지력 및 하중-침하특성, 하중-옹벽수평변위특성에 관하여 조사연구 하였다. 또한, 옹벽의 활동으로 인한 지반파괴의 영향을 받기 시작하는기초의 재하위치를 추정하기 위하여 종래의 얕은 기초의 극한지지력 실험을 수행하여 이들 결과와 함께 비교하였다. 한편, 모형실험결과와 기존의 이론식을 수정보완한 해석 결과와 비교분석하였다.

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Effects of Cyclic Loading Rate on response of Reinforced Concrete Structures (철근콘크리트 구조물에 대한 반복하중속도의 영향에 관한 연구)

  • Chung, Lan;Park, Hyun-Soo
    • Computational Structural Engineering
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    • v.2 no.3
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    • pp.77-84
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    • 1989
  • Small-scale models of reinforced concrete beam-column joints and anchorage-bond specimens were subjected to large cyclic displacements at two rates. To assess damage, free vibration tests were conducted. The reliability of the modeling techniques was established by comparison of the results for the slower rate with those obtained from the full-scale tests on prototype. The higher rate of loading caused a greater damage than that at the slower rate. This was evidenced by the measurements of the stiffness obtained from the free-vibration test. The relatively greater extent of damage appears to result from the different bond behavior at different rates of loading.

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Static Behavior Analysis of Spillway Pier for Dam Safety Evaluation (댐 안전성 평가를 위한 여수로 피어부의 정적 거동 분석)

  • Jang, Bong-Seok;Lim, Jeong-Yeul;Lee, Myung-Kue;Lee, Hyung-Jun
    • Journal of the Korea Concrete Institute
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    • v.19 no.1
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    • pp.11-18
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    • 2007
  • Seismic performance evaluation for dam safety evaluation has been continually conducted. However the behavior analysis for the spillway pier which is known as the weak point of dam is seldom reported. Therefore, this study performed the static loading tests for a prototype structures as elementary tests for the final seismic performance evaluation of dam safety. The prototype of pier structure has 1/20 scale and it adopts to strength model. And cracking loads and ultimate loads of real structures are calculated through numerical analysis using commercial FEM program (ABAQUS). The results of this study show some difference between the results of prototype tests and the results of numerical analysis. Also, the ultimate and cracking loads can be estimated through the prototype loading test and numerical analysis.

Evaluation of Lateral Pile Behavior under Cyclic Loading by Centrifuge Tests (원심모형 실험을 이용한 반복하중을 받는 모노파일 거동 평가)

  • Lee, Myungjae;Yoo, Mintaek;Park, Jeongjun;Min, Kyungchan
    • Journal of the Korean Geotechnical Society
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    • v.35 no.6
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    • pp.39-48
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    • 2019
  • This study investigated the lateral behavior of monopile embedded in the dry sand through cyclic lateral loading test using a centrifuge test. The sand sample for the experiment was the dry Jumunjin standard sand at 80% relative density and the friction angle of $38^{\circ}$. In the experimental procedure, firstly, it was determined the static lateral bearing capacity by performing the static lateral loading test to decide the cyclic load. This derived static lateral bearing capacity values of 30%, 50%, 80%, 120% were determined as the cyclic lateral load, and the number of cycle was performed 100 times. Through the results, the experiment cyclic p-y curve was calculated, and the cyclic p-y backbone curve by depth was derived using the derived maximum soil resistance point by the load. The initial slope at the same depth was underestimated than API (1987) p-y curves, and the ultimate soil resistance was overestimated than API (1987) p-y curves. In addition, the result of the comparison with the suggested dynamic p-y curve was that the suggested dynamic p-y curve was overestimated than the cyclic p-y backbone curve on the initial slope and soil resistance at the same depth. It is considered that the p-y curve should be applied differently depending on the loading conditions of the pile.

Ultimate Shear Capacity of Prestressed Girder of Ultra High Performance Fiber Reinforced Concrete (초고강도 섬유보강 콘크리트 프리스트레스트 거더의 극한 전단력)

  • Han, Sang-Mook;Wu, Xiang-Guo
    • Journal of the Korean Society of Hazard Mitigation
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    • v.8 no.2
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    • pp.51-58
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    • 2008
  • This study is to investigate the ultimate shear load of prestressed girder made of Ultra High Performance Fiber Reinforced Concrete (UHPFRC). Nine girders were tested until failure in shear. An analytical model to predict the ultimate shear load was formulated based on the Two Bounds Theory. A fiber reinforcing model was constituted based on the random assumption of steel fiber uniform distribution. The predicted values were compared with the conventional predictions and the test results. The proposed equations for computing the ultimate shear strength can be used for the ultimate failure status analysis, which could also be utilized for numerical limit analysis of prestressed UHPFRC girder. The established fiber reinforcing theoretical model can also be a reference for micro-mechanics analysis of UHPFRC.

An Experimental Study for Flexure/Shear Failure Behavior of Composite Beam with GFRP Plank Used As a Permanent Formwork and Cast-in-place High Strength Concrete (영구거푸집으로 사용한 유리섬유 FRP 판과 현장타설 고강도콘크리트로 이루어진 합성보의 휨/전단파괴거동에 관한 실험적 연구)

  • Yoo, Seung-Woon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.6
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    • pp.4245-4252
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    • 2015
  • In this study, an experiment which utilized glass fiber reinforced polymer(GFRP) plank as the permanent formwork of cast-in-place high strength concrete structures was performed. The GFRP plank currently being produced has smooth surface so that it causes problems in behavior with concrete. Therefore, this research analyzed the flexure/shear failure behavior of composite beams, which used GFRP plank as its permanent formwork and has short shear span ratio, by setting the sand coated at GFRP bottom surface, the perforation and interval of the GFRP plank web, and the width of the top flange as the experimental variables. As a result of the experiments for effectiveness of sand attachment in case of not perforated web, approximately 47% higher ultimate load value was obtained when the sand was coated than not coated case and bending/shear failure mode was observed. For effectiveness of perforation and interval of gap, approximately 24% higher maximum load value was seen when interval of the perforation gap was short and the fine aggregate was not coated, and approximately 25% lower value was observed when the perforation gap was not dense on the coated specimen. For effectiveness of top flange breadth, the ultimate load value was approximately 17% higher in case of 40mm than 20mm width.

Evaluation of Fire Performance of RC Slabs with Half-Depth Precast Panels (반단면 프리캐스트 패널을 적용한 RC 슬래브의 내화성능 평가)

  • Chung, Chul-Hun;Im, Cho-Rong;Kim, Hyun-Jun;Joo, Sang-Hoon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.30 no.4A
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    • pp.391-398
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    • 2010
  • The fire performance of RC slabs with half-depth precast panel after exposure to the ISO-834 fire standard without loading has been experimentally investigated. During heating, according to the ISO 834 fire curve, concrete spalling was observed for concrete without PP(polypropylene) fibers. No spalling occurred when heating concrete containing PP fibers. The maximum temperature of RC slabs with PP fibers with half-depth precast panel was lower than that of concrete without PP fibers. The ultimate load after cooling of the RC slabs that were not loaded during the furnace tests was evaluated by means of 3 points bending tests. The ultimate load of the RC slabs without PP fibers showed a considerable reduction (around 32.5%) of the ultimate load after cooling if compared with of RC slabs with PP fibers. The ultimate load of the RC slabs with half-depth precast panel with PP fibers is higher than that of a full-depth RC slabs with PP fibers. Also, the addition of PP fibers and the use of half-depth precast panel improve fire resistance.