• Title, Summary, Keyword: 항복하중

Search Result 480, Processing Time 0.034 seconds

The Effect of the Volume of the Cellular Bulkhead on the Yield Load (셀 구조물의 항복하중에 미치는 체적의 영향)

  • Jang, Jeong-Wook;Kim, Hyun-Guk;Lee, Jae-Seok
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.27 no.4
    • /
    • pp.197-201
    • /
    • 2015
  • Experimental and numerical analysis has been carried out in this paper to understand correlation between volume and yield of cellular bulkhead. It was firstly confirmed from these results that the conditions and parameters considered in the finite element analysis were reasonable and realistic due to the fact that the yield loads determined by the two different methods were equivalent in actual. Based on this results, a series of intensive numerical analysis has been further performed and revealed that the yield load varied in direct proportion to the change in the volume of the cellular bulkhead.

Yield Load Interpretation for Drilled Shaft Foundations by Hyperbolic Approximation (쌍곡선 근사에 의한 현장타설말뚝의 항복하중 판정)

  • Won, Sang-Yeon;Hwang, Seong-Il;Jo, Nam-Jun
    • Geotechnical Engineering
    • /
    • v.12 no.6
    • /
    • pp.79-86
    • /
    • 1996
  • This study develops a new method for interpreting the yield load from load tests on drilled shaft foundations ended on general soils, which is defined as a point where the maximum curvature on the hyperbolic-approximated load-settlement curve occurs. How ever, the point of maximum curvature is a variable depending on the units and scales of the load and settlement. Therefore, to obtain a unique maximum curvature point, both the load and settlement must be normalized by proper parameters, respectively, and be expressed on the same scaled arses(1:1). Normalization has been processed so that the yield load by the new interpretation is to be close to the average of yield loads interpreted by other methods investigated in this study. The quantitative comparison between the new criterion and other conventitonal methods is presented.

  • PDF

Application of The Bi-Directional Pile Load Test for The Yield Capacity of Rock Socketed Pile (양방향재하시험을 활용한 암반근입 말뚝의 항복하중 판별방법)

  • Kim, Jong-Woong;Jang, Kyung-Jun;Kim, Hak-Moon
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • /
    • pp.526-532
    • /
    • 2009
  • 말뚝의 정재하시험을 통하여 항복하중 및 극한하중을 판별하는 다양한 방법이 제안되어 왔다. 말뚝의 지지력은 주면마찰력과 선단지지력의 합으로 나타내어 왔으나 말뚝 재하시험을 통한 항복 하중 및 극한하중의 판별법은 대체로 총 침하량에 대해 판별하거나 재하하중-침하 그래프로부터 산정되는 경우가 대표적이다. 본 연구에서는 현장 대구경 양방향 재하시험 결과를 활용하여 말뚝의 주면부와 선단부로 나누어 항복하중을 판별할 수 있는 방법을 제안하고자 한다.

  • PDF

Estimating Unsaturated Shear Strength and Yield Load of Compacted Aggregate Sub-base Materials (다져진 보조기층 재료의 불포화 전단강도 및 항복하중 평가)

  • Jeon, Hye-Ji;Park, Seong-Wan
    • Journal of The Korean Society of Civil Engineers
    • /
    • v.31 no.4D
    • /
    • pp.571-576
    • /
    • 2011
  • In general, conventional road pavements are designed under the assumption that the shear strength of geomaterials are under saturated state. In reality, however, most of the pavement geomaterials exists under the unsaturated state. To deal with this gap between saturated and unsaturated conditions, in this paper, unsaturated shear strength was estimated using the results from the triaxial compression test and soil-water characteristics curves. Then, yield loads were assessed using 2-Dimensional finite element method with the selected nonlinear elastic model and the Mohr-Coulomb yield criteria. In addition, various unsaturated condition and surface layer effects on the yield load of granular materials were identified. Therefore, the results demonstrated would provide a possibility to estimate bearing capacity of paved or unpaved roads using unsaturated soil mechanics.

Mechanical Performance Evaluation of RC Beams with FRP Hybrid Bars under Cyclic Loads (FRP 하이브리드 보강근을 가지는 RC보의 반복하중에 대한 역학적 성능 평가)

  • Hwang, Chul-Sung;Park, Jae-Sung;Park, Ki-Tae;Kwon, Seung-Jun
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.21 no.1
    • /
    • pp.9-14
    • /
    • 2017
  • In the present work, a mechanical performances under cyclic loading in RC (Reinforced Concrete) beams with normal steel and FRPH (Fiber Reinforced Plastic Hybrid) bar are investigated. For the work, RC beam members with $200{\times}200{\times}2175mm$ of geometry and 24 Mpa of design strength are prepared, and 4-point-bending tests are performed for evaluation of cracking, yielding, and ultimate loads. Through static loading test, 48.9kN and 36.0 kN of yielding loads are measured for normal RC and FRPH beam, respectively. They have almost same ultimate load of 50.0 kN. Typical tension hardening behavior is observed in FRPH beam, which is caused by the behavior of FRPH bar with tension hardening. In cyclic loading conditions, FRPH beam has more smaller crack width and scattered crack pattern, and it shows more elastic recovery than normal RC beam. The energy dissipation ratio in FRPH beam is 0.83, which is greater than 0.62 in normal RC beam and it shows more effective resistance to cyclic loadings.

Effect of CPR Foundation Reinforcement Assessed by Compressive Loading Tests (CPR 공법의 압축재하시험을 통한 기초지반의 보강효과)

  • Kang, Seong-Seung;Kim, Jung-Han;Noh, Jeongdu;Ko, Chin-Surk
    • The Journal of Engineering Geology
    • /
    • v.29 no.3
    • /
    • pp.211-222
    • /
    • 2019
  • This study evaluates the yield load and allowable bearing capacity of ground in compressive loading tests to confirm the effect of CPR foundation reinforcement. The average compressive strength of the injection materials was higher than the planned compressive strength. Standard penetration tests for each stratum showed that foundation reinforcement improved the average N values, thereby increasing the bearing capacity of the ground. Compressive loading tests on two CPR piles revealed that the total and net settlement due to the maximum load exceed that permissible for the CPR pile diameter. The yield load and allowable bearing capacity calculated by the settlement criterion and the load-settlement curves varied greatly with the method applied. Therefore, it seems to be necessary to determine the optimum value through comprehensive analysis after applying various yield load calculation methods.

Flexural Behavior of Glass Fiber Reinforced Plastic Pipes (유리섬유 강화 플라스틱관의 휨거동에 관한 연구)

  • 장동일;고재원
    • Magazine of the Korea Concrete Institute
    • /
    • v.5 no.3
    • /
    • pp.187-194
    • /
    • 1993
  • 본 논문에서는 유리섬유의 적층수, 유리섬유의 배향각도에 대한 유리섬유 강화 플라스틱(Glass Fiber Reinforced Plastics ; GFRP)의 인장거동 변화를 고찰하고, 이들의 상관관계를 규명하기 위하여 일련의 GFRP 시험체에 대하여 인장실험을 수행하였다. 시험체는 폭12.5mm, 길이 60mm크기로 일정하게 제작하였으며, 시험체에 대하여 인장실험을 수행하였다. 시험체 제작시 유리섬유로 적층수는 14, 22, 30층, 유리섬유의 배향각도는 0$^{\circ}$, 30$^{\circ}$, 45$^{\circ}$로 하였다. 인장실험시 각 시험체의 파괴양상, 극한하중 및 하중변화에 대한 인장변형율을 조사하였고, 이들 결과를 토대로 유리섬유의 적층수와 배향각도에 따른 GFRP의 극한하중, 응력-변형율 선도 및 탄성계수 등을 비교 분석하였다. 한편 본 논문에서는 유리섬유의 적층수, 직경 변화에 따른 GFRP관의 파괴거동을 고찰하기 위하여 4점 재하법에 의한 GFRP관의 휨파괴실험을 수행하였다. 실험에 사용된 시험체는 길이 1200mm로 하였으며, 유리섬유의 적층수를 30, 35, 40층, 관의 직경을 50, 100, 150mm로 하였다. 파괴실험시 각 시험체의 하중변화에 대한 휨 변형율, 중앙점 처짐량 및 항복하중을 측정하였고, 이들 결과를 토대로 유리섬유으 적층수와 관의 직경에 따라 GFRP관의 항복하중 및 파괴에너지를 비교 분석 하였으며, 항복시 파괴에너지를 추정할 수 있는 제안식을 유도하였다.

Flexural Behavior of Composite Ring Stiffened by GFRP and Steel Pipe (GFRP와 강관으로 구성된 합성형 보강링의 휨거동)

  • Yoon, A Reum;Kim, Su Eun;Kim, Sung Bo
    • Journal of Korean Society of Steel Construction
    • /
    • v.29 no.1
    • /
    • pp.61-71
    • /
    • 2017
  • The flexural behavior of composite ring stiffened by GFRP and steel pipe is presented in this paper. The effective width is required to construct FEM beam element model to verify the composite flexural behavior of stiffened ring of cylindrical shell structure. The experimental results are compared with the theoretical and FEM results by commercial program ABAQUS to verify the effective width coefficient. The yield, crack and ultimate loads is calculated using theoretical strains that varies depending on yield state and compared with experiment result and FEM results by ABAQUS solid model.

Studies on Evaluation for Long-term Loading of Composite Wood-joint and Characteristics of Joint Strength (I) - The strength properties of mechanical joints of Pinus densiflora with drift pin and bolt - (목재 접합부의 강도특성 및 장기 내력 평가 (I) - 소나무재의 Bo1t 및 Drift pin 접합부 능력(耐力) 성능 평가 -)

  • Hong, Soon-Il;Hwang, Won-Jung;Kim, Eun-Sam;Jin, Kwang-Sung
    • Journal of the Korean Wood Science and Technology
    • /
    • v.29 no.4
    • /
    • pp.1-8
    • /
    • 2001
  • This study was carried out to investigate the strength and stiffness of drift pinned and bolted joints with steel-plates by the tension-type lateral strength tests. Specimens were solid wood of Pinus densiflora. Bolt and drift pin were jointed with inserted steel plates. Tests were conducted with combinations of two loading directions (parallel to the grain : 0 degree, perpendicular to the grain : 90 degree) and three diameters of fasteners (d = 6 mm, 10 mm, 12 mm). The results obtained were as follow: 1. In the test of the parallel to the grain, maximum loads were increased with increasing of the diameter of bolt and drift pin in the same end distance. In the test of perpendicular to the grain with diameter 10 mm and 12 mm, specimens mostly were failed with horizontal splits in woods reaching the yield load of drift pinned and bolted joints. 2. The ratio of maximum load to the yield load determined by the so-called "5% offset method", was great in bolted joints in the parallel to the grain This trend become more remarkable as the slenderness ratio was increased. 3. The calculated yield strength was agreed well with the experimental results of drift pinned joint(0 degree).

  • PDF

An Applicative Estimation of Safety Factors about Driven Pile Using the Results of Static Loading Test on the Ultimate State (극한상태의 정재하시험결과를 이용한 타입말뚝의 안전율 적용성 평가)

  • Ki, Wan-Seo;Park, Noh-Hwan;Kim, Sun-Hak
    • The Journal of Engineering Geology
    • /
    • v.19 no.4
    • /
    • pp.441-457
    • /
    • 2009
  • This study estimated ultimate load by the determination methods based on ultimate load, yield load and settlement using experimental data from static load tests that applied load to driven piles used in sandy grounds at home and overseas until failure appeared markedly. Estimated ultimate load was normalized with actually measured failure load, and was compared among the determination methods according to the characteristics of pile. In addition, I have identified to the determination methods suitable for estimating ultimate load, and reevaluated the safety factor when determining allowable load. From the results of this study were drawn conclusions as follows. Among ultimate loads estimated by the ultimate-load-based determination methods, the value interpreted by Chin's method tended to overestimate actual measurements, and B. Hansen 80% standard and the stability plot method were considered most reliable as their results were closest to actual measurements. According to the results of this study, in calculating the allowable load, if the safety factor to be applied to failing load obtained by the method of determining extreme load is converted to the safety factor applied to the Standards for Structure Foundation Design, a value larger than 3.0 should be applied except the B. Hansen 90% method, and a value larger than 2.0 should be applied in the methods of determining yield load. In addition, if the safety factor to be applied to load obtained by the settlement standard is converted based on safety factor 3.0 for extreme load, a value smaller than 3.0 should be applied to the total settlement standard and the net settlement standard.