• Title/Summary/Keyword: Load Capacity

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A Case Study of High Capacity Bi-Directional High Pressure Pile Load Test (초고용량 양방향 말뚝재하시험(BDH PLT) 수행사례 분석)

  • Kim, Sang-Il;Lee, Min-Hee;Jeong, Sung-Min;Jeong, Eun-Taeg;Choi, Yong-Kyu
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.03a
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    • pp.1156-1163
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    • 2010
  • The bi-directional high pile load test(BDH PLT) does not have weaknesses found in the existing bi-directional low pile load test(BDL PLT); it has strong economics, is unbound by load capacity limit and secures quality stability of working piles. In this study, Verification the field found a very high capacity level of stability and reliability of the BDH PLT, as well as outstanding field applicability. Field verifications reaffirmed the advantage of the BDH PLT device, which was capable of loading 90 MN capacities as maximum. It was also found to be durable enough to load high capacity with ease.

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Elastic Analysis of a Cracked Ellipsoidal Inhomogeneity in an Infinite Body

  • Cho, Young-Tae
    • Journal of Mechanical Science and Technology
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    • v.15 no.6
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    • pp.709-719
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    • 2001
  • In particle or short-fiber reinforced composites, cracking of reinforcements is a significant damage mode because the cracked reinforcements lose carrying capacity. This paper deals with elastic stress distributions and load carrying capacity of intact and cracked ellipsoidal inhomogeneities. Three dimensional finite element analysis has been carried out on intact and cracked ellipsoidal inhomogeneities in an infinite body under uniaxial tension and pure shear. For the intact inhomogeneity, as well known as Eshelbys solution, the stress distribution is uniform in the inhomogeneity and nonuniform in the surrounding matrix. On the other hand, for the cracked inhomogeneity, the stress in the region near the crack surface is considerably released and the stress distribution becomes more complex. The average stress in the inhomogeneity represents its load carrying capacity, and the difference between the average stresses of the intact and cracked inhomogeneities indicates the loss of load carrying capacity due to cracking damage. The load carrying capacity of the cracked inhomogeneity is expressed in to cracking damage. The load carrying capacity of the cracked inhomogeneity is expressed in terms of the average stress of the intact inhomogeneity and some coefficients. It is found that a cracked inhomogeneity with high aspect ratio still maintains higher load carrying capacity.

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A Comparative Study on the Bearing Capacity of Dynamic Load Test and Static Load Test of PHC Bored Pile (PHC 매입말뚝의 동재하시험과 정재하시험의 지지력 비교·분석 연구)

  • Park, Jongbae
    • Journal of the Korean GEO-environmental Society
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    • v.18 no.9
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    • pp.19-31
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    • 2017
  • In case of USA, the drilled shaft and the driven pile in the field showed a good correlation in the analysis of the bearing capacity between the dynamic load test and the static load test. However, in Korea, we mainly install the bored pile, which is not widely used overseas and we tried to confirm the reliability of the dynamic load test on the bored pile, because many people questioned the reliability of it. In this study, load tests were carried out on PHC bored piles in LH field (Cheonan, Incheon, Uijeongbu), and the bearing capacity of the dynamic load test (EOID 7times, Restrike 7times) and the static load test (7times) were compared and analyzed. As a result, the average of the bearing capacity of the static load test was 27% higher than that of the dynamic load test (reliability : 0.73, coefficient of variation : 0.3). And the average of the bearing capacity of the static load test (Davisson) was 27% higher than that of the bearing capacity of the dynamic load test (Davisson) (reliability : 0.73, coefficient of variation : 0.2). To reduce the difference between the bearing capacity of the dynamic load test and the static load test, we proposed modified bearing capacity of dynamic load test (base bearing capacity of EOID + skin frictional force of restrike) and difference between the bearing capacities was reduced to 9% (reliability : 0.91, coefficient of variation : 0.2). And the coefficient of variation was reduced to 0.2 and the consistency of analysis increased.

A Study on the Load Carrying Capacity Assessment of the Preflex Beam Bridge (프리플렉스 합성형교의 내하력 평가에 관한 연구)

  • 채원규
    • Proceedings of the Korean Institute of Industrial Safety Conference
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    • 1997.11a
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    • pp.145-150
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    • 1997
  • In this thesis, the field test by truck load and the structural analysis were performed on a preflex beam bridge to investigate the load carrying capacity. From the field test and the structural analysis results, K(corrective factor) and $P_n$(load carrying capacity) of the preflex beam bridges were studied, and these factors were applied to the load carrying capacity assessment of the preflex bridges.

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A Study on the Load Carrying Capacity Assessment Method of the Prestressed Concrete Beam Bridges (연속 프리스트레스트 콘크리트 빔교의 내하력 평가 기법에 관한 연구)

  • 채원규
    • Journal of the Korean Society of Safety
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    • v.13 no.3
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    • pp.126-134
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    • 1998
  • In this paper, the field test by truck load and the structural analysis were performed on a prestressed concrete beam bridge to investigate the load carrying capacity of the prestressed concrete beam bridges. From the results of the field test and the structural analysis, CAF (composite action factor), TIF(transformed impact factor), and $P_n$(load carrying capacity) of the prestressed concrete beam bridges were studied, and the load carrying capacity assessment of the prestressed concrete beam bridges were carried out using these factors.

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Estimation of Bearing Capacity for Open-Ended Pile Considering Soil Plugging (폐색정도를 고려한 개단말뚝의 지지력 산정)

  • 백규호
    • Proceedings of the Korean Geotechical Society Conference
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    • 2002.03a
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    • pp.397-404
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    • 2002
  • The bearing capacity of open-ended piles is affected by the degree of soil plugging, which is quantified by the IFR. There is not at present a design criterion for open-ended piles that explicitly considers the effect of IFR on pile load capacity In order to investigate this effect, model pile load tests using a calibration chamber were conducted on instrumented open-ended piles. The results of these tests show that the IFR increases with increasing relative density and increasing horizontal stress of soils. The unit base and shaft resistances decrease with increasing IFR. Based on the results of the model pile tests, new empirical relations for base load capacity and shaft load capacity of open-ended piles are proposed. In order to check the accuracy of predictions made with the proposed equations, the equations were applied to the full-scale pile load test preformed in this study, Based on the comparisons with the pile load test results, the proposed equations appear to produce satisfactory predictions.

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The Relationship between the Load Carrying Capacity and Transformed Impact Factor of Highway Bridge (교량의 공용내하력과 환산충격계수 관계 연구)

  • Chai, Won-Kyu;Lee, Myeong-Gu
    • Journal of the Korean Society of Safety
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    • v.27 no.6
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    • pp.138-143
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    • 2012
  • In this thesis, the relationship between the load carrying capacity and the transformed impact factor of the highway bridges were studied. The bridges are classified according to superstructures type. The result of the comparison between the load carrying capacity and the transformed impact factor, if the load capacity ratio of 0.57, the transformed impact factor was less in order of RC T-beam bridge, RC slab bridge, PC beam bridge, I-beam bridge. By the regression analysis on these results, the empirical formulae to predict the the load carrying capacity of bridge were suggested.

Experimental Study on the Load Carrying Performance and Driving Torque of Gas Foil Thrust Bearings (가스 포일 스러스트 베어링의 하중지지 성능 및 구동 토크에 관한 실험적 연구)

  • Kim, Tae Ho;Lee, Tae Won;Park, Moon Sung;Park, Jungmin;Kim, Jinsung;Jeong, Jinhee
    • Tribology and Lubricants
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    • v.31 no.4
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    • pp.141-147
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    • 2015
  • Gas foil thrust bearings (GFTBs) have attractive advantages over rolling element bearings and oil film thrust bearings, such as oil-free operation, high speed stability, and high-temperature operation. However, GFTBs have lower load carrying capacity than the other two types of bearings owing to the inherent low gas viscosity. The load carrying capacity of GFTBs depends mainly on the compliance of the foil structure and the formed hydrodynamic wedge, where the gas pressure field is generated between the top foil and the thrust runner. The load carrying capacity of the GFTBs is very important for the suitable design of oil-free turbomachinery with high performance. The aim of the present study is to identify the characteristics of the load carrying performance of GFTBs. A new test rig for the experimental measurements is designed to provide static loads up to 800 N using a pneumatic cylinder. The maximum operating speed of the driving motor is 30,000 rpm. A series of experimental tests—lift-off test, static load performance test, and maximum load capacity test—estimate the performance of a six-pad GFTB, in terms of the static load, driving torque, and temperature. The maximum load capacity is determined by increasing the static load until the driving torque rises suddenly with a sharp peak. The test results show that the torque and temperature increase linearly with the static load. The estimated maximum load capacity per unit area is approximately 80.5 kPa at a rotor speed of 25,000 rpm. The test results can be used as a design guideline for GFTBs for realizing oil-free turbomachinery.

A Study on Improved Allocations of Permissible Water Pollution Load at the Implementing Stage of Tatal Water Pollution Load Management Plan (수질오염총량관리계획의 시행단계에서 오염부하량 할당방안 개선에 관한 연구)

  • Kim Sie-Heon;Rim Jay-Myung
    • Journal of environmental and Sanitary engineering
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    • v.20 no.3 s.57
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    • pp.51-56
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    • 2005
  • Allocation of water pollution load from loading capacity can be much essential, controversial, and its standards can be applied case-by-case to the various situations. Allocation methods to point sources are generally 'Equal effluent concentration', 'Equal percent Treatment', Loading capacity at planning stage consists of basic pollution load, development pollution load, reserved pollution load and margin of safety. But at the implementing stage loading capacity can be consisted of allocatable load and margin of safety to give more flexibility in the total water pollution load management plan. In that case, we can re-adjust and altogether use the pollution load of point sources of series and non-point sources at the implementing stage.

Crack and Deformation Behaviors of Steel Fiber Reinforced Concrete Slab Model Specimens Using Domestic Steel Fiber (국내 강섬유를 사용한 강섬유보강 콘크리트 슬래브 모델의 균열 및 변형특성)

  • 박승범;홍석주;이봉춘;조춘근
    • Proceedings of the Korea Concrete Institute Conference
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    • 1999.04a
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    • pp.319-324
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    • 1999
  • This study is to investigate the properties on the load-deflection and fracture behaviors of the steel fiber reinforced concrete(SFRC) slab model specimens, Steel fibers of indent, crimp, and end hook shape were considered to reinforce the matrix under various mixing conditions and proportions. Initial cracking load, maximum load, and energy absorption capacity(load carrying capacity) of SFRC panel specimen increased with increase of steel fiber contents. And the plain concrete slab was fractured abruptly after maximum load but SRFC slabs were fractured smoothly by steel fibers in concrete matrix operated as cracking resistance force after maximum load. Indent, crimp and end hook shape steel fibers were effective in reinforcing the matrices but end hook type fiber were superior to indent and crimp type fibers.

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