• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.1819-1826
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• 2007

This study results of performed field load test in order to estimate the best pile length assessment and allowable bearing capacity of the pile foundation. End of initial driving(EOID) and restrike of pile dynamic loading tests were performed to calculate allowable bearing capacity of the experimental pile side and results were compared with the allowable bearing capacity estimated by theory. The results of allowable bearing capacity by EOID test is $1.08{\sim}1.21$ in the range of compared to the capacity calculated by the Structure Foundation Design Criterion. Allowable bearing Capacity by restrike of pile dynamic loading test is $1.32{\sim}1.48$ in the range of compared to the Structure Foundation Design Criterion. The Foundation Design Criterion underestimated the pile capacity. If the bearing capacity calculated by Structure Foundation Design Criterion is 100, EOID of pile dynamic loading test is 116, restrike of pile dynamic loading test is 138 for 20m pile used in this experimental.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 춘계 학술발표회
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• pp.1088-1093
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• 2010

The Smart bi-directional pile load test with variable end plate overcomes the shortcoming of the Osterberg cell test. It is possible that the ultimate bearing capacity of piles can be known by using two different end plates. The first step is to measure end bearing capacity with smaller end plate and the second step is similar to the conventional O-cell test. In this study, model test was performed to evaluate the smart bi-directional pile load test in sand. Vertical displacement of the model pile were messured at the axial loading condition.

• 풍력에너지저널
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• 제3권1호
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• pp.61-67
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• 2012

The loading test of wind turbine pitch and yaw bearings have been conducted using special test rig designed for the test of large slewing bearings. Test type was fatigue test that applied fatigue load to each bearing and followed the defined test process. Measurement data during test were rotational torque and raceway temperature, and inspected key components by disassembling the bearing after all test finished. As a results, the raceway temperature during test did not exceed the operational temperature range of lubricant and rotational torque was reduced as the bearing's rotational cycle increased. In the inspection of key components, some plastic deformation and flaking were detected at some raceway sections while other components such as ball, spacer and seal remain indefective conditions.

• 한국지반신소재학회논문집
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• 제12권4호
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• pp.99-107
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• 2013

매입말뚝의 수평저항 특성을 고찰하기 위하여 매입말뚝에 대한 수평재하시험을 실시하여 수평하중과 수평변위관계를 분석하였다. 말뚝수평재하시험은 시멘트 밀크가 말뚝매입길이의 50%, 70%, 100%로 주입된 6개의 말뚝에 대하여 실시하였다. 시멘트 밀크의 주입비(시멘트 밀크 주입길이/말뚝의 길이)는 매입말뚝의 수평변위, 항복하중, 수평지지력에 큰 영향을 미치는 것으로 나타났다. 시멘트 밀크의 주입비가 증가할수록 매입말뚝의 수평변위가 발생되기 시작하는 위치는 지표면에 가까워지며 말뚝의 수평변위는 감소한다. 그리고 말뚝의 수평지지력과 항복하중은 시멘트 밀크 주입비가 증가할 수록 크게 나타났다. 시멘트 밀크 주입비가 1인 매입말뚝의 항복하중과 극한수평지지력은 시멘트 밀크 주입비가 0.5인 경우보다 약 2~3배 정도 크게 나타났다.

• 한국지반공학회논문집
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• 제23권5호
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• pp.89-100
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• 2007

본 연구에서는 건조 고결층이 형성된 준설 매립 지반의 지반 개량 및 보강을 위한 시공 초기 단계에서 지반의 안정성과 장비의 주행성 평가 시 고려되는 지지력 산정과 관련하여 다양한 실내 및 현장 시험을 수행하였다. 지반조사를 통해 기본물성 특성을 파악하였고 현장 베인 시험 및 일축압축 직접전단시험을 통하여 지반의 깊이별 강도분포와 고결층의 강도 특성 및 응력-변형률 거동을 살펴보았다. 또한 지반의 지지력 평가와 하중-침하 곡선 및 파괴형태를 파악하기 위하여 평판재하시험을 수행하였다. 기존의 2층 지반 지지력 산정 기법을 이용하여 지지력을 산정하였으며 이를 평판재하시험 결과와 비교하여 지지력 산정 기법의 적용 방법에 대하여 논의해 보았다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1998년도 봄 학술발표회 논문집
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• pp.203-212
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• 1998

• 한국산학기술학회논문지
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• 제13권10호
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• pp.4863-4868
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• 2012

모래지반에 설치된 무리말뚝 중 두 개의 말뚝에 대하여 하중재하시험을 실시하고 그 결과를 하중전이법을 적용한 해석결과와 비교 분석하였다. 무리말뚝 설치 후 무리말뚝의 중앙부에 위치한 말뚝에 대한 해석결과에 따르면 하중지지능력이 재하시험결과보다 작게 나타났는데 주된 원인은 무리말뚝 설치로 인한 지반조밀화로 생각된다. 또한 API 방법과 Coyle and Sulaiman 방법을 적용하여 구한 하중-침하곡선으로부터 Davisson 방법을 통해 구한 말뚝의 극한지지력은 재하시험에 의한 극한지지력 값의 각각 77%와 90%였다. 무리말뚝 설치로 인한 지반 조밀화의 영향을 비교적 덜 받은 가장자리 말뚝에 대한 재하시험결과와 해석결과를 비교할 때 Davisson 방법을 통해 구한 말뚝의 극한지지력은 API 방법과 Coyle and Sulaiman 방법에 의할 경우 재하시험결과에 의한 값에 비해 각각 1.1배와 1.3배의 값을 보였다.

• 산업기술연구
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• 제21권B호
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• pp.205-212
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• 2001

This paper is experimental and numerical research about the sliding behavior of cantilever retaining walls resisting surcharge loads. In experimental research, centrifuge model tests at the lg and 40 g-level were performed by changing the location of model footing and its width. Bearing capacity of model footing and characteristics of load-settlement and load-lateral displacement of retaining wall were investigated. Test results of bearing capacity were compared with modified jarquio method, based on the limit equilibrium method with elasticity theory. For the numerical analysis, the commericially available program of FLAC was used by implementing the hyperbolic constitutive relationships to compare with test result about load-settlement and load-displacement of retaining wall, bearing capacity of strip footing.

• 한국안전학회지
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• 제16권3호
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• pp.99-105
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• 2001

This paper presents results km a series of model tests oil vertically loaded single piles to compare the behaviors of H and pipe piles under the same ground condition. The aims of this paper were to compare the bearing capacity of H-pile md pipe piles under in the same ground condition and to estimate the effect of gravity acceleration and relative soil density. Relative density of soil were made to be 40%, 80% and embedded length of pile on sand was increased by 10, 12, 14, 16 times of the diameter of pile, respectively. As a results of test series, allowable load of H-pile is from 6.4% to 18.2% larger than allowable load of pipe pile in relative density 80% and from 9.1% to 39.4% larger than allowable load of pipe pile in relative density 40%. As a results of numerical analysis, we were predicted behaviour of stress-displacement of pile with model test. In the case of relative density 80% and 40%, bearing capacity of H pile represent from 17.74% to 18.6% larger than allowable load of pipe pile.

• 한국철도학회논문집
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• 제3권2호
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• pp.84-91
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• 2000

The general concept of reinforced roadbed in the high-speed railway is to cope with the soft ground for the bearing capacity and settlement of foundation soil. The cyclic plate load tests were performed to determine the behavior of reinforced ground with multiple layers of geogrid underlying by soft soil. With the test results, the bearing capacity ratio, elastic rebound ratio, subgrade modulus and the strain of geogrids under loading were investigated. Based on these plate load tests, laboratory model tests under cyclic loading were conducted to estimate the effect of geogrid reinforcement in particular for the high-speed rail roadbed. The permanent settlement and the behavior of earth pressure in reinforced roadbed subjected to a combination of static and dynamic loading are presented.