• 한국안전학회지
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• 제18권1호
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• pp.81-88
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• 2003

Recently, pile foundations were constructed in rough or soft ground than ground of well condition thus it is important that prediction of ultimate bearing capacity and calculation of proper safety factor applied pile foundation design. This study were performed to dynamic loading tests for the thirty two piles at four different construction sites and selected pile at three site were performed to static loading tests and then compare with measured value and value of static and dynamic loading tests. The load-settlement curve form the dynamic loading tests by CAPWAP was very similar to the results obtained from the static load tests. Based on dynamic and static loading tests, the reliability of pile-driving formula were analyzed and then suggested with proper safety factor for prediction of allowable bearing capacity in this paper.

• 한국농공학회지
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• 제39권2호
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• pp.124-133
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• 1997

Pile load test is good for estimating pile bearing capacity, but using this method is limited by time and cost required. Dynamic and static method is more convenient and economical, but confidence of estimated value by dynamic and static method are lower than that of pile load test. After being compared pile bearing capacity data obtained from pile load test with those of other two methods, the results from this study were summarised as follows. For allowable bearing capacity values greater than 175t per pile, bearing capacity acquired from static method was higher than that acquired from pile load test, whereas bearing capacity acquired from pile load test was higher than that acquired from static method for values under 175 per pile. It was that variance of bearing capacity was large when bearing capacity obtained by dynamic method was higher than 250t. Also bearing capacity based on dynamic method was higher than that based on pile load test. Allowable bearing capacity get from dynamic method suggested that carefull precautions are necessary in application for allowable bearing capacity values higher than 2S0ton per pile.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2002년도 가을 학술발표회 논문집
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• pp.390-397
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• 2002

In this study, static pile load tests with load transfer measurement for a pile socketed into weathered rocks were performed. Axial load transfers during static pile load test were measured and analyzed. Three large diameter piles socketed into weathered rock were behavior behaved as friction pile.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1992년도 봄 학술발표회 논문집 깊은 기초의 연구와 실무(RESEARCH AND PRACTICE OF DEEP FOUNDATIONS)
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• pp.13-40
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• 1992

Static formulae based on limiting equilibrium theories often provide misleading predictions of pile bearing capacity in cohesionless soils due to the incorrect basic assumptions or oversimplification of actual soil conditions. Soil conditions prior to pile driving are significantly changed after pile installation and imposition of high stress levels. Therefore soi1 parameters at failure rather than those obtained at initial conditions should be used in application of static formulae. In this research. model pile test data were analyzed and compared with the predicted values obtained from the various static formulae. The results showed that the proper choice of soil parameters remarkably improve the reliability of static formulae.

• 한국지반환경공학회 논문집
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• 제18권9호
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• pp.11-18
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• 2017

수치해석기법을 이용한 말뚝의 거동특성 예측방법은 정재하시험비가 고가이기 때문에 공사 전 말뚝의 거동을 예측할 수 있다는 장점으로 설계단계에서 널리 이용되고 있지만 그 신뢰성에 대한 연구는 부족한 실정이다. 본 연구에서는 실제 현장에서 말뚝의 거동과 수치해석으로 예측한 말뚝의 거동을 비교함으로써 수치해석 기법의 신뢰성을 검증하였다. 지반과 말뚝의 상호작용에 의한 말뚝의 거동을 정확하게 파악하기 위하여 정재하시험이 수행되는 지반에서 시추조사, 현장원위치시험 등을 통해 지반특성을 확인하였고, 실규모 정재하시험을 수행하여 말뚝의 거동특성을 분석하였다. 정재하시험이 수행된 방식과 동일하게 수치해석을 모사하여 재하시험과 동일한 하중단계에서 말뚝의 거동을 수치해석으로 모사하여 현장시험 결과와 비교함으로써 수치해석 기법의 신뢰성을 검증하였다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1999년도 봄 학술발표회 논문집
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• pp.249-258
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• 1999

Dynamic load and static load tests are performed on steel pipe piles and concrete piles at five construction sites in highway to compare the difference of load bearing mechanisms. At each site, one steel pile is instrumented with electric strain gages and dynamic tests are performed on the pile during installation. Damages of strain gages due to the installation are checked and static test is performed upon the same pile after two or seven days as well. It shows that load transfer from side friction to base resistance behaves somewhat differently according to the results of load-settlement analysis obtained from PDA and static load test. Initial elastic stage of load settlement curves of two load tests is almost similar. But after the yielding point, dynamic resistance of pile behaves more stiffer than static resistance, thus, dynamic load test result might overestimate the real pile capacity compared with static result. Analysis of gage readings shows that unit skin friction increases exponentially with depth. The skin friction is mobilized at the 1∼2m above the pile tip and contributes to the considerable side resistance. Comparison of side and base resistances between the measured value and the calculated value by Meyerhof's bearing capacity equation using SPT N value shows that the calculated base resistance is higher than the measured. Therefore, contribution of side resistance to total capacity shouldn't be ignored or underestimated. Finally, based upon the overall test results, a construction control procedure is suggested.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2000년도 말뚝기초 학술발표회
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• pp.107-141
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• 2000

Large diameter piles can be defined as piles with diameter of at least 0.76 m (2.5 ft). In bridge foundation, large diameter piles have been used as pier foundations and their use has been increased greatly. In this study, static pile load tests for large diameter piles peformed in Kwangan Grande Bridge construction site were introduced. Also, various sensor installation methods for several types of piles (that is, open-ended steel pipe pile, drilled shafts and socketed pipe piles), pipe axial load measuring method, load transfer analysis method and pile load test results (pile-head load - settlement curve, and pile axial load distribution curve along the pile depth) were introduced.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1997년도 가을 학술발표회 논문집
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• pp.409-416
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• 1997

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2002년도 봄 학술발표회 논문집
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• pp.589-596
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• 2002

In this study, static pile load tests with load transfer measurement were accomplished in the field. Yield pile capacity (or ultimate pile capacity) determined by load-settlement-time relationship was determined and axial load transfer behavior was analyzed. In the test for the four test piles were behaved as end bearing pile but ratios of skin friction to total pile capacity were 27%∼33%.

• Geomechanics and Engineering
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• 제32권4호
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• pp.453-462
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• 2023

Designing pile foundations subjected to the uplift forces such as buildings, oil platforms, and anchors is becoming increasingly concerned. In this paper, the conceptual design of a new type of driven piles called expanding pile is presented and assessed. Some grooves have been created in the shaft of the novel pile, and some moveable arms have been designed at the pile tip. At first, static analyses using the finite element method were performed to evaluate the effectiveness of the innovative pile on the axial bearing capacity. Then its effect on seismic behavior of moment frame is considered. Results show that the expanding arms were provided an ideal anchorage system because of the soil's noticeable locking-up effect increasing uplift bearing capacity. For example at the end of the static tensile loading procedure, displacement decrement up to 55 percent is observed. In addition, comparing the uplift bearing capacity of the usual and new pile with different lengths in sand and clay layers shows noticeable effect and sharp increase up to about two times especially in longer piles. Besides, a sensible reduction in the seismic response and the stresses in the beam-column connection between 23-36 percent are achieved that ensures better seismic behavior of the structures.