• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1994년도 가을 학술발표회 논문집
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• pp.79-86
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• 1994

Two case studies on the application of Pile Driving Analyzer (PDA) are introduced. It is shown that the PDA and CAPWAP are effective tools for the construction control of pile foundations with minimum cost and time. The PDA and CAPWAP techniques are able to evaluate the performace of hammer and driving system: to check the stresses in the pile due to driving: to determine the damage of pile: to predict the ultimate bearing capacity of pile: to estimate the important soil paramaters such as the soil resistance, quake, and damping etc.: and to provide the load - displacement curve from the simulated static load test. Theoretical backgrounds of wave mechanics is briefly reviewed and the methodology of construction control using the PDA is also discussed.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2004년도 춘계학술발표회
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• pp.11-19
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• 2004

When pile foundation constructed by driving method, it is desirable to perform monitoring and estimation of pile drivability and bearing capacity using some suitable tools. Dynamic Pile Monitoring yields information regarding the hammer, driving system, and pile and soil behaviour that can be used to confirm the assumptions of wave equation analysis. Dynamic Pile Monitoring is performed with the Pile Driving Analyser. The Pile Driving Analyser (PDA) uses wave propagation theory to compute numerous variables that fully describe the condition of the hammer-pile-soil system in real time, following each hammer impact. This approach allows immediate field verification of hammer performance, driving efficiency, and an estimate of pile capacity. The PDA has been used widely as a most effective control method of pile installations. A set of PDA test was performed at the site of Donghea-1 Gas Platform Jacket which is located east of Ulsan. The drilling core sediments of location of jacket subsoil are composed of mud and sand, silt. In this case study, the results of PDA test which was applied to measurement and estimation of large diameter open ended steel pipe pile driven by underwater hydraulic hammer, MHU-800S, at the marine sediments were summarized.

• 한국지반공학회지:지반
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• 제13권5호
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• pp.145-154
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• 1997

말뚝재하시험방법 중 정적재하시험은 시험에 소요되는 시간과 비용측면에서 불리하여 이를 개선하기 위한 여러 가지의 시험방법이 개발되어 소개되고 있다. 국내에 소개된 시험방법으로는 동재하시험으로 불리는 항타분석기 (PDA : Pile Driving Analyzer)를 이용한 방법을 비롯하여 STATNAMIC. Osterberg cell등이 있다. 이들 중 동재하시험의 사용은 상당히 활성화되어 있는 실정이나 지반조건과 말뚝시공방법에 따라서는 지지력산정시 추가적인 해석모델을 사용하여야 보다 정확한 지지력을 평가 할 수 있는 것으로 알려져 있다. 본 논문에서는 현장에서 수행한 정적 및 동적 재하시험결과의 비교1분석으로 부터 주로 SIP말뚝에 대한 동재하시험시 발생할수 있는 기하감쇠(geometrical damping)의 영향을 고찰하였다. 해석결과로 부터 기하감쇠가 발생한 지반의 경우 CAPWAP에 의해 산정된 지지력이 정재하시험에 의한 지지력에 비해 30~60% 정도 과소평가 되었으며 이때 말뚝주면에 대한 Smith의 감쇠계수 (SSkn)가 1.0 sec/m를 초과 하였다. CAPWAP해석시 기하감쇠를 고려한 해석모델을 사용함으로써 정재하 시험결과와 근사한 지지력을 얻을 수 있었으며 SSkn값도 0.7sec/m이하의 일반적인 범위로 해석되었다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1996년도 가을 학술발표회 논문집
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• pp.357-362
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• 1996

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2002년도 봄 학술발표회 논문집
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• pp.405-412
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• 2002

The performance of a hammer/driving systems is a major factor which affects bearing capacity and integrity of installed piles. Hammer performance can be evaluated from the results of dynamic pile testing using Pile Driving Analyzer(PDA). By comparing the rated energy with measured maximum transferred energy(EMX), the energy transfer ratio(ETR) can be calculated. This paper based on the dynamic measurements of 442 cases in 130 piling projects and evaluated ETR according to the hammer types(hydraulic and drop hammers) and pile types(steel and concrete piles).

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2011년도 춘계 학술논문 발표대회 2부
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• pp.63-66
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• 2011

The aim of this study is to estimate the field applicability of PBFM to replace in-site soil with pile backfill used to replace the existing cement paste. As results, the flowability, segregation and bleeding, and bond strength of PBFM was a good performance than that of the existing cement paste. But the skin friction of pile by Pile Driving Analyzer (PDA) and compressive strength was slightly decreased than that of the existing cement paste. However, as pile backfill materials, and in terms of economics and environment, the applicability of PBFM is considered very effective.

• Geomechanics and Engineering
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• 제8권3호
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• pp.415-440
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• 2015

In the present case study, High Strain Dynamic Testing of piles is conducted at 3 different locations of Kolkata city of India. The raw field data acquired is analyzed using Pile Driving Analyzer (PDA) and CAPWAP (Case Pile Wave Analysis Programme) computer software and load settlement curves along with variation of force and velocity with time is obtained. A finite difference based numerical software FLAC3D has been used for simulating the field conditions by simulating similar soil-pile models for each case. The net pile displacement and ultimate pile capacity determined from the field tests and estimated by using numerical analyses are compared. It is seen that the ultimate capacity of the pile computed using FLAC3D differs from the field test results by around 9%, thereby indicating the efficiency of FLAC3D as reliable numerical software for analyzing pile foundations subjected to impact loading. Moreover, various parameters like top layers of cohesive soil varying from soft to stiff consistency, pile length, pile diameter, pile impedance and critical height of fall of the hammer have been found to influence both pile displacement and net pile capacity substantially. It may, therefore, be suggested to include the test in relevant IS code of practice.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2004년도 춘계학술발표회
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• pp.28-35
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• 2004

Driven pile has the excellent bearing characteristics and good economics, so it is known as the comparative piling method. To use the advantages of driven pile fully, it is necessary to perform the proper construction management. Engineers must drive pile to the proper bearing layer with proper blow energy and measure the blow count and penetration per certain depth to analyze the bearing capacity and driveability. In conventional method, these parameters have been measured manually so it was difficult to get good accuracy. After PIR-D(Pile Installation Recorder-Driven Pile) was attached to the driving equipment, the hammer efficiency, blow count and penetration in blow/10cm were measured automatically. In this paper, to givethe rational judgement criteria of bearing layer, driveability, blow/10cm according to pile depth during pile driving, the some relationship between the driving resistance and ground layer distribution was analyzed. The ground investigation during piles (PHC ${\Phi}450,\;{\Phi}400\;&\;Steel\;Pile\;{\Phi}609{\ast}16t$) installation in the marine clay layer in Incheon, the sandy soil layer in Yongin and the tuff layer in Pusan was done. And measuring hammer efficiency not doing recently, we could compare hammer efficiency(Eh) by PIR-D and energy transfer ratio(ETR) by Pile Dynamic Analyzer(PDA).

• 한국지반공학회논문집
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• 제22권12호
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• pp.33-43
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• 2006

직항타공법에서 사용되는 해머 쿠션의 재질 차이가 항타시 주변 지반의 진동과 발생 소음 및 에너지 전달효율에 미치는 영향을 실내 모형시험을 통해 평가하였다. 항타 과정을 모사할 수 있는 모델 말뚝과 항타시스템 및 스트레인 게이지와 홉킨슨 바(Hopkinson bar)를 이용한 에너지 전달효율 측정장치를 제작, 구성하였다. 해머 쿠션 재질로는 상용의 해머 쿠션재인 Micarta 이외, 현장에서 다수 사용하는 Plywood, Polyurethane, Rubber(SBR), Silicone rubber 등의 5가지 재료를 선정하여 항타시험을 실시하였다 항타시험결과 쿠션 재료별 에너지 전달효율은 (1)Micarta, (2)Polyurethane, (3)Plywood, (4)Rubber(SBR), (5)Silicone rubber의 순이었다. 또한 에너지 전달효율이 높은 쿠션재료가 음압레벨의 평균치 또한 높은 비례관계를 보였다. 항타 종료후 말뚝 정재하시험을 실시하여 말뚝의 지지력과 축하중전이 특성을 비교, 분석한 결과 Micarta와 Polyurethane이 다른 쿠션재료에 비해 높은 지지력 값을 보였다.

• 한국지반공학회논문집
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• 제29권12호
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• pp.105-111
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• 2013

국내외에서 널리 사용 중인 표준관입시험(Standard Penetration Test, SPT)은 작업의 용이성, 다양한 지반정수와 강도정수를 결정방법 등의 장점을 지니고 있다. 이러한 SPT 수행시에 발생하는 해머 에너지는 N치의 산정 및 보정에 매우 중요한 영향인자가 된다. SPT시험시 해머 타격에 의하여 롯드로 응력파가 전달되는 현상이 말뚝 항타 시에 발생하는 현상과 동일하다하여 SPT에 PDA장비를 적용하여 관입에너지를 측정하는 방법이 개발되어 사용 중에 있다. 본 연구에서는 SPT 롯드를 말뚝으로 가정하여 SPT 에너지 효율 측정롯드를 SPT시험과 동적콘관입시험에 적용하여 얻어진 힘과 속도의 파형을 매칭기법(CAPWAP, CAse Pile Wave Analysis Program) 분석을 수행하여 매입말뚝에 대한 극한선단지지력을 예측하는 기법을 제안하였다. 또한, SPT 에너지 효율 측정롯드에서 예측된 선단지지력과 실물 말뚝정재하시험을 통하여 산정된 선단지지력을 비교분석하였다. 연구결과를 토대로 SPT나 동적콘관입시험을 통하여 매입말뚝의 지지력을 간편하게 예측할 수 있는 경험식을 제시하였다.