• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2000년도 가을 학술발표회 논문집
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• pp.353-360
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• 2000

We developed large diameter sampler (we called KICT type large diameter sampler) to obtain undisturbed clay and sand samples. In-situ test carried out in the In-Chon international airport and Kim-Hae. Also we obtained undisturbed sample with a hydraulic piston sampler in the nearly site and carried out unconfined compression test, consolidation test and triaxial test. The result, unconfined compression strength, secant modules, preconsolidation pressure and undrained shear strength of samples to obtain KICT type large diameter sampler are larger than that of samples to obtain hydraulic piston sampler. But failure strains and volume changes at the consolidation of samples to obtain KICT type large diameter sampler are smaller than that of samples to obtain hydraulic piston sampler

• 한국지반환경공학회 논문집
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• 제6권3호
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• pp.5-15
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• 2005

연약지반에서 비교란 시료를 채취할 수 있는 대구경 샘플러(KICT형 샘플러)를 개발하였다. 이 대구경 샘플러로 채취한 시료와 종래의 피스톤 샘플러로 채취한 시료의 질을 평가하기 위하여 인천, 김해, 양산, 부산에서 각각의 샘플러로 시료를 채취하였으며, 실내에서 일축압축시험, 압밀시험, 삼축압축시험 및 공진주시험을 수행하였다. 그 결과, KICT형 대구경 샘플러로 채취한 시료의 일축압축강도, 할선탄성계수, 선행압밀응력, 비배수전단강도, 전단계수가 수압식 피스톤 샘플러로 채취한 시료의 그것들보다 더 크게 나타났으며, 파괴시 변형률과 압밀시 발생되는 체적변형률은 작게 나타났다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 추계 학술발표회
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• pp.1365-1369
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• 2008

A large diameter sampler (KICT-type large diameter sampler) was developed to take undisturbed samples from not only soft ground but also sandy and weathered ground. The KICT-type large diameter sampler was manufactured with the principle of triple core barrel sampling. In this study, the applicability to offshore ground sampling of the KICT-type large diameter sampler was confirmed at Inchoen Port construction site. And, in order to compare the quality of samples taken by the sampler with that of the traditional piston sampler, a series of laboratory tests were performed. From the test results, the samples taken by the KICT-type large diameter sampler showed higher quality than the traditional thin-walled tube samples.

• 한국지반환경공학회 논문집
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• 제9권1호
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• pp.27-31
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• 2008

본 연구는 직경 225mm의 KICT 대구경 샘플러와 NX size 피스톤 샘플러를 사용하여 채취한 점토시료의 강도정수를 비교하여 대구경 샘플러가 NX size 피스톤 샘플러에 비해 원지반 상태를 얼마나 잘 반영하는가를 평가하는데 그 목적이 있다. 이 연구를 위하여 두 가지 샘플러로 채취한 점토 시료를 동일 조건에서 표준압밀시험, 일축압축시험, 삼축압축시험을 수행하여 채취 시료의 교란도 분석을 하였다. 분석결과 초기간극비와 선행압밀응력 뿐만 아니라 시료의 일축 및 삼축압축 시험에 의한 강도정수도 KICT 대구경 샘플러에 의한 시료가 약 10% 이상 높게 나타났다.

• 한국지반환경공학회 논문집
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• 제9권3호
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• pp.29-34
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• 2008

한국건설기술연구원(KICT)에서는 트리플 코어 바렐의 원리를 적용하여 기존의 연약지반 뿐만 아니라 사질토 및 풍화토 지대에도 적용이 기능한 대구경 샘플러를 개발하였다. 특별히 제작된 시료 절단 및 추출 장치는 다양한 종류의 채취 시료에 적용하여 시료의 교란을 최대한 방지 할 수 있도록 고안되었다. 샘플러 두부에는 적절한 강성의 스프링을 설치하여 슈(shoe)와 비트(bit) 사이의 거리가 변화하도록 하여 대상지반의 강성에 맞추어 효과적인 시료채취가 가능하도록 하였다. 대구경 샘플러의 적용성을 확인하기 위하여 일반적으로 시용되는 피스톤 샘플러와 대구 경 샘플러를 이용해 여러 대상지반에서 채취한 시료의 교란도를 비교 분석하였으며, 다양한 공학적 특성 또한 비교 분석 하였다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2003년도 봄 학술발표회 논문집
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• pp.725-732
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• 2003

It was achieved that Rowecell test for this undisturbed sample was picked by Block sampler($\phi$:250mm, L:500mm) and hydraulic piston sampler($\phi$:76mm, L:850mm) in the marine clay of YONGYUDO and YEONGJONGDO in this research. Ratio of coefficient of consolidation was analyzed through comparison with C$\_$h/ by CPTu and C$\_$v/ and C$\_$h/ by existent consolidation test. According to analysis, coefficient of consolidation of block sample is fairly greater than coefficient of consolidation of piston sample. And the bigger diameter of undisturbed sample, sample disturbance could know decreasing. Coefficient of consolidation by Rowecell test measured more greatly than coefficient of consolidation by existent consolidation test. Rowecell test could know decreasing consolidation rate because of smear effect by Mandrel injection. Also, C$\_$h/ by CPTu shows deviation by each analysis method, selection of suitable analysis method judged by important leading in the coefficient of consolidation.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2000년도 봄 학술발표회 논문집
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• pp.639-646
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• 2000

It is important to estimate the mechanical properties of clay since it is directly related to the design and the construction of geotechnical structures. Site exploration, which is composed of boring, sampling, in-situ, or laboratory tests, is preformed to estimate the mechanical properties. However, mechanical properties of clay measured from laboratory test may be different from in-situ properties due to disturbances occurred during sampling, transportation, storage, and trimming. In this study, the degree of disturbance according to sampling method was estimated with the test results of CK/sub o/U triaxial compression test on Yangsan clay. The soil samples were obtained by three types of sampling method, j.e., 76mm-tube sampler, 76mm-piston sampler, and block sampler. In order to evaluate the quality of samples, volumetric strain, undrained shear strength, secant Young's modulus, and pore pressure coefficient at peak measured from each sample were compared with one another. From the test results, it was observed that mechanical properties of the block and piston samples were more reliable than those of tube samples. But it was observed that the water content of piston was similar to that of tube samples at given depths while the water content of block samples was 14.3∼15.8% smaller than that of piston and tube samples. In addition to the evaluation of the quality of samples, relationship between c/sub u// σ/sub vc/'and OCR was established from the results of the CK/sub o/U triaxial compression tests, which were carried out using SHANSEP method. And also undrained shear strength was analyzed using the in-situ test data such as Cone Penetration Test(CPT), Dilatometer Test(DMT), and Field Vane Test(FVT) and was compared with that evaluated from CK/sub o/U triaxial compression test.

• 한국지하수토양환경학회지:지하수토양환경
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• 제29권1호
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• pp.1-9
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• 2024

As part of monitoring technology aimed at verifying the stability of CO₂ geologic storage and mitigating concerns about leakage, a method for measuring the pH and alkalinity of high-pressure fluid samples was established to obtain practical technology. pH measurement for high-pressure samples utilized a high-pressure pH electrode, and alkalinity was measured using the Gran titration method for samples collected with a piston cylinder sampler (PCS). Experimental samples, referencing CO₂-rich water and CO₂ geologic storage studies, were prepared in the laboratory. The PCS controls the piston, preventing CO₂ degassing and maintaining fluid pressure, allowing mixing with KOH to fix dissolved CO₂. Results showed a 6.1% average error in high-pressure pH measurement. PCS use for sample collection maintained pressure, preventing CO₂ degassing. However, PCS-collected sample alkalinity measurements had larger errors than non-PCS measurements, limiting PCS practicality in monitoring field settings. Nevertheless, PCS could find utility in preprocessing for carbon isotope analysis and other applications. This research not only contributes to the field of CCS monitoring but also suggests potential applications in studies related to natural analogs of CCS, CO₂-rock interaction experiments, core flooding experiments, and beyond.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 지반공학 공동 학술발표회
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• pp.429-436
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• 2005

In this study, we have compared with the differences between the extent of sampling disturbance and consolidation characteristics by experiments, which are consolidation test and have been performed with Kwang-Yang clay samples. The effects on sampling disturbance to consolidation characteristics of soft clay have been inverstigated by using soil samples obtained from large block sampling and piston sampling methods. Through a few experiments, we've got important results which are that the consoilidation parameter of large block sample(Pc, Cc, Cv) is much larger than the value of parameter of piston sample. We've also found the fact that the large block sample using the large size sampler is much better than piston sample in the quality of goods to lessen the effects on disturbance of sampling. When compared to the parameter of consolidation along with the methods of experiment, we found that the result performed by large size consolidation test is the greatest one and CRS is much better than standard consolidation test to seek for proper parameter.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1999년도 가을 학술발표회 논문집
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• pp.95-102
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• 1999

It is important to estimate the magnitude of settlement and the time of primary consolidation in geotechnical engineering projects. For these purposes, site explorations and laboratory tests are usually performed. However, the mechanical properties determined from laboratory tests on the samples obtained by different sampling techniques show different trends. In this study, three types of consolidation test were carried out on the soil samples obtained by three different sampling techniques (76mm tube, 76mm piston, and block samples), to verify the effect of sample disturbance on consolidation properties. It was found that sampling methods have influence on the $\varepsilon$ - log $\sigma$'$_{v}$ relationship. While insignificant difference of compression indices from the samples obtained by different sampling techniques was observed in compression region, these values showed a different trend in precompression region. The values of $c_{v}$ and k of block samples had a tendency to be larger than those of piston and tube samples. At consolidation pressure larger than $\sigma$'$_{p}$, however, these properties became similar regardless of sampling methods. The block and piston samples gave slightly higher values of $C_{a/}$ $C_{c}$ than tube samples. In the results of I $L_{EOP}$ and CRS test, it was observed that the values of $\sigma$'$_{p measured}$/$\sigma$'$_{p best estimated}$ of Yang-San clay decreases when strain becomes larger than 1.0% and that precompression strain of block samples is in the range of 1.5~2.0% while those of piston and tube samples are 1.75~3.75%. It was also shown that the values of $\sigma$'$_{p}$ of block samples exceed those of piston and tube samples by about 6~10%.6~10%.%.%.%.%.