• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 세계 도시지반공학 심포지엄
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• pp.194-205
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• 2009

In geotechnical engineering, the mechanical characteristics of soil, the main material of geotechnical engineering, is highly related to the confining stress. Reduced-scale physical modeling is often conducted to evaluate the performance or to verify the behavior of the geotechnical systems. However, reduced-scale physical modeling cannot replicate the behavior of the full-scale prototype because the reduced-scale causes difference of self weight stress level. Geotechnical centrifuges are commonly used for physical model tests to compensate the model for the stress level. Physical modeling techniques using centrifuge are widely adopted in most of geotechnical engineering fields these days due to its various advantages. In this paper, fundamentals of geotechnical centrifuge modeling and its application area are explained. State-of-the-art geotechnical centrifuge equipment is also described as an example of KOCED geotechnical centrifuge facility at KAIST.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
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• pp.1372-1377
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• 2008

Recently, centrifuge tests have been widely used as tools in geotechnical engineering researches in domestic and foreign. However, the size of these centrifuge facilities is very large and thus the tests require for long time, high expense, and many labors. In this study, therefore, a small size of instructional centrifuge, which can conduct tests in a short period of time effectively, was introduced. This centrifuge facility introduced in here was developed for geotechnical engineering education for graduate and undergraduate students. The slope stability model having $65^{\circ}$ slope formed with clay was used to investigate the application of the instructional centrifuge by considering experimental procedures and results.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
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• pp.1254-1259
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• 2008

Recently, centrifuge tests have been widely used as tools in geotechnical engineering researches in domestic and foreign. However, the size of these centrifuge facilities is very large and thus the tests require for long time, high expense, and many labors. In this study, therefore, a small capacity(2g ton) of instructional centrifuge, which can conduct tests in a short period of time effectively, was introduced. The results of centrifuge tests conducted on the retaining wall both passive and active cases was used. Medium size of sand was used with sieve off fines in sand using #40 sieve. Based on the test results, this centrifuge facility introduced in here can be enough used for geotechnical engineering education for graduate and undergraduate students.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 추계 학술발표회
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• pp.395-406
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• 2008

An excavation with the depth of 32.7m will be constructed as a ventilation shaft in Shanghai metro Line 9. The excavation induced effect on a nearby undercrossing road in operation must be properly evaluated. A centrifuge model test was conducted to study the impact of deep excavation on this existing undercrossing. Detail simulation works are described in this paper. The excavation steps could be simulated in the no-stop state of centrifuge machine. And induced settlements of the undercrossing road in both parallel and vertical directions were analyzed. Protective partition cement soil piles were also simulated in the tests. Simulation test shows deep excavation has a great influence on undercrossing road and the partition pile can obviously deduce the influence.

• 한국지반공학회논문집
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• 제30권10호
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• pp.19-31
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• 2014

원심모형실험 중 지반모형의 상태 변화를 입체적으로 파악하기 위한 방법으로 전기비저항 탐사를 시도하였다. 탐사 시스템은 현장에서 널리 사용되는 검증된 상용 장비를 바탕으로 하였다. 컴퓨터 원격 조정으로 실험 시설 내에 설치된 탐사 장비를 통제하고 실시간 해석을 통해 결과 영상을 원심 모형실험 중에 바로 확인할 수 있도록 구성하였다. 구축된 탐사 시스템의 안정적 구동 여부를 점검하기 위해 불포화상태로 조성된 모형 지반 상단에 염수를 떨어뜨려 지반 내부로 이동하게 하고 전기비저항 탐사를 수행하였다. 10g로 원심력을 가한 상태에서 실험을 수행하고 시간대별 염수 침투상황을 전기비저항 영상으로 확인하였으며 일반 중력장에서 동일하게 실험한 결과와 비교하였다. 실험 종료 뒤 모형지반 수직 절단면을 이용하여 직접 측정한 전기비저항 값과 획득한 영상을 비교함으로써 신뢰성을 검증하였다.

• 한국지진공학회논문집
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• 제17권5호
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• pp.209-217
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• 2013

In order to verify the reliability of numerical site response analysis program, both soil free-field and base rock input motions should be provided. Beside the field earthquake motion records, the most effective testing method for obtaining the above motions is the dynamic geotechnical centrifuge test. However, need is to verify if the motion recorded at the base of the soil model container in the centrifuge facility is the true base rock input motion or not. In this paper, the appropriate input motion measurement method for the verification of seismic response analysis is examined by dynamic geotechnical centrifuge test and using three-dimensional finite difference analysis results. From the results, it appears that the ESB (equivalent shear beam) model container distorts downward the propagating wave with larger magnitude of centrifugal acceleration and base rock input motion. Thus, the distortion makes the measurement of the base rock outcrop motion difficult which is essential for extracting the base rock incident motion. However, the base rock outcrop motion generated by using deconvolution method is free from the distortion effect of centrifugal acceleration.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1997년도 가을 학술발표회 논문집
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• pp.349-356
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• 1997

• 산업기술연구
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• 제31권A호
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• pp.79-86
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• 2011

This paper is results of centrifuge model experiment of investigating geotechnical engineering behavior of waterproof dike, located in soft grounds, in Saemankem in progress of construction. Centrifuge test with artificially increased gravitational level of 50g were performed to find ground settlements and excess pore-pressures developed during construction of waterproof dike by simulating the construction stages being predicted to occur in field so that the stability of waterproof dike could be assessed.

• 산업기술연구
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• 제22권B호
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• pp.191-197
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• 2002

This paper is experimental and numerical research results of performing centrifuge model tests to investigate the geotechnical engineering behavior of slag compaction pile as a substitute of sand compaction pile. In order to find the geotechnical engineering characteristics of the soft clay and the slag used in centrifuge model experiments, basic soil property tests, consolidation test, permeability tests and triaxial compression tests were performed. For centrifuge model tests, slags with changing relative density were used and their bearing capacity, stress concentrations in between pile and soft clay, settlement characteristics, and failure modes were investigated. As a results of centrifuge model tests, it was found that the bearing, capacity of model was increased with increasing density of slag pile and general shear failures were occured. Miniature soil pressure gauges were installed on model pile and soft ground respectively and thus vertical stress acting on them were measured. Stress concentration ratio was found to be in the range of 2.0~3.0. Bearing capacity obtained from the model test with slag was greater than that from the model test with a sand having the identical layout to each other. Thus it was confirmed the slag was an appropriate substitution of pile for sand.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 춘계 학술발표회
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• pp.376-387
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• 2009

Piled raft foundation is a geotechnical composite construction to support the superstructure by pile-soil-raft interaction. General conventional design for piled raft doesn't consider the contribution of a raft. This is very conservative and requires more piles to satisfy the factor of safety. It is important to evaluate the load sharing features of piled raft. In this research, this characteristics of piled raft evaluated using both centrifuge and numerical modelings. The ultimate bearing capacity of piled raft foundation was also evaluated and predicted through comparisons of ultimate bearing capacity of single pile (SP), unpiled raft (UR), freestanding pile group (FPG) and piled raft (PR). $\xi_{pr}$ and $\eta$ were determined by centrifuge model tests to simply evaluate the ultimate bearing capacity of piled raft and bearing capacity of piled raft was predicted using the calibrated numerical model based on the centrifuge tests and laboratory tests data.