• The Journal of Engineering Geology
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• v.11 no.1
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• pp.25-35
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• 2001

For the ground resrxmse analysis, both in-situ and laboratory testing techniques such as downhole, SASW, resonant column and torsional shear tests were perlormed for Hong-Seong area. The grOlmd upper 30m is classified as SD since it has an average shear wave velocity as 209m/s. The response specLrums obtained by site-specific analyses generally satisfied the seismic code, but near the resonance period the motion was evaluated to be higher than the code.

• Journal of the Korean GEO-environmental Society
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• v.1 no.1
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• pp.71-78
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• 2000

In this study, the evaluation for effective utilization of waste landfill was performed by field test to use waste landfill as construction site(Nangido in Seoul). This site had been formed by dredging the household waste, building debris and industrial waste for fifteen years(78'3~93'3). The site where dynamic compaction test was divided by 4 yards. Yard-1, 2 were not eliminated widening of cover soil and Yard-3, 4 were eliminated it. Dynamic Compaction Pilot Test was carried out by the 15ton heavy tamper with drop height of 20m in Yard-1, 3 and with drop height of 15m in Yard-2, 4. We evaluated the compaction efficiency, optimum compaction number and noise vibration through field test, monitoring. As a result, if the countermeasures against vibration and noise by the method utilize, the dynamic compaction method is suitable for using in waste landfill as a construction site among the ground improvement method.

• Journal of the Korean Geotechnical Society
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• v.17 no.1
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• pp.57-65
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• 2001

역사적 지진 발생 기록이 풍부하고 양산 단층 영향권 내에 있어 지진 발생 가능성이 높은 경주 지역을 대상으로 지진민감도 분석을 수행하였다. 지형적 특성을 고려한 지반조사와 현장 및 실내 시험을 통하여 대상 지역 지반의 지층 구성과 각 지층의 동적 특성을 분석 평가하고, 이를 토대로 한 지반 응답 해석을 수행하였다. 9개의 시험공을 시추하여 2개소의 크로스홀 시험과 7개소의 다운홀 시험을 실시하였고, 시추부지 포함 13개소에서 SASW 시험도 수행하였다. X선 회절 및 풍화도 분석과 공진주 시험 등의 실내시험도 병행하였다. 이러한 시험 결과를 바탕으로 El Centro 지진에 의한 지표면 최대 가속도를 등가 선형 부지응답해석을 통해 평가한 결과 붕괴방지 수준에서 0.158g~0.286g, 기능수행 수준에서 0.067g~0.116g의 분포를 보였고 퇴적층에 의하여 형성된 경주 시가지 분지 지형에서 증폭정도가 심하다는 것을 알 수 있었다. 해석 결과로 볼 때, 현행 건교부 기준 설계응답스펙트럼은 경우에 따라 지반 운동을 과소평가하고 지반 고유의 공진 현상을 고려하지 못하였다. 이러한 문제를 해결하기 위하여 개선된 지반 분류방법을 소개하였고 부지고유의 지반응답평가의 중요성에 대해 제시하였다.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.4
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• pp.232-238
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• 2012

In this study, the noise mapping simulation is executed to design an effective barrier reducing noise levels of a school site. The geographical features of the ambient site and the school buildings are modelled in detail in order to consider sound propagation, deflection, and absorption phenomena etc. The main sound source, sound power level of expressway, is estimated on the basis of measured noise levels at several points of the site. The noise mapping simulation is performed by using ENPro, environmental noise prediction program based on ISO 9613 to analysis the effectiveness of noise barrier. Consequently, the noise barrier is designed to meet an environmental noise standard and satisfy low cost and safety conditions.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.3C
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• pp.187-196
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• 2008

An earthquake of magnitude 5.0 occurred at Ssang-gye-sa, a Buddhist temple in Jirisan, located near the southern border of the Korean peninsula on 4 July 1936. It resulted in severe damage of several buildings and structures in Ssang-gye-sa. Particularly, the top component of a five-story stone pagoda in the temple was tipped over and fell down during the earthquake. This earthquake damage case would be usefully applied to estimating the intensity of ground motion in the Korean peninsula, a moderate seismicity region, where strong motion has never been recorded with the exception of historic seismic events. In order to estimate the local site effects and the corresponding ground motion at Ssang-gye-sa site, intensive site investigations including borehole drilling and in-situ seismic tests such as crosshole and SASW tests were performed in the temple area. Based on the site characteristics, site-specific seismic response analyses using various input motions were conducted for a representative Ssang-gye-sa site by means of both one-dimensional equivalent-linear and nonlinear methods with six input rock outcrop acceleration levels ranging from 0.044g to 0.220g. The resultant site-specific seismic responses indicated the amplified ground motions in the short-period range near the site period of Ssang-gye-sa. Furthermore, the intensity on rock outcrop of the 1936 Jirisan earthquake was estimated by making a comparison between the site responses analysis results in this study and the full-scaled seismic test of pagoda model in the prior study.

• Journal of the Earthquake Engineering Society of Korea
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• v.3 no.4
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• pp.1-10
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• 1999

Free-field ground motion during earthquake is significantly affected by the local site conditions and it is essential for the seismic design to perform the site specific ground response analysis. In this paper, the procedures of site specific ground response analysis were suggested based on the Korean seismic guideline and the review of state of the art technologies. The concept of ground response analysis was introduced, and the techniques of obtaining soil data for one dimensional equivalent linear analysis which include site investigation planning, field and laboratory testing techniques, deformational characteristics of soils at small to large strains, and site characterization techniques combining field and laboratory test results, were suggested. Finally, the case study was performed at Inchon area following the suggested procedure.

• The Journal of Engineering Geology
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• v.22 no.3
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• pp.293-307
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• 2012

Shear wave velocity is commonly invoked in explaining geophysical phenomena and in solving geotechnical engineering problems. In particular, the importance of shear wave velocity in geotechnical earthquake engineering has been widely recognized for seismic design and seismic performance evaluation. In the present study, various insitu seismic tests were performed to evaluate geotechnical dynamic characteristics at 183 sites in Korea, and shear wave velocity profiles with depth were determined to be representative of the dynamic properties at the investigated sites. Subsurface soil and rock layers at the target sites were reclassified into five geotechnical layers: fill, alluvial soil, weathered soil, weathered rock, and bedrock, taking into account their general uses in geotechnical earthquake engineering practice. Average shear wave velocity profiles for the five geotechnical layers were obtained by synthesizing the shear wave velocity profiles from seismic tests in the field. Based on the profiles, a representative shear wave velocity value was determined for each layer, for use in engineering seismology and geotechnical earthquake engineering.

• Journal of the Korean Geotechnical Society
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• v.19 no.2
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• pp.135-146
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• 2003

Uphole test is a seismic field test using receivers on ground surface and a source in depth. In this paper, the uphole test using SPT(standard penetration test) which is economical and reliable for obtaining shear wave velocity profile was introduced. In the proposed uphole test, SPT sampler which is common in site investigation, was used as a source and several 1Hz geophones in line were used as receivers. Test procedures in field and interpretation methods for obtaining interval times and for determining shear wave velocity profile considering refracted ray path were introduced. Finally, uphole test was performed at three sites, and the applicability of the proposed uphole test was verified by comparing wave velocity profiles determined by the uphole test with the profiles determined by downhole test, SASW test and SPT-N values.

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.253-256
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• 2008

지하 토사 조건 및 지질 구조는 지진 시 지반 운동의 증폭에 관련된 부지 효과에 매우 큰 영향을 미친다. 본 연구에서는 국내 홍성 지역을 대상으로 시추 조사와 현장 탄성파 시험을 포함한 현장 조사 및 지표 부근지질 정보를 획득하기 위한 부지 답사를 통해 부지 효과를 확인하였다. 홍성 지역은 1978년 계기 지진이 발생한 지역으로서 기반암 상부에 최대 약 50 m 두께의 풍화대 지층이 분포한다. 연구 대상 지역의 공간 지층 구조를 효율적으로 확인하기 위하여 지리정보시스템(GIS) 기법 기반의 지반 정보 시스템(GTIS)의 구축하였으며, 홍성 지역은 분지는 얕고 넓은 형상임을 확인하였다. 홍성 지역의 부지 지진 응답을 평가하기 위하여 대표 단면에 대한 2차원 유한 요소 해석을 수행하였다. 도출된 지진 응답으로부터 지반 운동이 기반암 상부 토사층을 통해 전단파가 전파되면서 증폭되고 분지 형상에 따른 전단파의 상호 작용으로 생성된 표면파로 인해 분지 경계 부근 진동 지속 시간이 증가됨을 확인하였다. 뿐만 아니라, 분지 내의 선정된 토사 부지들에 대해서 추가적인 1차원 유한 요소 지진 응답 해석을 수행하였으며, 본 연구 대상 분지가 매우 얕고 넓음에 따라 분지 경계 부근을 제외하고는 분지 내 대부분의 위치에서 2차원 지진 응답과 유사한 결과를 보였다.

• Tunnel and Underground Space
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• v.33 no.3
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• pp.109-125
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• 2023

Disposal repository for high-level radioactive waste secures its safety by means of engineered and natural barriers. The performance of these barriers should be tested and verified through various aspects in terms of short and/or long-term. KAERI has been conducting various in-situ demonstrations in KURT (KAERI Underground Research Tunnel). After completing previous experiment, a conceptual design of an improved in-situ experiment, i.e. K-COIN (KURT experiment of THMC COupled and INteraction), was established and detailed planning for the experiment is underway. Preliminary characterizations were conducted in KURT for siting a K-COIN test site. 15 boreholes with a depth of about 20 m were drilled in three research galleries in KURT and intact rock specimens were prepared for laboratory tests. Using the specimens, physical measurements, uniaxial compression, indirect tension, and triaxial compression tests were conducted. As a result, specific gravity, porosity, elastic wave velocities, uniaxial compressive strength, Young's modulus, Poisson's ratio, Brazilian tensile strength, cohesion, and internal friction angle were estimated. Statistical analyses revealed that there did not exist meaningful differences in intact rock properties according to the drilled sites and the depth. Judging from the uniaxial compressive strength, which is one of the most important properties, all the specimens were classified as very strong rock so that mechanical safety was secured in all the regions.