• The Journal of Engineering Geology
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• v.33 no.2
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• pp.293-305
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• 2023

Three ground models are analyzed using a 1g shaking table and laminar shear box (LSB) to investigate the impact of the ground structure on seismic wave amplification during earthquakes. Multi-layer horizontal, embankment, and basin ground models are selected for this investigation, with each model being divided into dense and loose ground layers, Accelerometers are installed during the construction of each ground model to capture any seismic wave amplification owing th the propagation of an artificial seismic wave, sine wave sweep, and 10-Hz sine wave through a given ground model. The amplification of the tested seismic waves is analyzed using the observed peak ground acceleration and spectrum acceleration. The observed acceleration amplification in the multi-layer horizontal ground model is significantly higher the seismic waves that propagated across the dense ground-loose ground boundary compared with those that only propagated through the dense ground. Furthermore, the observed acceleration amplification gradually increases in the central part of the multi-layer embankment and basin models for the seismic waves that propagated across the dense ground-loose ground boundary.

• The Journal of Engineering Geology
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• v.33 no.4
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• pp.657-671
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• 2023

As large-scale earthquakes have occurred in Korea and their aftermath continues to be felt, laws and regulations on seismic design have been emphasized, and in Korea, the seismic design standards have been newly revised after the Gyeongju earthquake. In the revised seismic design standards, a stability review for the destruction of the support activity of the breakwater was newly added. Therefore, in this study, we conducted a stability analysis on the seismic reinforcement method for the study site, and checked the ground acceleration of the subgrade and the displacement of the structure over time. As a result of the stability analysis, the safety factor increased by at least 0.5 and up to 1.7. As a result of the time history analysis, the displacement of the superstructure decreased by up to 290 mm and down to 12 mm in both the shallow and deep sections before and after reinforcement, and the ground acceleration decreased by up to 5.33 m/s and down to 0.31 m/s after reinforcement.

• Proceedings of the KSEG Conference
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• 2004.03a
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• pp.17001-17013
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• 2004

암석의 물리적 성질이란 암석이 공학적으로 보편화 된 조건인 상온, 상압 하에서 고유하게 지니고 있는 특성으로 비중, 공극율, 강도 등이 있다. 물리적 성질은 무결암을 대상으로 주로 실험실내에서 정해진 방법에 따라 정량적으로 측정할 수 있으며, 특정 암석에서 측정한 여러 가지 간은 해당 암석의 특성을 고유하게 나타내고 있으므로 이를 암석의 물질 정수라고도 한다. 현재 암석의 물리적 성질을 측정하기 위한 방법으로는 국제암반공학회(ISRM. International Society for Rock Mechanics)가 제안한 방법(Brown, 1901)이 가장 널리 적용되고 있다. (중략)

• Proceedings of the KSEG Conference
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• 2004.03a
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• pp.22001-22109
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• 2004

사면 파괴의 분류에 대하여는 여러 학자들(Hutchinson, 1968; Varnes, 1978; Hoek and Bray, 1981)에 의하여 시도되어 왔으며, 일반적으로 파괴면의 기하학적 형상, 물질의 이동 형태와 이동 물질의 종류 등에 따라 분류한다. 현재 널리 사용되는 사면 파괴에 대한 분류로는 Varnes(1978)와 Hoek and Bray(1981)의 분류법이다. 이외 일본 지반 공학회에서는 파괴 두께와 관련된 사면 붕괴 유형을 구분하였다. 여기서는 각각의 분류에 대해 기술하고, 일반적으로 암반 사면에 대한 붕괴 유형 분류를 제시한다. (중략)

• Proceedings of the Korean Geotechical Society Conference
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• 2001.10a
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• pp.185-198
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• 2001

암반 불연속면에 대한 조사는 국제 암반역학회(ISRM)에서 추천하는 조사법이 합리적으로 불연속면이 특성을 기재할 수 있는 방안이기 때문에 널리 적용되고 있다 그러나, 이 안에서는 조사결과를 공학적 의미가 있는 암반특성치로 변환하는 방안에 대한 언급이 없다. 본고에서는 지질기술자들이 불연속면조사시 주로 사용하는 ISRM 추천안인 제시한 조사항목에 토목기술자들이 주로 사용하는 RMR 혹은 Q-system 분류안의 정량적인 값을 적용할 수 있을 지를 검토하였다. 이에 대한 관련기술자들의 관심이 모여질 때 정량적인 인자에 기초한 ISRM 조사법에 부합되는 암반분류안의 구축도 가능하리라 생각된다.

• Proceedings of the KSEEG Conference
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• 2003.04a
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• pp.265-268
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• 2003

댐(dam)의 기초지반에 시공되는 그라우트 커텐(grout curtain)은 댐 축조 후 기초지반을 통한 침투류를 차단하기 위하여 시행되며, 콘크리트 댐, 흙 댐, 사력 댐 등의 공학적 차이에 따라서 그 시공 위치 및 심도, 폭 등이 다르게 적용된다. 그라우트 커텐(grout curtain)의 설계ㆍ시공 요소는 기초지반의 투수성, 댐 내의 수심, 제체 성토재료의 투수성, 그라우트 커텐의 투수성 등에 의하여 결정되며, 설계 시공 요소들은 그라우팅 커텐의 길이, 폭, 투수도 등이다. (중략)

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 1994.03a
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• pp.56-61
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• 1994

최근 국내 광산들의 잇달은 폐광과 함께 광산관리의 부재로 말미암아 여러 가지 문제가 야기되고 있다. 그중 대형재해의 불씨를 안고 있는 광해의 하나가 바로 지표침하이다. 본 연구는 이러한 지표침하 문제에 과학적이고도 합리적인 방법으로 대처하기 위하여 4개분야(지질, 탐사, 암반공학 및 안전공학) 가 공동으로 연구한 결과를 기술 하고자 한다. (중략)

• The Journal of Engineering Geology
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• v.16 no.1 s.47
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• pp.85-96
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• 2006

This study was conducted to suggest a method to determine weighting values of each parameter of the RMR system considered with geologic characteristics of a study area. This study reviewed the weighting values of the RMR system for the Cretaceous sedimentary rocks distributed in Ulsan area. Based on the data of field survey at the study area, a multiple regression analysis was used to set up an optimal weighting values of the RMR parameters. For the multiple regression analysis, each parameter of the RMR and the slope gradient were regarded as the independent variable and the dependent variable, respectively. The analysis result suggested a modified weighting values of the RMR parameters as follows; 30 for the intact strength of rock; 18 for RQD; 8 for spacing of discontinuities; 32 for the condition of discontinuities; and 12 for ground water.

• The Journal of Engineering Geology
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• v.3 no.2
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• pp.101-114
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• 1993

GIS technique was applied to identify the regional hydrologic units for groundwater exploitation and recharge analysis in a study area. The technique was very effective to identify the potential areas for groundwater exploitation, and for groundwater management & land use planning. GIS database of environmental resources was complied from a variety of sources and scales as the foundation for analysis, including digitizing and scanning of hardcopy maps. A DEM(Digital Elevation Model) was used to dassify slopes, and identify problematic drainage system. Quantitative analysis of environmental resources helps us to develop the scoring system of GIS model, which evaluates each resource in relation to the others and reflects the relative importance of each resource. ARC4NFO was used to construct digital database, and the cartographic simulation techniques were applied in order to create new maps.

• The Journal of Engineering Geology
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• v.7 no.3
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• pp.161-171
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• 1997

The exact information on geological structures and characteristics of the subsurface must be acquired to secure quality and safety of constructions. GPR technique, one of the most updated geophysical methods, is known for its applicability to shallow-depth underground surveys. The purpose of this study is to examine the usefulness of GPR method in constructions for detailed subsurface investigations, especially detecting the boundary between basement rock and its overburden. To find appropriate depths of the geological boundaries, it is necessary to obtain velocity of electromagnetic wave propagating into the ground. Wave velocity 0.096 m/ns estimated from velocity analysis using CMP gathers is used for depth conversion from time section. The depths of geological boundaries from GPR profiles are very well correlated with boring data. In addition, GPR survey has found some undulations of the geological boundaries due to weathering, which cannot be provided by conventional coring approaches.