• Proceedings of the Korean Geotechical Society Conference
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• 2002.03a
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• pp.165-172
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• 2002

We presents an hazard zonation mapping technique in karst terrain and its assessment. From the detailed engineering geological mapping. Controlling factors of sink hole and limestone cave formation were discussed and 4 main hazard factors affecting hazard potential are identified as follows: prerequisite hazard factor(distributions of pre-existing sink holes and cavities), geomorphological hazard factors(slope gradient, vegetation, and drainage pattern etc.) geological hazard factors(lithology, fracture patterns and geological structures etc.) and hydraulic conditions(hydraulic head, annual fluctuation of ground water table and composition of g/w water). From the construction of hazard zonation map along the Jecheon-Maepo area, and vertical cross-sectional hazard zonations specific tunnel site we suggest hazard zonation rating systems.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.186-188
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• 2003

Rail Route Alignment in hilly terrain is a difficult task to implement as several natural constraints poses threat to the safety and stability of the alignment. The conventional methods followed to find out the final location survey or the feasibility analysis for alignment is time taking consuming. Some times, due to inaccessibility of the terrain it becomes impossible to carry out such works. The construction works in hilly terrain, which are associated with the proposed alignment, are not same as carried out in plane areas due to a vast contrast between the two areas. Different geological structures such as faults, thrusts, synclines and anticlines are a big problem to carry out normal construction practices. Thus for a safe and stable railway route in the unstable hilly areas, it is required to carry out the feasibility analysis of the proposed alignment to assist the policy makers for a successful implementation of the alignment. In the present work Remote Sensing and GIS has been successfully used to carry out geological feasibility and slope stability analysis for rail route alignment work.

• Steel and Composite Structures
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• v.48 no.5
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• pp.499-505
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• 2023

Geological hazards in landslide is one of the most extensive and destructive phenomena are among natural disasters. According to the topography high mountains, tectonic activity, high seismicity, diverse conditions Geology and climate, basically China to create a wide spectrum of landslides have natural conditions and these landslides are annual. They cause a lot of financial losses to the country. It is very difficult to predict the time of the landslide, hence the identification landslide sensitive areas and zoning of these areas based on the potential risk is very important. Therefore, it should be susceptible areas landslides should be identified in order to reduce damages caused by landslides find. the main purpose of landslide sensitivity analysis is identification high-risk areas and as a result, reducing damages caused by landslides It is the way of appropriate actions.

• The Journal of Engineering Geology
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• v.27 no.4
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• pp.367-376
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• 2017

Recently, tunneling under the seabed is becoming increasingly common in many countries. In Korea, there are proposals to tunnel from the mainland to Jeju Island. Safe construction requires geologic structures such as faults to be characterized during the design and construction phase; however, unlike on land, such structures are difficult to survey seabed. This study aims to develop an algorithm that uses geostatistics to automatically derive large-scale geological structures on the seabed. The most important considerations in this method are the optimal size of the moving window, the optimal type of spatial statistics, and determination of the optimal percentile standard. Finally, the optimal analysis algorithm was developed using the R program, which comprehensibly presents variations in spatial statistics. The program allows the type and percentile standard of spatial statistics to be specified by the user, thus enabling an analysis of the geological structure according to variations in spatial statistics. The geotechnical defense-training algorithm shows that a large, linear geological lineament is best visualized using a $3{\times}3$ moving window and a 10% upper standard based on the moving variance value and fractile. In particular, setting the fractile criterion to the upper 0.5% almost entirely eliminates the error values from the contour image.

• Journal of the Korean earth science society
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• v.25 no.7
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• pp.586-594
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• 2004

This study is the qualitative study in order to discover a direction of field courses by analyzing what elementary school students observe or hypothesis in field courses. The purpose of it is to find any relevancy between the observations and hypotheses generated. The result of the study were as follows; First, most participants have observed mostly based on their vision due to the characteristic of field courses, and the observations of sedimentary layers were mainly generated on the rocks while most hypotheses were on geological structures. Secondly, according to observational descriptions the frequency of the comparative observation was high as well as the cases when two different types of observations were joined together. The last conclusion from this investigation is, according to the standard of observational types, the hypotheses combined with the interpretive observation and comparative observation had the greatest percentage. This shows that many participants tried to rationalize their thoughts by interpreting geological structures and comparing them with other people's cases as well. Scientific explanatory hypotheses were mainly found according to the standard of hypothetical types, which can be constructed that those participants tried to explain and apply established knowledge and preconception.

• Journal of the Korean Geotechnical Society
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• v.20 no.5
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• pp.49-58
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• 2004

Consolidation properties of Shihwa deposits were analysed by means of depositional environments. Depositional environments including particle size distributions, sediment structures, geochemical properties, porewater chemistries and carbon age dating were analysed using undisturbed samples retrieved successively from a boring hole in the study area. Laboratory oedometer tests and anisotropic consolidated triaxial tests (CKoUC) for undisturbed samples were performed to examine the overconsolidation phenomena. Based on the results of analysis of depositional environments, it was found that the upper silt/clay mixed layer was deposited under marine condition while underlying sand and clay layers were deposited under fluvial condition. Planar laminated structures of silts and clays were dominant in marine deposits. Although there was no clear evidences that geological erosion had occurred in marine deposits, overconsolidation ratios of the upper marine samples were greater than unity Stress Paths of the upper marine samples behaved similarly to those of normally consolidated clays. Data plotted in stress state charts showed that the marine deposits were normally consolidated in geological meaning. These apparent overconsolidation of the marine deposits can be explained by the structures i.e. chemical bonding due to the difference of the rate of deposition, not by geological erosions and ground water fluctuations.

• Economic and Environmental Geology
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• v.52 no.5
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• pp.471-484
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• 2019

Liquefaction occurs by a temporal loss of sediment strength as a consequence of increased pore water pressure during the re-arrangement of unconsolidated, granular sediments. Liquefaction is dependent on the physical properties of the sediments and cause surface cracks, landslide, and the formation of soft-sediment deformation structures(SSDS). SSDS is formed by the combined action of the driving force and deformation mechanism(liquefaction, thixotropy, and fluidization) that is triggered by endogenic or exogenic triggers. So research on the SSDS can unravel syndepositional geological events. If detailed sedimentologic analysis together with surrounding geological context suggest SSDS formed by earthquakes, the SSDS provide a clue to unravel syndepositional tectonic activities and detailed paleoseismological information(> Mw 5) including earthquakes that leave no surface expression.

• The Journal of Engineering Geology
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• v.1 no.1
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• pp.109-120
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• 1991

Applications of microtremor to geological engineering are widely reviewed and observed microtremors are processed to show evidences of close relationship between the predominant periods of microtremor and underground structure. The ground vibrates continuously at all times and the elastic vibration is called microtremor (0.5-20Hz) or microseisms (0.01-0.1Hz) according to their frequency range. The vibration is believed to have propagative nature like those of the dispersive surface waves or multireflected shear waves. Microtremors were recorded at selected thress places of which subsoil structures are well distinguished in the Kyongsang Sedimentary Basin. It is found that the underground structures estimated from microtremor analysis coincide well with the known structures. The microtremor analysis of the long period range can be an inexpensive and effective tool in geological engineering for the evaluation of the underground structure, site-specific reponse spectrum, and seismic microzonations.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.276-285
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• 2006

Application of anchored or strutted wall system for the earth retention of excavation works in a populated urban area or a poor soil deposit can be limited due to various restrictions. Since the strut becomes longer in a wide excavation site, the stability of an earth retaining wall is decreased, the wall deformation is increased, and the ground settlement is also increased due to an increased buckling or bending deformation of struts. Especially, in a populated urban area, the installation of anchors can be problematic due to the property line of adjacent structures or facilities. Thus, a new concept of earth retaining system like Self-Supported diaphragm Wall can solve several problems expected to occur during excavation in the urban area. In this study, Numerical analyses of counterfort diaphragm wall was introduced and the monitored data from the site was compared with the original results of numerical analyses. Also, in the case of the deep excavation applied the counterfort diaphragm wall, numerical analyses was performed to predict the wall deformation and the reinforcement to reduce the wall deformation was suggested.

• Journal of the Mineralogical Society of Korea
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• v.5 no.1
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• pp.1-5
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• 1992

The manganese oxide ores in the Taebaeg Mt. region have been formed by supergene weathering of the primary hydrothermal or sedimentary manganese ores. The supergenesis is controlled by the physical chemistry of the descending groundwater in the supergene zone. It includes the fundamental geological processes, such as dissolution, oxidation, transportation, precipitation, and crystallization and recrystallization. However, the fundamental mechanisms for the formation of various manganese oxide minerals are 1) replacement, 2) precipitation from solution, and 3) solid state crystallization and recrystallization. Various textures and structures of ores have been formed by these processes. Detailed paragenetic sequence of manganese oxide minerals in each ore deposit is summerized.