• Journal of the Speleological Society of Korea
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• v.21 no.22
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• pp.17-56
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• 1990

Cheju Island, which was formed by volcanic activity, is an oval in its shape with the major axis of 80km and the minor axis of 40km. The island holds in its heart Mt. Hanla rising 1,950m above the sea. Petrological study of this volcanic island has been made actively by Sang-Man Lee, Chong-Kwan won and Moon-Won Lee. The chronological measurements of the island by Chong-Kwan Won and Moon-Won Lee showed that it is composed of Sanbangsan trachytes and Backlokdam trachytes(25,000 year ago). These reports are based on the chemical analysis and the rediometric chronological measurements on the ground. However, there has been no reports about the inside of caves. We made an (composition) analysis of the inside of Manjang Cave by the fundamental parameter method in X-ray fluorescence spectrometry. The fundamental parameter method in X-ray fluorescence spectrometry is nondestructive analysis, and it enables us to make the values processed by a computer. The results obtained by this methods are as follows : SiO$_2$(49％), $Al_2$O$_3$(17％), Fe$_2$O$_3$(13％), CaO(8.1％), MgO(5.5％), Na$_2$O(3.6％), TiO$_2$(2.1％), $K_2$O(0.86％), P$_2$O$_{5}$(0.28％), and MnO(0.20％), respectively. The data obtained by the fundamental parameter method in X-ray fluorescence was compared with the data provided by Chong-Kwan and Moon-Won Lee. Our measurement was made by K-Ar-method in cooperation with T.ITAYA. The samples are of 30,000～420,000 year ago. The composition of the values of our underground analysis with the existing values obtained by the analyses on the ground produced new data about Cheju volcanic island.d.

• Journal of the Korean Society of Food Culture
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• v.17 no.5
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• pp.638-645
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• 2002

The purpose of this study is to evaluate the quality characteristics and consumer acceptance of the Kimchi affected by the storage method and the duration. The characteristics of Kimchi fermented and stored in the traditional method, such as cave facility or pit storage on the shore were compared to the Kimchi which was stored in the Kimchi refrigerator using the physicochemical and sensory evaluation. The quality of Kimchi stored by the Kimchi refrigerator was most acceptable with 3 month storage, while that of Kimchi stored by the storage facility under the ground on the shore was 1 month storage. Shelf life of Kimchi was extended up to 5 month stored by Kimchi refrigerator, and 3 month for the Kimchi stored under the ground on the shore.

• Journal of the Korean Institute of Rural Architecture
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• v.1 no.1
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• pp.3-14
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• 1999

It is a important problem that the adjustment of a rural settlementas a unit of rural community, and many number of researcher tackled its. The aim of this paper is to verificate the process of rural con-struction, that is applied the regional resources, and to introduce the situation of attending inhabitants, and their employments as a results of this planning. We chose Odaira hamlets in Oomama town, it is located in Gunma prefecture as an object of this study. Odaira is a small village in the mauntain, and it is composed only 135 families. Odaira is an underpopulated hamlet. It is engaged no lively farming and forestry. Most of inhabitants are commuting to the cities around here. Inhabitants of Odaira who are conscious of the conditions of declining hamlet organized a group to improve it. This group have investigated all around the hamlet as a system of workshop. And they found the resources for sight-seeing, crops as the regional products, and other resources for rural planning under three keywords ; resources for the sight-seeing, the rigional products, and theimprovement of environments. In many resources, most important thing was the existens of a stalactite cave come down as a legend from old time. Local government of Oomama town and the inhabitants tried to explorate of stalactite cave and succesed to excavate it. They have constructed two facilities for management, parkaround the stalactite cave and these have been a new place of work for inhabitants. Arrangement of the rural constructions developed to other items schemed acording to the master plan, like as a camping ground, bungalows, a wet botanical garden, and a park beside a river. These also produced the new places of work for 54 people as a result of this rural planning. The most of them were the aged peoples and the women of farmer. The highest age was 83 years old, he is working at the camping ground. In the employment system at Odaira, people who desire to work and desire to employ both registrate to a commission of management of Odaira, and this commission arrange them in case of needs.

• The Journal of Engineering Geology
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• v.25 no.4
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• pp.511-524
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• 2015

Groundwater causing subsidence in limestone mines is uncommon, and thus relatively poorly investigated. This case study investigated the cause and possibility of future subsidence through an evaluation of ground stability at the Samsung limestone mine, Chungcheongbuk-do. The ground near the mine area was evaluated as unstable due to rainfall permeation, and subsidence in the unmined area resulted from groundwater level drawdown. Future subsidence might occur through the diffusion of subsidence resulting from the small thickness of the mined rock roof, fracture rock joints, and poor ground conditions around the mine. In addition, the risk of additional subsidence by limestone sinkage in corrosion cavities, groundwater level drawdown due to artificial pumping, and rainfall permeation in the limestone zone necessitates reinforcements and other preventative measures.

• Journal of the Korean GEO-environmental Society
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• v.23 no.4
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• pp.41-48
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• 2022

Jeju island has a special ground layer called 'Sumgol' due to the geological characteristics. The terminology 'Sumgol' is generally defined as the rain fall flows through the Sumgol without blocking and smaller size than cave, which men cannot enter. This paper presents the influence of the Sumgol on ground stability under various loading conditions using numerical simulations when the airport is constructed. The results showed that the vertical settlements of each section are within the allowable settlement.

• Journal of the Korean earth science society
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• v.21 no.4
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• pp.408-422
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• 2000

Multiple geophysical methods were applied over the Manjang cave area in Cheju Island to compare and contrast the effectiveness of each method for exploration of underground cavities. The used methods are gravity, magnetic, electrical resistivity and GPR(Ground Pentrating Radar) survey, of which instruments are portable and operations are relatively economical. We have chosen seven survey lines and applied appropriate multiple surveys depending on the field conditions. In the case of magnetic method. two-dimensional grid-type surveys were carried out to cover the survey area. The geophysical survey results reveal the characteristic responses of each method relatively well. Among the applied methods, the electric resistivity methods appeared to be the most effective ones in detecting the Manjang Cave and surrounding miscellaneous cavities. Especially, on the inverted resistivity section obtained from the dipole-dipole array data, the two-dimensional distribution of high resistivity cavities are revealed well. The gravity and magnetic data are contaminated easily by various noises and do not show the definitive responses enough to locate and delineate the Manjang cave. But they provide useful information in verifying the dipole-dipole resistivity survey results. The grid-type 2-D magnetic survey data show the trend of cave development well, and it may be used as a reconnaissance regional survey for determining survey lines for further detailed explorations. The GPR data show very sensitive response to the various shallow volcanic structures such as thin spaces between lava flows and small cavities, so we cannot identify the response of the main cave. Although each geophysical method provides its own useful information, the integrated interpretation of multiple survey data is most effective for investigation of the underground caves.

• Geomechanics and Engineering
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• v.16 no.2
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• pp.177-185
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• 2018

The subsidence mechanism of ground surface is a complex phenomenon when multiple seam coal mining operations are carried out. Particularly, the coal mining beneath karstic formations causes a very special form of subsidence. The subsidence causes elasto-plastic deformation of the karstic layers and the collapse of cavities leads to dolinization and/or sinkhole formation. In this study, a sinkhole with a depth of 90 m and a width of 25 m formed in Gelik district within the coal-basin of Zonguldak (NW, Turkey) induced by multiple seam coal mining operations in the past has been presented as a case-history together with two-dimensional numerical simulations and InSAR monitoring. The computational results proved that the sinkhole was formed as a result of severe yielding in the close vicinity of the faults in contact with karstic formation due to multiple seam longwall mining at different levels.

• Journal of architectural history
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• v.31 no.6
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• pp.33-45
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• 2022

The tombs at the royal level of the Western Han dynasties belong to the five kingdoms of Chu, Liang, Lu, Zhongshan and Changyi, representing the new forms and ideas of the tomb architecture. Taking Shanchuwang Tomb in BeidongShan, Xuzhou as an example, this paper analyzes the architectural structure and symbolic significance of the tomb, and tries to discuss the concept of burial reflected in it.The analysis of the structure of the main body of the tomb reveals the basic logic of the tomb imitating the palace on the ground, and the definition of the nature of the annex reflects its transcendence over the general form of the tomb.

• The Journal of the Petrological Society of Korea
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• v.16 no.2 s.48
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• pp.47-58
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• 2007

This study examines the distribution of basement rocks in Gyochon-ri, Muan-eup, Muan-gun, Jeonnam where ground subsidence occurred in June 2005, and traces corrosion of limestone. Mica schist and rhyolite are distributed in the surface of the study area, but thick limestone layer with large and small caverns are distributed underground. A horizon of limestone with maximum width of 300 m and 4 km of length was found along the detour which is in the north of pound subsidence. Such identification of limestone presence would be very useful to predict potential ground subsidence. Limestone in this area was disturbed by fold and fault due to severe shearing deformation. Small caverns were frequently found in anticline part of folds formed in limestone layer. Schists with different thicknesses were intercalated in the limestone with shearing deformation and consist of sheet silicate minerals (chlorite and mica) and quartz. In sections of weathered specimen, it is shown that biotite of schist part was altered into chlorite and corrosion of calcite around the schist followed. This suggest that ground water permeated between intercalated sheet silicate minerals and corrosion of limestone began. And small caverns were generated where active corrosion occurred. This study suggests that because of many reasons (for instance, reclamation of the Bulmu reservior and excess pumping), cavern water level was lowered and cave sediments were removed, and it caused ground subsidence to occur.

• Journal of KIBIM
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• v.11 no.4
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• pp.20-30
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• 2021

In the era of the 4th industrial revolution, smart construction is actively researched, in the domestic construction field, and one of the key elements in this field is Building Information Modeling(BIM). In Korea, smart construction is being implemented through BIM-based digitization and intelligence. The geotechnical engineering field should also prepare for the introduction of BIM. In this study, the concept and application status of GeoBIM were identified, and the direction of future research was presented. This study is a part of the study "Establishment of GeoBIM-based Digital Twin Maintenance System" in the current "Technology Development for Establishment of Jeju Ground Collapse Response System for Safe Road Operation". The subject and scope of the study is continuous excavation at caves located under roads in Jeju Island, and initial research is being conducted on Jaeamcheon-gul and Jeonggusu-gul. This study aims to build a digital twin through individual data construction and integration processes such as cave shape modeling using laser scanners, 3D stratum modeling using borehole information and geophysical exploration data, and modeling of surrounding conditions using drones.