• 한국지구물리탐사학회:학술대회논문집
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• 2009.10a
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• pp.136-138
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• 2009

• The Journal of Engineering Geology
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• v.8 no.2
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• pp.163-173
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• 1998

Suite of log analysis techniques consisting of geophysical well log, geological core log, and physical core log have been made to understand the well log responses and to determine the lithology of a test borehole-PABH1 located in Pungam sedimentary basin, Sosok, Hongchon-gun, Kangwon Province. Geological core logging has been precisely made over the cores taken between 64 and 124 meters, and 11 groups of rock types were deduced. Using the core samples divided by 11 groups, geophysical property measurements consisting of resistivity, natural gamma and density were made. Each rock group in the area is shown to have its characteristic physical response from geophysical well log and geophysical core logs. The outstanding physical responses particularly shown from siltstone, coarse sandstone to conglomerate, and granitic gneiss in the area were effectively used as keybeds in correlating the geophysical well logs to the result of geological core logs.

• Journal of the Korean earth science society
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• v.41 no.4
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• pp.367-380
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• 2020

LA-MC-ICP-MS zircon U-Pb dating was conducted to constrain the timing of fossil formation and the depositional age of the uppermost Jinju Formation located in Natural Monument No. 534 (Tracksite of Pterosaurs, Birds, and Dinosaurs in Hotandong, Jinju), and 87 Cretaceous, 1 Precambrian, and 2 Jurassic zircons were obtained from 90 valid analytical points. Most Cretaceous zircons were found to have a youngest graphical peak age of ca. 106.5 Ma, suggesting the depositional age of the uppermost Jinju Formation. Based on this study and previous works, the average sedimentation rate of the Jinju Formation was calculated to be approximately 0.17-0.31 mm/year in the Milyang Subbasin, and the Cretaceous zircons of the uppermost Jinju Formation seem to have originated mainly from the western or northwestern parts of the Gyeonggi Massif. Unlike the Nakdong and Hasandong formations of the Sindong Group, most zircons analyzed in the uppermost Jinju Formation were Cretaceous. This suggests that volcanic activity occurred in the area closer to the Gyeongsang Basin due to the roll-back of subducting paleo-Pacific Plates during the Jinju period.

• Geomechanics and Engineering
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• v.28 no.5
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• pp.531-546
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• 2022

Ground displacements caused by the construction of overlapping twin shield tunnels with small turning radius are complex, especially under special geological conditions of construction. To investigate the ground displacements caused due to shield machines in the unique calcareous sand layers in Israel for the first time and determine the main factors affecting the ground displacements, field monitoring, laboratory geological analysis, theoretical calculations, and parameter studies were adopted. By using rod extensometers, inclinometers, total stations, and automatic segment-displacement monitors, subsurface tunneling-induced displacement, surface settlement, and displacement of the down-track tunnel segments caused by the construction of an up-track tunnel were analyzed. The up-track tunnel and the down-track tunnel pass through different stratum, resulting in different construction parameters and ground displacements. The laws of variation of thrust and torque, soil pressure in the chamber, excavated soil quantity, synchronous grouting pressure, and grout volume of the two tunnels from parallel to fully overlapping orientations were compared. The thrust and torque of the shield in the fine sand are larger than those in the Kurkar layer, and the grouting amount in fine sand is unstable. According to fuzzy statistics and Gaussian curve fitting of the shield tunneling speed, the tunneling speed in the Kurkar stratum is twice that in the fine-sand stratum.

• Geomechanics and Engineering
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• v.13 no.1
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• pp.173-194
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• 2017

Access shaft is of critical importance to the construction and operation of underground rock caverns. It usually has a relatively large cross-section and penetrates through fill materials, soil layers, and weathered rocks before reaching the caverns excavated in solid bedrock. In this paper, the design and construction of vertical shafts are reviewed in terms of diameter, depth, geological conditions, and support structure. Three shaft alternatives, namely alternative I: vertical shaft with spiral roads, alternative II: upper shaft with spiral roads & lower tunnels, alternative III: plain shaft, are proposed based on a simplified geological profile of the Jurong formation, Singapore. The advantages and limitations of the three types of shafts are discussed. The key issues relating to shaft design and construction, such as the shaft sinking, water control, support structure, are also discussed with a series of solutions provided, such as the sequential excavation, pre-grouting and diaphragm walls.

• Nuclear Engineering and Technology
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• v.42 no.2
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• pp.145-150
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• 2010

The paper is describing work being developed in the frame of a 5-year IAEA Coordinated Research Programme (CRP) started in late 2005. Participants gained knowledge of modelling methodologies and experience in the development and use of rather sophisticated simulation tools in support of site characterization and performance assessment calculations. These goals were achieved by a coordinated effort, in which the advantages and limitations of numerical models are examined and demonstrated through a comparative analysis of simplified, illustrative test cases. This knowledge and experience should help them address these issues in their own country's nuclear waste program. Coordination efforts during the first three years of the project aimed at enabling this transfer of expertise and maximizing the learning experience of the participants as a group. This was accomplished by identifying common interests of the participants (i.e., Process Modelling and Total System Performance Assessment methodology), and by defining complementary tasks that are solved by the members. Synthesis of all available results by comparative assessments is planned in the coming months. The project will be completed end of 2010. This paper is summarizing activities up to November 2009.

• Journal of Environmental Science International
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• v.25 no.9
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• pp.1311-1322
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• 2016

Since the scale and disaster characteristics of volcanic eruptions are determined by their geological features, it is important not only to grasp the current states of the volcanoes in neighboring countries around the Korean Peninsula, but also to analyze the tectonic settings, tectonic regions, geological features, volcanic types, and past eruptional histories of these volcanoes. We created a database of 285 volcanoes around the Korean Peninsula, and then identified a high-risk groups of 29 volcanoes that are highly likely to affect the region, based on conditions such as volcanic activity, the type of rocks at risk of eruption, the distance from Seoul, and high VEI (volcanic explosivity index). In addition, we identified the 10 volcanoes that should be given the highest priority. We selected them through an analysis of data available in literature, such as volcanic ash dispersion results from previous Japanese eruptions, the definition of a large-scale volcano used by Japan's Cabinet Office, and examination of cumulative magma layer volumes from Japan's quaternary volcanoes.

• Geomechanics and Engineering
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• v.28 no.6
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• pp.573-584
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• 2022

Water inrush may occur during seaside urban tunnel excavation. Various factors affect the water inrush, and the water inrush mechanism is complex. In this study, nine evaluation indices having potential effects on water inrush were analysed. Specifically, the geographic and geomorphic conditions, unfavourable geology, distance from the tunnel to sea, strength of the surrounding rock, groundwater level, tidal action, cyclical footage, grouting pressure, and grouting reinforced region were analysed. Furthermore, a two-step interval risk assessment method for water inrush management during seaside urban tunnel excavation was developed by a multi-index system and interval risk assessment comprised of an interval analytic hierarchy process, fuzzy comprehensive evaluation, and relative superiority analysis. The novel assessment method was applied to the Haicang Tunnel successfully. A preliminary interval risk assessment method for water inrush was performed based on engineering geological conditions. As a result, the risk level fell into a risk level IV, which represents a section with high risk. Subsequently, a secondary interval risk assessment method was performed based on engineering geological conditions and construction conditions. The risk level of water inrush is reduced to a risk level II. The results agreed with the current tunnel situation, which verified the reliability of this approach.

• Korean Journal of Ichthyology
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• v.11 no.1
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• pp.72-85
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• 1999

A study on the larval fish assemblage around the front area was conducted in the Korea Strait in August, 1993. The front was found in the shelf break located in $35{\sim}36^{\circ}N$. A total of 125 species were found in the study area. Of these Engraulis japonicus was the most dominant species comprising 84.3% of the total fish larvae collected and followed by Maurolicus muelleri accounting for 7.7%. Gobiidae, Callionymidae and Pomacentridae showed higher frequency of occurrence. These five species can be divided into three groups. First group was comprised in the larval fish species such as E. japonicus and Callionymidae which were found in the whole study area. The second group was comprised of Gobiidae and Pomacentridae which were found in the warm area located in the southern part of the front area. The other species was M. muelleri found in the cold area located in the northern part of the front area including the front area. The assemblage, geological distribution and body length composition of the fish larvae in the Korea Strait would be mainly determined by the spawning ecology of the fishes, and the geological distribution and structure of the front which is formed in the ocean boundary between the Tsushima Current and the East Sea Cold Water.

• International Journal of High-Rise Buildings
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• v.3 no.1
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• pp.21-33
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• 2014

The tied braced frame (TBF) system was developed to achieve uniform seismic inelastic demand along the height of multi-storey eccentrically braced steel frames. A modular tied braced frame (M-TBF) configuration has been recently proposed to reach the same objective while reducing the large axial force demand imposed on the vertical tie members connecting the link beams together in TBFs. M-TBFs may however experience variations in storey drifts at levels where the ties have been removed to form the modules. In this paper, the possibility of reducing the discontinuity in displacement response of a 16-storey M-TBF structure by introducing energy dissipating (ED) devices between the modules is examined. Two M-TBF configurations are investigated: an M-TBF with two 8-storey modules and an M-TBF with four 4-storey modules. Three types of ED devices are studied: friction dampers (FD), buckling restrained bracing (BRB) members and self-centering energy dissipative (SCED) members. The ED devices were sized such that no additional force demand was imposed on the discontinuous tie members. Nonlinear response history analysis showed that all three ED systems can be used to reduce discontinuities in storey drifts of M-TBFs. The BRB members experienced the smallest peak deformations whereas minimum residual deformations were obtained with the SCED devices.