• Journal of Internet of Things and Convergence
• /
• v.7 no.4
• /
• pp.69-75
• /
• 2021

This study investigated the status of disaster response, focusing on modern architecture. The modern architecture is drawing more attention and being more used in the local community among the architectural heritage in downtown collective. The railway employee residence area in Soje-dong, Daejeon is a collective building group, and the efforts to evaluate and preserve its historical, cultural, and architectural values have been underway. However, the area is now an undesignated cultural property that does not receive institutional protection. It carries significance in preserving it as a collective building group. Yet, since the main structure is made of wood, the risk of being destroyed by fire or disaster is high, and disaster prevention measures are insufficient. Therefore, this study examined the structural and non-structural conditions such as the arrangement and architectural characteristics of official residence buildings, and looked into measures of the construction of a disaster prevention system and residents' participation. To preserve the urban historical environment created as a collective architectural heritage, it is necessary that the area reinforces its own disaster prevention capabilities, such as establishing an effective disaster prevention system considering village characteristics, strengthening disaster prevention capabilities based on residents' participation, and forging formal and informal governance in the local community.

• Journal of the Korean Geotechnical Society
• /
• v.26 no.12
• /
• pp.5-17
• /
• 2010

Coarse granular material is used as important fill material in most of large embankments such as railway, road, dam and so on. Therefore, the accurate design parameters of the coarse granular material are necessarily required in design and construction. The behavior of the coarse granular material was not well understood because of the lack of large testing equipment capable of coarse granular material. A large triaxial testing system was developed in this research, capable of large specimens of 500 mm, 300 mm and 150 mm in diameter. In the new large triaxial testing system, the load cell is installed inside the triaxial cell and axial displacement is measured locally on a specimen in order to improve control and measurement in small strain level. Urethane specimens of 300 mm and 50 mm in diameter were prepared. The large triaxial tests were performed on the 300 mm diameter urethane specimens while RC/TS and impact echo tests on the 50 mm diameter urethane specimens to verify this testing system. In this verification test results, we could ascertain the reasonable test results of the KRRI large triaxial testing system.

• Geomechanics and Engineering
• /
• v.37 no.6
• /
• pp.599-614
• /
• 2024

To evaluate the safety status of deteriorated segments in a submarine shield tunnel during its service life, a seepage model was established based on a cross-sea shield tunnel project. This model was used to study the migration patterns of erosive ions within the shield segments. Based on these laws, the degree of deterioration of the segments was determined. Using the derived analytical solution, the internal forces within the segments were calculated. Lastly, by applying the formula for calculating safety factors, the variation trends in the safety factors of segments with different degrees of deterioration were obtained. The findings demonstrate that corrosive seawater presents the evolution characteristics of continuous seepage from the outside to the inside of the tunnel. The nearby seepage field shows locally concentrated characteristics when there is leakage at the joint, which causes the seepage field's depth and scope to significantly increase. The chlorine ion content decreases gradually with the increase of the distance from the outer surface of the tunnel. The penetration of erosion ions in the segment is facilitated by the presence of water pressure. The ion content of the entire ring segment lining structure is related in the following order: vault < haunch < springing. The difference in the segment's rate of increase in chlorine ion content decreases as service time increases. Based on the analytical solution calculation, the segment's safety factor drops more when the joint leaks than when its intact, and the change rate between the two states exhibits a general downward trend. The safety factor shows a similar change rule at different water depths and continuously decreases at the same segment position as the water depth increases. The three phases of "sudden drop-rise-stability" are represented by a "spoon-shaped" change rule on the safety factor's change curve. The issue of the poor applicability of indicators in earlier studies is resolved by the analytical solution, which only requires determining the loss degree of the segment lining's effective bearing thickness to calculate the safety factor of any cross-section of the shield tunnel. The analytical solution's computation results, however, have some safety margins and are cautious. The process of establishing the evaluation model indicates that the secondary lining made of molded concrete can also have its safety status assessed using the analytical solution. It is very important for the safe operation of the tunnel and the safety of people's property and has a wide range of applications.