• Earthquakes and Structures
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• 제22권3호
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• pp.277-287
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• 2022

The ancient underground cities are a collection of self-supporting spaces that have been manually excavated in the soil or rock in the past. Because these structures have a very high cultural value due to their age, the study of their stability under the influence of natural hazards, such as earthquakes, is very important. In this research, while introducing the underground city of Ouyi Nushabad located in the center of Iran as one of the largest man-made underground cities of the old world, the analysis of dynamic stability is performed. For this purpose, the dynamic stress-displacement analysis has been performed through numerical modeling using the finite element software PLAXIS. At this stage, by simulating the Khorgo earthquake as one of the large-scale earthquakes that occurred in Iran, with a magnitude of 6.9 on the Richter scale, dynamic analysis by time history method has been performed on three selected sections of underground spaces. This study shows that the maximum amount of horizontal and vertical dynamic displacement is 12.9 cm and 17.7 cm, respectively, which was obtained in section 2. The comparison of the results shows that by increasing the cross-sectional area of the excavation, especially the distance between the roof and the floor, in addition to increasing the amount of horizontal and vertical dynamic displacement, the obtained maximum acceleration is intensified compared to the mapping acceleration applied to the model floor. Therefore, preventive actions should be taken to stabilize the excavations in order to prevent damage caused by a possible earthquake.

• 한국환경과학회지
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• 제21권8호
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• pp.997-1007
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• 2012

This study was performed to assess functions of 10 man-made wetlands in Gunsan City, Jeollabuk Province by means of RAM (Rapid Assessment Method), a technique recommended by Ramsar Convention to appraise wetlands. The assessment of the wetlands value found Gunsan reservoir to have the highest function points while Bukchosan reservoir was estimated to have the lowest function among the wetlands surveyed. By detailed factors of valued 10 man-made wetland, the wetlands were found to function most favorably in terms of vegetational variety and as habitat for wild animals. They need to have more improved functions as habitats for fish and amphibians reptiles, for preservation and betterment of water quality as well as for supplement of underground water, though. From the assessment of vegetational naturalness of the surveyed reservoirs, Gunsan reservoir turned out to be the most favorable wetland from the viewpoint of vegetation science whereas, however, Anjeong wetland was rated as the lowest in the assessment of vegetational value due to simplicity in its vegetation and lots of dangers in its neighborhood threatening its vegetation and ecology. The assessment of vegetational values for Gunsan, Gongchang, Daewi, Bukchosan, Anjeong, Geumgul, Changan and Chuksan reservoirs showed the same orextremely similar results as RAM function assessment. Geumsan reservoir only, however, featured the opposite result.

• 지질공학
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• 제28권2호
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• pp.207-215
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• 2018

지구온난화 문제가 인류 생존을 위협하는 중대한 이슈로 떠오르면서 세계 각국은 온실가스 감축에 적극 나서고 있다. 대표적 온실가스인 이산화탄소($CO_2$)는 석탄, 석유와 같은 화석연료를 연소하는 과정에서 대량으로 방출되고 있다. $CO_2$를 포집하고 저장하는 CCS ($CO_2$ Capture & Storage) 기술은 온실가스 저감의 대표적 기술로 세계 각국에서 연구가 활발하게 진행되고 있다. 본 연구는 대규모 $CO_2$ 배출원에서 포집된 $CO_2$를 대상으로, 국내 최초로 해상에서 지중저장을 하기 위한 고압 주입설비의 설계 및 구축에 관한 연구다. 이를 위해 2017년초 $CO_2$ 지중 주입설비가 구축되었으며 포항시 영일만 해상 플랫폼에서 $CO_2$ 시험주입을 국내 최초로 성공하였다. 그 결과 해상주입을 위한 주입설비의 운전 요구조건과 $CO_2$ 주입 특성이 파악되었고 주입장치 운영에 관한 노하우도 얻게 되었다. 시험주입에서 얻어진 결과는 향후 장치개선과 scale-up에 활용될 예정이다.