• Title/Summary/Keyword: Rock pool

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An Experimental Study on the Determination of Backlayering Distance in Tunnel Fires (터널 화재시 역기류의 위치 결정에 관한 실험적 연구)

  • 이성룡;유홍선
    • Tunnel and Underground Space
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    • v.14 no.4
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    • pp.269-274
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    • 2004
  • In this study reduced-scale experiments were conducted to determine the backlayering distance in tunnel fires. The 1/20 scale experiments were carried out under the Froude scaling using ethanol square pool fire ranging from 8 to 1km in each side with total heat release rate from 2.47 to 12.30 ㎾. It has been found that ventilation velocity increases with aspect ratio(tunnel height/tunnel width). At L$\_$B/$\^$*/ <5 the ventilation velocity increases proportional to the backlayering distance from 0.25 power of the heat release rate. However at L$\_$B/$\^$*/ $\geq$5 the ventilation velocity varies as the 0.3 power of the heat release rate.

An Experimental Study of Smoke Control in Tunnel Fires with Jet Fan (터널화재시 제트팬에 의한 연기제어에 관한 실험적 연구)

  • 이성룡;김충익;유홍선;방기영
    • Tunnel and Underground Space
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    • v.12 no.2
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    • pp.92-98
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    • 2002
  • In this study reduced-scale experiments were conducted to analyze smoke movement in tunnel fire with jet fan, The 1/20 scale experiments were carried out under the froude scaling using gasoline pool fire range from 6.6 to 12.5 cm in diameter with total heat release rate from 0.714 to 4.77 kW. In the case of fires under the 2.5kW, backlaying was reduced about 40cm and smoke was effectively controled in downstream of the fan when operating the fan. The smoke layer was moved down and the ceiling temperature was decreased compared to that of without fan case in upstream of the fan, but the temperature in the lower part of the tunnel was increased.

Species Composition and Vertical Distribution Pattern of Fish in Rock Tidal Pools at Mohang, Taeanhaean National Park (태안해안국립공원 모항 암반조간대 웅덩이의 어류 종조성과 수직분포)

  • Choi, Youn;Lee, Heung-Heon
    • Korean Journal of Ichthyology
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    • v.25 no.4
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    • pp.227-233
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    • 2013
  • Speceis composition and distribution by altitude of fish in the rock tide pools in Taean were determined using montly samples collected in the 9 tide pools from January to December 2010. Among 16 species collected, a forktongue goby Chaenogobius annularis was dominant accounting for 34.6% in the total number of individuals, and followed by Dictysoma burgeri (22.0%), Sebastes schlegelii (6.9%) and Tridentiger trigonocephalus (6.8%). A resident fish Dictyosoma burger occurred at all tide pools, and Chasmichthys dolichognathus was dominant in the upper tide pools and was collected throughout the study period. The resident fish is more abundant than the transient fish and occasional fish accounted for 61.4%, 14.2% and 24.4% in biomass, respectively.

Modelling of the effects of alkali-aggregate reaction in reinforced concrete structures

  • Pietruszczak, S.;Ushaksaraei, R.;Gocevski, V.
    • Computers and Concrete
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    • v.12 no.5
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    • pp.627-650
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    • 2013
  • This paper deals with application of a non-linear continuum model for reinforced concrete affected by alkali-aggregate reaction (AAR) to analysis of some nuclear structures. The macroscopic behaviour of the material affected by AAR is described by incorporating a homogenization/averaging procedure. The formulation addresses the main stages of the deformation process, i.e., a homogeneous deformation mode as well as that involving localized deformation, associated with formation of macrocracks. The formulation is applied to examine the mechanical behaviour of some reinforced concrete structures in nuclear power facilities located in Quebec (Canada). First, a containment structure is analyzed subjected to 45 years of continuing AAR. Later, an inelastic analysis is carried out for the spent fuel pool taking into account the interaction with the adjacent jointed rock mass foundation. In the latter case, the structure is said to be subjected to continuing AAR that is followed by a seismic event.

The Reduced Model Test for the Determination of Ventilation Velocity to Prevent Backflow in Uni-directional Road Tunnel during a Fire Disaster (일방향 도로터널내 화재 발생시 역류를 막는 환기속도결정에 관한 축소모형실험)

  • 유영일;이희근
    • Tunnel and Underground Space
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    • v.8 no.2
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    • pp.107-117
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    • 1998
  • In the case of a fire disaster in a uni-directional road tunnel, it is important to determine the critical ventilation velocity to prevent the backflow travelling toward the tunnel exit where vehicles are stopped. The critical ventilation velocity is horizontal velocity to prevent hot smoke from moving toward the tunnel exit. According to Froude modelling, the model tunnel whcih was 300mm in diameter and 21 m in length was made of acryl tubes. Inner section of acryl tubes was clothed with polycarbonate. 1/20 scaled model vehicles were installed to simulate the situation that vehicles are stopped in the tunnel exit. Methanol in a pool type burner was burned in the middle of tunnel to simulate a fire hazard. In this study, the basis of determining the critical ventilation velocity is the ventilation flow rate that is able to maintain the allowable CO concentration in the tunnel section. We assumed that the allowable CO concentration was backflow dispersion index. Futhermore, We intended to find out CO distribution and temperature distribution according as we changed ventilation velocity. The results of this study were that no backflow happened when ventilation velocity was 0.52 m/s in the case of 5.75 kW. If we adapt these results of a fire disaster releasing 10MW heat capacity in real tunnel which is 400m in length, no backflow happens when ventilation velocity is 2.31m/s. After we figured out dimensionless heat release rate and dimensionless ventilation velocity of model test and those of real test to verify experimental correctness, we tried to find out correlation between experimental results of model tunnel and those of real tunnel.

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A Study on the Actual Conditionis and Improvement Plan of Interior Landscape in the Subway Stations (지하철역내의 실내조경현황과 개선방안에 관한 연구)

  • 방광자;주진희;박혜경;박성은
    • Journal of the Korean Institute of Landscape Architecture
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    • v.26 no.3
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    • pp.258-266
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    • 1998
  • The purpose of this study is to investigate the actual conditions, to find problems, and to present an improvement plan of interior landscape in the subway stationis. Moreoiver, it will presume the possibilties to develop the subway and ways to utilie underground space effectively. The results are summarized as follows A light intensity was recorded 0-100 Lux as the lowest light and 500 Lux below as the highest in 61 subway stations. An average temperature of 12 $^{\circ}C$and an air humidity of 38% were recorded over a 4 month period from January to April, but includes a drastic variaton between -8.5$^{\circ}C$ and 21.5$^{\circ}C$. Soil acidity of pH 7 below and soil moisture of 1-2 wet degree were apeared in subway stations mostly. Plant forms consisted of artificial flower & flower. Plant species were recorded at a total of 54 species and appeared in the order of Araucaria heteropylla, Ophiophogon jaburan, Aspidistra elatior cv. 'Asahi' and Hedera helix. Plant height was, for the most part, below 0.5m. Plant species that was fined of conditions were Palm, Camellia japonica, Araucaria heterophylla as a high plant, dracaena fragrans, dracaena deremensis cv. Wakneckii as a middle plant, and Ophiopogon jaburan, Hedra helix, ytomium falcatum, Aspidistra elatior cv. Asahi as a low plant. It used to water materials such as small pool, small cascade, water cycles and natural materials such as natural rock, small rock, sand, bark and animal materials such as squirrels, birds, goldfish as an object for plants in the subway stations. From these actual conditions, First of all, It must make up physical environments such as light, temperature humidity, soil for plant growth, and is important to chooce suitable indoor plants and draw up systematic management in the subway environments. Also, it change plants frequently and uses variable objects for subway stationi individuatism, Moreover, indoor plants with strong environmental adaptation abities such as shade tolerance, drought tolerance and cold tolerance need to develope variable species possibly. If these improvements occur, utilization and amenity of subway stationis will increase, according to the use of interior landscape.

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Geomorphic Resources of Mt. Palgong, in Daegu (대구 팔공산의 지형자원)

  • JEON, Young-Gweon
    • Journal of The Geomorphological Association of Korea
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    • v.18 no.4
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    • pp.247-259
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    • 2011
  • This research aimed to analyse geomorphic resources of Mt. palgong(in Daegu city and Gyeongbuk province) through some field surveys, and then to clarify geomorphic features. The main results are as follows. 1) The geological boundary of the south slope(granite) is more clear than one of the north slope(granite bedrock and metamorphic sedimentary rock). Small basins are along with fault line between granite bedrock and metamorphic sedimentary rock. 2) It is estimated that relatively big valleys on the north slope are due to local climate, geomorphic and geological features. 3) Tor, sheeting joint, gutter are well developed both on the south slope and on the north slope, however the development of polygonal cracking and boulder stream are more dominant on the south slope; river cliff, pool, waterfall are more dominant on the north slope with valleys that well developed. 4) Scenic geomorphic landscapes are mainly developed in Dongsan valley and Chisan valley on the north slope. 5) There are many interesting geomorphic resources in the viewpoint of storytelling in Mt. Palgong. So the specific design to utilize such resources is required

Geomorphological Processes of Jaein Waterfall and Dissection Valley in Hantangang Lava Plateau, Central Korea (한탄강 용암대지의 재인폭포와 개석곡의 지형 형성)

  • Lee, Min-Boo;Lee, Gwang-Ryul
    • Journal of The Geomorphological Association of Korea
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    • v.24 no.3
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    • pp.47-59
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    • 2017
  • This study aims to analyze geomorphologically Jaein Falls in Hantangang Lava Plateau for the landform structure, landform classification, falls dissection and recession. The height and recession length of the Falls are approximately 18m and 340m. after dissection valley arrive at area of the Jijangbong Volcanic Rock Complex of Mesozoic era, the fall will disappear. The structure of the dissection valley shows totally well vertical columnar joint near falls and plunge pool, colluvial talus deposits toward lower reach by the freezing-thawing and wet-dry activities, and alluvial cone and delta in estuary to Hantangang River. The Falls' age date and recession rate in the valley maybe relate to the age of the lava plateau. The estimated recession rate of the fall should be 8.75m/ka to 2.3m/ka, depending on the age 500ka to 40ka in lava plateau.

A Landscape Possessor and Enjoyment of Jongho on the Mansutan River Traced by Stone Inscription and 'Jongho Eight Views' (바위글씨와 팔경으로 추적한 만수탄(萬水灘) 종호(鍾湖)의 경관 향유자와 풍류상)

  • Rho, Jae-Hyun;Kim, Hwa-Ok;Park, Yool-Jin;Kim, Hong-Gyun
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.38 no.1
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    • pp.53-66
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    • 2020
  • This study was attempted to seek the garden enjoyment of the Yang Un-geo etc., in the head house(宗宅) of Namwonyang's family and Jongho in Sunchang Gumiri through literature and field research. Admirers of Jongho were "six old Taoist hermit", including Cholo(楚老) Yang Un-geo(楊雲擧, 1613-1672) and Yangjindang Haman-ri, the author of Jongho-palgyeong, who was very close friends of Yang, as well as his son-in-law or out-law. Jonghojeong Pavilion, overland rock and nearby Takyeongjeong, which were built around a stone island shaped like a helmet, and a pool along the river, are known as 'Imcheonwonrim(林泉園林)' as the center of the custom that was conducted based on head house, which is up to 2km away from Jongho. Jongho-palgyeong is found to share the characteristics of Jeongja Palgyeong, which is based on Jonghoam, overland and Takyeongjeong, and the characteristics of the town's township of Namwonyang, Gumi-ri. The number of rock letters identified by the Mansutan members is a total of nine points, which clearly indicates that the scene was a scene where the custom of call to create poetry·fishing·playing musical instruments and drinking, as well as the scenery and landscape structure of the Jongho Palgyeong. Jongho Palgyeong, its customs and surrounding rock writing are highly suggestive and valid cultural views to remind or direct the old landscape of Mansutan Jongho and suggest to modern traditional landscapes as well as the "Noblesse oblige landscape enjoyment case."

The Geomorphological Features of Dongcheon-gugok in Korea (우리나라 동천구곡의 지형경관)

  • KEE, Keun-Doh
    • Journal of The Geomorphological Association of Korea
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    • v.19 no.3
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    • pp.123-134
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    • 2012
  • This work is to describe the geomorphological landscapes of of Dongcheon-gugok in Korea, and attempts to develop a basic data for traditional natural heritage. Dongcheon-gugok is a union of natural lanscape and human mind-activity. Therefore the study of natural landscape, which consists of geomorphological landscapes, provides a basic data for the use and conservation of traditional natural heritage. Dongcheon-gugok in Korea is almost distributed in the valley of mountainous areas of Taeback and Soback Mountain Ranges. The bedrocks of the areas of Dongcheon-gugok are almost granitic rocks and sedimentary rocks. The landscapes of Dongcheon-gugok is characterized by narrow meandering valley, so Gugok means nine-bended river. The elements of the geomorphological features is a broad flat rock with sheeting joints, joint-block seperated large blocks or tor, steep slope and rocky cliffs, pool, ripple, large or small scale waterfall, pot-hole, etc.