• 제목/요약/키워드: rock movement

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Countrol of Groundwater by Clay Grouting in Undergroun Excavation of Oil Storage Caverns (원유 저장용 지하공동의 건설중 점토 그라우팅에 의한 지하수 제어)

  • 김치환;박창우;이석천
    • Tunnel and Underground Space
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    • v.3 no.1
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    • pp.24-32
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    • 1993
  • Groundwater movement is one of the most important elements in the construction and management of underground oil storage cavern. To control the groundwater flow, grouting is run in parallel with water curtains. But as traditional grouting is conducted within cavern before and after excavation, the effect of grouting is delayed and the injection sphere is limited in the rock mass. Therefore, it is desirable to introduce a more extensive and effective grouting. This article is to present the caly grouting, which was the first to be carried out in the construction of underground caverns for oil storage in Japan. After conducting the clay grouting, the effect was confirmed by ground water level and infiltration quantity to the caverns.

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Demolition and Maintenance/Repair Cost Estimation of Road Drop Obstacle for Safety Risk Removal of Anti-tank Defense Facility (대전차 방어시설의 안전위해요소 제거를 위한 낙석 장애물 철거 및 유지보수 비용 산정 연구)

  • Yoo, Yang-Soo;Park, Young Jun;Eun, Hee-Chang;Baek, Jang-Woon
    • Journal of the Korea Institute of Building Construction
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    • v.20 no.4
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    • pp.375-382
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    • 2020
  • Rock drop obstacles on major roads in the border area in South Korea has been installed and operated to prevent and block the movement of enemy units. However, the increase in traffic volume due to the development of the border region causes many problems such as road traffic congestion due to rock drop, traffic safety, and impaired urban aesthetics. Therefore, this study aimed to provide guidelines for demolition and replacement facility installation for rock drop obstacles, which are differently applied to each unit, and to suggest the direction of the Ministry of National Defense's policy regarding maintenance cost for necessary rock drop obstacles required for operation. In this study, as part of a guideline study on the removal of rock drop obstacles and the installation of alternative facilities, a standard unit price was suggested for essential rock drop obstacles, so as to be used as judgment data when deciding whether to remove rock drop obstacles.

Analysis for the Behavior of Ridge-Cut Rock Slope (능선부 개착에 의해 형성된 암반사면 거동해석)

  • Cho, Tae-Chin;Hwang, Taik-Jean;Shin, Sun-Mi;Lee, Guen-Ho
    • Tunnel and Underground Space
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    • v.22 no.6
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    • pp.393-402
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    • 2012
  • A behavior of ridge-cut rock slope had been monitored by installing inclinometers and regional slope movement toward rear side of cut face was detected. To delineate the governing factors of slope behavior, especially backward slip of ridge-cut slope, petrographic characteristics of rock cores obtained from four drilled boreholes had been examined. BIPS images inside boreholes had been acquired and structural characteristics of slope rock had been studied. Mechanical properties of discontinuity planes distributed in the drilled core had been measured and the shear strength of coal seam imbedded-discontinuity planes also had been obtained by performing the direct shear test. Monitoring results of slope behavior had been analyzed by comprehensibly considering both the mechanical and structural characteristics of slope rock and coal seam-imbedded discontinuity planes, and the potential governance of coal seam and clay minerals embedded in the joint plane on the regional slope behavior has been also identified.

An Experimental Study on Smoke Movement by the External Wind in Road Tunnel Fires (도로터널 화재 시 외부 바람에 의한 연기거동 특성에 관한 실험적 연구)

  • Lee, Sung-Ryong
    • Tunnel and Underground Space
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    • v.24 no.4
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    • pp.308-315
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    • 2014
  • In this study, reduced scale experiments were carried out to evaluate the effect of external wind in a road tunnel fire. Experiments were conducted in a $1.1m{\times}0.5m{\times}50.4m$ tunnel. 4.5 litter gasoline was used as a fuel. Temperature, oxygen and carbon monoxide concentration were measured. Smoke reaching time to the tunnel exit was affected by the external wind. When a fire was fully developed, wind effect is reduced compared with the early stage of a fire. CO concentration was reached at more than 1,500 ppm.

Seismic wave monitoring of $CO_2$ migration in water-saturated porous sandstone

  • Xue Ziqiu;Ohsumi Takashi
    • Geophysics and Geophysical Exploration
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    • v.7 no.1
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    • pp.25-32
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    • 2004
  • We have carried out laboratory measurements of P-wave velocity and deformation strain during $CO_2$ injection into a porous sandstone sample, in dry and water-saturated conditions. The rock sample was cylindrical, with the axis normal to the bedding plane, and fluid injection was performed from one end. Using a piezoelectric transducer array system, we mapped fluid movement during injection of distilled water into dry sandstone, and of gaseous, liquid, and supercritical $CO_2$ into a water-saturated sample. The velocity changes caused by water injection ranged from $5.61\;to\;7.52\%$. The velocity changes caused by $CO_2$ injection are typically about $-6\%$, and about $-10\%$ for injection of supercritical $CO_2$, Such changes in velocity show that the seismic method may be useful in mapping $CO_2$ movement in the subsurface. Strain normal to the bedding plane was greater than strain parallel to the bedding plane during $CO_2$ injection; injection of supercritical $CO_2$ showed a particularly strong effect. Strain changes suggest the possibility of monitoring rock mass deformation by using borehole tiltmeters at geological sequestration sites. We also found differences associated with $CO_2$ phases in velocity and strain changes during injection.

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.

A Study on the Genre-Convergent Characteristics of Tropicália in Brazil -focused on Caetano Veloso- (브라질 '트로피칼리아'의 장르 융합적 특징 고찰 -카에타누 벨로주(Caetano Veloso) 작품을 중심으로-)

  • Park, Mi-Jin;Hong, Sung-Kyoo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.3
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    • pp.237-245
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    • 2020
  • Tropicália, which marked the beginning of Brazilian Popular Music (MPB), is a musical genre that originated in the Brazilian cultural movement and this arose in the late 1960s. The musicians who participated in this cultural movement delivered radical innovation by embracing the international music trend of the 60s, such as the Beatles phenomenon and the experimental and creative music of the electronic age. The music derived from this era incorporated the cannibalism of the Brazilian modernism cultural movement in the 1920s, and it presented a cultural consilience while maintaining the traditional Brazilian culture. In particular, the convergence of Tropicália with rock was especially prominent. As rock grew into the culture of resistance in both Britain and the United States, the convergent characteristic of Tropicália reflected the critical sociocultural view toward Brazil at that time. This paper focuses on the element of fusion of traditional Brazilian music and the rock music present in Tropicália. To present a case study, this paper selected music pieces by Caetano Veloso, the essential pillar of Tropicália, and examined each element through specific music analysis. This study aims to establish an academic foundation for third-world music and contributes to the development and creation of fusion music.

Hydrogeological Survey and Satellite Remote Sensing in the Dunhuang Area

  • Piao, Chunze;Tanimoto, Chikaosa;Koizumi, Keigo;Li, Zuixiong;Wang, Xudong;Guo, Qinglin
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.444-446
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    • 2003
  • Mogao Grottos are located at the eastern foot of the Mingsha Mountain, 25km southeast of Dunhuang City. The caves were excavated into the cliff on the west bank of the Daquan River. The wall paintings in the caves are subject to the severe deterioration generated by recrystallization of salt. It relates with the movement of water/moisture in rock formation. Through the satellite image analysis and geological survey it has been clarified that the movement of ground water is governed by the fault system. The geographical nature is specified by the aggressive tectonic movement from the south.

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Application of black box model for height prediction of the fractured zone in coal mining

  • Zhang, Shichuan;Li, Yangyang;Xu, Cuicui
    • Geomechanics and Engineering
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    • v.13 no.6
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    • pp.997-1010
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    • 2017
  • The black box model is a relatively new option for nonlinear dynamic system identification. It can be used for prediction problems just based on analyzing the input and output data without considering the changes of the internal structure. In this paper, a black box model was presented to solve unconstrained overlying strata movement problems in coal mine production. Based on the black box theory, the overlying strata regional system was viewed as a "black box", and the black box model on overburden strata movement was established. Then, the rock mechanical properties and the mining thickness and mined-out section area were selected as the subject and object respectively, and the influences of coal mining on the overburden regional system were discussed. Finally, a corrected method for height prediction of the fractured zone was obtained. According to actual mine geological conditions, the measured geological data were introduced into the black box model of overlying strata movement for height calculation, and the fractured zone height was determined as 40.36 m, which was comparable to the actual height value (43.91 m) of the fractured zone detected by Double-block Leak Hunting in Drill. By comparing the calculation result and actual surface subsidence value, it can be concluded that the proposed model is adaptable for height prediction of the fractured zone.

Spatial Compositional Variations and their Origins in the Buseok Pluton, Yeongju Batholith (영주저반의 부석심성암체 내에서 공간적 조성변화와 그 성인)

  • 황상구
    • Economic and Environmental Geology
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    • v.33 no.2
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    • pp.147-163
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    • 2000
  • The Buseok pluton in the Yeongju Batholith is a comagmatic plutonic rocks which haveconcentrically compositional zoning. The lithofacies of the Buseok pluton comprise hornblende biotite tonalite in the southern part of the pluton, porphyritic and equigranular biotite granodiorite in the northern part and biotite granite in the north-central part. The compositional variations change gradually with continuity both within and between the lithofacies. The concentrically zoned pattern is relatively mafic rocks composed of high-temperature mineral assemblages in margin of the southern part, passing inward and northward gradually to more felsic rock in core of the north-central part. Changes in the textures and microstructures, as well as in the mineral content, take place between rock types of the plutons. Darker colored, generally coarse-grained, well foliated tonalite pass inward to light colored, coarse-grained, poorly foliated granodiorite, and finally give way to lighter colored, medium-grained, nearly nonfoliated granite. The foliation are best developed in the marginal part of the tonalite. Here, the regional myolitic foliation in the tonalite is steep northward and parallels to its southeastern contact with the country rock, but the magmatic foliation from disc-shaped mafic microgranitoid enclaves is subvertical and parallels the contacts with the country rock. As the tonalite approaches biotite granite in composition, the foliation is indistinct. Modal and chemical data for the pluton show quantitative compositional variation from the margin of the southern part to the core of the north-central part. Quartz and K-feldspar increase toward the core of the pluton, whereas hornblende, biotite and color index decrease. /Abundances of $SiO_2$and $K_2O$$_2$O increase toward the core according to the variation in quartz and K-feldspar, whereas those of MnO, CaO, $TiO_2$, $Fe_2O_3$, MgO and $P_2O_5$ decrease corresponding to the variation in mafic and accessaries. The compositional zonation resulted from fractional crystallization involving downward settling of earlier crystals, accompanied by upward movement of melt and volatiles, and followed by accessary marginal accretion of crystalline material in the magma to the marginal part. Although a little crustal contamination by the wall rock is recognized from the isotope data, the contamination is not only dominated over but also appropriate for forming the compositional variation in the pluton.

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