• Title/Summary/Keyword: rock formation

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Design and construction of shaft for rock caverns in Singapore

  • Zhang, Xiao-Ping;Lu, Ming;Mao, Dawei;Zhao, Zhiye;Hao, Liu
    • 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.

The $Mer{\aa}ker$ TBM Project in Norway (노르웨이 메로케르 수력발전소의 TBM 굴착)

  • Park Yeonjun;Park Chulwhan
    • Tunnel and Underground Space
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    • v.15 no.1 s.54
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    • pp.22-27
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    • 2005
  • This paper presents an article explaining a TBM project overall in Norway. The paper which published in Norwegian TBM Tunnelling by Norwegian Soil and Rock Eng. Assoc. in 1998, contains most of the items considered in TBM tunnelling. New powerplants, tunnels and dams have been built at Meraker in Central Norway. A total of 44 km of tunnels with cross sections varying from $7\;m^2\;to\;32\;m^2$ have been excavated in hard rock formation. Tunnel of 10 km with the 3.5 m diameter was excavated by a HP TBM in a year. his project gives the special attention to the TBM drive and equipment selection, including planning, site organization and performance.

The Effect of the Thermal Stress on the Transport Property of Pocheon Granite (열응력이 포천화강암의 투수성에 미치는 영향)

  • Yoon, Yong-Kyun
    • Tunnel and Underground Space
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    • v.7 no.3
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    • pp.238-245
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    • 1997
  • A transient pulse methos has been used to measure the permeability of Pocheon granite pre-heated from $25^{\circ}C$ to $600^{\circ}C$ at effective pressure up to 32MPa. The permeability of whole rock ranged from 0.72 $\mu$d at 10MPa to 0.20 $\mu$d at 32MPa. The permeability of rock heated to $600^{\circ}C$ ranged from 18.07$\mu$d at 10MPa to 6.39$\mu$d at 32MPa. Confining pressure has greater effects on the rocks thermally treated to lower thermal-cycle temperatures than on the higher thermally treated rocks. The increase of permeability is most pronounced between 40$0^{\circ}C$ and $600^{\circ}C$. Below 40$0^{\circ}C$, permeability increase is expected to be associated with the formation of new cracks and widening of preexisting cracks, whereas above 40$0^{\circ}C$, permeability increase is expected to reflect widening of cracks. Using the equivalent channel model, author shows that the exponent n in the relationship relating the permebility(k) to porosity($\phi$) by k∝$$\phi$^n$ falls in the range 2.7$\leq$n$\leq$3.0.

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A Study on the Popular music and Fashion of youthful subculture (청소년 하위문화에 나타난 대중음악과 복식에 대한 연구-1970년대 이후를 중심으로-)

  • 엄소희
    • Journal of the Korean Society of Costume
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    • v.26
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    • pp.101-121
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    • 1995
  • The Purpose of this study was to investigate homology between the Popular music and Fashion of youthful subculture and how the image of popular music have influenced on the 90's fashion. As the result, Korean youthful subculture analized to be different from western youthful subculture. In western countries, the style of youthful subculture groups spread to tricle up as developed themselves but represented tricle down phenomenon in Korea. Because life con-dition of Korean Youthful was different from westerns in everything. The Image of popular music have an influenced on the 90's fashion, it is be classified into the Jazz image, the Country & Western image, the Rock image, and Hip-Hop, Ragge image. 1. The jazz image from Jazz music has come back dandism of the nostalgia mood and intro-duce ethnic sense into fashion. 2. The Country & Western image is reflected in fashion of accessories details, materials and Coordination item. 3. The rock image from Acid Rock and Punk Rock effected the advent of hippie mood fashion, ethnic, ecology, new unisex fashion and Punk fashion trend. 4. The hip-hop, raggae image from Rap and Raggae music showed on fashion of primitive mood's naturism, Sports wear's generalization and dualism. After the 90th, youthful fashion of new gener-ation may be infered constantly on the move toward $\ulcorner Fashion democracy \lrcorner$formation.

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Molecular cloning and expression analysis of a C-type lectin in the rock bream, Oplegnathus fasciatus

  • Kwon, Mun-Gyeong;Kim, Ju-Won;Park, Myoung-Ae;Hwang, Jee-Youn;Park, Hyung-Jun;Park, Chan-Il
    • Journal of fish pathology
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    • v.25 no.1
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    • pp.11-20
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    • 2012
  • C-type lectins are crucial for pathogen recognition, innate immunity, and cell-cell interactions. In this study, a C-type lectin gene was cloned from the rock bream. The full-length RbCTL cDNA was 729 bp with a 429 bp ORF encoding a 164-residue protein. The deduced amino acid sequence of RbCTL had all of the conserved features crucial for its fundamental structure, including the four cysteine residues involved in sulfide bridge formation and potential $Ca^2+$/carbohydrate-binding sites. RbCTL contains a signal peptide one single carbohydrate recognition domain. It showed 29.4% similarity to the C-type lectin of rainbow trout. RbCTL mRNA was predominately expressed in gill and head-kidney tissue and expressed less in peripheral blood leukocytes, trunk-kidney, spleen, liver, intestine and muscle. Expression of RbCTL was differentially upregulated in rock bream stimulated with LPS, Con A/PMA and poly I:C.

Characteristics of Roadside Cut-Slopes Failures along the 46th National Highway (남양주-춘천(국도 46 호선)간 도로절개면 붕괴 특성 고찰)

  • 구호본;정의진;박성욱
    • Proceedings of the Korean Geotechical Society Conference
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    • 2000.11a
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    • pp.527-534
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    • 2000
  • 136 cut slopes which extends from Namyangju to Chunchon city along the 46th national highway were investigated to analyze the influence factors affecting slope instability. Geologic and geotechnical conditions were examined and the detailed investigation were carried out for fifty five failed slopes. failure mode (wedge failure, planar failure, circular failure, sheet eroison and rock falls) are examined with respect to slope inclination, rock type, weathering grade and discontinuity patterns. It is suggested that the failure modes and their dimensions have relations to the morphology and geologic conditions of the slopes. Wedge failure has highest is the most frequent failure mode and falls, sheet erosions, planar failures and circular in descending order of failure percentage. Wedge failure is most dominant failure type over all lithology except quartzite formation. In slopes of well foliated and banded gneiss, failure ratio of wedge is up to 50% ca. Failure ratio(number of rock fall/number of total failure) of rock fall increases with increase fo slope inclinations and decrease of weathering grade. Dimension analyses of failed slopes shows wedge and circular failure has higher value of D/L and D/H than planar failure and sheet erosion.

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Effect of Starvation on Kidney Melano-macrophage Centre in Sub-adult Rock Bream, Oplegnathus fasciatus (Temminck and Schlegel)

  • Seol, Dong-Won;Hur, Jun-Wook;Kim, Dong-Soo;Nam, Yoon-Kwon;Bang, In-Chul;Park, In-Seok
    • Fisheries and Aquatic Sciences
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    • v.12 no.1
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    • pp.49-53
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    • 2009
  • We conducted a histological analysis to investigate the influence of nutritional changes on melano-macrophages (MMs) accumulation in the kidney of sub-adult rock bream (Oplegnathus fasciatus). Four experimental groups were established (initial control, control, fed and starved), and fed commercial feed amounting to 1-3% of their body weight for 2 weeks prior to initiation of experiments. Kidney MMs with dark brown pigment were randomly observed in the kidneys of starved fish, increasing rapidly after 4 weeks, while deposition levels remained low throughout the experiment in the control and fed groups. These results suggest that catabolic tissue breakdown is a major factor contributing to the formation of pigments within MMs. Results also suggest that the degree of MMs deposition in the kidney can be used as alternative indicators in identifying starvation in wild and cultured rock bream.

Numerical study on rock splitting using the cylindrical cavity (원형 자유면을 이용한 암반 파쇄의 수치해석적 연구)

  • Ahn, Sung Kwon
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.19 no.6
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    • pp.1013-1028
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    • 2017
  • This paper presents key findings obtained from the numerical experiment investigating into the use of the cylindrical cavity for rock splitting operations. The stress and strain path analyses were carried out in order to provide a better insight into the crack formation. The principal stress analysis carried out along the crack line using the results obtained from these numerical analyses allowed the failure of the brittle material and the crack propagation to be investigated. This paper also suggested possible reasons for the change in crack direction observed during the rock splitting operations using the results obtained.

Report on the Sam Han Chang Gun Manganese Deposits (삼한(三韓) 장군(將軍) 광산(鑛山) 조사(調査) 보문(報文))

  • Hwang, In Chon
    • Economic and Environmental Geology
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    • v.1 no.1
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    • pp.9-34
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    • 1968
  • Manganese ore deposits of the Samhan Changgun Properties are located at the valley of west-lope-side of Changgun-bong (1132m) occupied over the Myon border between Sochon-myon and Jaesan-myon Pongwha-gun, Kyongsang-Pukdo. Geology of the more property and it's vicinity consists of Wonnan formation and Yulri formation of pre-Cambrain and Changgun limestone formation, Mica-schist formation, quartizite formation and Jaesan formation (containing coal bearing zone the unknown age. And granites and dykes were intruded into the above formation later. 1. Management deposits is embedded the formation of Janggun limestone especially Contact zone in the contact zone to of Chunyang Granite limestone enclosed by Granite, and Maginal zone of fault line in the limestone. Therefore, Chunyang Granite is Closely related to ore deposit. Pegmatite which is near by ore deposit was intruded before mineralization and it seems to be a channelway of ore solution. The most important ore deposits of property grouped into south deposit, east deposit, east-Gachon deposit, South-Gachon deposit, Durimgok deposit and West deposit, out-crops at several place. Besides these deposits there also are several prospects on outcrop scathered. Hydrothermal alteration take place strongly in the well rock and it's sequence are Characterized as following; 1) Dolomitization 2) Carbonization 3) Mamgamotozation 4) Pyritization 5) Silicification 6) Oxidation 2. The grade of manganese dioxide is up to Mn 45% in Maximum, but generally, averaging Mn 30~35% of high grade ore and averaging Mn 30~32% of manganese carbonates are mined in his property.

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Analysis of Sinkhole Formation over Abandoned Mine using Active-Passive-Active Finite Elements (폐광지역에서의 싱크홀 발생 규명을 위한 Active-Passive-Active 유한요소 기법 연구)

  • Deb Debasis;Shin Hee-Soon;Choi Sung O.
    • Tunnel and Underground Space
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    • v.14 no.6 s.53
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    • pp.411-422
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    • 2004
  • Sinkhole subsidence occurs over abandoned mine workings and can be detrimental to human lives, damage to properties and other surface structures. In this study, simulation of sinkhole development process is performed using special finite element procedure. Especially, creation of mine voids due to roof falls and generation of goaf from broken rocks are simulated using active-passive-active finite elements. An active or solid element can be made passive or void once the tensile failure criterion is satisfied in the specified sinkhole formation zone. Upon completion of sinkhole development process, these passive elements in again be made active to simulate goal region. Several finite element models are analyzed to evaluate the relationships between sinkhole formation with width of gallery. depth of mine, roof condition and bulking factor of roof rocks. This study demonstrates that the concept of passive elements in numerical analysis can be used effectively for analyzing sinkhole formation or roof fall phenomenon in general.