• Title/Summary/Keyword: ground support

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The Operation Concept and Procedure of Mechanical Ground Support Equipment for KSLV-II Launch Complex (한국형발사체 발사대시스템 지상기계설비 운용개념 및 절차)

  • Lim, Chankyoung;Kim, Daerae;Yang, Seongpil;Lee, Yeongho;Kang, Sunil
    • Journal of the Korean Society of Propulsion Engineers
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    • v.22 no.4
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    • pp.125-132
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    • 2018
  • The mechanical ground support equipment of a Korea Space Launch Vehicle-II launch complex is a collection of systems used for transporting, erecting and lowering the launch vehicle. It also provides an interface for supplying propellants. In this paper, compositions, functions and design results of mechanical ground support equipment are introduced. Additionally, the operational concept of each piece of equipment is presented with operation procedure.

Behavior and Application of Jacket pack anchor in Soft ground (연약지반상에 자켓팩앵커의 적용과 거동특성)

  • Kim, Tae-Seob;Cho, Yoon-Ju;Jung, Chang-Won
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.09a
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    • pp.1065-1072
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    • 2010
  • The excavation site in the new city of inchon songdo is distributed with soft reclaimed soil and marine deposit. So, the general ground anchor is not applied to this layer of soft ground as the earth retaining support system, because of settlement. And then, Jacket pack anchor which is newly developed in order to increasing the pullout resistance by certain grout bulb formation and expansion effect in soft ground is applied to this site instead of the general ground anchor. Though the maximum horizontal displacement shows about 30mm~100mm (The maximum horizontal displacement/excavation depth$\fallingdotseq$0.32~1.0%) according to excavation sequence, generally excavation work finished stably. Also, load cell after setting shows almost increasing trend with increasing horizontal displacement. It means that the settlement of Jacket pack anchor in soft ground is good. From the result of this case, we knew that Jacket pack anchor was able to use the earth retaining support system in soft ground. Using Jacket pack anchor in soft ground, The allowance of the horizontal displacement is applied more than general value considering soil factors.

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Restoration of Antique (Sam-Sae Buddhistic Painting) In Song-Kwang Temple (전남 승주군 송광사 승보전 유물(삼세불화)보수)

  • Cheon, Kyeong-Mee;Cheon, Cheol
    • Journal of the Korean Wood Science and Technology
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    • v.27 no.3
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    • pp.82-90
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    • 1999
  • The buddhistic painting of Song-Kwang temple in Seungjoo-gun, Chonnam, Korea is not known in chronicle, but it could be estimated to works in the early 19th century through it's remaining records and qualities of materials. And it was analysed the qualities of materials consisting of pigment layer, silken-ground layer and support layer in order to preserve buddhistic painting, made back-adherent paper of the support layer proper to it, tested its compatibility, and then concluded as follows. 1. The section structures of buddhistic painting is consisted of the pigment layer, silken-ground layer of silk and the support layer of Korean hand made paper, it could be recognized that buddhistic painting in 19th century was basically composed of the pigment layer, the silken-ground layer and the support layer. Moreover the pigment layer and the silken-ground layer got adhered with glue, and sheets of support layers got back adhered with paste. 2. The support layer of buddhistic painting consisted of 5 layers and two kinds of paper were used for them. The first and second layers were composed of Korean hand made paper made of pure paper mulberry bast fibers, and the rest of them of paper that paper mulberry bast fibers were mixed into recycled hemp fibers. Though it is difficult to assert without the security of more data, finding out the then situation through the qualities of materials, it was presumed that the society in 19th century was suffered from economical difficulties and the operation of the paper industry of temples was rather difficult and so low-qualitative recycled hemp fibers might used for back-adherent paper. 3. Considering tension between silken-ground layers and support layers of this materials, newly made back-adherent paper was used for repair, and then I could conform that it was proper to back-adherent paper for repair.

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Basic Design of Propellant Ground Support Equipment and Flame Deflector for KSLV-II Launch Complex (한국형발사체 발사대시스템 추진제공급설비 및 화염유도로 설계)

  • Kang, Sunil;Oh, Hwayoung;Kim, Daerae
    • Journal of the Korean Society of Propulsion Engineers
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    • v.19 no.1
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    • pp.76-86
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    • 2015
  • KSLV-II, a new launch vehicle of Korea, requires a new launch complex(LC) for its own and proper launch operations. The new launch complex will be constructed in NARO Space Center neighboring KSLV-I launch complex for maximizing operation efficiency and economic matters. The launch complex consists of three ground support equipments, i.e., mechanical, electrical, and fuel in general. The fuel ground support equipment could be defined as a combination of systems for storage and supply of propellants and gases which are required by a launch vehicle. The compositions, functions and capabilities of fuel ground support equipment are introduced in this paper. In addition, basic design results of flame deflector configurations are included.

Introduction to the Compressed Gas Supply System of KSLV-II Launch Complex (한국형발사체 발사대 고압가스 공급시스템 소개)

  • Oh, Hwayoung;An, Jaechel;Kang, Sunil;Park, Junggeun
    • Journal of the Korean Society of Propulsion Engineers
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    • v.21 no.1
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    • pp.91-97
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    • 2017
  • The KSLV-II launch complex system consists of mechanical ground support equipment(MGSE), fuel ground support equipment(FGSE), electrical ground support equipment(EGSE) and infrastructures. Compressed gas supply system, as a part of FGSE, is responsible for launch operations such as gas intake, storage, supply to launch vehicle and ground support equipments. This system consists of three primary elements such as gas storage part, control panel and controller. Automatic panels, as a part of control panel, are manufactured to operate remotely by controller. This study presents compressed gas supply system which is designed for KSLV-II and ground support equipment characteristics.

Component fragility assessment of a long, curved multi-frame bridge: Uniform excitation versus spatially correlated ground motions

  • Jeon, Jong-Su;Shafieezadeh, Abdollah;DesRoches, Reginald
    • Structural Engineering and Mechanics
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    • v.65 no.5
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    • pp.633-644
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    • 2018
  • This paper presents the results of an assessment of the seismic fragility of a long, curved multi-frame bridge under multi-support earthquake excitations. To achieve this aim, the numerical model of columns retrofitted with elliptical steel jackets was developed and validated using existing experimental results. A detailed nonlinear numerical model of the bridge that can capture the inelastic response of various components was then created. Using nonlinear time-history analyses for a set of stochastically generated spatially variable ground motions, component demands were derived and then convolved with new capacity-based limit state models to obtain seismic fragility curves. The comparison of failure probabilities obtained from uniform and multi-support excitation analyses revealed that the consideration of spatial variability significantly reduced the median value of fragility curves for most components except for the abutments. This observation indicates that the assumption of uniform motions may considerably underestimate seismic demands. Moreover, the spatial correlation of ground motions resulted in reduced dispersion of demand models that consequently decreased the dispersion of fragility curves for all components. Therefore, the spatial variability of ground motions needs to be considered for reliable assessment of the seismic performance of long multi-frame bridge structures.

NATE터널의 갱문 가시설 배후 균열에 따른 조치 및 보강사례

  • Kil, Ho-Un;Kim, Jin-Hong;Yoo, Jai-Sung;Cha, Bok-Nam
    • 기술발표회
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    • s.2006
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    • pp.342-355
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    • 2006
  • The Tunnel portal is designed on temporary support system which is composed by 28m height H-Pile method and Ground Anchor method. The tunnel has excavated about 30m from the portal, but some deformation is found on the surface ground just above the tunnel face. It was investigated very carefully to find out the causes of deformation. By the observation and study, two main causes of deformation are found out. The one is earth pressure increase compared with classical earth pressure theory. That was due to the direction of ground rock mass's discontinuities. It causes the increase of earth pressure that are activated by the direction of discontinuity. The other one is that present design method neglect the transferred force by removal of temporary support members and ground anchor within the tunnel contour line as the tunnel excavation proceeds As the result of removals of the member and anchor, some force transferred from removed systems to remaining supporting systems. In designing the portal support systems, lt must be considered the discontiunity of ground mass and the transfered force due to excation.

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A Method for Assessing Structural Safety of Ground-Support Systems in Underground Rock Cavern (지하 암반 공동내 지보시스템의 구조적 안전성 평가 방법)

  • 장승필;서정문
    • The Journal of Engineering Geology
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    • v.6 no.1
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    • pp.23-31
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    • 1996
  • A stress redistribution process in ground support system is mpdeled taking into consideration of load transfer mechanism of unbalanced load within shotcrete in a rock cavern constructed by NATM. The corresponding analysis model for ground support system is proposed and the elastic behavior of the shotcrete is studied. The effect on the support system due to variation of several design parameters is analysed with the proposed model. The suggested model yields considerably reduced maximum compressive stresses in shotcrete. Both the pressure coefficient in horizontal direction and the elastic modulus of rock mass govern overall responses, whereas the variation of the properties in support system shows a little difference in system responses. Interaction equations for evaluating safety factors for structural members are suggested. The result of this study can be used in the structural safety assessment of underground structures.

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The Effects of the Foot Types and Structures of the Inner Arch Support Bands on Ground Reaction Force Variables and Sensations during 2nd Vertical Ballet Jump

  • Kim, Juhyun;Yi, Kyungock
    • Korean Journal of Applied Biomechanics
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    • v.27 no.1
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    • pp.25-33
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    • 2017
  • Objective: The purpose of this research was to establish the differences of ground reaction force variables and sensations according to the foot types and the structures of the inner arch support band during $2^{nd}$ vertical ballet jump. Method: 12 Female ballet majors in their twenties who have danced for more than 10 years and had no injuries were selected for this research. Independent variables consist of the foot type (pes rectus, pes planus) and the structure of the inner arch support band (no band, x-shaped, linear shaped). Dependent variables consist of ground reaction force variables and relative wearing sensation. Results: The impact decreased the most when x-shaped bands were used on pes rectus and rigid pes planus. When linear-shaped bands were used on flexible pes planus, the impact decreased. Conclusion: The bands also helped reduce the impact on pes rectus. Furthermore, it is clear that according to the foot type, the impact reducing band structures perform differently. The inner arch support bands were necessary for jump training for any foot type.

Ground support performance in deep underground mine with large anisotropic deformation using calibrated numerical simulation (case of mine-H)

  • Hu, Bo;Sharifzadeh, Mostafa;Feng, Xia-Ting;Talebi, Roo;Lou, Jin-Fu
    • Geomechanics and Engineering
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    • v.21 no.6
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    • pp.551-564
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    • 2020
  • High-stress and complex geological conditions impose great challenges to maintain excavation stability during deep underground mining. In this research, large anisotropic deformation and its management by support system at a deep underground mine in Western Australia were simulated through three-dimensional finite-difference model. The ubiquitous-joint model was used and calibrated in FLAC3D to reproduce the deformation and failure characteristics of the excavation based on the field monitoring results. After modeling verification, the roles of mining depth also the intercept angle between excavation axis and foliation orientation on the deformation and damage were studied. Based on the results, quantitative relationships between key factors and damage classifications were presented, which can be used as an engineering tool. Subsequently, the performance of support system installation sequences was simulated and compared at four different scenarios. The results show that, first surface support and then reinforcement installation can obtain a better controlling effect. Finally, the influence of bolt spacing and ring spacing were also discussed. The outcomes obtained in this research may play a meaningful reference for facing the challenges in thin-bedded or foliated ground conditions.