• 제목/요약/키워드: Block wall.

검색결과 330건 처리시간 0.024초

고대 한국 지방도시 격자형 토지구획의 형태특성에 관한 연구 (A Study on the Grid Land Subdivision of Ancient Local City in Korea)

  • 이경찬
    • 건축역사연구
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    • 제11권4호
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    • pp.45-69
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    • 2002
  • This study aims to find out the genetic characteristics of gridded subdivision area which has its origin from ancient local administrative city-Sangju, Jeonju, Namwon, Kwangju, Chungju. The spatial structure, based on the inter-relationship among gridded subdivision area, city wall, and topographic condition, and the morphological characteristics of gridded subdivision area are analyzed. The points of analysis on morphological characteristics of gridded subdivision area consist of the size of unit block, the organization system of unit block, the orientation of subdivision line. As a result of the analysis, three main characteristics are found. Firstly there can be found no same land subdivision rule among study areas. Secondly, the morphological features of study area were the products of cumulative process of different subdivision areas which were developed in different periods. Thirdly, the original regular gridded land subdivision seems to have been carried out in the object of a farm-land cultivation around 7th century. And there was a change of land-use from farm land to urban land-use during the later 7th century and 8th century.

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다중 블록 격자를 이용한 원뿔 직관 모양의 벌류트 유동의 수치해석 (NUMERICAL SIMULATION ON A VOLUTE OF STRAIGHT CONICAL DUCT TYPE BY MULTI-BLOCK GRID)

  • 배황;강현구;윤주식;박기철;장근식
    • 한국전산유체공학회지
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    • 제11권1호
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    • pp.1-7
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    • 2006
  • Numerical investigation of a centrifugal compressor volute having a modified straight conical duct hill been made. Three-dimensional Reynolds-Averaged Navier-Stokes equations with $k-{\varepsilon}$ turbulence equation are solved To avoid coordinate singularity at the central axis of the duct, multi-block H-type grid is generated on the circular cross-sections of the volute and stretched toward the solid wall boundary. We obtained numerical results with three different mass flow rates at the volute inlet, namely, with the inlet conditions that give small, medium and large mass flow rates at the outlet of the conical duct. Agreement with the experimental results is observed.

원심 압축기 벌류트 3차원 유동의 수치해석 (Numerical Study on the Three-Dimensional Centrifugal Compressor Volute Flow)

  • 윤주식;박기철;장근식;배황
    • 대한기계학회논문집B
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    • 제30권3호
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    • pp.222-229
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    • 2006
  • Three dimensional turbulent flow in the scroll volute of centrifugal compressor has been numerically investigated in this paper by solving the Navier-Stokes equations and $\kappa-\varepsilon$ equation model. The computational grid for the flow field of the scroll volute has been constructed based on the multi-block grid concept, which is good to avoid the central grid singularity as well as to promote grid stretching toward the volute wall. Numerical result has been obtained for both the two- and three- dimensions. For the latter flow, result of the scroll volute flow is compared with that of the straight conical volute. This comparison has sorted out the characteristic features of the three-dimensional scroll-type volute flow of centrifugal compressor.

주변이 RC로 구속된 조적조 벽체의 내진성능향상에 관한 실험적 연구 (Experimental Study for Higher Seismic Performance of Confined Masonry Wall System)

  • 김경태;서수연;윤승조;요시무라코지;성기태
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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    • pp.5-8
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    • 2004
  • In order to investigate the effect of the height of application point of lateral loads and reinforcing steel bars in walls and columns in improving the seismic behavior of confined concrete block masonry walls, an experimental research program is conducted. A total of four one-half scale specimens are tested under repeated lateral loads. Specimens are tested to failure with increasing maximum lateral drifts while a vertical axial load was applied and maintained constant. The constant vertical axial stresses applied are 0, 0.84 and 1.80MPa, while the amount of reinforcements in horizontal and vertical directions are $0\%,\;0.08\%\;and\;0.18\%$ respectively. Test results obtained for each specimen include cracking patterns, load-deflection data, and strains in reinforcement and walls in critical locations. Analysis of test data showed that above parameters generate a considerable effect on the seismic performance of confined concrete block masonry walls.

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한우(韓牛)의 척추측마취(脊椎側痲醉) (A Technique for Paravertebral Anesthesia in Korean Cattle)

  • 남치주;이흥식;이인세
    • 대한수의학회지
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    • 제23권1호
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    • pp.119-122
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    • 1983
  • Paravertebral anesthesia for operation of abdominal wall in Korean cattle were effectively accomplished with the following technique. Any problems in surgical procedure were not observed under the block of ventral branches of the last thoracic nerve and the first and second lumbar nerves with the administration of preanesthetic. The site of injection for blocking of ventral branches of the thirteenth thoracic nerve were approximately 5cm lateral to the midline from the posterior edge of spinous process of the 13th thoracic vertebra and about 10ml of local anesthetic was injected immediately anterior to the transverse process of the first lumbar vertebra through thin site. The block of ventral branches of the first and second lumbar nerves were obtained by injecting 10ml of local anesthetic immediately below the posterior edge of transverse process of the 2nd and 4th lumbar vertebra, respectively.

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An in-vitro evaluation of sealer placement methods in simulated root canal extensions

  • Kim, Sung-Young;Lee, Se-Jun;Lee, Kwang-Won
    • 대한치과보존학회:학술대회논문집
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    • 대한치과보존학회 2003년도 제120회 추계학술대회 제 5차 한ㆍ일 치과보존학회 공동학술대회
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    • pp.579-579
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    • 2003
  • I. Objectives The aim of this study was to evaluate and compare the effectiveness of sealer placement in simulated root canal extensions using the K file, ultrasonic file, lentulo spiral and EZ-Fill. II. Materials and Methods Forty resin blocks were attained from cutting Endo-training Bloc with diamond saw. In each parallelepiped block, the simulated root canal was made with #20, 08taper GT file. After each block was longitudinally split into two halves using mallet and chisel, a standardized groove of 4mm in length, located 2mmapart from the root apex, was prepared on one wall of two halves using the custom-made knife to simulate the canal extensions with various irregularities.(omitted)

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확공을 이용한 지압형 앵커의 인발거동 특성 연구 (The Study of Pullout-Behavior Characteristics of The Ground Anchor Using Expanded Hole)

  • 민경남;정찬묵;정대호
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2011년도 춘계학술대회 논문집
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    • pp.1502-1508
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    • 2011
  • Ground anchor expands the hollow wall of settled part and has the structure which resists the designed tensile load by the bearing pressure generated by the wedge of the anchor body pressing in the expanded part. Such ground anchor has been recognized for stability and economicality since 1960s in technologically advanced nations such as Japan and Europe, and in 1970s, the Japan Society of Soil Engineering has established and announced the anchor concept map. The ground anchor introduced in Korea, however, has the structural problem where the tensile strength is comes only from the ground frictional force due to expansion of the wedge body. In an interval where the ground strength is locally reduced due to fault, discontinuation or such, this is pointed out as a critical weakness where the anchor body of around 1.0m must resist the tensile load. Also, in the installation of concrete block, the concentrated stress of concrete block constructed on the uneven rock surface causes damage, and many such issues in the anchor head have been reported. Thus, in this study, by using the expanded bit for precise expansion of settled part, the ground anchor system was completed so that the bearing pressure of ground anchor can be expressed as much as possible, and the bearing plate was inserted into the ground to resolve the existing issues of concrete block. Through numerical analysis and pullout test executed for verification of site applicability, the pullout-behavior characteristics of anchor was analyzed.

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축소모형실험에 의한 지속하중하에서의 보강토 옹벽의 거동특성 연구 (Behavior of Geosynthetic Reinforced Modular Block Walls under Sustained Loading using Reduced-Scale Model Test)

  • 유충식;김선빈;변요셉;김영훈;한대희
    • 한국지반신소재학회논문집
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    • 제5권1호
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    • pp.1-7
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    • 2006
  • 보강토 옹벽이 콘크리트 옹벽에 비해 다양한 이점을 가짐에도 불구하고 영구구조물로서 지속하중이 작용하는 경우에 대해 장기변형이 발생할 소지가 있다는 우려가 있다. 본 논문에서는 이러한 관점에서 축소모형실험을 실시하여 수집된 보강토 옹벽의 장기변형 메카니즘에 대한 내용을 다루었다. 실험결과 지속하중이 작용하는 경우에 있어 장기적으로 잔류변형이 발생할 우려가 있는 것으로 나타났으며 이는 지속하중의 특성과 보강재 강성에 따라 좌우되는 것으로 나타났다.

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Sound transmission of lightweight block walls and panels-Theory and Experiments

  • S Kandaswamy;A Ramachandraiah
    • 한국음향학회:학술대회논문집
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    • 한국음향학회 2004년도 춘계학술발표대회 논문집 제23권 1호
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    • pp.235-239
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    • 2004
  • Sound transmission either as airborne or structure borne is a potential problem that occurs in buildings either from sources within or from outside. With the expansion of real estate activities in countries like India, the need to attend sound insulation requirements also assumes greater dimensions. The focus of this research is on studying the sound transmission characteristics of building structures made of hollow blocks, neocrete block, aerocon block and prefabricated panels such as Ferrocement panel. The tests were carried out the blocks with and without plastering and their sound reduction index was measured at one-third octave frequencies. In the case of ferrocement panels, different types of systems were tested in the TL suite. Panels with cavity, with cavity ties, with insulation, with stiffeners and with plasterboard were investigated. Sound reduction index of these panels was measured with additional quantities like longitudinal wavespeed, and loss factors (internal and total loss factor). Tests were also conducted on Cypcrete wall panel and Sandwiched wooden panel in a similar way. Theoretical investigations were carried out using Statistical Energy Analysis (SEA) for the above systems. Sound reduction index was then compared between the predicted and the measured values.

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Out of plane behavior of walls, using rigid block concepts

  • Gh.M, Mohammadi;F, Yasrebi
    • Structural Engineering and Mechanics
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    • 제34권3호
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    • pp.335-350
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    • 2010
  • Out of plane behaviors of walls and infills are investigated in this paper, using rigid block concepts. Walls and infills are sometimes separated from top beams because of in plane movement of the walls and crumbling mortar layers under the top beams. Therefore, sufficient strength should be supplied to hold them against out of plane forces. Such walls are studied here under some real and scaled earthquakes, regarding their out of plane behavior. Influences of some reinforcements, connecting the walls to frames or perpendicular walls, are also studied. It is shown that unreinforced walls of regular sizes (3 m high and 4.5 m long) are normally unstable in the earthquakes. However, performing some reinforced bars that connect them to adjacent elements- frames or perpendicular walls - stabilizes them. Eventually, it is concluded that supplying 3 reinforced bars at 1/4, 2/4 and 3/4 of the panel's height stabilizes the walls in the assumed earthquakes. In this regard, for 20 cm and 35 cm thick walls ${\Phi}$18mm and ${\Phi}$20mm bars are to be used, respectively. For walls with other configurations, the forces and required areas of the reinforcements can be determined by the developed method of this paper.