• Title/Summary/Keyword: 조적조

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A Study on Cumulative Structural Damage (누적된 손상을 입은 구조물의 거동)

  • Kim, Nam-Hee
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2005.03a
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    • pp.252-257
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    • 2005
  • 비보강 조적조는 비균일재료로 이루어진 합성재료에 가까우므로 그거동이 하중종류와 구조물의 손상정도에 따라서 매우 달라지게 된다. 본 연구에서는 작은 지진부터 큰 지진까지 수차례의 모의 지진을 받는 구조물의 손상거동을 살펴보기 위한 방법으로, 시간영역 자료를 여러구간으로 나누어서 주파수가 어떻게 변화해 가는지 살펴보았다. 또한 주파수와 강도와의 관계식을 이용하여 단자유도계의 이선형모델도 유도하였다. 하중이 커짐에 따라서 이선형 모델의 강성은 계속적으로 저하됨을 알 수 있다. 실제로 실험결과는 누적된 손상을 받는 구조물의 거동이므로, 조적조의 수치해석적 모델의 개발시 이러한 누적된 손상효과를 합리적으로 처래해야 되는 문제점이 있다.

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Modeling of Old Masonry Lining in Railroad Tunnels (철도터널내 조적식 라이닝의 모형화에 관한 연구)

  • Lee, J.S.;Shin, H.K.;Kim, M.I.
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.3 no.3
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    • pp.3-13
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    • 2001
  • The behavior of the masonry lining is studied to gain basic information on how to reinforce the masonry tunnels. Apart from the previous works on the masonry structures, the multi-course masonry structure, realistic in field condition, is considered and the constitutive relationship of the masonry is, therefore, established. The design charts of the orthotropic material properties are proposed according to the stiffness ratio and the crack initiation and subsequent propagation model is also considered to model the brittle nature of the masonry. A numerical analysis on the masonry panel is investigated to verify the proposed model and future works of the masonry lining are briefly explained.

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작은구슬산호말 (Corallina pilulifera)의 Methanol 추출물로부터 항적조물질 분리

  • ;Long-Guo JIN
    • Proceedings of the Korean Society of Fisheries Technology Conference
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    • 2001.05a
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    • pp.209-210
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    • 2001
  • 적조에 대한 대책으로서 가장 많이 이용되는 황토법은 적조생물을 침전시키므로써 제거하지만, 황토의 침전에 의한 2차적인 오염의 가능성이 있다 (Na et al., 1996). 황산구리, 과산화수소와 Triosyn에 의한 적조 살조효과가 있지만 이러한 화학물질은 모든 생물에 대한 살조효과가 있으므로 현상에 사용하기는 힘들다. 생물학적 방제에는 바이러스, 박테리아의 방법이 강구되고 있지만, 산소고갈 등의 2차적인 부작용이 야기된다. (중략)

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A Study on Structural reinforcement suggestions for improvement of Seismic Performance of Masonry Buildings in rural areas (농촌지역의 조적조 건축물의 내진성능 개선을 위한 구조적 보강법 제안에 관한 연구)

  • Lee, Deog-Yong;Kim, Il-Jung
    • Journal of the Korean Institute of Rural Architecture
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    • v.15 no.4
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    • pp.51-58
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    • 2013
  • This study Masonry Buildings in rural areas, due to the lateral load resistance for seismic reinforcement method is proposed. Some of the proposed methods for reinforcement directly through finite element analysis to evaluate the change in frequency. The results for the following: This paper has the object of investigating natural frequencies of opening thick plates on Pasternak foundation by means of finite element method and providing Kinematic design data for mat of building structures. In this paper, vibration analysis of rectangular opening thick plate is done by use of Serendipity finite element with 8 nodes by considering shearing strain of plate. It is shown that natrural frequencies depend on not only Winkler foundation parameter but also shear foundation parameter, opening position.

Composite Action in Masonry Columns Due to Damage and Creep Interaction (손상과 크리프의 상호작용에 의한 조적조 기둥의 복합거동)

  • Kim, Jung Joong
    • Journal of the Korean Society for Advanced Composite Structures
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    • v.5 no.2
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    • pp.27-32
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    • 2014
  • Since the collapse of historical masonry structures in Europe in the late 1990's, the interests in understanding the long-term effect of masonry under sustained compressive stresses have increased. That requires combining the significance of time-dependent effects of creep with the effect of damage due to overstress to realize the evolution of cracks and then failure in masonry. Meanwhile, composite analysis of masonry columns was proven effective for realizing ultimate strength capacity of masonry column. In this study, a simplified mechanical model with step-by-step in time analysis was proposed to incorporate the interaction of damage and creep to estimate the maximum stress occurred in masonry. It was examined that the interaction of creep and damage in masonry can accelerate the failure of masonry.

Estimation of critical vibration level on structural damage of brick house induced by blasting (발파진동으로 인한 조적조 가옥 피해의 임계수준 평가)

  • 양형식;김남수;전양수;정지문;문승백;조상호
    • Tunnel and Underground Space
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    • v.9 no.1
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    • pp.72-77
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    • 1999
  • New criteria to evaluate blasting damage to structure is proposed considering environmental caused daily deformation of cracks in structures. Results from 3 brick houses in fishing village shows that more than 10 times higher vibration level than design criteria of 0.5 kine is required to cause structural damage.

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Rural areas, Vibration Stability Analysis of Wall and Retaining Wall of Low-rise Masonry Buildings (농촌지역 저층 조적조 건축물의 벽체 및 옹벽의 진동 안정 해석 - 전북 정읍시 ◯◯면 농촌지역 사례를 중심으로 -)

  • Lee, Deog-Yong;Kim, Il-Jung
    • Journal of the Korean Institute of Rural Architecture
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    • v.16 no.4
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    • pp.59-66
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    • 2014
  • This paper deals with vibration of plates with concentrated mass on elastic foundation. The object of investigating natural frequencies of tapered thick plate on pasternak foundation by means of finite element method and providing kinetic design data for mat of building structures. Free vibration analysis that tapered thick plate in this paper. Finite element analysis of rectangular plate is done by use of rectangular finite element with 8-nodes. In order to analysis plate which is supported on pasternak foundation. The Winkler parameter is varied with 10, $10^2$, $10^3$ and the shear foundation parameter is 5, 10. This paper is analyzed varying thickness by taper ratio. The taper ratio is applied as 0.0, 0.25, 0.5, 0.75, 1.0. And the Concentrated Mass is applied as P1, Pc, P2 respectively.

A Study on the Strengthening effect of Concrete Reinforcement Bracket on the External Clay Brick Wall (외부치장적벽돌 벽체에 대한 콘크리트 보강브라켓의 보강효과에 관한 연구)

  • Kim, Sun-Woo;Kim, Yang-Jung
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2020.06a
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    • pp.117-118
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    • 2020
  • The masonry structure is constructed by cement mortar binding material of brick objects and uses reinforced hardware (connected hardware or wall tie) together when building. However, over time, the corrosion of reinforced steel and the deterioration of joint mortar as well as bricks cause the risk of collapse. In particular, when the externally decorated brick wall is installed on the concrete girder for each floor, the angle bracket is not constructed or corroded, the full-layer weight load is applied to the wall of 0.5B, which is an example of full-scale or collapse. The purpose of this study is to provide numerical information on the reinforcement design by experimentally studying the structural performance of concrete reinforcement brackets that reinforce the vertical load of the exterior wall.

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