• Title/Summary/Keyword: 경계부재

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The Inelastic Behavior of High Strength Reinforced Concrete Tall Walls (고강도 철근콘크리트 고층형 내력벽의 비탄성 거동에 관한 실험 연구)

  • 윤현도;정학영;최창식;이리형
    • Magazine of the Korea Concrete Institute
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    • v.7 no.3
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    • pp.139-148
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    • 1995
  • The test results from three one fourth scale models using high strength Reinforced Concrete $f_x=704\;kg/cm^2,\;f_y=5.830\;kg/cm^2$ are presented. Such specimens are considered to represent the critical 3 storics of 60-story tall building of a structural wall system in area of high seismicity respectively. They are tested under inplane vertical and horizontal loading. The main varlable is the level of axial stress. The amounts of vertical and horizontal reinforcement are identical for the three walls testcd. The cross-section of all walls is barbell shape. The aspectratio($h_w/I_w$) of test specimen is 1.8. The aim of the study is to investigate the effects of levels of applied axial stresses on the inelastic behavior of high-strength R /C tall walls. Experimental results of high strength R /C tall walls subjected to axial load and simulated sels rnic loading show that it is possible to insure a ductlle dominant performance by promotmg flex ural yielding of vertical reinforcement and that axial stresses within $O.21f_x$ causes an increase in horizontal load-carrying capacity, initial secant st~ffness characteristics, but an decrease in displacement ductility. energy dissipation index and work damage index of high strength K /C tall walls

Analytical Structural Stability Evaluation for H-section Beams Made of Ordinary Structural Steels Based on Boundary Conditions at High Temperatures (일반 구조용 강재 적용 정정 및 부정정 보부재의 고온 시 해석적 내력 평가 연구)

  • Kwon, In-Kyu
    • Fire Science and Engineering
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    • v.29 no.4
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    • pp.33-38
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    • 2015
  • Loads applied on the floor are transferred through beams to columns. The beams can be designed as both end fixed or simple beams. The load bearing capacity of a beam depends on each boundary condition. However, when the load bearing capacity of a beam is evaluated in fire tests, all kinds of beams are tested using simple beam conditions. In this study, an analytical method performed using heat transfer theory and heat stress analysis based on the mechanical and thermal properties of SS-400 steel at high temperature. This method was used to clarify the differences between the two types of boundary conditions at normal and high temperature. The results show that the load bearing capacity of a both-end fixed beam at high temperature is superior to that of a simple beam. Therefore, the application of simple beam conditions in fire tests for evaluation of load bearing capacity is conservatively safe compared to fixed boundary conditions.

Hysteretic Behavior of R/C Shear Wall with Various Lateral Reinforcements in Boundary Columns for Cyclic Lateral Load (경계부재내 횡보강근 배근방법에 따른 R/C전단벽의 반복하중에 대한 이력거동)

  • Seo, Soo-Yeon;Oh, Tae-Gun;Kim, Kyeong-Tae;Yoon, Seong-Joe
    • Journal of the Korea Concrete Institute
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    • v.22 no.3
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    • pp.357-366
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    • 2010
  • This paper presents experimental results about shear wall with various lateral reinforcement details in boundary elements. The research objective is to study the structural behavior of shear wall with boundary column confined by rectangular spiral hoops and headed cross ties developed to improve workability in the fabrication of boundary columns. These two details can be fabricated in a factory and put together on-site after being delivered so that the construction work may be reduced. Main parameters in the experimental study were the types of hoop and cross tie: rectangular spiral hoop and headed cross tie vs. standard hoop and cross tie with hook. Four half scaled shear wall specimens with babel shape were made and tested by applying horizontal cyclic load under constant axial force, 10% of nominal compressive strength of concrete. Based on the test result, it was shown that the shear wall with rectangular spiral hoop and headed cross tie in boundary columns has structural capacity compatible with conventional shear wall. The specimen SW-Hh which has bigger hoop bar and higher volumetric ratio of transverse reinforcements than other showed improved energy dissipating characteristic but it presented a rapid reduction of strength after peak point. The results indicates that, it is necessary to consider volumetric ratio of transverse reinforcements as well as hoop space in designing of shear wall with boundary columns for improved strength and ductility.

An Analytic Study on Structural Stability according to Boundary Conditions and H-section Column Lengths Made of An Ordinary Grade Structural Steels (SS 400) at High Temperatures (일반구조용 강재(SS 400)기둥부재의 경계조건과 부재 길이변화에 따른 고온 내력의 해석적 연구)

  • Kwon, In-Kyu
    • Fire Science and Engineering
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    • v.28 no.1
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    • pp.20-25
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    • 2014
  • Steel column is very important an structural element in steel framed building and plays a key role in sustataining the applied external load. Generally, the fire resistance performance of steel column has been executed by application of fire standard and vertical furnace having a limitation in height. Therefore, the fire resistance test was conducted with a H-section column having 3500 mm in length and hinge to hinge boundary condition. And the fire protective material derived from the fire test can be applied to any kind of boundary conditions and lengths. However, it is hard to determine the fire resistance. In this paper, to make sure the structural stability of them at high temperature according to various boundary conditions and lengths of H-section column, an analysis was done by using the mechanical properties and an heat transfer theory.

Seismic Fragility Analysis by Boundary Conditions of a Two-pylon Concrete Cable-stayed Bridge (2주탑 콘크리트 사장교의 경계조건별 지진 취약도 분석)

  • Shin, Yeon-Woo;Hong, Ki-Nam;Yeon, Yeong-Mo;Ji, Sang-Won
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.24 no.5
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    • pp.77-85
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    • 2020
  • In this study, the seismic fragility curve according to the boundary conditions is created for a two-pylon concrete cable-stayed bridge, and the effect of the boundary conditions on the seismic fragility of the target bridge is evaluated. An analysis model for the target bridge is constructed using Midas Civil, and a nonlinear time history analysis is performed by applying the fiber element, concrete and rebar material models. The boundary conditions between the pylon and the stiffened girder are classified into four types: rigid, unconstrained, pot bearing, and seismic isolation bearing, and the seismic fragility curves are created for each boundary condition. The plastic hinge section of the pylon, the connection part, and the cable are selected as weak members, and the earthquake vulnerability curve is created for them. As a result of the analysis, it is found that the seismic isolation bearing model shows the lowest damage probability in the pylon and the connection part, and the seismic fragility of the cable is less affected by the boundary conditions than other members.

Out-of-Plane Effective Length Factor of X-Bracing System (X-브레이싱의 면외 유효 좌굴길이 계수)

  • Moon, Ji Ho;Yoon, Ki Yong;Lee, Hak Eun
    • Journal of Korean Society of Steel Construction
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    • v.19 no.1
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    • pp.129-137
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    • 2007
  • In this study, the elastic out-of-plane buckling load and the effective length factor of X-bracing systems were studied. Points of the intersection of diagonals were modeled as a rigid connection or a pinned connection depending on the connection method of diagonals. The boundary condition of the intersection influences the buckling load of X-bracing systems. For each boundary condition of the intersection, effective out-of-plane length factors of X-bracing systems were derived as a function of the length ratio of tension and compression diagonals $L_P$/$L_T$, the applied force ratio of tension and compression diagonals T/P, and the Euler buckling load ratio of tension and compression diagonals $P_{ET}$/$P_{EP}$. The proposed effective out-of-plane length factors of X-bracing systems were compared with the results of previous researchers and those of the finite element analysis and their properties were verified. Finally, the effects of the boundary condition of the intersection on the out-of-plane buckling load of X-bracing systems were investigated.

Algorithm for the Reinforced Concrete Framework Materials Take-off (철근콘크리트조의 골조물량산출 알고리즘)

  • Kim Tae-Hui;Hong Chae-Gon;Kim Sun-Kuk
    • Korean Journal of Construction Engineering and Management
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    • v.4 no.1 s.13
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    • pp.114-121
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    • 2003
  • The precise quantity of materials is not yet taken off by the CAD system although it has Influenced in design productivity and automatic estimate. And various estimate systems developed so far deal with the quantity take-off of building members separately, which caused to over-estimate the part of each member. Therefore, the purpose of this paper is to develop algorithms of more precise estimate than that of current estimate by solving boundary conditions of the connection parts of building members, such as column, girder, beam, wall and slab. The algorithms are proposed to take off the quantity of concrete and form work and they will be used for the estimate of building structure more precisely and automatically than ever.

A Study on the Case Analysis by Type of the Cadastral Surveying Screening (지적측량 적부심사 유형별 사례분석에 관한 연구)

  • OH, Yi-Kyun
    • Journal of Cadastre & Land InformatiX
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    • v.52 no.2
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    • pp.137-152
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    • 2022
  • The cadastral boundary points which cadastral surveyor presented on the ground by conducting cadastral surveying represents the limits of land ownership and give binding force and determination power. However the land disputes have increased these days mainly due to cadastral registration errors, surveying errors and land owners recognition error. In these cases, the cadastral survey interests try to find solution by either a administrative procedures by appealing civil complaint or border determination litigation through court. The neighboring residents and related organization have difficulties in resolving the civil complaints. In this study cadastral surveying and cadastral boundary determination process has been reviewed and the results of cadastral surveying screening by Central Cadastre Committee from 2016 to 2021 have been classified. The outcomes of this research will be used for cadastral surveying and contribute for reducing land disputes and improve reliablity of cadastral surveying.

Finite Element Analysis of the Reinforced Concrete Boundary-Beam-Wall System Subjected to Axial Load (축하중이 작용하는 RC 경계보-벽체 시스템의 해석적 평가)

  • Son, Hong-Jun;Kim, Seung-Il;Kim, Dae-Jin
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.34 no.2
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    • pp.93-100
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    • 2021
  • In Korea, one of the most used structural systems for residential apartment buildings is the combination of the reinforced concrete (RC) wall and rahmen structures in the upper and lower floors, respectively. To alleviate the significant difference between the stiffnesses of these two structural systems, large transfer girders are generally required in the transition zone of the structure, which then results in the use of large amounts of construction materials and low economic feasibility. This paper proposes a new RC boundary-beam-wall system that can minimize the disadvantages of the RC transfer girder system. The structural performance of the proposed system subjected to axial loading was evaluated via rigorous three-dimensional nonlinear finite element analysis. Four parameters, namely the ratio of lower wall to upper wall lengths, distance between stirrups, main bar slope ratio, and slab length, were considered in the finite element analysis, and their effects on the maximum axial load were analyzed and discussed.

Substrucuring Technique for Local Vibration of Building Structures (부분구조법에 의한 건축물의 국부진동해석)

  • 이동근;안상경;김진구
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.12 no.1
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    • pp.57-66
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    • 1999
  • 국부진동에 의하여 영향을 받는 일부 부재를 분석하기 위하여 구조물 전체의 대하여 동적해석을 수행하는 것은 비경제적일 수 있다. 본 논문에서는 국부진동의 효율적인 해석을 위하여 부분구조법을 사용하였다. 선택된 부재의 해석에 사용할 경계조건을 구하기 위하여 자유도를 응축하는 행렬응축기법을 사용하였다. 해석의 정당성을 검토하기 위하여 경계조건을 고정지지와 단순지지한 경우와 비교하였다. 본 연구에서 제시한 부분구조기법을 이용하면 가진층에 대해서는 효율적으로 매우 정확한 거동을 예측할 수 있지만, 가진층에서 멀리 떨어진 곳에 대한 거동 예측 시에는 다소 오차가 발생한다.

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