• 제목/요약/키워드: structural deficiencies

검색결과 64건 처리시간 0.019초

능력스펙트럼법을 이용한 성능점 결정에서 지진기록이 미치는 영향 (Effects of Earthquake Ground Motion Sets on Performance Point of Capacity Spectrum Method)

  • 김선우;한상환
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2001년도 가을 학술발표회 논문집
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    • pp.523-528
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    • 2001
  • The Capacity Spectrum Method (CSM) was first introduced in the 1970's as rapid evaluation procedure. The procedure compares the capacity of the structure (in the form of a pushover curve) with the demands on the structure (in the form of a response spectrum). The graphical intersection of the two curves approximates the response of the structure. In order to account for nonlinear inelastic behavior of the structural system, effective ductility ratios(μ) are applied to the elastic-linear response spectrum to imitate an inelastic response spectrum. CSM in ATC-40 has deficiencies such as performance point does not converge and the peak deformation of inelastic systems is to be inaccurate when compared against results of nonlinear response history analysis. The purpose of this paper is to investigate the variation of performance points of Capacity Spectrum Method (CSM) are investigated with respect to the different sets of earthquake ground motions. The earthquake sets were used in this study selected by Miranda(1993), Riddell(1991), Seed et al. (1976).

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슬래브의 효율적인 구조 거동을 위한 강섬유보강 콘크리트의 부분적 활용에 관한 실험적 연구 (Study on the Utilization of Steel Fiber Reinforced Concrete for Efficient Structural Behavior in Slab System)

  • 윤영수;데니스미첼;최응규;박성균
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1998년도 봄 학술발표회논문집(II)
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    • pp.469-474
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    • 1998
  • To overcome the common deficiencies found in two-way slabs, such as excessive cracking around columns, excessive deflections and low punching shear strength, it was proposed to investigate the strategic use of steel fiber-reinforced concrete. Providing fiber-reinforced concrete results in an increase in the punching shear resistance, a significant increase in the ductility, greater post-cracking stiffness and better crack control.

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이방향 슬래브의 구조성능 향상을 위한 배근상세의 제안 (Proposed Detailing of Reinforcement to Enhance the Structural Performance in Two-way Slab System)

  • 윤영수;;최응규;최한태
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1998년도 봄 학술발표회 논문집(I)
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    • pp.379-384
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    • 1998
  • To overcome the common deficiencies found in such two-way slabs, such as excessive cracking around columns, excessive deflections and low punching shear strength, it was proposed to investigate the strategic reinforcing steel distribution detailings. Concentration of the top mat of flexural reinforcement result in a higher punching shear resistance, higher post cracking stiffness, a more uniform distribution of strains in the top bars and smaller cracks at all levels of loading.

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건축 거푸집 설계 응력산정 프로그램 개발에 관한 기초적 연구 (Programming for the Structural Analysis of Form Structure)

  • 손기상
    • 한국안전학회지
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    • 제8권1호
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    • pp.21-28
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    • 1993
  • Occupational Safety & Health Code requires to calculate Design Load and stress for the approval within thirty working days prior to initiating each construction site work This study is to develop an easy and useful program that each safety manager. Controller or engineers are able to make output for the above mentioned form structure analyses without knowledge or engineering background of it. Therefore. three, randomly selected. different major student and engineers verified if they could make output. really without the engineering background. And then some deficiencies are corrected after finding those from the program operation.

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Comparative assessment of seismic rehabilitation techniques on a full scale 3-story RC moment frame structure

  • Di Ludovico, M.;Balsamo, A.;Prota, A.;Manfredi, G.
    • Structural Engineering and Mechanics
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    • 제28권6호
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    • pp.727-747
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    • 2008
  • In the framework of the SPEAR (Seismic PErformance Assessment and Rehabilitation) research Project, an under-designed three storey RC frame structure, designed to sustain only gravity loads, was subjected, in three different configurations 'as-built', Fiber Reinforced Polymer (FRP) retrofitted and rehabilitated by reinforced concrete (RC) jacketing, to a series of bi-directional pseudodynamic (PsD) tests under different values of peak ground acceleration (PGA) (from a minimum of 0.20g to a maximum of 0.30g). The seismic deficiencies exhibited by the 'as-built' structure after the test at PGA level of 0.20g were confirmed by a post - test assessment of the structural seismic capacity performed by a nonlinear static pushover analysis implemented on the structure lumped plasticity model. To improve the seismic performance of the 'as-built' structure', two rehabilitation interventions by using either FRP laminates or RC jacketing were designed. Assumptions for the analytical modeling, design criteria and calculation procedures along with local and global intervention measures and their installation details are herein presented and discussed. Nonlinear static pushover analyses for the assessment of the theoretical seismic capacity of the structure in each retrofitted configuration were performed and compared with the experimental outcomes.

Design and implementation of a SHM system for a heritage timber building

  • Yang, Qingshan;Wang, Juan;Kim, Sunjoong;Chen, Huihui;Spencer, Billie F. Jr.
    • Smart Structures and Systems
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    • 제29권4호
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    • pp.561-576
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    • 2022
  • Heritage timber structures represent the history and culture of a nation. These structures have been inherited from previous generations; however, they inevitably exhibit deterioration over time, potentially leading to structural deficiencies. Structural Health Monitoring (SHM) offers the potential to assess operational anomalies, deterioration, and damage through processing and analysis of data collected from transducers and sensors mounted on the structure. This paper reports on the design and implementation of a long-term SHM system on the Feiyun Wooden Pavilion in China, a three-story timber building built more than 500 years ago. The principles and features of the design and implementation of SHM systems for heritage timber buildings are systematically discussed. In total, 104 sensors of 6 different types are deployed on the structure to monitor the environmental effects and structural responses, including air temperature and humidity, wind speed and direction, structural temperatures, strain, inclination, and acceleration. In addition, integrated data acquisition and transmission subsystem using a newly developed software platform are implemented. Selected preliminary statistical and correlation analysis using one year of monitoring data are presented to demonstrate the condition assessment capability of the system based on the monitoring data.

C.G.S에 의한 기초지반보강효과에 관한 연구 (A Study on the Ground Improvement by Compaction Grouting System)

  • 천병식;여유현;최현석;오일석
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 1999년도 춘계학술대회 논문집
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    • pp.375-382
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    • 1999
  • The use of compaction grouting system(C.G.S) evolved in the 1950's to correct structural settlement of buildings. Over the almost 50 years, the technology has developed and is currently used in wide range of applications. Compaction Grouting, the injection of a very stiff 'zero-slump' mortar grout under relatively high pressure, displaces and compacts soils. It can effectively repair natural or man-made soil strength deficiencies in variety of soil formations. Major uses of Compaction Grouting include densifying loose soils or fill voids caused by sinkholes, poorly compacted fills, broken utilities, improper dewatering, or soft ground tunneling excavation. Other application include preventing liquefaction, re-leveling settled structures, and using compaction grout bulbs as structural elements of minipiles or underpinning. So, on the basis of the case history constructed in recent year, a study has been performed to analyze the basic mechanism of the Compaction Grouting and verify the effectiveness of the ground improvement.

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9절점 가변형도 쉘요소를 이용한 콘크리트 구조물의 후-정점하중 해석 (A post-peak analysis of concrete structures using a 9-node assumed strain shell element)

  • 이상진;이홍표;서정문
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2001년도 가을 학술발표회 논문집
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    • pp.59-66
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    • 2001
  • The post-peak analysis of concrete structures is carried out using a nine-node Reissner-Mindlin(RM) shell element which is formulated by using degenerated solid concepts. In order to avoid element deficiencies inherited in the standard RM shell element, assumed strains are adopted in the present shell element. A microscopic material model is adopted to represent the inelastic characteristic of concrete material. In particular, a concrete softening model is introduced to this material model. The arc-length control method is used to trace the post-peak behaviour of concrete structures. From the numerical test of the single-edge-notched beam, the present shell element shows a reasonable agreement with experimental data.

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90K 초전도체 Gd1Ba2Cu3O9-x의 구조에 관한 연구 (Structural Study of 90K Superconductor Gd1Ba2Cu3O9-x)

  • 이성익;권기정;이기봉;박병규;박병학;신현준
    • 한국세라믹학회지
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    • 제25권6호
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    • pp.577-584
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    • 1988
  • Gd1Ba2Cu3O9-x has been found to be a high Tc superconductor with a transitiion onset at 91K and zero resistance achieved at 87K. The structure as determined from x-ray diffraction is orthorhombic, with lattice constants b=3.842$\pm$0.002$\AA$, b=3.895$\pm$0.003$\AA$, and c=11.684$\pm$0.007$\AA$. The structural similarities between the Gd1Ba2Cu3O9-x compound and the well-studied single phase perovskite, Y1Ba2Cu3O9-x are discussed. A correlation between the observed x-ray spectrum and the effect of oxygen deficiencies in several of the unit cell planes is also discussed.

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Effective CFRP retrofit strategy for flexural deficient RC beams

  • Banjara, Nawal Kishor;Ramanjaneyulu, K.
    • Structural Engineering and Mechanics
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    • 제69권2호
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    • pp.163-175
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    • 2019
  • Structural deterioration arises due to aging, environmental effects, deficiencies during design and construction phase, and overloading. Experimental and numerical investigations are carried out in this study to evaluate the performance of control and flexural deficient reinforced concrete (RC) beams under monotonic loading. Three levels of flexural deficiency are considered in this study. After confirming load carrying capacities of control and flexural deficient beams, the flexural deficient RC beams are strengthened with carbon fibre reinforced polymer (CFRP) fabric. CFRP strengthened RC beams are tested under monotonic loading and compared with the performance of control specimen. Further, non-linear finite element analyses are also carried out to evaluate the flexural performance of control, deficient and CFRP strengthened flexural deficient RC beams. There is good correlation between results of experimental and numerical investigations. Numerical approach presented in this study can be adopted for assessing the adequacy of CFRP retrofit measure.