• Title, Summary, Keyword: short column

Search Result 247, Processing Time 0.047 seconds

Punching Shear Strength and Behavior of CFT Column to RC Flat Plate connections (CFT기둥-RC 무량판 접합부의 펀칭전단강도 및 거동)

  • Lee, Cheol-Ho;Kim, Jin-Won;Lee, Seung-Dong;Ahn, Jae-Kwon
    • Proceedings of the Earthquake Engineering Society of Korea Conference
    • /
    • /
    • pp.168-179
    • /
    • 2006
  • This paper summarizes full-scale test results on CFT column-to-flat plate connections subjected to gravity loading. CFT construction has gained wide acceptance in a relatively short time in domestic building construction practice due to its various structural and construction advantages. However, efficient details for CFT column to flat plate connections have not been proposed yet. Based on the strategies that maximize economical field construction, several connecting schemes were proposed and tested. Test results showed that the proposed connections can exhibit punching shear strength and connection stiffness exceeding those of R/C flat plate counterparts. A semi-analytical procedure is presented to model the behavior of CFT column-to-flat plate connections. The five parameters to model elastic to post-punching catenary action range are calibrated based on the limited test data of this study. The application of the proposed modeling procedure to progressive collapse prevention design is also illustrated.

  • PDF

Strength of biaxially loaded high strength reinforced concrete columns

  • Dundar, Cengiz;Tokgoz, Serkan
    • Structural Engineering and Mechanics
    • /
    • v.44 no.5
    • /
    • pp.649-661
    • /
    • 2012
  • An experimental research was conducted to investigate the strength of biaxially loaded short and slender reinforced concrete columns with high strength concrete. In the study, square and L-shaped section reinforced concrete columns were constructed and tested to obtain the load-deformation behaviour and strength of columns. The test results of column specimens were analysed with a theoretical method based on the fiber element technique. The theoretical ultimate strength capacities and the test results of column specimens have been compared and discussed in the paper. Besides this, observed failure mode and experimental and theoretical load-lateral deflection behaviour of the column specimens are presented.

Soil interaction effects on the performance of compliant liquid column damper for seismic vibration control of short period structures

  • Ghosh, Ratan Kumar;Ghosh, Aparna Dey
    • Structural Engineering and Mechanics
    • /
    • v.28 no.1
    • /
    • pp.89-105
    • /
    • 2008
  • The paper presents a study on the effects of soil-structure-interaction (SSI) on the performance of the compliant liquid column damper (CLCD) for the seismic vibration control of short period structures. The frequency-domain formulation for the input-output relation of a flexible-base structure with CLCD has been derived. The superstructure has been modeled as a linear, single degreeof-freedom (SDOF) system. The foundation has been considered to be attached to the underlying soil medium through linear springs and viscous dashpots, the properties of which have been represented by complex valued impedance functions. By using a standard equivalent linearization technique, the nonlinear orifice damping of the CLCD has been replaced by equivalent linear viscous damping. A numerical stochastic study has been carried out to study the functioning of the CLCD for varying degrees of SSI. Comparison of the damper performance when it is tuned to the fixed-base structural frequency and when tuned to the flexible-base structural frequency has been made. The effects of SSI on the optimal value of the orifice damping coefficient of the damper has also been studied. A more convenient approach for designing the damper while considering SSI, by using an established model of a replacement oscillator for the structure-soil system has also been presented. Finally, a simulation study, using a recorded accelerogram, has been carried out on the CLCD performance for the flexible-base structure.

Investigation of the performance of externally collared RC short columns via aspect ratio

  • Dirikgil, Tamer;Dugenci, Oguz
    • Structural Engineering and Mechanics
    • /
    • v.68 no.3
    • /
    • pp.277-287
    • /
    • 2018
  • This paper presents the experimental study of nine pieces of reinforced concrete (RC) short columns. RC short columns were tested with cyclic loading with displacement control under the influence of constant axial load with load index of 0.2. Three columns within the tested nine columns are reference columns which have the details of the reinforcement given in the modern regulations and six of them are 150 mm and 100 mm externally collared columns. In addition to the parameter of the collar spacing, aspect ratio (as=2-1.5-1) is also considered as a parameter. The data obtained from experimental results have shown that externally collar contributes significantly to increasing the shear resistance of RC short columns and limiting the shear dominant behavior. It has been observed that the effectiveness of the externally collar increases with the decrease of the aspect ratio.

Compressive behavior of galvanized steel wire mesh (GSWM) strengthened RC short column of varying shapes

  • Marthong, Comingstarful
    • Structural Monitoring and Maintenance
    • /
    • v.7 no.3
    • /
    • pp.215-231
    • /
    • 2020
  • In a reinforced concrete building different shapes of column are adopted depending on the structural orientation and the architectural aspect. When there is an increase in loading due to changes in usage or revision in the design codes these columns need to be strengthened for enhanced performance during their service life. Strengthening materials such as carbon fiber and glass fiber polymer has been successfully used however, due to high cost application other alternative materials need to be explore. Galvanized steel wire mesh (GSWM) is one of the suitable materials locally available. High tensile strength, low weight, corrosion resistance, easy installation, minimum change in dimensions of the sections and cost effectives are the advantages of GSWM. Therefore, in this paper, four different shapes of column such as circular, square, rectangular and L were wrapped with different layers GSWM and jacketed with mortar. All the specimens were tested under axial compression. The objective of the study is to investigate the effectiveness of GSWM as a confining material for strengthening of column having varying shape. Test results shows that the axial strength enhanced with wrapping of GSWM jacket and a circular column presented the highest load carrying capacity and ductility as compared to the others. From the study of 22 column specimens, it is found that axial load is increased upto 20% and 19% when circular and square column are strengthened with one wrap of GSWM respectively, while a rectangular and L column required a wraps of two and three layers respectively in order to achieved the same load capacity as that of a circular column. Based on the present study, it is concluded that GSWM can be effectively used for strengthening of different shapes of concrete columns economically.

Analysis and Design of RC Short Columns in biaxial bending and Compression using Spreadsheets (스프레드시트를 이용한 2축 휨과 압축을 받는 철근 콘크리트 단주의 해석 및 설계)

  • 진치섭;엄장섭;노경배;박현재;이승훈
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • /
    • pp.627-632
    • /
    • 1998
  • This study developed practical computer program COL2 to design of generic shape reinforced concrete short columns subjected to combined compression and biaxial bending. The program COL2 has been developed for user-friendly environment using Excel 97 for windows 95. Several examples including for analysis of geometrically complex column sections subjected biaxial bending are included in this paper.

  • PDF

Shear Characteristics of RC Short Column Strengthened with Steel Fiber (강섬유로 보강된 RC 단주의 전단특성)

  • 장극관;이현호;양승호
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • /
    • pp.157-162
    • /
    • 2001
  • The purpose of this study is to investigate the enhancement of shear capacity according to steel fiber contents in RC short columns. Lateral force resistance test was performed with the parameters of steel fiber contents in concrete volume. From the test results, shear and ductility capacity was improved with steel fiber contents Increased. In addition, an optimal steel fiber content was evaluated as a 1.5 % of concrete volume.

  • PDF

Development of Portable Gas Chromatography / Photoionization Detector System (휴대용 기체 크로마토그래피 / 광이온화 검출기 시스템의 개발)

  • Kim, Man Gu;Sim, Ji Hui;Lee, Dong Su;Lee, Yong Geun
    • Journal of the Korean Chemical Society
    • /
    • v.38 no.2
    • /
    • pp.151-159
    • /
    • 1994
  • The portable gas chromatography system was developed which was consisted of ambient vapor sampler(AVS), short capillary column(3 m long, 0.32 mm i.d. GC(SCCGC), photoionization detector (PID) and vacuum pump which was operated at subambient pressure. The seletion of capillary column was based on the theoretical calculation from Golay equation. The pressure ratio of column inlet and outlet appropriated between 1.03 and 1.2 in the system. The available column flow were 0.87∼4.63 ml/min at the pressure ratios. The AVS consisted of three concentric tubes and enables rapid, repetitive introduction of vapor samples directly into capillary column and showed good reproducibility. The subambient column outlet pressure with PID resulted in a significant increase in the optimum column flow, permitting rapid analysis. The baseline separation of m-xylene and o-xylene was able to within 40 second with the system. Parameters affecting the column resolving power were sampling duration, column length and diameter, and the pressure ratio. Effects of these parameters were investigated using bezene derivative compounds.

  • PDF

Behaviour of cold-formed steel concrete infilled RHS connections and frames

  • Angeline Prabhavathy, R.;Samuel Knight, G.M.
    • Steel and Composite Structures
    • /
    • v.6 no.1
    • /
    • pp.71-85
    • /
    • 2006
  • This paper presents the results of a series of tests carried out on cold-formed steel rectangular hollow and concrete infilled beam to column connections and frames. A stub column was chosen such that overall buckling does not influence the connection behaviour. The beam chosen was a short-span cantilever with a concentrated load applied at the free end. The beam was connected to the columns along the strong and weak axes of columns and these connections were tested to failure. Twelve experiments were conducted on cold-formed steel direct welded tubular beam to column connections and twelve experiments on connections with concrete infilled column subjected to monotonic loading. In all the experiments conducted, the stiffness of the connection, the ductility characteristics and the moment rotation behaviour were studied. The dominant mode of failure in hollow section connections was chord face yielding and not weld failure. Provision of concrete infill increases the stiffness and the ultimate moment carrying capacity substantially, irrespective of the axis of loading of the column. Weld failure and bearing failure due to transverse compression occurred in connections with concrete infilled columns. Six single-bay two storied frames both with and without concrete infill, and columns loaded along the major and minor axes were tested to failure. Concentrated load was applied at the midspan of first floor beam. The change in behaviour of the frame due to provision of infill in the column and in the entire frame was compared with hollow frames. Failure of the weld at the junction of the beam occurred for frames with infilled columns. Design expressions are suggested for the yielding of the column face in hollow sections and bearing failure in infilled columns which closely predicted the experimental failure loads.

Dynamic Instability Analysis of Euler Column under Impact Loading (충격하중을 받는 Euler기둥의 동적좌굴 해석)

  • 김형열
    • Computational Structural Engineering
    • /
    • v.9 no.3
    • /
    • pp.187-197
    • /
    • 1996
  • An explicit direct time integration method based solution algorithm is presented to predict dynamic buckling response of Euler column. On the basis of large deflection beam theory, a plane frame finite element is formulated and implemented into the solution algorithm. The element formulation takes into account geometrical nonlinearity and overall buckling of steel structural frames. The solution algorithm employs the central difference method. Using the computer program developed by the author, dynamic instability behavior of Euler column under impact loading is investigated by considering the time variation of load, load magnitude, and load duration. The free vibration of Euler column caused by a short duration impact load is also studied. The validity and efficiency of the present formulation and solution algorithm are verified through illustrative numerical examples.

  • PDF