The document summarizes a study that investigated the seismic behavior of columns in ordinary moment resisting concrete frames (OMRCF) and intermediate moment resisting concrete frames (IMRCF). Eight column specimens were tested under various loading conditions to evaluate factors like axial load type, existence of lap splices, and frame type. The test results showed that the column specimens had strengths and drift capacities greater than code requirements, though capacities varied depending on lap splices and transverse reinforcement spacing.
Seismic Capacity Comparisons of Reinforced Concrete Buildings Between Standar...drboon
Earthquakes are cause of serious damage through the building. Therefore, moment resistant frame buildings are widely used as lateral resisting system. Generally three types of moment resisting frames are designed namely Special ductile frames (SDF), Intermediate ductile frames (IDF) and Gravity load designed (GLD) frames, each of which has a certain level of ductility. Comparative studies on the seismic performance of three different ductility of building are performed in this study. The analytical models are considered about failure mode of column (i.e. shear failure, flexural to shear failure and flexural failure); beam-column joint connection, infill wall and flexural foundation. Concepts of incremental dynamic analysis are practiced to assess the required data for performance based evaluations. This study found that the lateral load capacity of GLD, IDF, and SDF building was 19.25, 27.87, and 25.92 %W respectively. The average response spectrum at the collapse state for GLD, IDF, and SDF are 0.75 g, 1.19 g, and 1.33 g, respectively. The results show that SDF is more ductile than IDF and the initial strength of SDF is close to IDF. The results indicate that all of frames are able to resistant a design earthquake.
Reinforced concrete special moment frames • are used as part of seismic force-resisting systems in buildings that are designed to resist earthquakes. • Beams, columns, and beam-column joints in moment frames are prop... more abstract
Effect of non Seismic Walls
On Moment Resisting Frames in buildings.
Can we neglect reinforce concrete walls like
(stairwells, elevator shafts and so forth)?
*And what are the behavior of these walls during the yielding
point for the steel in work stress stage uncracked section
[Elastic Response Parameters] and after the yielding point in Plastic stage cracked section (Ultimate strength) since
*(Plastic Hinges) will occur in the Frames during plastic
stage And the frames shall peer all the entire seismic loads
And what are these Condition and arrangements to keep
the section walls in safety during plastic stage
so they can carry just the ordinary(D+L) axial loads.
Dose reinforcement for axial ordinary loads enough for these walls from collapsing?
All these answers you will get it when you look at the Dissertation
Comparison of performance of lateral load resisting systems in multi storey f...eSAT Journals
Abstract This paper introduces the comparison between lateral load resisting systems in multi storey building. Multi storey building
composed of very special class of structure and therefore require special treatment. Hence to overcome the effects of seismic
forces, Flat slab system in which slab rests on drop or capital which is connected to column is induced with different load
resisting systems. The combined systems which is used to withstand seismic forces in this study are 1. Flat slab without lateral
load resisting system, 2. Flat slab with shear wall, 3. Flat slab with infill wall, 4. Flat slab with bracings, 5. Flat slab with shear
wall and bracings. ETABS software version is used to accomplish dynamic analysis and also building is investigated for nonlinear
static analysis in order to identify seismic demands. From the obtained results conclusions are drawn.
Keywords: Capital, Bracings, Dynamic, and Treatment etc…
Analysis of outrigger system for tall vertical irregularites structures subje...eSAT Journals
Abstract The Analysis of the tall building is carried out to find the optimum position of outrigger system and belt truss by using lateral loads. The three dimensional model is considered and designed for the gravity load and placing of first and second position of the outrigger. Considering the design of Wind load is calculated by using IS 875 (Part 3) and Design of Earthquake load is calculated by using code IS 1893(part-1): 2000 in order to achieve reduction in drift, Deflection and story shear. The analysis is done by considering tall vertical irregularity of 30th storey of 7 X 7 bay for 1 to 10th storey and 7X6 bay 11th to 20th storey and 7X5 Bay 21st to 30th storey. Keywords: vertical irregularities, outrigger, linear static analysis Wind and earthquake load.
Seismic Capacity Comparisons of Reinforced Concrete Buildings Between Standar...drboon
Earthquakes are cause of serious damage through the building. Therefore, moment resistant frame buildings are widely used as lateral resisting system. Generally three types of moment resisting frames are designed namely Special ductile frames (SDF), Intermediate ductile frames (IDF) and Gravity load designed (GLD) frames, each of which has a certain level of ductility. Comparative studies on the seismic performance of three different ductility of building are performed in this study. The analytical models are considered about failure mode of column (i.e. shear failure, flexural to shear failure and flexural failure); beam-column joint connection, infill wall and flexural foundation. Concepts of incremental dynamic analysis are practiced to assess the required data for performance based evaluations. This study found that the lateral load capacity of GLD, IDF, and SDF building was 19.25, 27.87, and 25.92 %W respectively. The average response spectrum at the collapse state for GLD, IDF, and SDF are 0.75 g, 1.19 g, and 1.33 g, respectively. The results show that SDF is more ductile than IDF and the initial strength of SDF is close to IDF. The results indicate that all of frames are able to resistant a design earthquake.
Reinforced concrete special moment frames • are used as part of seismic force-resisting systems in buildings that are designed to resist earthquakes. • Beams, columns, and beam-column joints in moment frames are prop... more abstract
Effect of non Seismic Walls
On Moment Resisting Frames in buildings.
Can we neglect reinforce concrete walls like
(stairwells, elevator shafts and so forth)?
*And what are the behavior of these walls during the yielding
point for the steel in work stress stage uncracked section
[Elastic Response Parameters] and after the yielding point in Plastic stage cracked section (Ultimate strength) since
*(Plastic Hinges) will occur in the Frames during plastic
stage And the frames shall peer all the entire seismic loads
And what are these Condition and arrangements to keep
the section walls in safety during plastic stage
so they can carry just the ordinary(D+L) axial loads.
Dose reinforcement for axial ordinary loads enough for these walls from collapsing?
All these answers you will get it when you look at the Dissertation
Comparison of performance of lateral load resisting systems in multi storey f...eSAT Journals
Abstract This paper introduces the comparison between lateral load resisting systems in multi storey building. Multi storey building
composed of very special class of structure and therefore require special treatment. Hence to overcome the effects of seismic
forces, Flat slab system in which slab rests on drop or capital which is connected to column is induced with different load
resisting systems. The combined systems which is used to withstand seismic forces in this study are 1. Flat slab without lateral
load resisting system, 2. Flat slab with shear wall, 3. Flat slab with infill wall, 4. Flat slab with bracings, 5. Flat slab with shear
wall and bracings. ETABS software version is used to accomplish dynamic analysis and also building is investigated for nonlinear
static analysis in order to identify seismic demands. From the obtained results conclusions are drawn.
Keywords: Capital, Bracings, Dynamic, and Treatment etc…
Analysis of outrigger system for tall vertical irregularites structures subje...eSAT Journals
Abstract The Analysis of the tall building is carried out to find the optimum position of outrigger system and belt truss by using lateral loads. The three dimensional model is considered and designed for the gravity load and placing of first and second position of the outrigger. Considering the design of Wind load is calculated by using IS 875 (Part 3) and Design of Earthquake load is calculated by using code IS 1893(part-1): 2000 in order to achieve reduction in drift, Deflection and story shear. The analysis is done by considering tall vertical irregularity of 30th storey of 7 X 7 bay for 1 to 10th storey and 7X6 bay 11th to 20th storey and 7X5 Bay 21st to 30th storey. Keywords: vertical irregularities, outrigger, linear static analysis Wind and earthquake load.
seismic response of multi storey building equipped with steel bracingINFOGAIN PUBLICATION
Steel bracing has proven to be one of the most effective systems in resisting lateral loads. Although its use to upgrade the lateral load capacity of existing Reinforced Concrete (RC) frames has been the subject of numerous studies, guidelines for its use in newly constructed RC frames still need to be developed. In this paper the study reveals that seismic performance of moment resisting RC frames with different patterns of bracing system. The three different types of bracings were used i.e. X - bracing system, V - bracing system and Inverted V - bracing system. This arrangement helped in reducing the structural response (i.e. displacement, interstorey drift, Shear Forces & Bending Moments) of the designed building structure. An (G+6) storey building was modelled and designed as per the code provisions of IS-1893:2002. And linear analysis is been carried out in the global X direction. The analysis was conducted with a view of accessing the seismic elastic performance of the building structure.
A study on behaviour of outrigger system on high rise steel structure by vary...eSAT Journals
Abstract The outrigger system is one of the most efficient system used for high rise structures to resist lateral forces. In the present study an attempt has been made to study the static and dynamic behavior of the outrigger structural system on steel structure by reducing the depth of outrigger.5X5 bay 40 story 3D steel structures is modeled in ETABS v2013 software. Steel structure with central core and steel structure with outrigger structural system of varied depth of outrigger are compared. The depth of the outrigger is reduced to 2/3rd and 1/3rd of the story height along with the full story height. The depth of the belt-truss is equal to the height of the typical story and maintained same in all the structures. The key parameters discussed in this paper include lateral deflection and storey drift. From the analysis results it has been found that the comparative performance of outrigger with depth of full storey height and decreased depth shows minor difference in resistance towards lateral loads. Keywords: Outrigger system, Lateral Displacement, Inter story drift
Study of Eccentrically Braced Outrigger Frame under Seismic ExitationIJTET Journal
Outrigger braced structures has efficient structural form consist of a central core, comprising braced frames with
horizontal cantilever ”outrigger” trusses or girders connecting the core to the outer column. When the structure is loaded
horizontally, vertical plane rotation of the core is restrained by the outriggers through tension in windward column and
compression in leeward column. The effective structural depth of the building is greatly increased, thus augmenting the lateral
stiffness of the building and reducing the lateral deflections and moments in core. In effect, the outriggers join the columns to the
core to make the structure behave as a partly composite cantilever. By providing eccentrically braced system in outrigger frame by
varying the size of links and analyzing it. Push over analysis is carried out by varying the link size using computer programs, Sap
2007 to understand their seismic performance. The ductile behavior of eccentrically braced frame is highly desirable for structures
subjected to strong ground motion. Maximum stiffness, strength, ductility and energy dissipation capacity are provided by
eccentrically braced frame. Studies were conducted on the use of outrigger frame for the high steel building subjected to
earthquake load. Braces are designed not to buckle, regardless of the severity of lateral loading on the frame. Thus eccentrically
braced frame ensures safety against collapse.
The design of Elements of Lifts and Escalator from Civil Engineering point of view. Mainly Raft foundation, Machine Foundation, and Shear walls are discussed.
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The papers for publication in The International Journal of Engineering& Science are selected through rigorous peer reviews to ensure originality, timeliness, relevance, and readability.
Determination of period of vibration of buildings with open stilt floor and s...eSAT Journals
Abstract To estimate the natural period of vibration, codes consign the empirical formula that solely relies on height of the structure. Present dissertation is carried out considering aspects such as building material, type of structure and structural dimensions. The foremost objective of the present systematic study has led to a simplified period-height equation for use in the seismic evaluation of reinforced concrete structures, taking due significance of the existence of stilt floors and shear walls. Current study also highlights the criteria that affects the period of vibration. The period of vibration which has been procured in this study represents the time period of first mode of vibration. This article comprises the seismic response of structures on different types of soil. The parameters considered for the given study are three different types of soil i.e., soft soil, medium soil and hard rock for high seismic zone and different building irregularities as per IS: 1893-2002 for 10, 15, 20 storey buildings. The analytical models for the modulus study are modeled through ETABS.V.9.2. Various parametric studies are carried out to determine the fundamental time period of the structures. These ameliorate formulas to determine the fundamental time period are developed using nonlinear regression analysis through ORIGIN pro software. The generalized equation finally obtained can be used in general form to calculate the time period of structures with open stilt floor and shear walls irrespective of soil types, seismic zone or building height. Keywords- Time period, open stilt floor, Shear walls, Irregularities in buildings, nonlinear regression
Evaluation of the Seismic Response Parameters for Infilled Reinforced Concret...IOSRJMCE
RC frames with unreinforced masonry infill walls are a common form of construction all around the world. Often, engineers do not consider masonry infill walls in the design process because the final distribution of these elements may be unknown to them, or because masonry walls are regarded as non-structural elements. Separation between masonry walls and frames is often not provided and, as a consequence, walls and frames interact during strong ground motion. This leads to structural response deviating radically from what is expected in the design. The presence of masonry infills can result in higher stiffness and strength and it is cheap and built with low cost labor. Under lateral load, Masonry walls act as diagonal struts subjected to compression, while reinforced concrete confining members (Frames) act in tension and/or compression, depending on the direction of lateral earthquake forces. The main objective of this research is to develop a realistic matrix for the response modification factors for medium-rise skeletal buildings with masonry infills. In this study, the contribution of the masonry infill walls to the lateral behavior of reinforced concrete buildings was investigated. For this purpose, a five, seven and ten stories buildings are modelled as bare and infilled frames. The parameters investigated were infill ratio, panel aspect ratio, unidirectional eccentricity, bidirectional eccentricities. A Parametric study was developed on the behavior of medium rise infilled frame buildings under lateral loads to investigate the effect of these parameters as well as infill properties on this behavior
Code approaches to seismic design of masonry infiled rc framesBinay Shrestha
Masonry infill (MI) increases the initial stiffness of reinforced concrete RC frames. Behavior of MI is difficult to predict because of significant variations in material properties and because of failure modes that are brittle in nature.
EFFECT OF POSITIONING OF RC SHEAR WALLS OF DIFFERENT SHAPES ON SEISMIC PERFOR...IAEME Publication
The buildings situated on hill slopes in earthquake prone areas are generally irregular, torsionally coupled. Hence, subjected to severe damage when affected by earthquake ground motion. Such buildings have mass & stiffness varying along the vertical & horizontal planes, resulting the center of mass & center of rigidity do not coincide on various floors, they demand torsional analysis, in addition to lateral forces under the action of earthquakes. This study compels with a studies on the seismic behavior of buildings resting on sloping ground with a shear walls. It is observed that the seismic behavior of buildings on sloping ground differ from other buildings.
Analysis and Optimum Design for Steel Moment Resisting Frames to Seismic Exci...IJCMESJOURNAL
The essential purpose of this wander is to develop an Interior Penalty Function (IPF) based estimation to multi-storey steel traces for slightest weight of frames. The frames are proposed for contradicting even impact in view of seismic stacking close by gravity forces. Various structural stems are used for restricting seismic (lateral) forces; however steel moment resisting frames (MRFs) are considered for the present work. The framework solidifies codal courses of action of IS 800-2007, as needs be gets the edges with perfect weight for in-plane moments with lateral support of beam element. Strength and buckling criteria are considered as direct goals close by side constraints in formulating optimization problem. A Software program is made that uses an interior penalty function (IPF) for weight minimization of two-dimensional moment restricting steel encompassed structures. The program uses MATLAB, performs one dimensional interest, and structural design in an iterative technique. The design cases have exhibited that the proposed estimation gives a beneficial instrument to the practicing fundamental algorithm. The program is associated with 6 and 9 storey (4 bays) moment resisting frames (MRFs). The program showed its capacity of optimizing the largeness of two medium size frames. To get part obliges in frames an examination technique must be associated. In the present work Equivalent Lateral Force framework (ELF) and material nonlinear time history analysis (NTH) are associated and perfect qualities gained from both the examinations are contemplated.
seismic response of multi storey building equipped with steel bracingINFOGAIN PUBLICATION
Steel bracing has proven to be one of the most effective systems in resisting lateral loads. Although its use to upgrade the lateral load capacity of existing Reinforced Concrete (RC) frames has been the subject of numerous studies, guidelines for its use in newly constructed RC frames still need to be developed. In this paper the study reveals that seismic performance of moment resisting RC frames with different patterns of bracing system. The three different types of bracings were used i.e. X - bracing system, V - bracing system and Inverted V - bracing system. This arrangement helped in reducing the structural response (i.e. displacement, interstorey drift, Shear Forces & Bending Moments) of the designed building structure. An (G+6) storey building was modelled and designed as per the code provisions of IS-1893:2002. And linear analysis is been carried out in the global X direction. The analysis was conducted with a view of accessing the seismic elastic performance of the building structure.
A study on behaviour of outrigger system on high rise steel structure by vary...eSAT Journals
Abstract The outrigger system is one of the most efficient system used for high rise structures to resist lateral forces. In the present study an attempt has been made to study the static and dynamic behavior of the outrigger structural system on steel structure by reducing the depth of outrigger.5X5 bay 40 story 3D steel structures is modeled in ETABS v2013 software. Steel structure with central core and steel structure with outrigger structural system of varied depth of outrigger are compared. The depth of the outrigger is reduced to 2/3rd and 1/3rd of the story height along with the full story height. The depth of the belt-truss is equal to the height of the typical story and maintained same in all the structures. The key parameters discussed in this paper include lateral deflection and storey drift. From the analysis results it has been found that the comparative performance of outrigger with depth of full storey height and decreased depth shows minor difference in resistance towards lateral loads. Keywords: Outrigger system, Lateral Displacement, Inter story drift
Study of Eccentrically Braced Outrigger Frame under Seismic ExitationIJTET Journal
Outrigger braced structures has efficient structural form consist of a central core, comprising braced frames with
horizontal cantilever ”outrigger” trusses or girders connecting the core to the outer column. When the structure is loaded
horizontally, vertical plane rotation of the core is restrained by the outriggers through tension in windward column and
compression in leeward column. The effective structural depth of the building is greatly increased, thus augmenting the lateral
stiffness of the building and reducing the lateral deflections and moments in core. In effect, the outriggers join the columns to the
core to make the structure behave as a partly composite cantilever. By providing eccentrically braced system in outrigger frame by
varying the size of links and analyzing it. Push over analysis is carried out by varying the link size using computer programs, Sap
2007 to understand their seismic performance. The ductile behavior of eccentrically braced frame is highly desirable for structures
subjected to strong ground motion. Maximum stiffness, strength, ductility and energy dissipation capacity are provided by
eccentrically braced frame. Studies were conducted on the use of outrigger frame for the high steel building subjected to
earthquake load. Braces are designed not to buckle, regardless of the severity of lateral loading on the frame. Thus eccentrically
braced frame ensures safety against collapse.
The design of Elements of Lifts and Escalator from Civil Engineering point of view. Mainly Raft foundation, Machine Foundation, and Shear walls are discussed.
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The papers for publication in The International Journal of Engineering& Science are selected through rigorous peer reviews to ensure originality, timeliness, relevance, and readability.
Determination of period of vibration of buildings with open stilt floor and s...eSAT Journals
Abstract To estimate the natural period of vibration, codes consign the empirical formula that solely relies on height of the structure. Present dissertation is carried out considering aspects such as building material, type of structure and structural dimensions. The foremost objective of the present systematic study has led to a simplified period-height equation for use in the seismic evaluation of reinforced concrete structures, taking due significance of the existence of stilt floors and shear walls. Current study also highlights the criteria that affects the period of vibration. The period of vibration which has been procured in this study represents the time period of first mode of vibration. This article comprises the seismic response of structures on different types of soil. The parameters considered for the given study are three different types of soil i.e., soft soil, medium soil and hard rock for high seismic zone and different building irregularities as per IS: 1893-2002 for 10, 15, 20 storey buildings. The analytical models for the modulus study are modeled through ETABS.V.9.2. Various parametric studies are carried out to determine the fundamental time period of the structures. These ameliorate formulas to determine the fundamental time period are developed using nonlinear regression analysis through ORIGIN pro software. The generalized equation finally obtained can be used in general form to calculate the time period of structures with open stilt floor and shear walls irrespective of soil types, seismic zone or building height. Keywords- Time period, open stilt floor, Shear walls, Irregularities in buildings, nonlinear regression
Evaluation of the Seismic Response Parameters for Infilled Reinforced Concret...IOSRJMCE
RC frames with unreinforced masonry infill walls are a common form of construction all around the world. Often, engineers do not consider masonry infill walls in the design process because the final distribution of these elements may be unknown to them, or because masonry walls are regarded as non-structural elements. Separation between masonry walls and frames is often not provided and, as a consequence, walls and frames interact during strong ground motion. This leads to structural response deviating radically from what is expected in the design. The presence of masonry infills can result in higher stiffness and strength and it is cheap and built with low cost labor. Under lateral load, Masonry walls act as diagonal struts subjected to compression, while reinforced concrete confining members (Frames) act in tension and/or compression, depending on the direction of lateral earthquake forces. The main objective of this research is to develop a realistic matrix for the response modification factors for medium-rise skeletal buildings with masonry infills. In this study, the contribution of the masonry infill walls to the lateral behavior of reinforced concrete buildings was investigated. For this purpose, a five, seven and ten stories buildings are modelled as bare and infilled frames. The parameters investigated were infill ratio, panel aspect ratio, unidirectional eccentricity, bidirectional eccentricities. A Parametric study was developed on the behavior of medium rise infilled frame buildings under lateral loads to investigate the effect of these parameters as well as infill properties on this behavior
Code approaches to seismic design of masonry infiled rc framesBinay Shrestha
Masonry infill (MI) increases the initial stiffness of reinforced concrete RC frames. Behavior of MI is difficult to predict because of significant variations in material properties and because of failure modes that are brittle in nature.
EFFECT OF POSITIONING OF RC SHEAR WALLS OF DIFFERENT SHAPES ON SEISMIC PERFOR...IAEME Publication
The buildings situated on hill slopes in earthquake prone areas are generally irregular, torsionally coupled. Hence, subjected to severe damage when affected by earthquake ground motion. Such buildings have mass & stiffness varying along the vertical & horizontal planes, resulting the center of mass & center of rigidity do not coincide on various floors, they demand torsional analysis, in addition to lateral forces under the action of earthquakes. This study compels with a studies on the seismic behavior of buildings resting on sloping ground with a shear walls. It is observed that the seismic behavior of buildings on sloping ground differ from other buildings.
Analysis and Optimum Design for Steel Moment Resisting Frames to Seismic Exci...IJCMESJOURNAL
The essential purpose of this wander is to develop an Interior Penalty Function (IPF) based estimation to multi-storey steel traces for slightest weight of frames. The frames are proposed for contradicting even impact in view of seismic stacking close by gravity forces. Various structural stems are used for restricting seismic (lateral) forces; however steel moment resisting frames (MRFs) are considered for the present work. The framework solidifies codal courses of action of IS 800-2007, as needs be gets the edges with perfect weight for in-plane moments with lateral support of beam element. Strength and buckling criteria are considered as direct goals close by side constraints in formulating optimization problem. A Software program is made that uses an interior penalty function (IPF) for weight minimization of two-dimensional moment restricting steel encompassed structures. The program uses MATLAB, performs one dimensional interest, and structural design in an iterative technique. The design cases have exhibited that the proposed estimation gives a beneficial instrument to the practicing fundamental algorithm. The program is associated with 6 and 9 storey (4 bays) moment resisting frames (MRFs). The program showed its capacity of optimizing the largeness of two medium size frames. To get part obliges in frames an examination technique must be associated. In the present work Equivalent Lateral Force framework (ELF) and material nonlinear time history analysis (NTH) are associated and perfect qualities gained from both the examinations are contemplated.
Analysis and Optimum Design for Steel Moment Resisting Frames to Seismic Exci...IJCMESJOURNAL
The essential purpose of this wander is to develop an Interior Penalty Function (IPF) based estimation to multi-storey steel traces for slightest weight of frames. The frames are proposed for contradicting even impact in view of seismic stacking close by gravity forces. Various structural stems are used for restricting seismic (lateral) forces; however steel moment resisting frames (MRFs) are considered for the present work. The framework solidifies codal courses of action of IS 800-2007, as needs be gets the edges with perfect weight for in-plane moments with lateral support of beam element. Strength and buckling criteria are considered as direct goals close by side constraints in formulating optimization problem. A Software program is made that uses an interior penalty function (IPF) for weight minimization of two-dimensional moment restricting steel encompassed structures. The program uses MATLAB, performs one dimensional interest, and structural design in an iterative technique. The design cases have exhibited that the proposed estimation gives a beneficial instrument to the practicing fundamental algorithm. The program is associated with 6 and 9 storey (4 bays) moment resisting frames (MRFs). The program showed its capacity of optimizing the largeness of two medium size frames. To get part obliges in frames an examination technique must be associated. In the present work Equivalent Lateral Force framework (ELF) and material nonlinear time history analysis (NTH) are associated and perfect qualities gained from both the examinations are contemplated.
Out of Plane Behavior of Contained Masonry Infilled Frames Subjected to Seism...paperpublications3
Abstract: Brick masonry infill although considered as non-structural element largely affects the strength, stiffness and ductility of the reinforced concrete frames during the application of lateral loads due to wind or earthquake. Contained masonry refers here to the brick masonry which is used as infill in a reinforced concrete frame, wound round with 8mm diameter mild steel wires in vertical and horizontal directions and stitched to the brick masonry as well as to the reinforced concrete frames. This thesis focuses on the seismic behaviour of reinforced concrete structures with contained masonry infill, with a particular interest in the development of rational procedures for the analysis and design of RC frames with contained masonry infill. The estimation of the natural frequencies of the structural system is the basic investigation in dynamic analysis of a structure. Therefore the analysis is primarily to find out the modal frequencies of the structure and to simulate the mathematical model to earthquake loads. The structure vibrates in different modes when the earthquake takes place. The methodology suggested is to carry out a detailed study on the influence of contained masonry infill including un-reinforced masonry infill in multi-storey Reinforced Concrete frames on the fundamental natural frequencies and response due to various earthquake excitation forces. Numerical Finite element analysis is carried out on two dimensional Reinforced Concrete Frames under different configurations of contained masonry infill in addition to plain masonry and bare frames. The RC frames were designed and detailed as per relevant Indian standard codes. The present work consists of study of the behaviour of five storeyed RC frames infilled with contained masonry and also infilled with plain masonry, subjected to various earthquake excitation forces. Three types of models are considered for analysis; five storey frames of 4m wide, 5m wide and 6m wide models having total height of 16m with plain masonry infill and contained masonry infill are considered.
A Study of R. C. C. Beam Column Junction Subjected To QuasiStatic (Monotonic)...IOSR Journals
Abstract - Beam and column where intersects is called as joint or junction. The different types of joints are
classified as corner joint, exterior joint, interior joint etc. on beam column joint applying quasi-static loading on
cantilever end of the beam. and study of various parameters as to be find out on corner and exterior beam
column joint i.e. maximum stress, minimum stress, displacement and variation in stiffness of beam column joint
can be analyzed in Ansys software ( Non-Linear FEM Software) Significant experimental research has been
conducted over the past three decades on hysteretic behavior of beam-column joints of RC frames under cyclic
displacement loading. The various research studies focused on corner and exterior beam column joints and
their behavior, support conditions of beam-column joints. Some recent experimental studies, however,
addressed beam-column joints of substandard RC frames with weak columns, poor anchorage of longitudinal
beam bars and insufficient transverse reinforcement. the behavior of exterior beam column joint is different
than the corner beam column joint
Study of variations in dynamic stability of tall structure corresponding to s...ijceronline
Construction of tall buildings, both residential and commercial are in insistance. In case of tall structure high lateral forces develops due to earthquake load and wind load are crucial. Thus the effects of lateral loads needs consideration for strength and stability of the structures. In tall buildings, lateral loads are critical as it increases drastically after a certain height of the structure. Shear wall systems are one of the most commonly used dynamic load resisting systems in high-rise buildings which help in achieving strength and stability along with economy. In this study, an attempt has been carried out to check the dynamic stability of a tall residential structure by applying variations symmetric arrangement of the shear wall. The Case study of a 26 storied RCC structure situated in Pune region of Maharashtra, India has been carried out. The effect of location of shear wall on dynamic behaviour of building is analysed using ETABS software using response spectrum method for earthquake analysis and IS875 (III) for wind analysis. The proposed position of shear wall gives the effective results as compare to other position.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
International Journal of Engineering Research and Applications (IJERA) is a team of researchers not publication services or private publications running the journals for monetary benefits, we are association of scientists and academia who focus only on supporting authors who want to publish their work. The articles published in our journal can be accessed online, all the articles will be archived for real time access.
Our journal system primarily aims to bring out the research talent and the works done by sciaentists, academia, engineers, practitioners, scholars, post graduate students of engineering and science. This journal aims to cover the scientific research in a broader sense and not publishing a niche area of research facilitating researchers from various verticals to publish their papers. It is also aimed to provide a platform for the researchers to publish in a shorter of time, enabling them to continue further All articles published are freely available to scientific researchers in the Government agencies,educators and the general public. We are taking serious efforts to promote our journal across the globe in various ways, we are sure that our journal will act as a scientific platform for all researchers to publish their works online.
Welcome to WIPAC Monthly the magazine brought to you by the LinkedIn Group Water Industry Process Automation & Control.
In this month's edition, along with this month's industry news to celebrate the 13 years since the group was created we have articles including
A case study of the used of Advanced Process Control at the Wastewater Treatment works at Lleida in Spain
A look back on an article on smart wastewater networks in order to see how the industry has measured up in the interim around the adoption of Digital Transformation in the Water Industry.
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)MdTanvirMahtab2
This presentation is about the working procedure of Shahjalal Fertilizer Company Limited (SFCL). A Govt. owned Company of Bangladesh Chemical Industries Corporation under Ministry of Industries.
Immunizing Image Classifiers Against Localized Adversary Attacksgerogepatton
This paper addresses the vulnerability of deep learning models, particularly convolutional neural networks
(CNN)s, to adversarial attacks and presents a proactive training technique designed to counter them. We
introduce a novel volumization algorithm, which transforms 2D images into 3D volumetric representations.
When combined with 3D convolution and deep curriculum learning optimization (CLO), itsignificantly improves
the immunity of models against localized universal attacks by up to 40%. We evaluate our proposed approach
using contemporary CNN architectures and the modified Canadian Institute for Advanced Research (CIFAR-10
and CIFAR-100) and ImageNet Large Scale Visual Recognition Challenge (ILSVRC12) datasets, showcasing
accuracy improvements over previous techniques. The results indicate that the combination of the volumetric
input and curriculum learning holds significant promise for mitigating adversarial attacks without necessitating
adversary training.
Hybrid optimization of pumped hydro system and solar- Engr. Abdul-Azeez.pdffxintegritypublishin
Advancements in technology unveil a myriad of electrical and electronic breakthroughs geared towards efficiently harnessing limited resources to meet human energy demands. The optimization of hybrid solar PV panels and pumped hydro energy supply systems plays a pivotal role in utilizing natural resources effectively. This initiative not only benefits humanity but also fosters environmental sustainability. The study investigated the design optimization of these hybrid systems, focusing on understanding solar radiation patterns, identifying geographical influences on solar radiation, formulating a mathematical model for system optimization, and determining the optimal configuration of PV panels and pumped hydro storage. Through a comparative analysis approach and eight weeks of data collection, the study addressed key research questions related to solar radiation patterns and optimal system design. The findings highlighted regions with heightened solar radiation levels, showcasing substantial potential for power generation and emphasizing the system's efficiency. Optimizing system design significantly boosted power generation, promoted renewable energy utilization, and enhanced energy storage capacity. The study underscored the benefits of optimizing hybrid solar PV panels and pumped hydro energy supply systems for sustainable energy usage. Optimizing the design of solar PV panels and pumped hydro energy supply systems as examined across diverse climatic conditions in a developing country, not only enhances power generation but also improves the integration of renewable energy sources and boosts energy storage capacities, particularly beneficial for less economically prosperous regions. Additionally, the study provides valuable insights for advancing energy research in economically viable areas. Recommendations included conducting site-specific assessments, utilizing advanced modeling tools, implementing regular maintenance protocols, and enhancing communication among system components.
CFD Simulation of By-pass Flow in a HRSG module by R&R Consult.pptxR&R Consult
CFD analysis is incredibly effective at solving mysteries and improving the performance of complex systems!
Here's a great example: At a large natural gas-fired power plant, where they use waste heat to generate steam and energy, they were puzzled that their boiler wasn't producing as much steam as expected.
R&R and Tetra Engineering Group Inc. were asked to solve the issue with reduced steam production.
An inspection had shown that a significant amount of hot flue gas was bypassing the boiler tubes, where the heat was supposed to be transferred.
R&R Consult conducted a CFD analysis, which revealed that 6.3% of the flue gas was bypassing the boiler tubes without transferring heat. The analysis also showed that the flue gas was instead being directed along the sides of the boiler and between the modules that were supposed to capture the heat. This was the cause of the reduced performance.
Based on our results, Tetra Engineering installed covering plates to reduce the bypass flow. This improved the boiler's performance and increased electricity production.
It is always satisfying when we can help solve complex challenges like this. Do your systems also need a check-up or optimization? Give us a call!
Work done in cooperation with James Malloy and David Moelling from Tetra Engineering.
More examples of our work https://www.r-r-consult.dk/en/cases-en/
2. 952 S.W. Han, N.Y. Jee / Engineering Structures 27 (2005) 951–962
Fig. 1. Minimum reinforcement details for columns.
Notation
Ag gross area of column
fc specified compressive strength of concrete
fy specified yield strength of nonprestressed
reinforcement
Mmax maximum moment resistance of the specimen
MACI moment capacity calculated using ACI 318-99
procedures
VACI nominal shear strength according to ACI 318-
99
∆max maximum displacement
θmax maximum drift angle
shear force shall be calculated by elastic strength demand
divided by R factor (≥1). R factor accounts for ductility,
overstrength, redundancy, and damping inherent in a
structural system. Current design provisions assigned the
highest R factor to SMRCF, and the lowest R factor to
OMRCF because of its less stringent design requirement. It
should be noted that design base shear becomes larger with
decreasing R factor.
This study focused on the behaviors of first story columns
in moment resisting frames. For this purpose, three-story
OMRCF and IMRCF buildings were designed according
to ACI 318-02. Experimental test of columns in the first
story of those buildings was carried out to investigate the
seismic behavior of the columns. This study considered that
a column consisted of an upper part and lower part divided
at the point of inflection.
Eight 2/3 scale column specimens (2 × 2 × 2 = 8)
representing the lower and upper part (2) of the exterior and
interior columns (2) in the OMRCF and IMRCF (2) were
made. Lower column specimens had lap splices whereas
upper column specimens had continuous longitudinal
reinforcement. The most significant difference in OMRCF
and IMRCF columns is the spacing of the transverse
reinforcement at the end of the column. Quasi-static reversed
cyclic loading was applied to the specimens with either fixed
or varying axial forces.
The test variables in this study were type of axial force
(constant and varying, and low and high), existence of lap
splices (with or without lap splice) and type of moment
resisting concrete frames (OMRCF or IMRCF).
2. Previous studies
Han et al. [6,7] have evaluated the seismic performance
of a three-story OMRCF. In their studies maximum lateral
force was measured during the test and compared with the
design base shear force specified in current codes. Moreover,
this study carried out seismic performance evaluation of the
three-story OMRCF using a capacity spectrum method.
Lee and Woo [9] investigated the seismic performance
of low-rise reinforced concrete (RC) frames with non-
seismic detailing. They considered a bare frame and a
masonry infilled frame. An experiment was conducted
3. S.W. Han, N.Y. Jee / Engineering Structures 27 (2005) 951–962 953
using 1/5 scaled specimens having two bays and three
stories. They found that RC moment frames had a certain
seismic resistance even though they were designed without
considering seismic loads. Furthermore, masonry infill was
beneficial to the seismic performance of the frame.
Aycardi et al. [10] investigated the behavior of gravity
load-designed reinforced concrete column members under
simulated seismic loading. They tested four column
specimens governed by flexure under reversed cyclic loading
at increasing drift amplitudes. It was observed that all
column specimens were capable of sustaining at least two
cycles of loading at a 4% drift angle.
Lynn et al. [11] tested eight reinforced concrete column
specimens having typical details of those built before the
mid-1970s. This study observed that column specimens that
were governed by shear experienced gravity load failure
soon after loss of lateral force resistance. When flexure
was dominant in specimens, gravity load capacity was
maintained to large displacement.
3. Experimental program
3.1. Design of building frames
Typical three-story office buildings were designed.
Seismic resistance for these buildings was provided by
OMRCF and IMRCF. The dimension and design loads were
adopted from Han [6]. Fig. 2 shows the dimensions of the
building.
Specified compressive strength ( fc) of concrete was
assumed to be 23.5 MPa. Longitudinal reinforcement and
reinforcement for hoop and stirrup were assumed to have a
yield strength ( fy) of 392.3 MPa. Design loads for a typical
office building were used (5.2 kPa for dead load and 2.4 kPa
for live load). The section of all columns and beams in the
model frames were assumed to be 330 mm × 330 mm and
250 mm × 500 mm, respectively.
The buildings were assumed to be located in seismic
zone 1 as classified in UBC [2]. Member forces were
obtained using SAP 2000 (2000). Gravity loads governed the
member design. Since the seismic load was small, OMRCF
and IMRCF had the same member sizes as well as the
same amount of reinforcement except for the transverse
reinforcement in columns and beams (see Fig. 3). This
design was desirable for this study since this study attempted
to investigate the effect of different reinforcement details
of OMRCF and IMRCF columns on seismic behaviors of
those columns without interference of other factors such as
amount of longitudinal reinforcement and different member
sizes.
3.2. Column specimens
As shown in Fig. 2, only the columns in the first story
were evaluated since these columns should resist the largest
axial and lateral forces during an earthquake. The exterior
(a) Plan view.
(b) Elevation.
Fig. 2. Building layouts.
columns in the first story of the two model frames were
designed for an axial force of 644.3 kN and a bending
moment of 37 kN m, and the interior columns were designed
for an axial load of 1234.7 kN and a bending moment of
47.1 kN m. It is noted that those design forces contain load
factors.
All columns had a section of 330 mm × 330 mm
and contained four longitudinal reinforcements (D19
(19.1 mm diameter), fy = 392.3 MPa). Column
longitudinal reinforcement ratio (ρ) was 1.01%, which
slightly exceeded a minimum longitudinal reinforcing steel
of 1.0% (Section 10.9.1 in ACI 318-02).
Maximum shear force in the first story columns induced
by factored gravity loads was 31.4 kN. According to the
formula in Section 11.3.1.2 of the ACI 318-02, the concrete
shear strength of the first story columns (Vc) was calculated
as 73.5 kN. Minimum tie reinforcement (D10 with a
diameter of 9.53 mm) with spacing of 300 mm was placed
throughout the column in the OMRCF (Section 7.10.5.2
in ACI 318-02) and the first tie reinforcement was placed
150 mm from the slab or footing surface according
4. 954 S.W. Han, N.Y. Jee / Engineering Structures 27 (2005) 951–962
Fig. 3. Column specimens.
to the requirement of the first tie location specified in
Section 7.10.5.4 in ACI 318-02.
Fig. 3 shows that the first tie was placed 100 mm from the
slab in 2/3 scale specimens. The longitudinal reinforcement
details in the IMRCF columns and the OMRCF columns
were exactly the same. Tie spacing in the plastic hinging
region of the IMRCF columns, however, was half of the tie
spacing in the OMRCF columns. The yield strength of D10
was 392.3 MPa. A lap splice length of 525 mm was required
for tension according to Section 12.15 in ACI 318-02. Lap
splices in a column were placed just above the slabs (see
Figs. 1 and 3).
It is worthwhile to note that as shown in Fig. 1 the upper
part of columns has continuous longitudinal bars whereas
the lower part of columns has lap splices. Thus this study
made specimens representing the upper part and lower part
of columns (see Fig. 2). It was assumed that the inflection
point was located at the mid-height of the column during
earthquakes.
Fig. 3 shows the reinforcement details and dimensions
of the 2/3 scale column test specimens. Table 1 describes
the characteristics of the specimens. All reinforcements
were scaled by 2/3 for test specimens. A total of eight
specimens were made (upper and lower part (2) of interior
and exterior columns in OMRCF and IMRCF (2)). Lap
splice length (350 mm) was also simply scaled by 2/3 of
the original length (525 mm). No attempt was made to re-
calculate lap splice length for scaled reinforcement. Rebar
D13 (12.7 mm diameter) and D6 (6.35 mm diameter) were
used for longitudinal and transverse tie reinforcement to
represent 2/3 of D19 and D10 in the columns of model
frames.
The dimension of column base is shown in Fig. 3.
The longitudinal reinforcement of column specimens was
anchored to the column base satisfying development length
required by ACI 318-02 (chapter 12). In order to fix the
specimen to the strong floor, four high strength bolts having
a diameter of 70 mm were installed (see Fig. 4(a)). All bolts
are fully tightened to provide specimens with fixed base
conditions. In column base, sufficient closed type stirrups
using reinforcement of D13 (13 mm diameter) were placed
to resist the forces transferred from the specimen. No cracks
were detected in the column base after test (see Fig. 4(a)).
3.3. Material tests
Based on concrete trial mixes from various recipes for
attaining the 28-day target strength ( fc) of 23.5 MPa, a
design mix was determined. The maximum size of aggregate
for 2/3 scale model specimens was 25 mm. Cylinder tests
were performed. Each concrete cylinder was 200 mm in
height and 100 mm in diameter. Cylinder test results are
given in Table 2.
Longitudinal and transverse reinforcement in the column
specimens (2/3 scale) were D13 (13 mm diameter) and D6
(6 mm diameter), respectively. The results of material tests
are given in Table 3.
3.4. Loading and measurements
All eight-column specimens were laterally loaded at the
level of 1000 mm above the base (mid-height of a column)
(see Fig. 4). It was assumed that the inflection point of a
column is located at mid-height of the column.
5. S.W. Han, N.Y. Jee / Engineering Structures 27 (2005) 951–962 955
Fig. 4. Test setting.
Table 1
Characteristics of the column specimens
Location Specimen name Loading plan Lap splice
OMRCF (IMRCF)
Interior
Lower part OIL (IIL)
Constant
column axial load
Upper part OIN (IIN)
(P = 0.28)
×
Exterior
Lower part OEL (IEL)
Varying
column axial load
Upper part OEN (IEN)
(P = 1.83V + 17.1)
×
O I L
(1): OMRCF (O), IMRCF (I) : having lap splices
(1) (2) (3)
(2): Interior (I), Exterior (E) ×: not having lap splices
(3): with lap splice (L), without lap splice (N)
Quasi-static reversed cyclic loading (displacement con-
trolled) was applied. Two cycles were applied for each load-
ing amplitude. The loading history is shown in Fig. 5. Since
fluctuation of axial loads in the exterior columns was more
significant than in the interior columns, varying axial load-
ing was applied to the exterior column specimens, whereas a
constant axial load was applied to the interior column spec-
imens. Larger axial loads were applied to interior columns
due to a larger tributary area.
Axial loads were calculated by frame analysis using
SAP 2000 commercial software [5] without considering load
factors. Since specimens were scaled by 2/3, calculated
6. 956 S.W. Han, N.Y. Jee / Engineering Structures 27 (2005) 951–962
Fig. 5. Loading history.
Table 2
Concrete properties of the specimens
Design strength 28 day strength Strain at ultimate Young’s modulus
(MPa) (MPa) strength, εco (MPa)
23.5 24.6 0.003 23,438
Table 3
Reinforcing steel properties
Bar Yielding strength Yielding strain Ultimate strength Young’s modulus
(MPa) (×10−6) (MPa) (MPa)
D6 374 2206 598 176,520
D13 397 2035 594 194,956
force for original frame members should be scaled by 4/9
for the scaled model. Interior column specimens (OIL, OIN,
IIL, IIN) were tested with a constant axial load of 333.4 kN
(0.28 Ag fc; Ag is the gross sectional area of a column). For
exterior column specimens, varying axial loads (P (axial
force) = 1.83V (lateral force) + Pg) were applied. Pg is
gravity axial load, which is 167.6 kN, and V is lateral
shear force acting on the column. This relationship was
also obtained using SAP 2000 under first mode lateral force
profile. The range of varying axial loads for exterior column
specimens is 0.07 ∼ 0.20Ag fc.
As shown in Fig. 4, one actuator was installed to control
lateral forces and two actuators were used to control
axial forces. Three pairs of linear transducers were placed
at the column faces to capture column curvatures (see
Fig. 4(a)). However, curvature results were not included in
this paper. One LVDT was also placed to measure a lateral
displacement of the stub of column specimens. Since it
was observed that slip between the stub and strong floor is
negligible during the test, recorded displacement of column
specimens was not modified. This was due to tightened bolts
passing through stubs of specimens. Curvature of stubs was
not measured since it was assumed that tightened bolts made
a rigid base condition. Four linear transducers were installed
to measure the lateral displacements of specimens.
4. Test results and observation
4.1. Observations
Within a drift ratio of ±1%, the first flexural crack was
observed in all specimens. The lateral force causing the first
crack in all specimens was about 25 kN. At a drift ratio of
±3%, the concrete cover started spalling at the column ends.
It is noted that drift ratio was defined as a measured lateral
displacement divided by the height of specimens.
In the exterior column specimens having lap splices
(OEL, IEL), spalling and cracks (vertical and horizontal)
were more prominent when applied lateral loading was in
the positive direction (the direction in which axial load
increases). As mentioned earlier, varying axial loads (P =
1.83V + 167.6 (kN)) were applied to exterior column
specimens. Moreover, many vertical cracks in the region of
lap splices were observed. Flexural cracks were relatively
uniformly distributed in the plastic hinging region of the
specimens.
In the final stage of the test, all column specimens failed
due to buckling of the longitudinal bars and crushing of the
concrete.
4.2. Hysteretic performance
Hysteretic curves for the OMRCF and IMRCF columns
are presented in Figs. 6 and 7, respectively. Fig. 6(a), (b) and
(c), (d) shows the hysteretic curves for the interior specimens
OIL and OIN, and for the exterior column specimens OEL
and OEN of the OMRCF. Fig. 7(a), (b) and (c), (d) show
the curves for the interior specimens IIL and IIN, and for
the exterior column specimens IEL and IEN of the IMRCF.
All column specimens behaved almost elastically until a drift
ratio of ±0.3%.
According to Fig. 6(a) and (b), strength of specimens
OIN and OIL was similar irrespective of the existence
of lap splices. However, specimen OIN exhibited greater
deformation capacity than the OIL specimen having lap
splices. In the IMRCF interior column specimens, IIN and
8. 958 S.W. Han, N.Y. Jee / Engineering Structures 27 (2005) 951–962
IIL, (Fig. 7(a) and (b)), no discernible difference could be
found in either strength or deformation capacity.
The strength of all the OMRCF and IMRCF interior
column specimens (OIN, OIL, IIN, IIL) was similar,
whereas OMRCF interior columns had inferior deformation
capacities to the IMRCF interior columns. Moreover,
pinching was detected more prominently in OMRCF
specimens. Strength drops in the second cycle were,
however, similar between the OMRCF interior column
specimens and their corresponding IMRCF specimens.
In interior column specimens, IMRCF has a more stable
and fuller hysteretic curve than OMRCF. In particular, the
improvement was more prominent when columns had lap
splices (compare Figs. 6(a) and 7(a)). The better hysteretic
behavior in interior columns of IMRCF was attributed to
narrower spacing of transverse reinforcement in the plastic
hinging region of the column.
Fig. 8(a) shows the envelope curves extracted from
the hysteretic curves of the interior column specimens.
According to this figure, the IMRCF specimens had fuller
envelope curves than the OMRCF specimens. Thus, it
is expected that interior column specimens of IMRCF
exhibited better seismic behavior than those of OMRCF.
Since larger axial force was applied to the interior specimens
due to a larger tributary area of gravity loads, narrower
spacing of transverse reinforcement in the plastic hinge
region improved the seismic behavior of the columns
significantly.
Figs. 6(c) and (d), and 7(c) and (d) show hysteretic
behaviors of the exterior column specimens of the OMRCF
(OEL, OEN) and IMRCF (IEL, IEN), respectively. In these
figures, the positive loading direction was the direction in
which the axial load increases.
The hysteretic behaviors of the exterior OMRCF
and IMRCF column specimens were relatively similar
between the OMRCF specimens and corresponding IMRCF
specimens (OEN versus IEN, and OEL versus IEL).
However, the strength drop of specimen OEL in the
second cycle was greater than that of specimen IEL. The
specimens having lap splices showed inferior deformation
capacities compared to the specimens without lap splices
(OEL versus OEN, and IEL versus IEN). Unlike interior
columns, hysteretic behavior was not significantly improved
by narrower spacing of lateral reinforcement (OEL versus
IEL, and OEN versus IEN). Fig. 8(b) shows the envelope
curves. From this figure, the specimens having lap splices
also had narrower envelope curve. Also, this figure shows
that the envelope curves of the exterior column specimens
of OMRCF and IMRCF are quite similar (OEN versus
IEN, and OEL versus IEL). However, more strength drop in
specimen OEL was observed than that in IEL in the negative
loading direction. In exterior column specimens, lateral
reinforcement spacing does not affect seismic behavior as
much as in the interior column specimens. However, it was
observed that seismic behavior in exterior column specimens
became poor when they had lap splices.
4.3. Maximum strength
Table 4 shows the ratio of actual maximum strength Mmax
obtained from experimental tests to the calculated strength
(MACI). Actual maximum strength Mmax is calculated by
maximum shear force times the height of the column
specimen (Mmax = Vmax × 1m(h)). Fig. 9 shows P–M
interaction curves of column specimens. This figure also
includes the actual moment strength (Mmax) of column
specimens. All nominal strength (MACI) in this study was
calculated using material strength obtained from material
tests. According to Fig. 9 and Table 4(7), all OMRCF
and IMRCF column specimens have strength larger than
calculated nominal strength.
In exterior column specimens, moment capacities (Mmax)
in the positive loading direction were greater than those in
the negative loading direction. Since axial loads in the test
are not large, strength of column specimens is below the
balanced failure point in P–M interaction curve. Thus, in
exterior column specimens, moment strength increases as
axial force is larger (positive lateral loading direction).
In the P–M interaction curve (Fig. 9), calculated moment
strength (MACI) of exterior column specimens in the positive
loading direction is larger than that in the negative loading
direction as well. In those specimens with relatively low
axial loads, the ratio of maximum strength (Mmax) to
calculated strength (MACI) was almost the same as that of
the interior column specimens.
It is worthwhile to note that all column specimens
were designed according to the minimum design and detail
requirements in ACI 318-02. Since all specimens in this
study were governed by flexure rather than shear (see
Table 4(10)), different results can be obtained for columns
governed by shear.
4.4. Deformation capacity
In this study the maximum drift ratio (θmax = ∆max/h)
was used to determine the drift capacities, where ∆max is
the maximum drift and h is the height of column specimens.
The maximum drift was obtained when the lateral strength
of the specimen was reduced by 20% of maximum strength.
Table 4 and Fig. 10 show the maximum drift ratios of the
specimens.
Table 4 shows that the drift capacities (θmax) of
OMRCF and IMRCF exceeded 3.0% and 4.5%, respectively.
Specimen IEN had the largest drift capacity (5.98%) in the
negative loading direction, whereas specimen OEL had the
least drift capacity (3.00%) in the negative loading direction.
Among the interior column specimens that resisted a
larger constant axial load throughout the test, the IMRCF
columns had greater drift capacity. This is due to the
narrower spacing of transverse reinforcement in the plastic
hinging region. It should be noted that the drift capacity of
the specimen IIL having lap splices was even greater than
that of OIN without lap splices. Moreover, the difference
10. 960 S.W. Han, N.Y. Jee / Engineering Structures 27 (2005) 951–962
Table 4
Test result of specimens
Specimen Pu
Ag fc
Vmax ∆max µ∆ θu MACI
Mmax
MACI
VACI VP
VP
VACI
(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
OMRCF
OIL
+
0.28
49.1 34.9 4.26 3.49 36.8 1.33 74.3 37.9 0.51
− 49.5 35.3 4.46 3.53 36.8 1.33 74.3 37.9 0.51
OIN
+ 46.9 44.5 4.41 4.45 36.8 1.28 74.3 37.9 0.51
− 48.8 44.5 4.39 4.35 36.8 1.33 74.3 37.9 0.51
OEL
+ 0.2 36.9 42.6 4.34 4.26 33.3 1.25 69.6 32.6 0.47
− 0.07 37.2 28.5 3.02 3.01 25.5 1.25 63.4 26.0 0.41
OEN
+ 0.2 48.5 45.3 4.59 4.53 33.4 1.45 69.6 32.6 0.47
− 0.07 28.3 58.1 6.05 5.81 25.5 1.11 63.4 26.0 0.41
IMRCF
IIL
+
0.28
48.7 53.8 6.02 5.38 38.8 1.28 9.83 3.88 0.39
− 45.9 53.5 5.57 5.35 38.8 1.21 9.83 3.88 0.39
IIN
+ 46.0 49.5 6.10 4.95 38.8 1.34 9.83 3.88 0.39
− 47.6 50.5 6.01 5.05 38.8 1.22 9.83 3.88 0.39
IEL
+ 0.2 45.5 45.2 5.82 4.52 33.0 1.55 9.36 3.30 0.35
− 0.07 33.2 47.0 5.90 4.70 26.2 1.10 8.72 2.62 0.30
IEN
+ 0.2 49.4 48.0 5.9 4.80 33.0 1.37 9.36 3.30 0.35
− 0.07 34.2 59.8 6.27 5.98 26.2 1.31 8.72 2.62 0.30
(2) = maximum shear force (kN), (3) = maximum displacement (mm), (4) = displacement ductility (= ∆max/∆y), where ∆y is yield displacemet, (5)
= maximum drift angle (%), (6) = moment capacity calculated using ACI 318-02 procedures (kN m), (7) = ratio of the maximum moment capacity,
Mmax(Vmax × h) to MACI (h: height of specimen (m)), (8) = nominal shear strength according to ACI 318-02 (kN), (9) = shear force corresponding to
MACI or 2MACI/l, where l = the column clear height (kN), (10) = ratio of VP to VACI.
Fig. 10. Drift capacity (%).
between drift capacities of specimens OIL and IIL was
greater than that of specimens OIN and IIN. Thus, spacing of
transverse reinforcement in the plastic hinging region affects
the drift capacity of the interior columns significantly. This
was more prominent when the specimen had lap splices.
It is noted that larger gravity load (0.28Ag fc) was applied
to interior column specimens. Also, in interior column
specimens of OMRCF, the existence of lap splices in the
column specimen prominently influences the drift capacity.
In contrast, the existence of lap splices did not affect drift
capacities of IMRCF column specimens.
In the exterior column specimens that resisted varying
axial loads during the test, the existence of lap splices also
affected drift capacities. Specimens IEL and OEL having lap
splices had smaller drift capacities. The difference between
drift capacities of the exterior columns of the OMRCF and
IMRCF was small compared to that between the interior
columns of the OMRCF and IMRCF. Thus, in the exterior
columns, the spacing of transverse reinforcement was not
influential. It is noted that this study considered a three-story
building, in which axial forces in columns are small
compared with those in high-rise buildings. When axial
forces in columns become large, the spacing of transverse
reinforcement may be influential even on the behavior of
exterior columns.
This study also calculated the displacement ductility
of each specimen, which is shown in Table 4. Yield drift
(∆y or θy) was obtained from a bilinear representation of
force (V) versus drift ratio (∆ or θ). Secant stiffness was
used to connect the origin to the point of 0.75Vmax. The
11. S.W. Han, N.Y. Jee / Engineering Structures 27 (2005) 951–962 961
Fig. 11. Energy dissipation.
maximum drift (∆max, θmax) was approximated as the drift
ratio corresponding to the strength deteriorated by 20% of
Vmax (0.8 times Vmax). As shown in Table 4, all specimens
have a ductility capacity exceeding 3.0. The IMRCF exterior
column specimen without lap splices (IEN) has the largest
ductility capacity (6.27) in the negative loading direction
which has the least axial loading condition ( Pu
Ag fc
= 0.07).
In contrast, the OMRCF exterior column specimen with lap
splices (OEL) has the smallest ductility capacity (3.02) in
the negative loading direction. Specimen IEL has a ductility
capacity of 5.90 in the negative loading direction. Thus the
effect of lateral reinforcement spacing on displacement and
ductility capacity becomes important to all interior column
specimens, and exterior specimens having lap splices.
4.5. Energy dissipation
Fig. 11 shows the amount of energy dissipated in each
loading cycle. According to this figure, all specimens
dissipated a similar amount of energy until cycle 6 (1%
drift ratio). Beyond that cycle, every specimen dissipated a
different amount of energy.
Specimens IIN, IIL, and IEN dissipated similar amounts
of energy until failure. They have larger energy dissipation
capacity than other specimens. Specimens OEN, OIN, and
IEL dissipated similar amounts of energy until cycle 13
(5%). Since specimen OIL failed in an earlier loading stage
(cycle 11), the amount of energy of specimen OIL is smaller
than specimens OEN, OIN and IEL. Specimen OEL has
the least amount of energy dissipation capacity among the
specimens.
5. Conclusions
This study investigates the seismic behaviors of columns
in OMRCF and IMRCF. For this purpose eight specimens
were modeled and tested. The specimens were designed
and reinforced in compliance with the ACI 318-02 for
OMRCF and IMRCF. It should be noted that all specimens
were governed by flexure rather than shear. Thus, different
results may be obtained for columns governed by shear. The
conclusions of this study are as follows:
(1) The strength of all OMRCF and IMRCF column
specimens exceeded the strength calculated with the
code formula (ACI 318-02). Thus, the OMRCF and
IMRCF columns had satisfactory strength irrespective
of the existence of the lap splices and the transverse
reinforcement spacing in the plastic hinging region.
(2) The IMRCF interior column specimens had superior
drift capacities compared to the OMRCF column
specimens. Existence of lap splices influenced drift
capacities of the OMRCF columns. However, the effect
of lap splice in the IMRCF columns was not as large as
that in the OMRCF specimens. This is attributed to the
narrower transverse reinforcement spacing in the plastic
hinging region of the IMRCF.
(3) In the exterior column specimens, no discernible
differences in the hysteretic behaviors were found
between OMRCF and IMRCF column specimens. The
specimens having lap splices showed inferior hysteretic
behavior to the corresponding specimens without lap
splices. Since smaller axial force was applied to the
exterior column specimens, the effect of transverse
reinforcement spacing seems to be less influential than
interior columns. However, it is noted that the effect of
transverse reinforcement spacing becomes important to
exterior specimen having lap splices, particularly in the
negative loading direction.
(4) IMRCF interior column specimens had more stable and
fuller hysteretic curves than OMRCF interior column
specimens. In OMRCF interior column specimens,
existence of lap splices changed the shape of hysteretic
curve significantly. However, in IMRCF interior column
specimens, the change due to lap splices was not
noticeable.
12. 962 S.W. Han, N.Y. Jee / Engineering Structures 27 (2005) 951–962
(5) In exterior column specimens of OMRCF and IMRCF,
hysteretic curves became narrower when they had lap
splices. However, the hysteretic curves of OMRCF
exterior columns are similar to those of corresponding
IMRCF exterior columns.
(6) According to the test results, the OMRCF and IMRCF
column specimens had drift capacities greater than
3.0% and 4.5%, respectively. Ductility capacity of those
specimens exceeded 3.01 and 4.53, respectively.
Acknowledgement
The support of Hanyang University is greatly acknowl-
edged.
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Sang Whan Han. Associate Professor, Dept. of Architectural Eng.,
Hanyang Univ., Seoul 133-791, Korea. Ph.D. (1994), University of Illinois
at Urbana-Champaign, Professional Engineer (US, Korea).
N.Y. Jee. Professor, Dept. of Architectural Eng., Hanyang Univ., Seoul 133-
791, Korea. Ph.D. (1992), Tokyo National University.