This document discusses seismic strengthening of multi-storey buildings with soft storeys. It defines local and global damage indices, with interstorey drift ratio (IDR) identified as an easy way to find the damage index. Analytical approaches like pushover analysis and time history analysis are evaluated. Experimental problems analyze buildings with varying soft storey heights subjected to earthquakes, comparing damage indices among storeys. The conclusion is that damage index increases with more storeys and higher soft storeys, and can exceed 1 based on IDR. Pushover analysis provides capacity while time history gives maximum IDR under seismic loads.
Sesmic strengthining of multi storey building with soft storey week 3SVMohtesham
The document describes a study on a gap interface brace (GIB) system used to retrofit existing soft-story buildings. The GIB system consists of a pinned brace and gap element added to the first story columns. It reduces axial loads on the columns in a controlled way and increases lateral deformation capacity while not increasing stiffness or resistance. The GIB properties depend on its initial angle, the gap distance, and the brace material. Nonlinear analyses found the GIB variant had significantly increased drift capacity compared to unretrofitted or fully infilled variants, without major changes in stiffness or resistance.
Sesmic strengthining of multi storey building with soft storey week 2SVMohtesham
This document discusses techniques for seismically strengthening buildings with soft stories. It focuses on using friction dampers as energy dissipation devices. The document provides background on soft story buildings and issues. It then describes the modeling and analysis of a multi-story frame building strengthened with slotted bolted friction dampers on chevron braces. The analysis considers different ground motions and evaluates performance indices like inter-story drift, acceleration, and strain energy. The results show that using friction dampers can enhance stiffness, control drift, reduce acceleration, and lower strain energy compared to an unbraced or braced soft story building.
This document discusses reinforced concrete shear walls. It provides definitions, design considerations, placement guidelines, and seismic behavior analysis. Shear walls are designed to resist lateral forces from earthquakes by providing strength, stiffness, and minimizing structural sway. Case studies demonstrate that high axial load ratios decrease ductility, and shear walls with staggered openings perform better seismically than those with regular openings.
Seismic soil retaining walls - ضغط تربة الزلازل على جدران الأقبية -الساندة ...Dr.Youssef Hammida
Seismic Earth Pressures on Retaining Structures and Basement Walls
In the present state of knowledge, the recommended method of obtaining seismic soil forces is that using equivalent-static analysis. Only for exceptional structures would dynamic analyses using finite elements seem warranted.
In the equivalent-static method, a horizontal earthquake force equal to the weight of the soil wedge multiplied by a seismic coefficient is assumed to act at the centre of gravity of the soil mass. This earthquake force is additional to the static forces on the wall.
In general, the total soil pressure on a wall during an earthquake equals the sum of three possible components:
(1) static pressure due to gravity loads;
(2) dynamic pressure due to the earthquake;
(3) pressure due to the wall being displaced into the backfill by an external force, e.g. by the horizontal sway of a bridge deck at a monolithic abutment
1 seismic behaviors of columns in ordinary and intermediate moment resisting ...sharif tanvir
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.
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.
Sesmic strengthining of multi storey building with soft storey week 3SVMohtesham
The document describes a study on a gap interface brace (GIB) system used to retrofit existing soft-story buildings. The GIB system consists of a pinned brace and gap element added to the first story columns. It reduces axial loads on the columns in a controlled way and increases lateral deformation capacity while not increasing stiffness or resistance. The GIB properties depend on its initial angle, the gap distance, and the brace material. Nonlinear analyses found the GIB variant had significantly increased drift capacity compared to unretrofitted or fully infilled variants, without major changes in stiffness or resistance.
Sesmic strengthining of multi storey building with soft storey week 2SVMohtesham
This document discusses techniques for seismically strengthening buildings with soft stories. It focuses on using friction dampers as energy dissipation devices. The document provides background on soft story buildings and issues. It then describes the modeling and analysis of a multi-story frame building strengthened with slotted bolted friction dampers on chevron braces. The analysis considers different ground motions and evaluates performance indices like inter-story drift, acceleration, and strain energy. The results show that using friction dampers can enhance stiffness, control drift, reduce acceleration, and lower strain energy compared to an unbraced or braced soft story building.
This document discusses reinforced concrete shear walls. It provides definitions, design considerations, placement guidelines, and seismic behavior analysis. Shear walls are designed to resist lateral forces from earthquakes by providing strength, stiffness, and minimizing structural sway. Case studies demonstrate that high axial load ratios decrease ductility, and shear walls with staggered openings perform better seismically than those with regular openings.
Seismic soil retaining walls - ضغط تربة الزلازل على جدران الأقبية -الساندة ...Dr.Youssef Hammida
Seismic Earth Pressures on Retaining Structures and Basement Walls
In the present state of knowledge, the recommended method of obtaining seismic soil forces is that using equivalent-static analysis. Only for exceptional structures would dynamic analyses using finite elements seem warranted.
In the equivalent-static method, a horizontal earthquake force equal to the weight of the soil wedge multiplied by a seismic coefficient is assumed to act at the centre of gravity of the soil mass. This earthquake force is additional to the static forces on the wall.
In general, the total soil pressure on a wall during an earthquake equals the sum of three possible components:
(1) static pressure due to gravity loads;
(2) dynamic pressure due to the earthquake;
(3) pressure due to the wall being displaced into the backfill by an external force, e.g. by the horizontal sway of a bridge deck at a monolithic abutment
1 seismic behaviors of columns in ordinary and intermediate moment resisting ...sharif tanvir
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.
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.
The document summarizes seismic damages from the 2001 Bhuj earthquake in India. It killed over 13,000 people and destroyed nearly 400,000 homes. Common failures of reinforced concrete structures included soft stories, floating columns, strong column weak beam configurations, mass and plan irregularities, poor construction materials and techniques, and pounding between adjacent buildings. Soft story failures occurred particularly in buildings with large ground floor openings. Floating columns and strong column weak beam designs led to column failures. Masonry structures commonly experienced out-of-plane wall failures, in-plane shear failures, connection failures between walls and floors, diaphragm failures, and failures around wall openings.
Design of Low Rise Reinforced Concrete Buildings Toe Myint Naing
This document summarizes key aspects of lateral force resisting systems for low-rise reinforced concrete buildings. It discusses response to wind and earthquake forces, including how buildings experience horizontal shaking during earthquakes. It describes different lateral force resisting systems such as bearing wall, frame, moment frame, shear wall-frame interactive, and dual systems. It also covers determining seismic design category, distribution of lateral forces to elements through diaphragms, and ensuring a continuous load path.
Special moment frames are reinforced concrete frames designed to resist earthquakes through flexural, axial, and shearing actions. They have additional proportioning and detailing requirements compared to intermediate or ordinary moment frames to improve seismic resistance. This includes the strong column weak beam design where the sum of the flexural strengths of the columns at a joint must exceed 120% of the sum of the flexural strengths of the beams to ensure plastic hinges form in the beams before the columns. Proper hinge reinforcement is also required to allow hinges to undergo large rotations without losing strength.
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
The design of Elements of Lifts and Escalator from Civil Engineering point of view. Mainly Raft foundation, Machine Foundation, and Shear walls are discussed.
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.
Peer review presentation for the strut and tie method as an analysis and design approach for the mat on piles foundations of the primary separation cell (vessel).
Seismic Analysis of regular & Irregular RCC frame structuresDaanish Zama
This document discusses seismic analysis of regular and irregular reinforced concrete framed buildings. It analyzes 4 building models - a regular 4-story building, a stiffness irregular building with a soft ground story, and two vertically irregular buildings with setbacks on the 3rd floor and 2nd/3rd floors. Static analysis was performed to compare bending moments, shear forces, story drifts, and joint displacements. Results showed irregular buildings experienced higher seismic demands. The regular building performed best, with the single setback building also performing well. Irregular configurations increase seismic effects and should be minimized in design.
Seismic performance of adjacent building using fluid viscous dampersAyaz Malik
This presentation highlights the effect of Fluid Viscous Dampers (FVDs) on the seismic performance of adjacent buildings connected through a ped-way. A part of this project also deals with the Qualitative Damage Analysis of the structure during an earthquake, with and without FVDs.
Seismic performance of structure with fixed base, base isolated structure and...eSAT Journals
Abstract Earthquakes can create serious damage to structures. The structures already built are vulnerable to future earthquakes. The damage to structures causes deaths, injuries, economic loss, and loss of functions. Damage to the structure causes due to ground acceleration. This can be minimizing by increasing strength of the structure. Sometimes it is not possible to increase the strength of the structure indefinitely. So it should be tried to increase the capacity of structure using seismic improvement techniques. In this study, there are three different types of G+10 structures with fixed base, structure with viscous damper and structure with high damping rubber bearing are considered. These structures are modeled using finite element software SAP2000v16. These structures have same plan area and are assumed to be situated in seismic zone IV and having medium soil condition. The analysis of these structures is done by performance based pushover analysis method and response spectrum method. The pushover analysis method is used to find out the performance point and capacity of structure. High damping rubber bearing isolators (HDRB) and viscous damper (VD) are use for seismic improvement of RC structure. The procedure of analysis adopted for fixed base structure is same repeated for structure with viscous damper (VD) and base isolated (HDRB) structure. So it will help in comparative parametric study. The results of analysis are compared in terms of storey displacements, modal time period, storey acceleration, performance point, storey drift. The comparative study shows that storey displacement, storey acceleration, storey drift is reduced substantially for structure with high damping rubber bearing (base isolated structure). Key Words: Base isolated structure, Pushover analysis method, Response spectrum method, Viscous damper, High damping rubber bearing, SAP2000v16 etc.
This document provides guidelines for seismic retrofitting of existing unreinforced masonry bearing wall buildings. It outlines two procedures for analysis: the General Procedure based on strength design and allowing 75% of code seismic loads, and the Special Procedure using limit state design based on dynamic testing of flexible diaphragms and URM wall responses. Key aspects covered include material strength values, masonry testing requirements, analysis methods, use of cross-walls to reduce diaphragm deflections, and displacement control of wood diaphragms.
1) The document discusses calculating seismic loads on buildings according to Indian Standard IS 1893:2002. It provides steps to calculate the design horizontal seismic coefficient, seismic weight of the building, and design seismic lateral force.
2) Examples are given to demonstrate calculating seismic shear force for single storey buildings located in different seismic zones and for a four storey building in Bhuj accounting for soil conditions and distributing the design force to each floor.
3) Key parameters that influence seismic load calculation include zone factor, importance factor, response reduction factor, and spectral acceleration depending on soil type and location.
This document summarizes the seismic design of a building structure. It includes a plan and elevation view of the building. It then discusses the seismic design category and load combinations considered. Story shear and lateral load distributions are calculated for the moment frames and braced frames. Frame elements are modeled and their stiffness, deflections, and drift ratios are analyzed. Vertical and horizontal irregularities are checked. Steel members are selected and designed for the special moment frames, eccentric braced frames, links, beams, braces, and connections. Sample calculations are also presented.
Performance of shear wall building during seismic excitationsIAEME Publication
This document summarizes a study on the performance of shear wall buildings during seismic excitations. The study analyzed a 25-story building located in seismic zone 3, comparing the performance of two models: one with an L-shaped shear wall and one with a core-type shear wall. Time history analyses found that the building with the L-shaped wall experienced greater maximum displacement than the building with the core wall. Thus, providing shear walls as a core type can reduce story drift. Additionally, as the height of the building increases, shear walls absorb more lateral force than frames. Previous studies have also shown that shear walls with flanges perform better than walls without due to interaction between the flange and web.
Seismic Analysis of Multistoreyed RC Building Due to Mass Irregularity by Tim...IRJET Journal
This document presents a study on the seismic analysis of a 12-story reinforced concrete building with and without mass irregularity using time history analysis. The building is modeled and analyzed using ETABS software considering the Bhuj earthquake record. Lead rubber bearings are designed and used as base isolators. Parameters like base shear, time period, and story displacement are compared for regular and irregular buildings with fixed base and base isolated conditions. The results show that base isolation is effective in reducing base shear by up to 49% and increasing time period, while mass irregularity increases base shear and time period compared to the regular fixed base building.
This document provides an overview of different seismic analysis methods for reinforced concrete buildings according to Indian code IS 1893-2002, including linear static, nonlinear static, linear dynamic, and nonlinear dynamic analysis. It describes the basic procedures for each analysis type and provides examples of how to calculate design seismic base shear, distribute seismic forces vertically and horizontally, and determine drift and overturning effects. Case studies are presented comparing the results of static and dynamic analysis for regular and irregular multi-storey buildings modeled in SAP2000.
This lecture discusses analysis of indeterminate beams. It begins with an introduction to structures, including what structures are, what they do, and how their performance is assessed. Structures must carry and transfer loads safely while maintaining equilibrium. The degree of indeterminacy, or whether a structure has enough equations to solve for its unknown forces, is then introduced. The document provides equations to assess the degree of indeterminacy in two-dimensional and three-dimensional truss and framed structures based on the number of members, joints, and external constraints. Various examples of determinate and indeterminate structures are shown.
The document provides notes on masonry structures from a course at the University of Illinois. It discusses lateral strength and behavior of unreinforced masonry (URM) shear walls, including design criteria, failure modes, and examples. Key points include allowable stresses for flexure, shear, and axial loading; effects of perforations on stiffness and force distribution; and checking stresses in piers between openings.
This document provides information on designing and detailing steel reinforcement in combined footings. It begins by defining a combined footing as a single spread footing that supports two or more columns in a straight line. It then discusses types of combined footings and provides steps for their design including proportioning the footing size, calculating shear forces and bending moments, and designing the longitudinal and transverse reinforcement. The document concludes by providing an example problem demonstrating how to design a combined footing with a central beam.
This document discusses ring shaped steel plate shear walls (RS-SPSWs) as an alternative to conventional steel plate shear walls (SPSWs). It presents the results of parametric studies and experimental testing that demonstrate the advantages of RS-SPSWs. The parametric studies found that RS-SPSWs mitigate buckling, provide higher strength, stiffness and energy dissipation compared to SPSWs. Experimental testing confirmed RS-SPSWs are capable of developing plastic hinging and exhibiting full hysteretic behavior with less pinching. The document concludes RS-SPSWs have improved seismic performance and design advantages over conventional SPSWs.
This document discusses different methods for seismic analysis of reinforced concrete buildings, including linear static, nonlinear static, linear dynamic, and nonlinear dynamic analysis. It provides details on each analysis method, including the steps involved. It also presents a case study that compares the results of static and dynamic analysis methods on regular and irregular multi-storey buildings, finding that dynamic analysis more accurately predicts structural response.
This document discusses different methods for seismic analysis of reinforced concrete buildings, including linear static, nonlinear static, linear dynamic, and nonlinear dynamic analysis. It provides details on each analysis method and outlines the general procedures. It also presents a case study that compares the results of equivalent static, response spectrum, and time history analysis of regular and irregular multi-storey buildings to determine storey displacements and seismic behavior.
The document summarizes seismic damages from the 2001 Bhuj earthquake in India. It killed over 13,000 people and destroyed nearly 400,000 homes. Common failures of reinforced concrete structures included soft stories, floating columns, strong column weak beam configurations, mass and plan irregularities, poor construction materials and techniques, and pounding between adjacent buildings. Soft story failures occurred particularly in buildings with large ground floor openings. Floating columns and strong column weak beam designs led to column failures. Masonry structures commonly experienced out-of-plane wall failures, in-plane shear failures, connection failures between walls and floors, diaphragm failures, and failures around wall openings.
Design of Low Rise Reinforced Concrete Buildings Toe Myint Naing
This document summarizes key aspects of lateral force resisting systems for low-rise reinforced concrete buildings. It discusses response to wind and earthquake forces, including how buildings experience horizontal shaking during earthquakes. It describes different lateral force resisting systems such as bearing wall, frame, moment frame, shear wall-frame interactive, and dual systems. It also covers determining seismic design category, distribution of lateral forces to elements through diaphragms, and ensuring a continuous load path.
Special moment frames are reinforced concrete frames designed to resist earthquakes through flexural, axial, and shearing actions. They have additional proportioning and detailing requirements compared to intermediate or ordinary moment frames to improve seismic resistance. This includes the strong column weak beam design where the sum of the flexural strengths of the columns at a joint must exceed 120% of the sum of the flexural strengths of the beams to ensure plastic hinges form in the beams before the columns. Proper hinge reinforcement is also required to allow hinges to undergo large rotations without losing strength.
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
The design of Elements of Lifts and Escalator from Civil Engineering point of view. Mainly Raft foundation, Machine Foundation, and Shear walls are discussed.
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.
Peer review presentation for the strut and tie method as an analysis and design approach for the mat on piles foundations of the primary separation cell (vessel).
Seismic Analysis of regular & Irregular RCC frame structuresDaanish Zama
This document discusses seismic analysis of regular and irregular reinforced concrete framed buildings. It analyzes 4 building models - a regular 4-story building, a stiffness irregular building with a soft ground story, and two vertically irregular buildings with setbacks on the 3rd floor and 2nd/3rd floors. Static analysis was performed to compare bending moments, shear forces, story drifts, and joint displacements. Results showed irregular buildings experienced higher seismic demands. The regular building performed best, with the single setback building also performing well. Irregular configurations increase seismic effects and should be minimized in design.
Seismic performance of adjacent building using fluid viscous dampersAyaz Malik
This presentation highlights the effect of Fluid Viscous Dampers (FVDs) on the seismic performance of adjacent buildings connected through a ped-way. A part of this project also deals with the Qualitative Damage Analysis of the structure during an earthquake, with and without FVDs.
Seismic performance of structure with fixed base, base isolated structure and...eSAT Journals
Abstract Earthquakes can create serious damage to structures. The structures already built are vulnerable to future earthquakes. The damage to structures causes deaths, injuries, economic loss, and loss of functions. Damage to the structure causes due to ground acceleration. This can be minimizing by increasing strength of the structure. Sometimes it is not possible to increase the strength of the structure indefinitely. So it should be tried to increase the capacity of structure using seismic improvement techniques. In this study, there are three different types of G+10 structures with fixed base, structure with viscous damper and structure with high damping rubber bearing are considered. These structures are modeled using finite element software SAP2000v16. These structures have same plan area and are assumed to be situated in seismic zone IV and having medium soil condition. The analysis of these structures is done by performance based pushover analysis method and response spectrum method. The pushover analysis method is used to find out the performance point and capacity of structure. High damping rubber bearing isolators (HDRB) and viscous damper (VD) are use for seismic improvement of RC structure. The procedure of analysis adopted for fixed base structure is same repeated for structure with viscous damper (VD) and base isolated (HDRB) structure. So it will help in comparative parametric study. The results of analysis are compared in terms of storey displacements, modal time period, storey acceleration, performance point, storey drift. The comparative study shows that storey displacement, storey acceleration, storey drift is reduced substantially for structure with high damping rubber bearing (base isolated structure). Key Words: Base isolated structure, Pushover analysis method, Response spectrum method, Viscous damper, High damping rubber bearing, SAP2000v16 etc.
This document provides guidelines for seismic retrofitting of existing unreinforced masonry bearing wall buildings. It outlines two procedures for analysis: the General Procedure based on strength design and allowing 75% of code seismic loads, and the Special Procedure using limit state design based on dynamic testing of flexible diaphragms and URM wall responses. Key aspects covered include material strength values, masonry testing requirements, analysis methods, use of cross-walls to reduce diaphragm deflections, and displacement control of wood diaphragms.
1) The document discusses calculating seismic loads on buildings according to Indian Standard IS 1893:2002. It provides steps to calculate the design horizontal seismic coefficient, seismic weight of the building, and design seismic lateral force.
2) Examples are given to demonstrate calculating seismic shear force for single storey buildings located in different seismic zones and for a four storey building in Bhuj accounting for soil conditions and distributing the design force to each floor.
3) Key parameters that influence seismic load calculation include zone factor, importance factor, response reduction factor, and spectral acceleration depending on soil type and location.
This document summarizes the seismic design of a building structure. It includes a plan and elevation view of the building. It then discusses the seismic design category and load combinations considered. Story shear and lateral load distributions are calculated for the moment frames and braced frames. Frame elements are modeled and their stiffness, deflections, and drift ratios are analyzed. Vertical and horizontal irregularities are checked. Steel members are selected and designed for the special moment frames, eccentric braced frames, links, beams, braces, and connections. Sample calculations are also presented.
Performance of shear wall building during seismic excitationsIAEME Publication
This document summarizes a study on the performance of shear wall buildings during seismic excitations. The study analyzed a 25-story building located in seismic zone 3, comparing the performance of two models: one with an L-shaped shear wall and one with a core-type shear wall. Time history analyses found that the building with the L-shaped wall experienced greater maximum displacement than the building with the core wall. Thus, providing shear walls as a core type can reduce story drift. Additionally, as the height of the building increases, shear walls absorb more lateral force than frames. Previous studies have also shown that shear walls with flanges perform better than walls without due to interaction between the flange and web.
Seismic Analysis of Multistoreyed RC Building Due to Mass Irregularity by Tim...IRJET Journal
This document presents a study on the seismic analysis of a 12-story reinforced concrete building with and without mass irregularity using time history analysis. The building is modeled and analyzed using ETABS software considering the Bhuj earthquake record. Lead rubber bearings are designed and used as base isolators. Parameters like base shear, time period, and story displacement are compared for regular and irregular buildings with fixed base and base isolated conditions. The results show that base isolation is effective in reducing base shear by up to 49% and increasing time period, while mass irregularity increases base shear and time period compared to the regular fixed base building.
This document provides an overview of different seismic analysis methods for reinforced concrete buildings according to Indian code IS 1893-2002, including linear static, nonlinear static, linear dynamic, and nonlinear dynamic analysis. It describes the basic procedures for each analysis type and provides examples of how to calculate design seismic base shear, distribute seismic forces vertically and horizontally, and determine drift and overturning effects. Case studies are presented comparing the results of static and dynamic analysis for regular and irregular multi-storey buildings modeled in SAP2000.
This lecture discusses analysis of indeterminate beams. It begins with an introduction to structures, including what structures are, what they do, and how their performance is assessed. Structures must carry and transfer loads safely while maintaining equilibrium. The degree of indeterminacy, or whether a structure has enough equations to solve for its unknown forces, is then introduced. The document provides equations to assess the degree of indeterminacy in two-dimensional and three-dimensional truss and framed structures based on the number of members, joints, and external constraints. Various examples of determinate and indeterminate structures are shown.
The document provides notes on masonry structures from a course at the University of Illinois. It discusses lateral strength and behavior of unreinforced masonry (URM) shear walls, including design criteria, failure modes, and examples. Key points include allowable stresses for flexure, shear, and axial loading; effects of perforations on stiffness and force distribution; and checking stresses in piers between openings.
This document provides information on designing and detailing steel reinforcement in combined footings. It begins by defining a combined footing as a single spread footing that supports two or more columns in a straight line. It then discusses types of combined footings and provides steps for their design including proportioning the footing size, calculating shear forces and bending moments, and designing the longitudinal and transverse reinforcement. The document concludes by providing an example problem demonstrating how to design a combined footing with a central beam.
This document discusses ring shaped steel plate shear walls (RS-SPSWs) as an alternative to conventional steel plate shear walls (SPSWs). It presents the results of parametric studies and experimental testing that demonstrate the advantages of RS-SPSWs. The parametric studies found that RS-SPSWs mitigate buckling, provide higher strength, stiffness and energy dissipation compared to SPSWs. Experimental testing confirmed RS-SPSWs are capable of developing plastic hinging and exhibiting full hysteretic behavior with less pinching. The document concludes RS-SPSWs have improved seismic performance and design advantages over conventional SPSWs.
This document discusses different methods for seismic analysis of reinforced concrete buildings, including linear static, nonlinear static, linear dynamic, and nonlinear dynamic analysis. It provides details on each analysis method, including the steps involved. It also presents a case study that compares the results of static and dynamic analysis methods on regular and irregular multi-storey buildings, finding that dynamic analysis more accurately predicts structural response.
This document discusses different methods for seismic analysis of reinforced concrete buildings, including linear static, nonlinear static, linear dynamic, and nonlinear dynamic analysis. It provides details on each analysis method and outlines the general procedures. It also presents a case study that compares the results of equivalent static, response spectrum, and time history analysis of regular and irregular multi-storey buildings to determine storey displacements and seismic behavior.
Seismic Analysis of Multi-Storey Structure Subjected To Different (1).pptxGoneJustin
This document summarizes a presentation on analyzing the seismic behavior of multi-story buildings with varying heights using ETABS software. It analyzes buildings with 5, 6, 7, and 8 stories under seismic, dead, and live loads. The objectives are to check the seismic response of buildings using ETABS, analyze forces, moments, stresses, strains, and deformations, and analyze story drift, displacement, shear, stiffness, period, and frequency on different floors. The methodology involves modeling the buildings in ETABS and subjecting them to static and dynamic analysis to determine responses like base shear, maximum displacement, tensile forces, and moments and shear forces.
This document provides an analysis and design of a G+3 residential building. It includes details of the building such as dimensions, material properties, and load calculations. An equivalent static analysis is performed to calculate the seismic lateral loads at each floor level. The results of the structural analysis including bending moment and shear force diagrams are presented. Slab, beam, column and footing designs are to be covered in the thesis work according to the scope.
1. The document discusses modeling and analyzing a 10-story building with different shear wall configurations to determine the optimal layout. 5 models were considered: without shear walls, with center/side shear walls, and with corner shear walls extending different lengths.
2. Model 3, with corner shear walls extending 3m on each side, performed best with the lowest drift, highest stiffness, and least displacement under seismic and wind loads. Proper shear wall positioning improves a building's earthquake resistance.
3. Static analysis yielded higher drifts than response spectrum analysis for all models. Shear walls significantly influence member forces and building performance during seismic events. Model 3 displayed the best structural behavior overall.
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Importance of Non Structural Elements during Earthquakemehul doshi
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Earthquake Resistance Design-Impact On Cost Of Reinforced Concrete BuilidingsIJMER
Earthquakes strike suddenly, violently and without warning at any time of the day or night.It
is highly impossible to prevent an earthquake from occuring, but the damage to the builiding can be
controlled through proper design and detailing. Hence it is mandatory to do the sesmic analysis and
design to structure against collapse. This study addresses the performance and variation of precentage
steel and concrete quantity of R.C framed structure in different seismic zones and influence on overall
cost of construction. This study mainly focuses on the comparision of percentage steel and concrete
quantities when the builiding is designed for gravity loads as per IS 456:2000 and when the builiding is
designed for earthquake forces in different seismic zones as per IS 1893:2002. A five storied R.C.C
framed structure has been analyse and designed using STAAD ProV8i. Ductile detailing has been done
in conformation with IS:13920
This document summarizes the seismic analysis of a 5-storey reinforced concrete frame building located in seismic zones II, III, and IV of India. The analysis was conducted using both manual calculations and ETABS software. Key results such as storey shear, lateral forces, and bending moments were calculated and compared for each zone and loading condition. Overall, the manual and software results showed good agreement with only minor differences.
DESIGN AND ANALYSIS OF EARTH-QUAKE RESISTANT FOR MULTI-STORIED BUILDING ON A ...Ijripublishers Ijri
his project named as “DESIGN OF EARTH-QUAKE RESISTANT MULTI-STORIED RCC BUILDING ON A SLOPING
GROUND” involves the analysis of simple 2-D frames of varying floor heights and varying no of bays using a very popular
software tool STAAD Pro. Using the analysis results various graphs were drawn between the maximum axial force,
maximum shear force, maximum bending moment, maximum tensile force and maximum compressive stress being
developed for the frames on plane ground and sloping ground. The graphs used to drawn comparison between the two
cases and the detailed study of “SHORT COLOUMN EFFECT” failure was carried up. In addition to that the detailed
study of seismology was undertaken and the feasibility of the software tool to be used was also checked. Till date many
such projects have been undertaken on this very topic but the analysis were generally done for the static loads i.e. dead
load, live load etc, but to this the earthquake analysis or seismic analysis is to be incorporated. To create a technical
knowhow, two similar categories of structures were analyzed, first on plane ground and another on a sloping ground.
Then the results were compared. At last the a structure would be analyzed and designed on sloping ground for all possible
load combinations pertaining to IS 456, IS 1893 and IS 13920 manually.
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Static and Dynamic Behavior of Reinforced Concrete Framed Building: A Compara...IOSR Journals
Reinforced concrete frame buildings are most common type of construction in urban India, which is subjected to several types of forces during their life time such as static forces and dynamic forces due to wind and earthquakes. The static loads are constant with time, while dynamic loads are time varying, causing considerable inertia effects .It depends mainly on location of building, importance of its use and size of the building. Its consideration in analysis makes the solution more complicated and time consuming and its negligence may sometimes becomes the cause of disaster during earthquake.
So it is growing interest in the process of designing civil engineering structures capable to withstand dynamic loads . The behavior of building under dynamic forces depends upon its mass and stiffness properties, whereas the static behavior is solely dependent upon the stiffness characteristics.
MODAL AND RESPONSE SPECTRUM (IS 18932002) ANALYSIS 0F R.C FRAME BUILDING (IT ...Mintu Choudhury
This document discusses modeling a reinforced concrete frame building for seismic analysis. It describes modeling the building using frame elements in SAP 2000. Key elements include:
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Dynamics analysis of structures subjected to earthquake load 53037EditorIJAERD
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Earthquake Analysis of Multi Storied Residential Building - A Case StudyIJERA Editor
Earthquake occurred in multistoried building shows that if the structures are not well designed and constructed
with and adequate strength it leads to the complete collapse of the structures. To ensure safety against seismic
forces of multi-storied building hence, there is need to study of seismic analysis to design earthquake resistance
structures. In seismic analysis the response reduction was considered for two cases both Ordinary moment
resisting frame and Special moment resisting frame. The main objective this paper is to study the seismic
analysis of structure for static and dynamic analysis in ordinary moment resisting frame and special moment
resisting frame. Equivalent static analysis and response spectrum analysis are the methods used in structural
seismic analysis. We considered the residential building of G+ 15 storied structure for the seismic analysis and it
is located in zone II. The total structure was analyzed by computer with using STAAD.PRO software. We
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values with deflection diagrams in static and dynamic analysis. The special moment of resisting frame structured
is good in resisting the seismic loads.
seismic analysis of structures presentationDrAhmedNabil2
This document discusses analyzing the seismic performance of symmetric and asymmetric buildings. It begins by introducing the importance of evaluating seismic performance of buildings and how irregularities in mass, stiffness, and strength distribution (asymmetry) can cause serious damage during earthquakes. The document then outlines various structural analysis methods that will be used in the study, including equivalent static analysis, response spectrum analysis, nonlinear static pushover analysis, and nonlinear time history analysis. Finally, it proposes analyzing different plan configurations (rectangular, C, L, T, and I-shaped) of an 8-story building located in seismic zone 2 using the outlined analysis methods to compare the seismic behavior of symmetric versus asymmetric designs.
Dynamic Analysis of Multi-Storeyed Frame-Shear Wall Building Considering SSIIJERA Editor
The structural system of a high-rise building often has a more pronounced effect than a low rise building on the
total building cost and the architecture aspect of building. Shear walls are lateral load resisting structural
systems which provide stability to structures from lateral loads like wind and seismic Loads. The design of multi
storey building is to have good lateral load resisting System along with gravity load system for safety of
occupant and for better performance of structure even in most adverse condition. The main scope of this project
is to apply class room knowledge in the real world by designing a multi-storied residential building. Shear walls
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wind forces. To solve this purpose shear walls are a very powerful structural elements, if used judiciously can
reduce deflections and stresses to a very great extent. Our project contains a brief description of building with
shear wall and without shear wall thoroughly discussed structural analysis of a building to explain the
application of shear wall. The design analysis of the multi storied building in our project is done through
STAAD-PRO, most popular structural engineering software. It is featured with some ultimate power tool,
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4. INTRODUCTION
Since the early 1970's, there has been considerable research on the
assessment of damage of RC and other buildings.
Damage indices : Local damage indices
Global damage indices
• Local damage index is an indicator of damage for a part of the structure such as a
member or a storey.
• Global damage index involves the damage to the whole structure.
5. EVALUTION OF SESMIC DESIGN
A. J. Kappos
• clarified the basic concepts
involved in defining seismic
damage indices and critically
review the different schemes for
classifying these indices.
• The available analytical
procedures for the determination
of damage indices are evaluated.
Park and Ang
• Approached a method for
evaluating structural damage of
reinforced concrete buildings
under random earthquake
excitations.
• Based on these results,
Siddhartha Ghosh (2010)
• Used Park–Ang damage index to
estimate the damage demand on
a MDOF system,
• By comparing the estimates
from a nonlinear response
history analysis (NLRH) of the
SDOF model.
• These schemes are verified for
both global and local damage
indices.
Damage index =
characteristic intensity
structural damage
6. CONTD….,
Then, Banon used the rotational ductility
(μθ) at the end of a structural member as its
damage index.
Where,
θm= is the maximum rotation (including
both elastic and plastic rotations) under an
earthquake
θy = is the yield rotation.
• Given expression
Where,
du = ultimate deformation (capacity) under
monotonic static loading,
dm = maximum deformation (demand) under dynamic
loading,
dEh = incremental hysteretic energy(demand),
Vy = yield strength,
a non-negative non-dimensional parameter
7. DAMAGE INDEX
The degree of structural damage can be estimated through damage index DI
=
maximum inelastic response quantity (e.g. displacement, curvature,
etc.) during a ground excitation
the capacity of the structure
• numeric value varies between 0 and 1.
• Value of DI = zero denotes the non-damaged structure, (i.e. linear elastic behaviour of the structure
during an earthquake)
• Value of DI = 1 denotes the failure of the structure, (i.e. local or general collapse of the structure)
9. INTERSTOREY DRIFT
RATIO (IDR)interstorey drift ratio (IDR) is defined as the ratio of the relative displacements
between two consecutive floors divided by storey height
IDR =
the relative displacements between two consecutive floors
storey height
several researchers evaluated various types of damage indices of a structure
Among them IDR is one of the easiest way to find the damage index
IDR =
∆ i-1 - ∆i
hs
Where ,
∆ i-1 = Displacement at plinth level,
∆ i = Displacement of immediately above floor
hs = Soft storey height
10. ANALYTICAL APPROACH
Pushover analysis provides a ‘capacity curve’ of structure and relates the
deformation parameters of the system (i.e. roof displacement) to the
force parameter of the system (i.e. base shear).
• Pushover analysis is an effecitve way to the behavior & capacity of the
structure, highlighting the sequence of member cracking and yielding
as the base shear value increases.
Time History provides the Dynamic response of the structure at every
moment of time during the ground motion.
• Obtain the Inter storey drift (As Damage Index), dissipated hysteretic
energy under dynamic excitation.
Nonlinear static
pushover analysis
Time History analysis
11. CONTD…,
1. Calculate the total weight of individual structural elements like beam, column, slab and
strut.
2. Lumped mass at each floor was calculated taking into account a constant cross sectional
properties of columns and beams.
3. Overall stiffness at each floor was calculated considering the column at floor effectively
held in position and restrained against rotation in both ends.(fixed)
4. The natural frequency ω and Eigen vector Ф evaluated by using the characteristic
equation given above.
5. Change in time period at every stage of pushover analysis implies stiffness degradation
occurred due to increase in base shear and it is noted in SAP2000.
6. The changed frequency/damaged frequency ω* is calculated.
7. After knowing the value of ω and ω*, storey stiffness and flexibility matrix before and
after damage can be calculated.
12. EXPERIMENTAL PROBLEM
Description
• The storey height = 3.3m. (each frame)
• length of beam= 4m.
• Soft storey height=2.75m, 3.5m, 4.25m (each
building)
• Eccen back type strut member is applied as
infill (increase the stiffness of the building)
• X-direction ---> 3 bays.
• M20 & Fe415.
• Reinforced concrete code of practice (IS
456:2000).
• Design lateral forces due to earthquake ware
Calculated as per I.S. 1893:2002 (Part1).
• Gravity loads along with live loads as per
IS 875 (Part II).
LOADS
All the floors of the building structure
to carry
1. A triangular dead load =7.5 kN/m
2. A live load =6.0kN/m
3. Wall load =14kN/m.
4. In roof level, live load =3.0kN/m and
wall load=5kN/m.
Initially the seismic zone considered is
Zone-V with a factor (Z)= 0.36.
The importance factor (I) =1.0.
The response reduction factor= 5.0
(initially assumed).
15. Damage index is compared among different storey of buildings with
varrying soft storey height for four different earthquake:
16. CONCLUSION :
• Damage index (↑) increases with increasing
number of storey (↑) of a building.
• Damage index (↑) also increases with increasing of
height of a soft storey (↑) of a building.
• Damage index in terms of IDR may be more than
unity. ( IDR = 1 to 0 & IDR>1)
• Pushover analysis gives the capacity of the
building under monotonic loading.
• Time History Analysis provides the maximum IDR
in each node under seismic excitation.
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