This document discusses how wind can affect roof systems on buildings. It examines various factors that influence wind resistance, such as basic wind speed, wind-building interactions, topography, and internal pressure. The highest wind pressures typically occur at edges of roofs, ridges, and corners. These localized pressures can damage roof components and cladding and lead to further structural failure if not properly designed and constructed to withstand anticipated wind loads. The document also provides examples of wind pressure calculations and zones on buildings based on standards to help design roof systems that can resist damage from wind events.
This document provides an overview of analysis and design methods for concrete slabs, including:
1. Elastic analysis methods like grillage analysis and finite element analysis can be used to determine moments and shear forces in slabs.
2. Yield line theory is an alternative plastic/ultimate limit state approach for determining the ultimate load capacity of ductile concrete slabs. It involves assuming yield line patterns that divide the slab into rigid regions and equating external and internal work.
3. Examples are provided to illustrate yield line analysis for one-way spanning slabs and rectangular two-way slabs. Conventions, assumptions, and calculation procedures are explained.
This document provides information on the design of reinforced concrete beams, including:
1. It outlines the three basic design stages: preliminary analysis and sizing, detailed analysis of reinforcement, and serviceability calculations.
2. It describes how to calculate the lever arm, depth of the neutral axis, and required area of tension and compression reinforcement for singly and doubly reinforced beams.
3. It discusses considerations for preliminary sizing of beams, including required cover, breadth, effective depth, shear stress limits, and span-depth ratios. Trial calculations are suggested to determine suitable beam dimensions.
1) The conjugate beam method uses mathematical analogies between slope-deflection equations of actual beams and load-shear-moment equations of imaginary conjugate beams.
2) The method establishes mathematical equivalence between the behavior of actual beams and their conjugate beams, allowing values like shear (V) and moment (M) to be obtained for actual beams using deflections (w) of corresponding conjugate beams.
3) Conjugate beams are imaginary beams used for mathematical convenience without consideration of their physical stability; their deflections allow determining shear and moment in actual beams using simple equations.
Analysis And Design Of G+7 Story Building Using E-tabs SoftwareIRJET Journal
This document analyzes and designs a 7-story building using ETABS software. It models the building with and without a base isolation system. Time history analyses are conducted using earthquake records to compare the seismic responses. Base isolation is found to reduce base shear, story acceleration, drift, and column/beam forces compared to a fixed base structure. The document outlines the building specifications, modeling methodology, analysis results for shear/moments, reinforcement design, and time history analysis outputs like displacement and acceleration. It concludes that base isolation improves seismic performance by decreasing seismic demands.
This document provides details on the design of a continuous one-way reinforced concrete slab. It includes minimum thickness requirements, equations for calculating moments and shear, maximum reinforcement ratios, and minimum reinforcement ratios. An example is then provided to demonstrate the design process. The slab is designed to have a thickness of 6 inches with 0.39 in2/ft of tension reinforcement in the negative moment region and 0.33 in2/ft in the positive moment region.
This publication provides a concise compilation of selected rules in the Eurocode 8, together with relevant Cyprus National Annex, that relate to the design of common forms of concrete building structure in the South Europe. Rules from EN 1998-1-1 for global analysis, regularity criteria, type of analysis and verification checks are presented. Detail design rules for concrete beam, column and shear wall, from EN 1998-1-1 and EN1992-1-1 are presented. This guide covers the design of orthodox members in concrete frames. It does not cover design rules for steel frames. Certain practical limitations are given to the scope.
Ch8 Truss Bridges (Steel Bridges تصميم الكباري المعدنية & Prof. Dr. Metwally ...Hossam Shafiq II
This chapter discusses truss bridges. It begins by defining a truss as a triangulated assembly of straight members that can be used to replace girders. The main advantages of truss bridges are that primary member forces are axial loads and the open web system allows for greater depth.
The chapter then describes the typical components of a through truss bridge and the most common truss forms including Pratt, Warren, curved chord, subdivided, and K-trusses. Design considerations like truss depth, economic spans, cross section shapes, and wind bracing are covered. The chapter concludes with sections on determining member forces, design principles, and specific design procedures.
This document provides an overview of analysis and design methods for concrete slabs, including:
1. Elastic analysis methods like grillage analysis and finite element analysis can be used to determine moments and shear forces in slabs.
2. Yield line theory is an alternative plastic/ultimate limit state approach for determining the ultimate load capacity of ductile concrete slabs. It involves assuming yield line patterns that divide the slab into rigid regions and equating external and internal work.
3. Examples are provided to illustrate yield line analysis for one-way spanning slabs and rectangular two-way slabs. Conventions, assumptions, and calculation procedures are explained.
This document provides information on the design of reinforced concrete beams, including:
1. It outlines the three basic design stages: preliminary analysis and sizing, detailed analysis of reinforcement, and serviceability calculations.
2. It describes how to calculate the lever arm, depth of the neutral axis, and required area of tension and compression reinforcement for singly and doubly reinforced beams.
3. It discusses considerations for preliminary sizing of beams, including required cover, breadth, effective depth, shear stress limits, and span-depth ratios. Trial calculations are suggested to determine suitable beam dimensions.
1) The conjugate beam method uses mathematical analogies between slope-deflection equations of actual beams and load-shear-moment equations of imaginary conjugate beams.
2) The method establishes mathematical equivalence between the behavior of actual beams and their conjugate beams, allowing values like shear (V) and moment (M) to be obtained for actual beams using deflections (w) of corresponding conjugate beams.
3) Conjugate beams are imaginary beams used for mathematical convenience without consideration of their physical stability; their deflections allow determining shear and moment in actual beams using simple equations.
Analysis And Design Of G+7 Story Building Using E-tabs SoftwareIRJET Journal
This document analyzes and designs a 7-story building using ETABS software. It models the building with and without a base isolation system. Time history analyses are conducted using earthquake records to compare the seismic responses. Base isolation is found to reduce base shear, story acceleration, drift, and column/beam forces compared to a fixed base structure. The document outlines the building specifications, modeling methodology, analysis results for shear/moments, reinforcement design, and time history analysis outputs like displacement and acceleration. It concludes that base isolation improves seismic performance by decreasing seismic demands.
This document provides details on the design of a continuous one-way reinforced concrete slab. It includes minimum thickness requirements, equations for calculating moments and shear, maximum reinforcement ratios, and minimum reinforcement ratios. An example is then provided to demonstrate the design process. The slab is designed to have a thickness of 6 inches with 0.39 in2/ft of tension reinforcement in the negative moment region and 0.33 in2/ft in the positive moment region.
This publication provides a concise compilation of selected rules in the Eurocode 8, together with relevant Cyprus National Annex, that relate to the design of common forms of concrete building structure in the South Europe. Rules from EN 1998-1-1 for global analysis, regularity criteria, type of analysis and verification checks are presented. Detail design rules for concrete beam, column and shear wall, from EN 1998-1-1 and EN1992-1-1 are presented. This guide covers the design of orthodox members in concrete frames. It does not cover design rules for steel frames. Certain practical limitations are given to the scope.
Ch8 Truss Bridges (Steel Bridges تصميم الكباري المعدنية & Prof. Dr. Metwally ...Hossam Shafiq II
This chapter discusses truss bridges. It begins by defining a truss as a triangulated assembly of straight members that can be used to replace girders. The main advantages of truss bridges are that primary member forces are axial loads and the open web system allows for greater depth.
The chapter then describes the typical components of a through truss bridge and the most common truss forms including Pratt, Warren, curved chord, subdivided, and K-trusses. Design considerations like truss depth, economic spans, cross section shapes, and wind bracing are covered. The chapter concludes with sections on determining member forces, design principles, and specific design procedures.
This document summarizes an experiment to determine the relationship between water discharge (Q) and head (H). Students measured discharge at various head levels by collecting water discharged over time from a small tank. Their results showed a linear relationship between Q and H that could be expressed as Q = aH + b. The experiment helped establish the equation relating discharge and head but had some errors due to imperfectly closing the tap at recorded times, leading to issues with surface tension.
This document discusses influence lines for statically indeterminate beams and frames. It defines influence lines as the variation in reaction, shear, moment, or deflection at a specific point due to a concentrated force moving on the beam or frame. For indeterminate structures, qualitative influence lines can be drawn using the Muller-Breslau principle by releasing the structure at the point of interest. Quantitative influence lines can then be used to determine critical load patterns that produce maximum responses, which is important for designing structures to code-specified live loads.
This document describes an experiment to determine the stiffness of an open and closed coil spring and the modulus of rigidity of the spring material. A spring testing machine is used to apply loads to the springs and measure the deflection. The stiffness and modulus of rigidity are calculated based on equations that relate the applied load, spring geometry, and measured deflection. Test procedures are outlined for performing compression and tension tests on open and closed coil springs. Measurements of spring dimensions, number of coils, and load-deflection data are collected and used to calculate values for stiffness, shear stress, strain energy, and modulus of rigidity.
The document provides information on column design according to BS 8110-1:1997, including general recommendations, classifications of columns, effective length and minimum eccentricity, design moments, and design. Short columns have a length to height or breadth ratio less than 15 for braced or 10 for unbraced. Braced columns have lateral stability from walls or bracing. Additional moments are considered for slender or unbraced columns based on deflection. Design moments are calculated considering axial load and biaxial bending for different column classifications. Shear design also considers axial load and reinforcement is required if shear exceeds the shear capacity. The interaction diagram is constructed based on equilibrium equations relating stresses on a column cross section to axial load and bending
This document discusses the concepts of stability, determinacy, and consistent deformations as they relate to analyzing structures. It defines a stable structure as one that remains stable under any conceivable loading system. Determinacy refers to whether the internal forces in a structure can be fully determined from the available equilibrium equations. A structure is considered statically indeterminate if additional equations are needed beyond equilibrium to solve for all internal forces. The document outlines methods for assessing the external, internal, and total stability and determinacy of structures like trusses and frames through properties such as the number of members, joints, and reactions. Several examples are provided and worked through to demonstrate the application of these analytical methods.
The document discusses the design of steel structures according to BS 5950. It provides definitions for key terms related to steel structural elements and their design. These include beams, columns, connections, buckling resistance, capacity, and more. It then discusses the design process and different types of structural forms like tension members, compression members, beams, trusses, and frames. The properties of structural steel and stress-strain behavior are also covered. Methods for designing tension members, including consideration of cross-sectional area and end connections, are outlined.
The document discusses the historical background and advantages of the strength design method for reinforced concrete structures. It provides details on how structural safety is assured through factored loads and reduced material strengths. Key aspects of the strength design method covered include derivation of expressions for beam design, minimum and balanced steel ratios, requirements for under-reinforced and over-reinforced beams, and minimum thickness and deflection requirements.
Module 1 Behaviour of RC beams in Shear and TorsionVVIETCIVIL
This document summarizes key concepts related to shear and torsion behavior in reinforced concrete beams. It discusses modes of cracking in shear, shear failure modes, critical sections for shear design, the influence of axial forces and longitudinal reinforcement on shear strength, and shear transfer mechanisms. The key points covered include web shear cracking, flexure-shear cracking, diagonal tension failure, shear-compression and shear-tension failures, and the four mechanisms that contribute to shear transfer: aggregate interlock, dowel action, stirrups, and the interaction between axial compression and shear strength.
The document provides details on the design of a reinforced concrete column footing to support a column with a load of 1100kN. It includes calculating the footing size as a 3.5m x 3.5m square to support the load, determining the reinforcement with 12mm diameter bars at 100mm spacing, and checking that the design meets requirements for bending capacity, shear strength, and development length. The step-by-step worked example shows how to analyze and detail the reinforcement of the column footing.
This document provides an overview of design in reinforced concrete according to BS 8110. It discusses the basic materials used - concrete and steel reinforcement - and their properties. It describes two limit states for design: ultimate limit state considering failure, and serviceability limit state considering deflection and cracking. Key aspects of beam design are summarized, including types of beams, design for bending and shear resistance, and limiting deflection. Reinforcement detailing rules are also briefly covered.
This document provides information on analysis and design of reinforced concrete beams. It discusses key concepts such as modular ratio, neutral axis, stress diagrams, and types of reinforcement. It also defines under-reinforced, balanced, and over-reinforced beam sections. Several examples are provided to illustrate determination of neutral axis depth, moment of resistance, steel percentage, and stresses in concrete and steel reinforcement. Design aspects like maximum load capacity are also explained through examples.
This document provides definitions and explanations of key concepts in reinforced concrete design. It defines reinforced concrete as a composite material made of concrete and steel reinforcement. The purpose of reinforcement is to improve the tensile strength of concrete. The Limit State Method of design considers both the strength limit state and serviceability limit state, making it a more realistic and economical approach compared to other methods like Working Stress Method and Ultimate Load Method. Key factors of safety in the Limit State Method include partial factors for concrete γc = 1.5, and for steel γs = 1.15.
Design of compression members in steel structures - civil EngineeringUniqueLife1
This document discusses the design of steel compression members. It covers columns, beams, truss members and different cross section shapes. It explains the allowable stress design and limit state design methods. The key points are:
- Compression members must be designed to resist buckling based on their length, cross section and end conditions.
- A step-by-step example is provided to demonstrate the design procedure for a compression member with fixed ends using limit state design as per IS 800-2007.
- The design compressive stress is calculated based on the effective slenderness ratio and stress reduction factor.
The document provides a summary of modeling and analyzing slabs in ETABS, including:
1) Common assumptions made in slab modeling such as element type, meshing, shape, and acceptable error.
2) Steps for initial analysis including sketching expected results and comparing total loads.
3) Formulas and coefficients for calculating maximum bending moments in one-way and two-way slabs.
4) A process for designing solid slabs according to Eurocode 2 involving determining reinforcement ratios and areas.
05-Strength of Double Angle Bolted Tension Members (Steel Structural Design &...Hossam Shafiq II
1. The document discusses the limit states and failure modes of bolted double angle tension members, including yielding of the gross section, fracture at the net section, and block shear failure.
2. It provides equations to calculate the effective net area considering shear lag effects, and the block shear strength considering both shear and tensile strengths.
3. An example calculation is shown to determine the tensile resistance of a double unequal angle member bolted at one leg, where fracture at the net section governs with a strength of 393.9 kN.
The static loading test bengt h. felleniuscfpbolivia
The document discusses instrumentation and interpretation of static loading pile tests. It provides details on different methods for determining pile capacity from load-movement curves. It also discusses using strain gauges and telltales to measure load distribution in piles. Group effects are illustrated with examples showing how load-movement curves change from single pile to group tests. Determining the modulus of concrete from strain measurements during testing is also covered.
Study Effective of Wind Load on Behavior of ShearWall in Frame StructureIJERA Editor
Wind load is really the result of wind pressures acting on the building surfaces during a wind event. This wind
pressure is primarily a function of the wind speed because the pressure or load increases with the square of the
wind velocity.Structural walls, or shear walls, are elements used to resist lateral loads, such as those generated
by wind and earthquakes. Structural walls are considerably deeper than typical beams or columns. This attribute
gives structural walls considerable in-plane stiffness which makes structural walls a natural choice for resisting
lateral loads. In addition to considerable strength, structural walls can dissipate a great deal of energy if detailed
properly. Walls are an invaluable structural element when protecting buildings from seismic events. Buildings
often rely on structural walls as the main lateral force resisting system. Shear walls are required to perform in
multiple ways. Shear walls can then be designed to limit building damage to the specified degree. The loaddeformation
response of the structural walls must be accurately predicted and related to structural damage in
order to achieve these performance goals under loading events of various magnitudes. The applied load is
generally transferred to the wall by a diaphragm or collector or drag member. The performance of the framed
buildings depends on the structural system adopted for the structure The term structural system or structural
frame in structural engineering refers to load-resisting sub-system of a structure. The structural system
transfers loads through interconnected structural components or members. These structural systems need to be
chosen based on its height and loads and need to be carried out, etc. The selection of appropriate structural
systems for building must satisfy both strength and stiffness requirements. The structural system must be
adequate to resist lateral and gravity loads that cause horizontal shear deformation and overturning deformation.
The efficiency of a structural system is measured in terms of their ability to resist lateral load, which increases
with the height of the frame. A building can be considered as tall when the effect of lateral loads is reflected in
the design. Lateral deflections of framed buildings should be limited to prevent damage to both structural and
nonstructural elements. In the present study, the structural performance of the framed building with shear wall
will be analysis.
This document summarizes an experiment to determine the relationship between water discharge (Q) and head (H). Students measured discharge at various head levels by collecting water discharged over time from a small tank. Their results showed a linear relationship between Q and H that could be expressed as Q = aH + b. The experiment helped establish the equation relating discharge and head but had some errors due to imperfectly closing the tap at recorded times, leading to issues with surface tension.
This document discusses influence lines for statically indeterminate beams and frames. It defines influence lines as the variation in reaction, shear, moment, or deflection at a specific point due to a concentrated force moving on the beam or frame. For indeterminate structures, qualitative influence lines can be drawn using the Muller-Breslau principle by releasing the structure at the point of interest. Quantitative influence lines can then be used to determine critical load patterns that produce maximum responses, which is important for designing structures to code-specified live loads.
This document describes an experiment to determine the stiffness of an open and closed coil spring and the modulus of rigidity of the spring material. A spring testing machine is used to apply loads to the springs and measure the deflection. The stiffness and modulus of rigidity are calculated based on equations that relate the applied load, spring geometry, and measured deflection. Test procedures are outlined for performing compression and tension tests on open and closed coil springs. Measurements of spring dimensions, number of coils, and load-deflection data are collected and used to calculate values for stiffness, shear stress, strain energy, and modulus of rigidity.
The document provides information on column design according to BS 8110-1:1997, including general recommendations, classifications of columns, effective length and minimum eccentricity, design moments, and design. Short columns have a length to height or breadth ratio less than 15 for braced or 10 for unbraced. Braced columns have lateral stability from walls or bracing. Additional moments are considered for slender or unbraced columns based on deflection. Design moments are calculated considering axial load and biaxial bending for different column classifications. Shear design also considers axial load and reinforcement is required if shear exceeds the shear capacity. The interaction diagram is constructed based on equilibrium equations relating stresses on a column cross section to axial load and bending
This document discusses the concepts of stability, determinacy, and consistent deformations as they relate to analyzing structures. It defines a stable structure as one that remains stable under any conceivable loading system. Determinacy refers to whether the internal forces in a structure can be fully determined from the available equilibrium equations. A structure is considered statically indeterminate if additional equations are needed beyond equilibrium to solve for all internal forces. The document outlines methods for assessing the external, internal, and total stability and determinacy of structures like trusses and frames through properties such as the number of members, joints, and reactions. Several examples are provided and worked through to demonstrate the application of these analytical methods.
The document discusses the design of steel structures according to BS 5950. It provides definitions for key terms related to steel structural elements and their design. These include beams, columns, connections, buckling resistance, capacity, and more. It then discusses the design process and different types of structural forms like tension members, compression members, beams, trusses, and frames. The properties of structural steel and stress-strain behavior are also covered. Methods for designing tension members, including consideration of cross-sectional area and end connections, are outlined.
The document discusses the historical background and advantages of the strength design method for reinforced concrete structures. It provides details on how structural safety is assured through factored loads and reduced material strengths. Key aspects of the strength design method covered include derivation of expressions for beam design, minimum and balanced steel ratios, requirements for under-reinforced and over-reinforced beams, and minimum thickness and deflection requirements.
Module 1 Behaviour of RC beams in Shear and TorsionVVIETCIVIL
This document summarizes key concepts related to shear and torsion behavior in reinforced concrete beams. It discusses modes of cracking in shear, shear failure modes, critical sections for shear design, the influence of axial forces and longitudinal reinforcement on shear strength, and shear transfer mechanisms. The key points covered include web shear cracking, flexure-shear cracking, diagonal tension failure, shear-compression and shear-tension failures, and the four mechanisms that contribute to shear transfer: aggregate interlock, dowel action, stirrups, and the interaction between axial compression and shear strength.
The document provides details on the design of a reinforced concrete column footing to support a column with a load of 1100kN. It includes calculating the footing size as a 3.5m x 3.5m square to support the load, determining the reinforcement with 12mm diameter bars at 100mm spacing, and checking that the design meets requirements for bending capacity, shear strength, and development length. The step-by-step worked example shows how to analyze and detail the reinforcement of the column footing.
This document provides an overview of design in reinforced concrete according to BS 8110. It discusses the basic materials used - concrete and steel reinforcement - and their properties. It describes two limit states for design: ultimate limit state considering failure, and serviceability limit state considering deflection and cracking. Key aspects of beam design are summarized, including types of beams, design for bending and shear resistance, and limiting deflection. Reinforcement detailing rules are also briefly covered.
This document provides information on analysis and design of reinforced concrete beams. It discusses key concepts such as modular ratio, neutral axis, stress diagrams, and types of reinforcement. It also defines under-reinforced, balanced, and over-reinforced beam sections. Several examples are provided to illustrate determination of neutral axis depth, moment of resistance, steel percentage, and stresses in concrete and steel reinforcement. Design aspects like maximum load capacity are also explained through examples.
This document provides definitions and explanations of key concepts in reinforced concrete design. It defines reinforced concrete as a composite material made of concrete and steel reinforcement. The purpose of reinforcement is to improve the tensile strength of concrete. The Limit State Method of design considers both the strength limit state and serviceability limit state, making it a more realistic and economical approach compared to other methods like Working Stress Method and Ultimate Load Method. Key factors of safety in the Limit State Method include partial factors for concrete γc = 1.5, and for steel γs = 1.15.
Design of compression members in steel structures - civil EngineeringUniqueLife1
This document discusses the design of steel compression members. It covers columns, beams, truss members and different cross section shapes. It explains the allowable stress design and limit state design methods. The key points are:
- Compression members must be designed to resist buckling based on their length, cross section and end conditions.
- A step-by-step example is provided to demonstrate the design procedure for a compression member with fixed ends using limit state design as per IS 800-2007.
- The design compressive stress is calculated based on the effective slenderness ratio and stress reduction factor.
The document provides a summary of modeling and analyzing slabs in ETABS, including:
1) Common assumptions made in slab modeling such as element type, meshing, shape, and acceptable error.
2) Steps for initial analysis including sketching expected results and comparing total loads.
3) Formulas and coefficients for calculating maximum bending moments in one-way and two-way slabs.
4) A process for designing solid slabs according to Eurocode 2 involving determining reinforcement ratios and areas.
05-Strength of Double Angle Bolted Tension Members (Steel Structural Design &...Hossam Shafiq II
1. The document discusses the limit states and failure modes of bolted double angle tension members, including yielding of the gross section, fracture at the net section, and block shear failure.
2. It provides equations to calculate the effective net area considering shear lag effects, and the block shear strength considering both shear and tensile strengths.
3. An example calculation is shown to determine the tensile resistance of a double unequal angle member bolted at one leg, where fracture at the net section governs with a strength of 393.9 kN.
The static loading test bengt h. felleniuscfpbolivia
The document discusses instrumentation and interpretation of static loading pile tests. It provides details on different methods for determining pile capacity from load-movement curves. It also discusses using strain gauges and telltales to measure load distribution in piles. Group effects are illustrated with examples showing how load-movement curves change from single pile to group tests. Determining the modulus of concrete from strain measurements during testing is also covered.
Study Effective of Wind Load on Behavior of ShearWall in Frame StructureIJERA Editor
Wind load is really the result of wind pressures acting on the building surfaces during a wind event. This wind
pressure is primarily a function of the wind speed because the pressure or load increases with the square of the
wind velocity.Structural walls, or shear walls, are elements used to resist lateral loads, such as those generated
by wind and earthquakes. Structural walls are considerably deeper than typical beams or columns. This attribute
gives structural walls considerable in-plane stiffness which makes structural walls a natural choice for resisting
lateral loads. In addition to considerable strength, structural walls can dissipate a great deal of energy if detailed
properly. Walls are an invaluable structural element when protecting buildings from seismic events. Buildings
often rely on structural walls as the main lateral force resisting system. Shear walls are required to perform in
multiple ways. Shear walls can then be designed to limit building damage to the specified degree. The loaddeformation
response of the structural walls must be accurately predicted and related to structural damage in
order to achieve these performance goals under loading events of various magnitudes. The applied load is
generally transferred to the wall by a diaphragm or collector or drag member. The performance of the framed
buildings depends on the structural system adopted for the structure The term structural system or structural
frame in structural engineering refers to load-resisting sub-system of a structure. The structural system
transfers loads through interconnected structural components or members. These structural systems need to be
chosen based on its height and loads and need to be carried out, etc. The selection of appropriate structural
systems for building must satisfy both strength and stiffness requirements. The structural system must be
adequate to resist lateral and gravity loads that cause horizontal shear deformation and overturning deformation.
The efficiency of a structural system is measured in terms of their ability to resist lateral load, which increases
with the height of the frame. A building can be considered as tall when the effect of lateral loads is reflected in
the design. Lateral deflections of framed buildings should be limited to prevent damage to both structural and
nonstructural elements. In the present study, the structural performance of the framed building with shear wall
will be analysis.
IRJET- Effect of Wind on Tall StructuresIRJET Journal
1) The document discusses the effects of wind on tall structures and the complexities involved in wind loading design for such structures.
2) Simple quasi-static treatment of wind loading is too conservative for very tall buildings and does not account for important dynamic factors like resonance, damping, and cross-wind response.
3) Advanced wind loading design considers dynamic response, interference from nearby structures, wind direction asymmetry, and results from physical testing of structures.
Parametric Study for Wind Design of Vertical Pressure Vessel as per Indian St...IJMER
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
International Journal of Modern Engineering Research (IJMER) covers all the fields of engineering and science: Electrical Engineering, Mechanical Engineering, Civil Engineering, Chemical Engineering, Computer Engineering, Agricultural Engineering, Aerospace Engineering, Thermodynamics, Structural Engineering, Control Engineering, Robotics, Mechatronics, Fluid Mechanics, Nanotechnology, Simulators, Web-based Learning, Remote Laboratories, Engineering Design Methods, Education Research, Students' Satisfaction and Motivation, Global Projects, and Assessment…. And many more.
Study of Comparison Between Static and Dynamic Analysis Subjected to Wind and...IRJET Journal
This document discusses a study comparing static and dynamic analysis of wind and earthquake loads on high-rise buildings. It provides background on wind loads, describes the objectives of investigating parameters like fundamental time period and displacements under dynamic loads. It also outlines the methodology, including design wind load calculation according to Indian codes, modeling a 150m building as a case study, and analyzing it both statically and dynamically under along-wind and across-wind loads.
Wind and Architecture: Design to the flowIRJET Journal
1) The document discusses how wind characteristics impact building design and how architects can design structures to accommodate wind flows.
2) It describes different wind types and how building plans, forms, heights, and construction materials affect wind pressure on structures. Taller and more slender buildings require more advanced dynamic modeling of wind forces.
3) The document provides examples of structural designs that mitigate wind impacts for very tall skyscrapers like Burj Khalifa, including its Y-shaped plan and stepped wings that reduce wind pressure, and mass dampers that absorb vibrations. Proper design of plans, forms, and construction can help buildings withstand wind forces.
This document discusses the calculation of wind loads for structural design. It provides background on wind loads and defines key terms. It outlines wind speed areas in Tanzania and the design procedure, which involves determining the site wind speed, characteristic wind pressure, external and internal pressures on the structure, and the net pressure. Examples are provided to demonstrate calculating wind loads. Load factors of safety and load combinations are also defined.
This document analyzes the response of different building models subjected to blast loads using ETABS software. A 12-story building is analyzed for 4 cases with different explosive charge weights (100kg and 200kg) and standoff distances (20m and 40m). Blast parameters are calculated using code standards. Four building models are then analyzed - a normal model, and models with increased member sizes, added shear walls, and added bracing. Storey displacement and drift are compared to determine the most blast resistant model.
Effects of shape on the wind instigate response of high rise buildingseSAT Journals
Abstract A large number of structures that are being constructed at present tend to be wind-sensitive because of their slenderness, shapes, size, lightness and flexibility. With the ever increase in the vertical growth of urban cities, high rise buildings are being constructed in large numbers. In this study, analytical investigation of different shapes of buildings are taken as an example and various analytical approaches are performed on the building. These plans are modeled and wind loads are found out according to I.S 875(part 3)-1987 by taking gust factor and without taking gust factor. These models are compared in different aspects such as storey drift, storey displacement, storey shear, etc. for different shapes of buildings by using finite element software package ETAB’s 13.1.1v. Among these results, which shape of building provide sound wind loading to the structure as well as the structural efficiency would be selected. Key Words: Storey displacement, Storey drift, Storey shear, Gust, Wind load
This document discusses wind loads on structures. It describes how high velocity winds create low pressure areas that exert lifting and pulling forces on buildings. Wind load is classified as static or dynamic, with static wind causing elastic bending and twisting, while dynamic wind from gusts induces oscillations. Wind load analysis is used for structures over 10-30 meters tall. Design wind speed is calculated per IS code 875 using factors for probability, terrain height/structure size, and topography. The key effects of wind load are uplift, shear, and lateral loads.
This document provides details about a master's thesis project on the design of an adaptive facade system for windload reduction in high-rise buildings. The project aims to study wind behavior and its effects on buildings to design a facade that can adapt its shape or surface to reduce wind loads and minimize the need for structural materials. The document outlines the introduction, problem statement, research objectives, questions, scope and methodology of the project, which involves literature research and experiments to understand wind effects and develop options for an adaptive facade system to efficiently reduce wind loads and building structure requirements.
This document discusses analyzing the response of a reinforced concrete building to blast loads. The building was modeled in Inventor and analyzed in Altair and Staad Pro. Transient structural analysis was used to simulate the effects of uniform blast pressure loads at different standoff distances. The objectives were to study deformation of the structure under positive and negative blast phases and compare effects of blast pressure at 5m and 6m standoffs. A 3-story commercial building was modeled and analyzed, with blast assumed from the front corner at 5m and 6m distances.
This document discusses wind loads on structures. It begins by explaining that wind is moving air with mass and velocity that exerts kinetic energy. The intensity of wind load depends on wind velocity squared and the dimensions of resisting members. Wind velocity varies by location, structure height, terrain, and surroundings. Wind pressure depends on velocity, building shape/surface, terrain protection, and air density. Structures respond to wind loads through static deflection and dynamic vibration. Both external and internal wind pressures must be considered to calculate net pressure. Internal pressure depends on opening distribution. Several examples are provided to demonstrate calculating wind loads on buildings.
IRJET- A Review on “Analysis, design and study of behavior of RC Structur...IRJET Journal
This document reviews research on analyzing and designing reinforced concrete structures to withstand blast loads of various intensities. It discusses how blast loads generate pressure waves that can damage structures and cause loss of life. The study aims to understand blast wave parameters like overpressure for different explosive charge amounts and distances. It also looks at how blast loads affect structures differently based on factors like surface bursts versus air bursts. The goal is to minimize damage to structures and occupants from explosive events.
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Similar to 10_BADIU Bratucu_07.04 THE EFFECTS OF WIND ON ROOF SYSTEMS FOR BUILDINGS (20)
10_BADIU Bratucu_07.04 THE EFFECTS OF WIND ON ROOF SYSTEMS FOR BUILDINGS
1. Bulletin of the Transilvania University of Braşov
Series II: Forestry • Wood Industry • Agricultural Food Engineering • Vol. 7 (56) No.1 - 2014
THE EFFECTS OF WIND ON ROOF
SYSTEMS FOR BUILDINGS
E. BADIU1
Gh. BRĂTUCU1
Abstract: This paper presents a study on climatic factors, especially wind,
that can affect a roof’s structure. Studies have shown that most damage
occurs because various building elements have limited wind resistance due to
inadequate design, application, material deterioration, or roof system abuse.
In order to assess the risk caused by high winds on roof systems, the building
aerodynamics, the topography, the wind-building interactions, the
atmospheric corrosion etc. must be taken into account.
Key words: climatic factors, roof system, wind resistance.
1
Dept. of Engineering and Management in Food and Tourism, Transilvania University of Braşov.
1. Introduction
The durability of the roofing system is
the result of many parameters, such as, but
not limited to: local climate, local
temperature which is correctly considered
as a result of changes in solar radiation,
wind, rain, and other environmental
influences. Another important factor is the
resistance to water penetration under
driving rain and deluge conditions [1].
2. Basic Wind Speed
ASCE 7 defines the basic wind speed as
the wind speed with a 50-year mean
recurrence interval (2% annual
probability), measured at 33 feet above
grade in Exposure C (flat open terrain). If
the building is located in Exposure B or D,
rather than C, an adjustment for the actual
exposure is made in the ASCE 7
calculation procedure.
In determining wind pressures, the basic
wind speed is squared; therefore, as the
velocity is increased, the pressures are
exponentially increased. For example, the
uplift load on a 30-foot high roof covering
at a corner area of an office building in
Exposure B is 37.72 pounds per square
foot (psf) with a basic wind speed of 85
mph (per ASCE 7-02). If the speed is
doubled to 170 mph, the roof corner load
increases by a factor of four to 151 psf [4].
3. Wind-Building Interactions
When wind interacts with a building,
both positive and negative pressures occur
simultaneously (Figure 1). Negative
pressures are less than ambient pressure,
and positive pressures are greater than
ambient pressure.
A building must have sufficient strength
to resist the applied loads in order to
prevent wind-induced building failure [2].
The magnitude of the pressures is
influenced by the following primary
factors: exposure, basic wind speed,
topography, building height, internal
pressure, building aerodynamics etc.
It is important to calculate wind
2. Bulletin of the Transilvania University of Braşov • Series II • Vol. 7 (56) No. 1 - 201468
pressures for both the structural frame
(called the Main Wind Force Resisting
System, or MWFRS, in ASCE 7-98) and
for building components and cladding.
Components and cladding include
elements such as roof sheathing, roof
coverings, exterior siding, windows, doors,
soffits, facia, and chimneys.
Fig. 1. Schematic of wind-induced pressures on a building [4]
Investigations of wind-damaged
buildings after disasters have shown that
many buildings failures start because a
component or piece of cladding is blown
off the building, allowing wind and rain to
enter the building. The uncontrolled entry
of wind into the building creates internal
pressure that, in conjunction with negative
external pressures, can blow the building
apart [3].
The effects of wind on buildings can be
summarized as follows:
• windward walls and steep-sloped roofs
are acted on by inward-acting, or positive
pressures;
• leeward walls and steep and low-sloped
roofs are acted on by outward-acting, or
negative pressures;
• air flow separates at sharp edges and it
points where the building geometry
changes;
• localized suction or negative pressures at
eaves, ridges, and the corners of roofs and
walls are caused by turbulence and flow
separation. These pressures affect loads on
components and cladding.
Figure 2 shows the effects of wind on
buildings.
Fig. 2. The effects of wind on buildings [6]
3. E. BADIU et al.: The Effects of Wind on Roof Systems for Buildings 69
The phenomena of localized high
pressures occurring at points where the
building geometry changes are accounted
for by the various shape coefficients in the
equations for both the MWFRS and
components and cladding. Internal
pressures must be included in the
determination of wind pressures and are
additive to (or subtractive from) the
external pressures. Openings and the
natural porosity of the building
components contribute to internal pressure.
The magnitude of internal pressures
depends on whether the building is
enclosed, partially enclosed, or open as
defined by ASCE 7-98.
Fig. 3. Wind pressure zones for MWFRS [6]
The external pressure coefficients (CP)
for the 10 zones indicated are provided for
the case of wind direction from the east
(Figure 3) [6]. The summary of wind
pressures (p) for MWFRS is presented in
Table 1.
Summary of Wind Pressures (p) for MWFRS [5] Table 1
Wind Direction
Wind Pressure Zone
East West North South
1. Porch overhang -45.45 -12.30 -22.14 -45.45
2. Front roof -12.63 -20.01 -27.39 -27.39
3. Rear roof -20.01 -12.63 -27.39 -27.39
4. Left hip roof -27.39 -27.39 -20.01 4.60
5. Right hip roof -27.39 -27.39 4.60 -20.01
6. Left front gable -27.39 -27.39 -20.01 4.60
7. Front wall 14.44 -17.55 -22.47 -22.47
8. Rear wall -17.55 14.44 -22.47 -22.47
9. Left side wall -22.47 -22.47 -15.09 14.44
10. Right side wall -22.47 -22.47 14.44 -15.09
4. Bulletin of the Transilvania University of Braşov • Series II • Vol. 7 (56) No. 1 - 201470
Locations on the building are taken from
the east, facing the building. All pressures
are in lb/ft2
and have been rounded to the
nearest two decimal places, positive
pressures act toward the building and
negative pressures act away from the
building. Highest pressures are indicated in
bold. The wind pressure zones for
components and cladding are shown in
Figure 4.
Fig. 4. Wind pressure zones for components and cladding and most severe negative
pressure coefficients shown [6]
The computed pressures are listed in
Table 2. All pressures are in lb/ft2
and have
been rounded to the nearest two decimal
places.
Positive pressures act in toward the
building and negative pressures act away
from the building. An effective area of 20
ft2
is assumed.
The computed pressures [5] Table 2
Wind Pressure Zone GCp Coeficients
Wind Pressure
(lb/ft2
)
Corners of hip roof and front porch -3.3 -119.48
Interior of hip and porch roofs -0.9 -31.47
Steep-sloped hip and gable roofs -0.9 -31.47
Hip roof overhang edge -2.2 -87.42
Steep hip and gable and edges -1.9 -78.68
Wall corner -1.3 -43.13
Main wall area -1.1 -37.3
Porch roof edge -2.2 -69.36
5. E. BADIU et al.: The Effects of Wind on Roof Systems for Buildings 71
Wind striking a building can cause either
an increase in the pressure within the
building (positive pressure), or it can cause
a decrease in the pressure (negative
pressure). Internal pressure changes occur
because of the porosity of the building
envelope.
If the porosity of the windward wall is
greater than the combined porosity of the
side and rear walls, the interior of the
building is pressurized.
A pressurized building increases the
wind load on the side and rear walls
(Figure 5) as well as on the roof.
Fig. 5. Schematic of internal pressure condition when the dominant opening is in the
windward wall [4]
When a building is pressurized, the
internal pressure pushes up on the roof.
When a building is depressurized, the
internal pressure pulls the roof down,
which reduces the amount of uplift exerted
on the roof.
The decreased internal pressure also
pulls inward on the windward wall, which
increases the wind load on that wall
(Figure 6).
In both figures arrays indicate direction
and amplitude of applied force.
Fig. 6. Schematic of internal pressure condition when the dominant opening is in the
leeward wall [4]
6. Bulletin of the Transilvania University of Braşov • Series II • Vol. 7 (56) No. 1 - 201472
4. Conclusions
A well-designed building may be
damaged by a wind event that is much
stronger than what the building was
designed for. The most damage occurs
because various building elements have
limited wind resistance due to inadequate
design or material deterioration.
When high winds affect a building, it is
well established that the highest forces
occur along the building edges. On the
roof, these locations are near the eaves,
ridges, hips and rakes. Damage initiated on
these edges can lead to progressive failure
of the rest of the roofing.
The magnitude and frequency of strong
wind varies by locale, and buildings should
be constructed to avoid wind damage.
When designing a new roof, the designer
must determine the design wind pressure for
the geographic location and selects a roofing
system appropriate for the local climatic
wind conditions.
References
1. Badiu E., Brătucu Gh., 2013.
Researches regarding the causes of
degradation of roof systems. The 5th
International Conference
Computational Mechanics and Virtual
Engineering, 24-25 October 2013,
COMEC 2013, Brasov, Romania,
p. 353-356.
2. Baskaran A., 2002. Dynamic Wind
Testing of Commercial Roofing
Systems. Available at: http://www.nrc-
cnrc.gc.ca/ctu-sc/files/doc/ctu-sc/ctu-
n55_eng.pdf.
3. Cash C.G., 2003. Roofing failures.
Spon Press, London.
4. Smith T., 2010. Wind Safety of the
Building Envelope. Available at:
http://www.wbdg.org/resources/env_w
ind.php.
5. *** ASCE Standard, 2003. Minimum
Design Loads for Buildings and Other
Structures. Available at:
https://law.resource.org/pub/us/cfr/ibr/00
3/asce.7.2002.pdf.
6. *** Federal Emergency Management
Agency, 2009. Roof Coverings and Best
Practices. Available at:
http://www.fema.gov/media-library-
data/20130726-1706-25045-9843/
logcc_rev1.pdf.