Seismic retrofitting is the modification of existing structures to make them more resistant to seismic activity, ground motion, or soil failure due to earthquakes.
This document discusses retrofitting of structures. Retrofitting is required when structures are damaged or do not meet current seismic standards. It summarizes various retrofitting techniques such as adding shear walls, infill walls, steel bracing, wall thickening, wing walls, mass reduction, base isolation, and jacketing structural elements. It provides examples of existing retrofitted structures in Gujarat. Retrofitting increases strength and ductility but can reduce space and increase foundation loads. Materials discussed include steel, fiber reinforced polymer, and reinforced concrete.
This document discusses various techniques for retrofitting concrete structures to make them more resistant to seismic activity and other natural hazards. It defines retrofitting as modifying existing structures to increase resistance. Key techniques mentioned include adding new shear walls, steel bracing, column and beam jacketing with steel or concrete, base isolation using seismic isolators, mass reduction by removing floors, and wall thickening. The document also discusses challenges in retrofitting and standards from Indian codes for earthquake-resistant design. The conclusion emphasizes that retrofitting has matured but expertise is still lacking, and optimization is needed to determine the most cost-effective technique for a given structure.
This document discusses retrofitting techniques to strengthen existing structures against seismic activity. It describes upgrading reinforced concrete and masonry structures through methods like reinforced concrete jacketing, steel plate bonding, and adding new structural elements. Recent trends in Pakistan involve using carbon fiber reinforced polymer composites for flexural and shear strengthening. The document provides examples of retrofitting projects completed in Pakistan using these composite systems.
Retrofitting is the seismic strengthening of existing damaged or undamaged structures.
Retrofitting a building involves changing its systems or structure after its initial construction and occupation. This work can improve amenities for the building's occupants and improve the performance of the building
Reinforced concrete buildings in seismic regions often include vertical shear walls that run from the foundation to the roof. Shear walls help buildings withstand earthquakes by carrying lateral forces down to the foundation. They perform much better when properly designed with features like symmetrical placement, ductile reinforcement, and thickened boundary elements at the ends that experience high stresses. Buildings with sufficient shear walls have shown good performance during past earthquakes, making shear wall construction a popular approach in seismic design.
This document summarizes techniques for seismic retrofitting of existing structures. It defines seismic retrofitting as modifying structures to make them more resistant to earthquakes. Common retrofitting techniques discussed include adding new shear walls, steel bracing, jacketing columns and beams, using innovative materials like fiber reinforced polymers, base isolation using elastomeric bearings or sliding systems, and installing seismic dampers. The document also discusses retrofitting performance objectives, codes and guidelines, and provides examples of retrofitted structures.
CE 72.52 - Lecture 8a - Retrofitting of RC MembersFawad Najam
Ā
The document outlines a presentation on retrofitting concrete structures. It discusses two approaches to retrofitting: global (system) strengthening which adds new elements to enhance stiffness, and local (element) strengthening which targets insufficient member capacities. Examples of global retrofitting mentioned include adding reinforced concrete shear walls and buckling restrained braces. Local retrofitting examples discussed are reinforcement concrete jacketing of columns and beams.
This document discusses retrofitting of structures. Retrofitting is required when structures are damaged or do not meet current seismic standards. It summarizes various retrofitting techniques such as adding shear walls, infill walls, steel bracing, wall thickening, wing walls, mass reduction, base isolation, and jacketing structural elements. It provides examples of existing retrofitted structures in Gujarat. Retrofitting increases strength and ductility but can reduce space and increase foundation loads. Materials discussed include steel, fiber reinforced polymer, and reinforced concrete.
This document discusses various techniques for retrofitting concrete structures to make them more resistant to seismic activity and other natural hazards. It defines retrofitting as modifying existing structures to increase resistance. Key techniques mentioned include adding new shear walls, steel bracing, column and beam jacketing with steel or concrete, base isolation using seismic isolators, mass reduction by removing floors, and wall thickening. The document also discusses challenges in retrofitting and standards from Indian codes for earthquake-resistant design. The conclusion emphasizes that retrofitting has matured but expertise is still lacking, and optimization is needed to determine the most cost-effective technique for a given structure.
This document discusses retrofitting techniques to strengthen existing structures against seismic activity. It describes upgrading reinforced concrete and masonry structures through methods like reinforced concrete jacketing, steel plate bonding, and adding new structural elements. Recent trends in Pakistan involve using carbon fiber reinforced polymer composites for flexural and shear strengthening. The document provides examples of retrofitting projects completed in Pakistan using these composite systems.
Retrofitting is the seismic strengthening of existing damaged or undamaged structures.
Retrofitting a building involves changing its systems or structure after its initial construction and occupation. This work can improve amenities for the building's occupants and improve the performance of the building
Reinforced concrete buildings in seismic regions often include vertical shear walls that run from the foundation to the roof. Shear walls help buildings withstand earthquakes by carrying lateral forces down to the foundation. They perform much better when properly designed with features like symmetrical placement, ductile reinforcement, and thickened boundary elements at the ends that experience high stresses. Buildings with sufficient shear walls have shown good performance during past earthquakes, making shear wall construction a popular approach in seismic design.
This document summarizes techniques for seismic retrofitting of existing structures. It defines seismic retrofitting as modifying structures to make them more resistant to earthquakes. Common retrofitting techniques discussed include adding new shear walls, steel bracing, jacketing columns and beams, using innovative materials like fiber reinforced polymers, base isolation using elastomeric bearings or sliding systems, and installing seismic dampers. The document also discusses retrofitting performance objectives, codes and guidelines, and provides examples of retrofitted structures.
CE 72.52 - Lecture 8a - Retrofitting of RC MembersFawad Najam
Ā
The document outlines a presentation on retrofitting concrete structures. It discusses two approaches to retrofitting: global (system) strengthening which adds new elements to enhance stiffness, and local (element) strengthening which targets insufficient member capacities. Examples of global retrofitting mentioned include adding reinforced concrete shear walls and buckling restrained braces. Local retrofitting examples discussed are reinforcement concrete jacketing of columns and beams.
Shear walls are vertical reinforced concrete walls that resist lateral forces like wind and earthquakes. They provide strength and stiffness to control lateral building movement. Shear walls are classified into different types including simple rectangular, coupled, rigid frame, framed with infill, column supported, and core type walls. Design of shear walls involves reviewing the building layout, determining loads, estimating earthquake forces, analyzing the structural system, and designing for flexural and shear strengths with proper reinforcement detailing. The behavior of shear walls under seismic loading depends on their height to width ratio, with squat walls experiencing more shear deformation and slender walls undergoing primarily bending deformation.
This document discusses concrete distress, its causes, and concrete repair systems. It defines distress as damage to concrete that can occur during production or service life due to varying conditions. Common causes of distress include structural loads, errors in design and construction, drying shrinkage, corrosion, and deterioration over time from chemical reactions, freezing/thawing, or weathering. Proper concrete repair requires determining the cause of damage, evaluating its extent, selecting repair methods, preparing the surface, applying repair materials, and curing. Durable repairs depend on high quality workmanship and materials to ensure the repair is well-bonded and resistant to future distress.
Shear walls are vertical structural elements designed to resist lateral forces like winds and earthquakes. They work by transferring shear forces throughout their height and resisting uplift forces. Properly designed and constructed shear wall buildings are very stable and ductile, providing warnings before collapse during severe earthquakes. Common types of shear walls include reinforced concrete, plywood, and steel plate shear walls. Shear walls are an effective and efficient way to resist lateral loads in seismic regions.
The document discusses retrofitting of reinforced concrete beam-column joints through various techniques like jacketing, case studies, and concludes with key findings. Specifically, it summarizes three case studies: 1) Retrofitting using reinforced concrete jacketing improved strength and ductility over the brittle original joint. 2) Using carbon fiber reinforced polymer on a damaged joint improved shear strength and ductility. 3) Glass fiber reinforced polymer wrapping a joint improved its shear and bond-slip resistance, producing more ductile failures in beams.
The document discusses factors that affect the health of structures such as design flaws, environmental effects, material quality issues, and deterioration over time. It also covers various types of structural defects, distress, and deterioration that can occur like cracking, spalling, corrosion, and outlines the importance of maintenance to address these issues through preventative, remedial, routine and special maintenance practices as well as regular inspections. The stages of inspection including pre-monsoon, monsoon and post-monsoon checks are important to properly maintain structures.
The document discusses properties and testing of concrete. It provides information on the constituents of concrete including cement, coarse aggregate, fine aggregate, and water. It also discusses properties of concrete and reinforcements, including their relatively high compressive strength and lower tensile strength. Various tests performed on concrete are mentioned, including tests on workability, compressive strength, flexural strength, and fresh/hardened concrete. Design philosophies for reinforced concrete include the working stress method, ultimate strength method, and limit state method.
The document discusses the design of footings for structures. It begins by explaining that footings are needed to transfer structural loads from members made of materials like steel and concrete to the underlying soil. It then describes different types of shallow and deep foundations, including spread, strap, combined, and raft footings. The document provides details on designing isolated and combined footings to resist vertical loads and moments based on provisions in IS 456. It also discusses wall footings and combined footings that support multiple columns. In summary, the document covers the purpose of footings, various footing types, and design of isolated and combined footings.
This document discusses various techniques for repairing and rehabilitating concrete structures. It covers topics such as concrete deterioration mechanisms, materials used for repair like cement mortars and polymers, and techniques like grouting, jacketing, and external bonding. Assessment of damaged structures involves preliminary investigation, detailed investigation using techniques like core cutting, rebar location, corrosion measurement, and pull-out tests to determine repair requirements. Underwater repair of structures also requires special considerations and techniques.
Kiran more (retrofitting presentation)te bKiranMore87
Ā
This document discusses retrofitting techniques for concrete structures. Retrofitting involves strengthening existing structures that may be damaged or undamaged. It is required when structures are subjected to excessive loading, seismic damage, or do not meet current design standards. The objectives of retrofitting are to increase lateral strength, ductility, and provide better connections between structural elements. Common retrofitting techniques discussed include adding shear walls, infill walls, bracing, wall thickening, and base isolation. Local retrofitting involves jacketing beams, columns, and joints using steel, fiber reinforced polymers, or concrete. Examples of retrofitted structures in Gujarat, India are provided.
This document discusses various techniques for retrofitting existing structures to improve their resistance to seismic activity. It describes adding new shear walls, steel bracing, or jacketing columns as common retrofitting methods. Base isolation, which isolates the structure from foundations, is also discussed. The objectives of retrofitting are outlined as increasing strength, ductility, and protecting life safety. Different classification of retrofitting techniques are provided based on addressing local deficiencies or global irregularities.
Seismic Retrofitting of RC Building with Jacketing and Shear Wall Seismic Ret...Bala murali
Ā
It is a part of retrofitting i.e. repair, renovation, strengthening.
Retrofitting is the modification of existing structures to make them more resistant.
Jacketing is the most popularly used method for strengthening of building columns.
Jacketing consists of added concrete with longitudinal and transverse reinforcement around the existing column.
It improves axial and shear strength of column and major strengthening of foundation may be avoided.
This document discusses column jacketing, which is a method of retrofitting and strengthening existing columns. It involves adding reinforced concrete, steel, or fiber-reinforced polymer around the column. The key steps are preparing the column surface, adding shear keys and reinforcement, applying a bonding agent, and casting the new concrete or installing the jacket. Column jacketing increases the strength and seismic capacity of the column. It improves confinement and increases axial, shear, and foundation load capacity without significant weight addition.
The document discusses methods for strengthening structural members like beams and slabs that have insufficient strength. For beams, additional reinforcement can be added on the bottom and sides, and bonded with epoxy. For slabs, a reinforced concrete topping can be applied to create a composite section with the existing slab, using mechanical anchors and epoxy bonding. Proper preparation of surfaces, curing, and controlling deflection during strengthening are emphasized.
(1) The document discusses the durability and serviceability of concrete. It defines durability as the ability to resist weathering and chemical attacks. (2) The resistance of concrete depends on its quality, constituent materials, and curing process. Well-made concrete that is properly compacted and cured can remain durable if micro-cracks do not connect to the surface. (3) The document presents three holistic models of deterioration in reinforced concrete. The first two models describe a two-stage process where micro-cracks first interconnect, then allow water and chemicals to penetrate and cause damage. The third model emphasizes the role of water cement ratio and the interaction of porosity, chemicals, and intermittent water presence in causing
This document summarizes Indian Standard IS 4326:1993, which provides guidelines for earthquake-resistant design and construction of buildings. It covers terminology, general principles, special construction features, types of construction, categories of buildings, and masonry, timber, and precast construction. For masonry, it specifies use of strong materials and mortar, wall thickness, reinforcement, and strengthening with horizontal bands and vertical dowels. Vertical reinforcement is also required at wall corners and junctions.
Reinforced concrete columns and beams are important structural elements that carry compressive and bending loads respectively. Columns can be categorized as short or long based on their height-width ratio and as spiral or tied columns based on their shape. Beams are classified based on their supports as simply supported, fixed, continuous, or cantilever beams. The construction of RCC columns and beams involves laying reinforcement, forming the structure, and pouring concrete to create these load-bearing elements.
The document provides information on methods of prestressing in concrete, including pretensioning and post-tensioning. It discusses:
- Pretensioning involves stressing steel tendons before the concrete is cast around them.
- Post-tensioning involves stressing steel tendons after the concrete has cured using jacks, then grouting the voids.
- Both methods put the concrete in compression and increase its strength and durability compared to conventional reinforced concrete.
It contains details of retrofitting techniques and their application in various aspects in historical monuments. It would help to protect several heritage structures from the devastating effect of the earthquake. Some applications are also helpful too counter act the severe effect of the wind load. There are many historical heritages especially in India, are reopened to the public after being retrofitted and renovated.
Seismic retrofitting is a collection mitigation technique for earthquake engineering.
It is the modification of existing structures to make them more resistant to seismic activity, ground motion, or soil failure due to earthquake.
It is of utmost important for historic monuments, areas prone to severe earthquakes and tall or
expensive structures.
The retrofitting techniques are also applicable for other natural hazards such as tropical cyclones, tornadoes and severe winds from thunderstorms.
Retrofitting proves to be a better economic consideration and immediate shelter to problems
rather than replacement of building.
Shear walls are vertical reinforced concrete walls that resist lateral forces like wind and earthquakes. They provide strength and stiffness to control lateral building movement. Shear walls are classified into different types including simple rectangular, coupled, rigid frame, framed with infill, column supported, and core type walls. Design of shear walls involves reviewing the building layout, determining loads, estimating earthquake forces, analyzing the structural system, and designing for flexural and shear strengths with proper reinforcement detailing. The behavior of shear walls under seismic loading depends on their height to width ratio, with squat walls experiencing more shear deformation and slender walls undergoing primarily bending deformation.
This document discusses concrete distress, its causes, and concrete repair systems. It defines distress as damage to concrete that can occur during production or service life due to varying conditions. Common causes of distress include structural loads, errors in design and construction, drying shrinkage, corrosion, and deterioration over time from chemical reactions, freezing/thawing, or weathering. Proper concrete repair requires determining the cause of damage, evaluating its extent, selecting repair methods, preparing the surface, applying repair materials, and curing. Durable repairs depend on high quality workmanship and materials to ensure the repair is well-bonded and resistant to future distress.
Shear walls are vertical structural elements designed to resist lateral forces like winds and earthquakes. They work by transferring shear forces throughout their height and resisting uplift forces. Properly designed and constructed shear wall buildings are very stable and ductile, providing warnings before collapse during severe earthquakes. Common types of shear walls include reinforced concrete, plywood, and steel plate shear walls. Shear walls are an effective and efficient way to resist lateral loads in seismic regions.
The document discusses retrofitting of reinforced concrete beam-column joints through various techniques like jacketing, case studies, and concludes with key findings. Specifically, it summarizes three case studies: 1) Retrofitting using reinforced concrete jacketing improved strength and ductility over the brittle original joint. 2) Using carbon fiber reinforced polymer on a damaged joint improved shear strength and ductility. 3) Glass fiber reinforced polymer wrapping a joint improved its shear and bond-slip resistance, producing more ductile failures in beams.
The document discusses factors that affect the health of structures such as design flaws, environmental effects, material quality issues, and deterioration over time. It also covers various types of structural defects, distress, and deterioration that can occur like cracking, spalling, corrosion, and outlines the importance of maintenance to address these issues through preventative, remedial, routine and special maintenance practices as well as regular inspections. The stages of inspection including pre-monsoon, monsoon and post-monsoon checks are important to properly maintain structures.
The document discusses properties and testing of concrete. It provides information on the constituents of concrete including cement, coarse aggregate, fine aggregate, and water. It also discusses properties of concrete and reinforcements, including their relatively high compressive strength and lower tensile strength. Various tests performed on concrete are mentioned, including tests on workability, compressive strength, flexural strength, and fresh/hardened concrete. Design philosophies for reinforced concrete include the working stress method, ultimate strength method, and limit state method.
The document discusses the design of footings for structures. It begins by explaining that footings are needed to transfer structural loads from members made of materials like steel and concrete to the underlying soil. It then describes different types of shallow and deep foundations, including spread, strap, combined, and raft footings. The document provides details on designing isolated and combined footings to resist vertical loads and moments based on provisions in IS 456. It also discusses wall footings and combined footings that support multiple columns. In summary, the document covers the purpose of footings, various footing types, and design of isolated and combined footings.
This document discusses various techniques for repairing and rehabilitating concrete structures. It covers topics such as concrete deterioration mechanisms, materials used for repair like cement mortars and polymers, and techniques like grouting, jacketing, and external bonding. Assessment of damaged structures involves preliminary investigation, detailed investigation using techniques like core cutting, rebar location, corrosion measurement, and pull-out tests to determine repair requirements. Underwater repair of structures also requires special considerations and techniques.
Kiran more (retrofitting presentation)te bKiranMore87
Ā
This document discusses retrofitting techniques for concrete structures. Retrofitting involves strengthening existing structures that may be damaged or undamaged. It is required when structures are subjected to excessive loading, seismic damage, or do not meet current design standards. The objectives of retrofitting are to increase lateral strength, ductility, and provide better connections between structural elements. Common retrofitting techniques discussed include adding shear walls, infill walls, bracing, wall thickening, and base isolation. Local retrofitting involves jacketing beams, columns, and joints using steel, fiber reinforced polymers, or concrete. Examples of retrofitted structures in Gujarat, India are provided.
This document discusses various techniques for retrofitting existing structures to improve their resistance to seismic activity. It describes adding new shear walls, steel bracing, or jacketing columns as common retrofitting methods. Base isolation, which isolates the structure from foundations, is also discussed. The objectives of retrofitting are outlined as increasing strength, ductility, and protecting life safety. Different classification of retrofitting techniques are provided based on addressing local deficiencies or global irregularities.
Seismic Retrofitting of RC Building with Jacketing and Shear Wall Seismic Ret...Bala murali
Ā
It is a part of retrofitting i.e. repair, renovation, strengthening.
Retrofitting is the modification of existing structures to make them more resistant.
Jacketing is the most popularly used method for strengthening of building columns.
Jacketing consists of added concrete with longitudinal and transverse reinforcement around the existing column.
It improves axial and shear strength of column and major strengthening of foundation may be avoided.
This document discusses column jacketing, which is a method of retrofitting and strengthening existing columns. It involves adding reinforced concrete, steel, or fiber-reinforced polymer around the column. The key steps are preparing the column surface, adding shear keys and reinforcement, applying a bonding agent, and casting the new concrete or installing the jacket. Column jacketing increases the strength and seismic capacity of the column. It improves confinement and increases axial, shear, and foundation load capacity without significant weight addition.
The document discusses methods for strengthening structural members like beams and slabs that have insufficient strength. For beams, additional reinforcement can be added on the bottom and sides, and bonded with epoxy. For slabs, a reinforced concrete topping can be applied to create a composite section with the existing slab, using mechanical anchors and epoxy bonding. Proper preparation of surfaces, curing, and controlling deflection during strengthening are emphasized.
(1) The document discusses the durability and serviceability of concrete. It defines durability as the ability to resist weathering and chemical attacks. (2) The resistance of concrete depends on its quality, constituent materials, and curing process. Well-made concrete that is properly compacted and cured can remain durable if micro-cracks do not connect to the surface. (3) The document presents three holistic models of deterioration in reinforced concrete. The first two models describe a two-stage process where micro-cracks first interconnect, then allow water and chemicals to penetrate and cause damage. The third model emphasizes the role of water cement ratio and the interaction of porosity, chemicals, and intermittent water presence in causing
This document summarizes Indian Standard IS 4326:1993, which provides guidelines for earthquake-resistant design and construction of buildings. It covers terminology, general principles, special construction features, types of construction, categories of buildings, and masonry, timber, and precast construction. For masonry, it specifies use of strong materials and mortar, wall thickness, reinforcement, and strengthening with horizontal bands and vertical dowels. Vertical reinforcement is also required at wall corners and junctions.
Reinforced concrete columns and beams are important structural elements that carry compressive and bending loads respectively. Columns can be categorized as short or long based on their height-width ratio and as spiral or tied columns based on their shape. Beams are classified based on their supports as simply supported, fixed, continuous, or cantilever beams. The construction of RCC columns and beams involves laying reinforcement, forming the structure, and pouring concrete to create these load-bearing elements.
The document provides information on methods of prestressing in concrete, including pretensioning and post-tensioning. It discusses:
- Pretensioning involves stressing steel tendons before the concrete is cast around them.
- Post-tensioning involves stressing steel tendons after the concrete has cured using jacks, then grouting the voids.
- Both methods put the concrete in compression and increase its strength and durability compared to conventional reinforced concrete.
It contains details of retrofitting techniques and their application in various aspects in historical monuments. It would help to protect several heritage structures from the devastating effect of the earthquake. Some applications are also helpful too counter act the severe effect of the wind load. There are many historical heritages especially in India, are reopened to the public after being retrofitted and renovated.
Seismic retrofitting is a collection mitigation technique for earthquake engineering.
It is the modification of existing structures to make them more resistant to seismic activity, ground motion, or soil failure due to earthquake.
It is of utmost important for historic monuments, areas prone to severe earthquakes and tall or
expensive structures.
The retrofitting techniques are also applicable for other natural hazards such as tropical cyclones, tornadoes and severe winds from thunderstorms.
Retrofitting proves to be a better economic consideration and immediate shelter to problems
rather than replacement of building.
The document discusses various methodologies for seismic retrofitting of structures. It begins with defining seismic retrofitting as the modification of existing structures to make them more resistant to earthquakes. It then discusses why retrofitting is required, such as for earthquake damaged or vulnerable buildings. Some common retrofitting approaches are described, including adding shear walls, infill walls, steel bracings, wing walls, wall thickening, mass reduction, base isolation, seismic dampers, and jacketing. The document concludes that retrofitting is a suitable technology to protect structures from earthquakes but that optimization techniques are still needed.
This document discusses the earthquake design philosophy of making buildings resistant to earthquakes. It explains that earthquakes are divided into minor, moderate and strong shaking based on frequency and intensity. The goal of earthquake resistant design is to mitigate earthquake effects by designing structures to withstand smaller forces than actual earthquake forces. The document then outlines the expected damage to buildings under minor, moderate and strong shaking. It emphasizes designing key structural elements like beams and columns to be ductile to absorb energy and prevent collapse during earthquakes. Shear walls are also discussed as important seismic resistant elements.
Framed structures are building skeleton frameworks formed by columns and beams. There are two main types: in-situ reinforced concrete frames and prefabricated frames. Rectangular framed structures use columns and beams arranged at right angles to support floors, walls, and roofs. They are commonly used for multi-story buildings like offices, schools, and hospitals. Framed structures provide large open floor plans and are adaptable to different shapes. Earthquake-resistant features in framed structures include shear walls, moment-resisting frames, and braced structures which resist lateral forces during seismic activity.
This document summarizes a student's seminar report on seismic retrofitting of reinforced concrete structures. It provides background on seismic retrofitting, including definitions and the need for retrofitting existing earthquake vulnerable buildings. It describes various retrofitting strategies classified as global and local techniques. Case studies from the earthquakes in Latur and Gujarat are presented. Indian codes for designing earthquake resistant buildings are also summarized. The conclusion discusses challenges in retrofitting and the need for optimization techniques and professional codes of practice.
The document discusses various types of tall buildings and earthquake resistant design strategies. It describes bundled tube, framed tube, braced tube, and tube-in-tube structural systems that are used for tall buildings. The document also summarizes the Bhuj earthquake that occurred in Gujarat in 2001 and killed over 19,000 people. It provides steps for seismic design including planning symmetrical buildings, avoiding soft stories, using ductile materials, and providing vertical load paths like shear walls, bracing, and tuned mass dampers.
A technical approach to designing earthquake resistant buildings. Contains a brief overview of why a structure fails, building foundation problems and what are the possible solutions
The document discusses various techniques for making earthquake-resistant buildings, including:
1) Bearing wall systems that provide vertical support and lateral resistance through structural walls.
2) Frame systems that use diagonal braces or shear walls to provide lateral rigidity.
3) Moment-resisting frame systems that use rigid beam-column connections to resist lateral forces.
4) Dual systems that combine moment frames and walls/braces to resist both vertical and lateral loads.
5) Cantilever column systems. The document also discusses earthquake building codes in Japan and case studies like Shigeru Ban's paper tube schools.
Seismic retrofitting involves modifying existing structures to increase their resistance to seismic activity like earthquakes. It is important for historically significant buildings, areas prone to earthquakes, and tall or expensive structures. Retrofitting techniques can strengthen structures by increasing lateral strength, ductility, and strength-ductility. Some common retrofitting methods include adding new shear walls, steel bracing, base isolation, and column jacketing. Column jacketing involves wrapping columns with steel, reinforced concrete, or fiber-reinforced polymers to improve shear and flexural capacity. The selection of a retrofitting technique depends on factors like the structure type, material condition, cost, and effectiveness for the situation.
Structural retrofitting involves strengthening existing structures to withstand earthquake loads. Retrofitting techniques discussed include adding shear walls, concrete or steel jacketing of columns, steel plating or fiber wrapping of beams, and upgrading foundations. The objectives of retrofitting are to increase strength and ductility, provide unity to the structure, eliminate weaknesses, avoid brittle failures, and enhance redundancy. Effective retrofitting ensures the intended performance is reliably achieved in a cost-effective manner.
This document provides information on high-rise buildings. It begins with definitions of high-rise, skyscraper, and supertall buildings based on height. It then discusses the demands and drivers for high-rise construction such as land scarcity and prestige. The document outlines the development of high-rise buildings from early structures made of stone/brick and iron to modern steel and concrete designs. It provides details on structural systems such as tube, shear wall, braced frame, and core structures. Finally, it discusses structural loads, foundation types, construction materials and interior/exterior structural components of high-rise buildings.
1. The document discusses techniques for seismic retrofitting of existing structures, including adding new shear walls, steel bracing, jacketing columns and beams, using innovative materials like FRP composites, base isolation, seismic dampers, and tuned mass dampers.
2. It provides an overview of when seismic retrofitting is needed and objectives like ensuring public safety or maintaining structure functionality.
3. A case study describes retrofitting a historic structure in India damaged in an earthquake, including adding diagonal bracing, shotcreting walls, and cross pinning wall corners.
This document discusses techniques for making buildings earthquake resistant. It covers base isolation, which involves supporting a building on bearing pads to allow flexibility during earthquakes. It also discusses energy dissipation devices like friction dampers, metallic dampers, and viscoelastic dampers that can absorb seismic energy. The document provides details on how each technique works and their advantages, such as reducing displacement and maintaining structural performance during earthquakes. It concludes that base isolation and friction dampers are commonly used techniques for earthquake-resistant construction.
The document discusses different types of retaining walls, including gravity, cantilever, counterfort, buttress, sheet pile, bridge, and mechanically stabilized earth retaining walls. It describes the basic design and components of each type of wall. It also covers earth pressure on retaining walls, advantages and disadvantages of retaining walls, and recent advancements in retaining wall technology such as various precast concrete panel systems and geosynthetic reinforced soil structures.
The document discusses high rise buildings and their structures. It defines high rise buildings as between 35-100 meters tall or 12-39 floors. Buildings over 100m are called skyscrapers and over 600m are mega-tall. High rises are constructed to address land scarcity in urban areas and increasing demand for space. Their structures have evolved from early stone and iron frames to steel skeleton frames to reinforced concrete shear walls and core structures. Foundations must transfer enormous loads into the ground through methods like raft or pile foundations. Interior structures use rigid frames, shear walls, and exterior structures employ tube systems to resist lateral wind and seismic loads.
This document discusses seismic retrofitting and base isolation systems. It defines seismic retrofitting as modifying existing structures to make them more resistant to seismic activity. The most widely used retrofitting method is base isolation, which involves inserting rubber or similar isolators between a building's foundation and superstructure. This allows for slight lateral movement during an earthquake to increase the building's natural period and reduce seismic forces. There are two main types of base isolators: sliding systems and elastometric isolators, with lead rubber bearings being a common elastometric isolator that uses lead plugs to dissipate energy and limit displacement. Base isolation has been used worldwide to reinforce historical structures and reduce earthquake damage to buildings and artifacts.
This document summarizes a student project on seismic retrofitting of buildings in Sikkim, India. The project aims to make existing buildings more earthquake resistant by modifying structural components and strengthening materials. Several retrofitting techniques are described, including reinforcement concrete jacketing, steel jacketing, steel caging, crack stitching, grouting, and shotcreting. The objectives are to prevent building collapse and loss of life during earthquakes by upgrading buildings to withstand seismic forces. The conclusion is that retrofitting provides sufficient strengthening to reduce earthquake damage to structures.
This document presents a major project on seismic retrofitting of building structures in Sikkim. The project is submitted by 7 students and aims to make buildings earthquake resistant through retrofitting. It provides background on the 2011 Sikkim earthquake and introduces various retrofitting techniques like reinforcement concrete jacketing, steel jacketing, steel caging, crack stitching, grouting, and shotcreting. The objective is to modify existing structures to protect them from earthquake damage and reduce risks to lives. In conclusion, retrofitting can significantly improve a building's seismic performance and provide sufficient protection.
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Cricket management system ptoject report.pdfKamal Acharya
Ā
The aim of this project is to provide the complete information of the National and
International statistics. The information is available country wise and player wise. By
entering the data of eachmatch, we can get all type of reports instantly, which will be
useful to call back history of each player. Also the team performance in each match can
be obtained. We can get a report on number of matches, wins and lost.
Better Builder Magazine brings together premium product manufactures and leading builders to create better differentiated homes and buildings that use less energy, save water and reduce our impact on the environment. The magazine is published four times a year.
This is an overview of my career in Aircraft Design and Structures, which I am still trying to post on LinkedIn. Includes my BAE Systems Structural Test roles/ my BAE Systems key design roles and my current work on academic projects.
Sachpazis_Consolidation Settlement Calculation Program-The Python Code and th...Dr.Costas Sachpazis
Ā
Consolidation Settlement Calculation Program-The Python Code
By Professor Dr. Costas Sachpazis, Civil Engineer & Geologist
This program calculates the consolidation settlement for a foundation based on soil layer properties and foundation data. It allows users to input multiple soil layers and foundation characteristics to determine the total settlement.
2. INTRODUCTION
ā¢ Earthquake creates great devastation in terms of life, money and failures
of structures
ā¢ Upgrading of certain building systems (existing structures) to make them
more resistant to seismic activity (earthquake resistance) is really of
more importance.
ā¢ Structures can be (a) Earthquake damaged, (b) Earthquake vulnerable
ā¢ Retrofitting proves to be a better economic consideration and immediate
shelter to problems rather than replacement of building.
3. RETROFITTING
IT IS THE MODIFICATION OF EXISTING STRUCTURES TO MAKE THEM MORE RESISTANT TO
SEISMIC ACTIVITY, GROUND MOTION, OR SOIL FAILURE DUE TO EARTHQUAKES.
THE RETROFIT TECHNIQUES ARE ALSO APPLICABLE FOR OTHER NATURAL HAZARDS SUCH AS
TROPICAL CYCLONES, TORNADOES, AND SEVERE WINDS FROM THUNDERSTORMS.
4. NEED FOR SEISMIC RETROFITTING
ā¢ To ensure the safety and security of a building, employees,
structure functionality, machinery and inventory
ā¢ Essential to reduce hazard and losses from non-structural
elements.
ā¢ predominantly concerned with structural improvement to reduce
seismic hazard.
ā¢ Important buildings must be strengthened whose services are
assumed to be essential just after an earthquake like hospitals.
5. PROBLEMS FACED BY STRUCTURAL
ENGINEERS AND BASIC CONCEPT OF
RETROFITTING
PROBLEMS
ā¢ Lack of standards for retrofitting methods
ā¢ Effectiveness of each methods varies a lot depending upon parameters like
type of structures, material condition, amount of damage etc.,
BASIC CONCEPT OF RETROFITTING
The aim is at:-
ā¢ Upgradation of lateral strength of the structure
ā¢ Increase in the ductility of the structure
ā¢ Increase in strength and lateral stiffness of a building.
6. CLASSIFICATION OF RETROFITTING
TECHNIQUES
RETROFITTING TECHNIQUES ARE CLASSIFIED INTO TWO GROUPS
ā¢ GLOBAL RETROFITTING TECHNIQUES:- Global retrofit strategies aim to stiffen the building, by providing additional lateral load resisting elements, or to reduce the irregularities or mass. It includes
ā¢ Addiing Infill walls
ā¢ Additng Shear walls
ā¢ Adding Steel Bracing
ā¢ Reduction of irregularities
ā¢ Mass reduction
ā¢ Base Isolation
LOCAL RETROFITTING TECHNIQUES:- Local retrofit strategies include local strengthening of beams, columns, slabs, beam-to-column or slab-to-column joints, walls and foundations.
Local strengthening allows one or more under-strength elements or connections to resist the strength demands predicted by the analysis, without affecting the overall response of the structure. This scheme tends to be the most economical alternative when
only a few of the buildingās elements are deficient.It includes:-
ā¢ Jacketing of beams
ā¢ Jacketing of columns
ā¢ Jacketing of Beam- Column joints
ā¢ Strengthning of isolated footings
7. ADDITION OF INFILL WALL
The infill wall is the supported wall that closes the perimeter of a building constructed with
a three-dimensional framework structure. Therefore, the structural frame ensures the
bearing function, whereas the infill wall serves to separate inner and outer space, filling up
the boxes of the outer frames. The infill wall has the unique static function to bear its own
weight. The infill wall is an external vertical opaque type of closure.
FEATURES:-
ā¢ Increases lateral stiffness of the building.
ā¢ Due to āStrut Actionā of the infill walls, the flexural and shear forces and ductility
demand on the ground story columns are substantially reduced.
ā¢ It doesnot increase the ductility of structure.
8. ADDITION OF SHEAR WALL
Shear wall is a structural member in a reinforced concrete
framed structure to resist lateral forces such as wind
forces. Shear walls are generally used in high-rise buildings
subject to lateral wind and seismic forces.It increases the
lateral strength, stiffness and ductility of the building
substantially.
9. ADDING STEEL BRACING
ā¢ An effective solution when large openings are required.
ā¢ Potential advantages due to higher strength and stiffness,
opening for natural light can be provided, amount of work is
less since foundation cost may be minimized and adds much
less weight to the existing structure.
10. REDUCTION OF IRREGULARITIES AND MASS
REDUCTION
ā¢ Torsional irregularities can be corrected by the addition of frames or
shear walls. Eccentric masses can be relocated. Seismic joints can be
created to transform an irregular building into multiple regular
structures. Partial demolition can also be an effective measure,
although this may have significant impact on the utility of the
building. Discontinuous components such as columns can be
extended beyond the zone of discontinuity. Walls or braces can
alleviate the deficiency of soft and weak storey
ā¢ Reduction of mass results in reduction of the lateral force demand,
and therefore, can be used in specific cases in lieu of structural
strengthening.
11. BASE ISOLATION
ā¢ This method is based on separating the structure and
foundation by introduction of low stiffness bearings or flexible
layer. This technique is effectively being used in various
structures in countries like USA, Japan, Italy etc.
ā¢ Useful for retrofitting important structures like hospitals,
important historic monuments etc.
ā¢ In India, after 26th jan 2001 Bhuj earthquake, the four āBhuj
Hospital Buildingā was constructed using this technique.
ā¢ Introduction of such system provides Isolation in building and
chances of Toppling down are reduced.
12. JACKETING (LOCAL RETROFITTING
TECHNIQUE)
ā¢ Jacketing a Reinforced concrete member is done to enhance it's strength. This may be
necessary either in case of increase of load or to overcome deficiencies that may
develop over time.
ā¢ This is mostly done for compression members like columns in a building, piers and
abutments of bridges. The process is similar to wearing a jacket in extreme weather
conditions and hence the name.
ā¢ The old concrete surface is thoroughly cleared of loose material or Cement plaster if any
and cleaned properly. Reinforcement bars both vertical and horizontal are provided as
per design and concrete is poured.
ā¢ RCC jacketing can also be carried out for masonry members. Indian Railways have
extensively strengthened the century old bridges this way.
13. STRENGTHENING OF ISOLATED FOOTINGS
Generally, strengthening of the foundations might be needed due to the
alterations in serviceability of the buildings. One method of
strengthening can be carried out by constructing a concrete jacket to
the existing footings. Strengthening foundations by installing jackets can
be achieved either without increase in bearing area at the base or
increasing it, whenever the soil has inadequate bearing capacity.
14. CONCLUSION
ā¢ Seismic Retrofitting is a suitable technology for protection of a variety of structures.
ā¢ It has matured in the recent years to a highly reliable technology.
ā¢ But, the expertise needed is not available in the basic level.
ā¢ The main challenge is to achieve a desired performance level at a minimum cost,
which can be achieved through a detailed nonlinear analysis.
ā¢ Optimization techniques are needed to know the most efficient retrofit for a particular
structure.
ā¢ Proper Design Codes are needed to be published as code of practice for professionals
related to this field
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