This paper deals with the step-by-step retrofitting of buildings by using steel plate shear walls
(SPSWs) with the aid of SAP2000 programme. One type of reinforced concrete building is selected for
evaluation. This building represents the most used forms of residential buildings in the Sudan, in terms of
geometric form, and dimensions. This paper uses the equivalent static method provided in the regulations
proposed by the Egyptian Society for Earthquake Engineering. One typical model was selected from the existing
residual buildings in Khartoum city, as a case study. The proposed methodology that has been used to evaluate
the seismic resistance of chosen building is done through the design of the structural elements of the buildings
before and after adding the seismic forces. The retrofitting of building was done by using steel plate shear walls
with thicknesses of 5mm, 7mm and 10mm. From the results obtained, it was found that the use of two additional
SPSWs with 7 mm thickness placed at the internal frame of the existing system, resulted in a reduction of
bending moments in the columns and beams. The increase of thickness has a clear effect on the bending moment
of the columns, but has little effects on the bending moments of the beams.
Methods for seismic retrofitting of structures commentsGuille Campos
This document discusses various methods for seismic retrofitting of existing structures, including both conventional and innovative approaches. Conventional methods include adding structural walls, bracing, and jacketing beams and columns. Innovative methods discussed are use of fiber reinforced polymer composites to strengthen members and base isolation, which places flexible isolation systems between the foundation and structure. Supplemental energy dissipation devices are also presented as an alternative retrofitting strategy to base isolation. Overall the document provides an overview of different retrofitting techniques and highlights important considerations for selecting and implementing optimal seismic retrofitting solutions.
CE 72.52 - Lecture 8a - Retrofitting of RC MembersFawad Najam
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 provides an overview of seismic retrofitting techniques for reinforced concrete (RC) structures. It discusses common structural systems and deficiencies seen in mid-rise RC buildings with masonry infill walls in India. Retrofitting aims to enhance structural capacity and integrity, while rehabilitation focuses on repairing damage. Key retrofitting techniques include jacketing columns and beams, adding steel or CFRP, strengthening joints with dovels or clamps, and improving the slab and wall diaphragm. Occupant friendly retrofitting uses epoxy-bonded precast concrete panels inserted through doors to reinforce infill walls without disrupting occupants. Overall, seismic retrofitting can significantly increase a structure's lateral load capacity, stiffness,
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 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 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.
Seismic Retrofitting On RC Structures-Pushover AnalysisRamesh M
Seismic retrofitting provides techniques to strengthen existing structures and improve their resistance to earthquakes. Common deficiencies in mid-rise reinforced concrete buildings include insufficient stiffness, poor reinforcement, and workmanship. Retrofitting aims to enhance structural capacity through methods like column jacketing, beam strengthening with carbon fiber, and improving the roof diaphragm. Pushover analysis evaluates a structure's strength and deformation before and after retrofitting to assess performance improvement. Occupant friendly rehabilitation uses lightweight epoxy-bonded concrete panels connected to masonry infill walls and frames, improving lateral load capacity and stiffness without disrupting occupants. Proper design codes and expertise are still needed to optimize efficient retrofitting.
Methods for seismic retrofitting of structures commentsGuille Campos
This document discusses various methods for seismic retrofitting of existing structures, including both conventional and innovative approaches. Conventional methods include adding structural walls, bracing, and jacketing beams and columns. Innovative methods discussed are use of fiber reinforced polymer composites to strengthen members and base isolation, which places flexible isolation systems between the foundation and structure. Supplemental energy dissipation devices are also presented as an alternative retrofitting strategy to base isolation. Overall the document provides an overview of different retrofitting techniques and highlights important considerations for selecting and implementing optimal seismic retrofitting solutions.
CE 72.52 - Lecture 8a - Retrofitting of RC MembersFawad Najam
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 provides an overview of seismic retrofitting techniques for reinforced concrete (RC) structures. It discusses common structural systems and deficiencies seen in mid-rise RC buildings with masonry infill walls in India. Retrofitting aims to enhance structural capacity and integrity, while rehabilitation focuses on repairing damage. Key retrofitting techniques include jacketing columns and beams, adding steel or CFRP, strengthening joints with dovels or clamps, and improving the slab and wall diaphragm. Occupant friendly retrofitting uses epoxy-bonded precast concrete panels inserted through doors to reinforce infill walls without disrupting occupants. Overall, seismic retrofitting can significantly increase a structure's lateral load capacity, stiffness,
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 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 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.
Seismic Retrofitting On RC Structures-Pushover AnalysisRamesh M
Seismic retrofitting provides techniques to strengthen existing structures and improve their resistance to earthquakes. Common deficiencies in mid-rise reinforced concrete buildings include insufficient stiffness, poor reinforcement, and workmanship. Retrofitting aims to enhance structural capacity through methods like column jacketing, beam strengthening with carbon fiber, and improving the roof diaphragm. Pushover analysis evaluates a structure's strength and deformation before and after retrofitting to assess performance improvement. Occupant friendly rehabilitation uses lightweight epoxy-bonded concrete panels connected to masonry infill walls and frames, improving lateral load capacity and stiffness without disrupting occupants. Proper design codes and expertise are still needed to optimize efficient retrofitting.
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.
Comparison of Mesh Type Seismic Retrofitting for Masonry Structureschali090
The tremendous loss of life that resulted in the aftermath of recent earthquakes in developing countries is mostly due to the collapse of non-engineered building structures. It has been observed that these buildings cannot withstand the lateral loads imposed by an earthquake and often fails, in a brittle manner. This underscores the urgency to find simple and economic solutions to reinforce these buildings. Different conventional retrofitting techniques are available to increase the strength and/or ductility of unreinforced masonry walls. Recent years, several researches work on mesh type retrofitting for masonry structures to delay or prevent the collapse of buildings and reduce the number of lives lost during devastating earthquake events. This paper reviews and discusses the state-of-the-art on seismic retrofitting of masonry walls with emphasis on the mesh type retrofitting techniques include retrofitting procedures, cost, improvement in structural performance and limitations.
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.
Past earthquakes have shown that existing buildings designed to older seismic codes are vulnerable. Retrofitting techniques can upgrade seismic capacity. This paper evaluates four retrofitting techniques applied to four existing reinforced concrete building models: adding reinforced concrete walls, steel bracing, column jacketing, and strengthening columns with steel angles. Each technique is examined to determine its effect on top displacement, acceleration, base shear, and period. The technique with the minimum response for each model will be selected as the optimal retrofitting method for that structure. Several retrofitting techniques are described, including concrete jacketing, walls, and bracing. Factors such as strength, ductility, stiffness, bond, and material properties must be considered in retrofitting design.
Seismic Retrofitting of Masonry StructuresDr K M SONI
Large number of masonry buildings are susceptible to damages during earthquakes due to no provisions of features of seismic requirements. Such features can be included during seismic retrofitting to increase resistance of buildings to earthquakes.
Seismic retrofitting modifies existing structures to increase their resistance to earthquakes. Common techniques include base isolators, which separate the structure from the ground using flexible bearings; supplementary dampers, which absorb and dissipate vibrational energy; tuned mass dampers, which reduce vibrations; and slosh tanks and active control systems, which also increase damping. The goal of retrofitting is to protect lives and ensure structural survivability, functionality, and integrity for historically significant buildings. Retrofitting techniques have evolved with new materials and provisions, helping structures withstand seismic impacts.
This document discusses the use of textiles in earthquake prevention. It notes that masonry structures and soil embankments are vulnerable during earthquakes due to inability to withstand dynamic loads and risk of landslides. Multifunctional textile structures are being developed to retrofit existing buildings and earthworks. Different textile materials discussed that can be used include fiber reinforced polymers, carbon fiber reinforced concrete, aramid fibers, and glass fiber. Applications described are using fiber reinforced polymer plates and wrapping to strengthen concrete, aramid fiber sheets to retrofit walls, and base isolation systems to protect structures during seismic events.
Kiran more (retrofitting presentation)te bKiranMore87
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 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.
Retrofitting of irrigation structures- Prakasam Barrage, Andhra Pradesh, -A...IEI GSC
1) The document discusses the retrofitting of the Prakasam Barrage irrigation structure across the Krishna River in Andhra Pradesh.
2) Retrofitting is done to strengthen structures and prolong their lifespan by enhancing safety against damage from loads, disasters, or aging.
3) The Prakasam Barrage was originally conceived in the 19th century and upgraded in the 20th century. It underwent retrofitting from 2002-2004 to reinforce it and sustain its life in response to changing design standards.
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.
Retrofitting case study of RCC structureManish Sharma
This document discusses several case studies of seismic retrofitting techniques used to improve the performance of vulnerable or earthquake damaged reinforced concrete buildings. It describes the features and damage observed in five buildings from earthquakes in Mexico and Turkey. For each building, it outlines the retrofitting techniques employed such as adding concrete shear walls, bracing, jacketing of columns and beams, and infilling frame bays with shear walls. The expected performance of the retrofitted buildings, based on analytical modeling, was improved seismic resistance and reduced vibration periods.
Comparison of Different Retrofitting Techniques for Masonry BuildingsNitin Kumar
The document compares different retrofitting techniques for masonry buildings, including jacketing using steel wire meshing, GI welded wire meshing, and polypropylene bands, as well as splint and bandage techniques using RCC and GI welded wire meshing. It provides details on the retrofitting process using polypropylene bands, which involves fixing vertical and horizontal bands to the walls with welding and wires, and connecting them to roof and floor elements. It also describes the retrofitting process using wire mesh, which involves removing plaster, raking mortar joints, drilling walls, and applying concrete in layers with embedded reinforcement. The document aims to present comparative results of various retrofitting techniques.
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
Seismic retrofit for rcc structureslocal global consequencesHashim k abdul azeez
This document discusses various schemes for retrofitting reinforced concrete structures to improve their seismic performance. It begins by outlining the objectives and framework for rehabilitation, including setting performance targets based on acceptable damage levels. It then describes several local and global intervention methods. Local methods include injecting cracks, using shotcrete, steel plate adhesion, steel jacketing, and externally bonded fiber-reinforced polymers. Global methods involve overall structural modification through techniques like base isolation or supplemental damping. The document stresses the importance of considering both structural and non-structural elements as well as foundation systems when selecting rehabilitation strategies.
This document discusses retrofitting techniques for masonry buildings to strengthen them against earthquakes. It describes various structural and member retrofitting methods such as adding shear walls, jacketing beams and columns. Failure mechanisms of masonry buildings are outlined, including out-of-plane failure, in-plane failure and connection failure. Repair techniques like jacketing are explained. The document also references Indian codes for earthquake design and concludes that retrofitting is an effective technology for protecting structures, but expertise is still needed at the basic level.
Seismic Retrofitting of RC Buildingwith Jacketing and Shear Wall Seismic Ret...Bala murali
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.
The document discusses seismic retrofitting of buildings to make them more resistant to earthquakes. It describes how seismic retrofitting includes strengthening structural elements like connections, walls, and foundations. It outlines several methods for retrofitting such as adding new structural elements like walls, using innovative materials like fiber reinforced plastics, implementing base isolation systems, and supplemental energy dissipation. The document provides details on evaluating seismic vulnerability and the need for retrofitting to improve building safety, reduce hazards, and limit losses from earthquakes.
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.
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.
Comparison of Mesh Type Seismic Retrofitting for Masonry Structureschali090
The tremendous loss of life that resulted in the aftermath of recent earthquakes in developing countries is mostly due to the collapse of non-engineered building structures. It has been observed that these buildings cannot withstand the lateral loads imposed by an earthquake and often fails, in a brittle manner. This underscores the urgency to find simple and economic solutions to reinforce these buildings. Different conventional retrofitting techniques are available to increase the strength and/or ductility of unreinforced masonry walls. Recent years, several researches work on mesh type retrofitting for masonry structures to delay or prevent the collapse of buildings and reduce the number of lives lost during devastating earthquake events. This paper reviews and discusses the state-of-the-art on seismic retrofitting of masonry walls with emphasis on the mesh type retrofitting techniques include retrofitting procedures, cost, improvement in structural performance and limitations.
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.
Past earthquakes have shown that existing buildings designed to older seismic codes are vulnerable. Retrofitting techniques can upgrade seismic capacity. This paper evaluates four retrofitting techniques applied to four existing reinforced concrete building models: adding reinforced concrete walls, steel bracing, column jacketing, and strengthening columns with steel angles. Each technique is examined to determine its effect on top displacement, acceleration, base shear, and period. The technique with the minimum response for each model will be selected as the optimal retrofitting method for that structure. Several retrofitting techniques are described, including concrete jacketing, walls, and bracing. Factors such as strength, ductility, stiffness, bond, and material properties must be considered in retrofitting design.
Seismic Retrofitting of Masonry StructuresDr K M SONI
Large number of masonry buildings are susceptible to damages during earthquakes due to no provisions of features of seismic requirements. Such features can be included during seismic retrofitting to increase resistance of buildings to earthquakes.
Seismic retrofitting modifies existing structures to increase their resistance to earthquakes. Common techniques include base isolators, which separate the structure from the ground using flexible bearings; supplementary dampers, which absorb and dissipate vibrational energy; tuned mass dampers, which reduce vibrations; and slosh tanks and active control systems, which also increase damping. The goal of retrofitting is to protect lives and ensure structural survivability, functionality, and integrity for historically significant buildings. Retrofitting techniques have evolved with new materials and provisions, helping structures withstand seismic impacts.
This document discusses the use of textiles in earthquake prevention. It notes that masonry structures and soil embankments are vulnerable during earthquakes due to inability to withstand dynamic loads and risk of landslides. Multifunctional textile structures are being developed to retrofit existing buildings and earthworks. Different textile materials discussed that can be used include fiber reinforced polymers, carbon fiber reinforced concrete, aramid fibers, and glass fiber. Applications described are using fiber reinforced polymer plates and wrapping to strengthen concrete, aramid fiber sheets to retrofit walls, and base isolation systems to protect structures during seismic events.
Kiran more (retrofitting presentation)te bKiranMore87
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 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.
Retrofitting of irrigation structures- Prakasam Barrage, Andhra Pradesh, -A...IEI GSC
1) The document discusses the retrofitting of the Prakasam Barrage irrigation structure across the Krishna River in Andhra Pradesh.
2) Retrofitting is done to strengthen structures and prolong their lifespan by enhancing safety against damage from loads, disasters, or aging.
3) The Prakasam Barrage was originally conceived in the 19th century and upgraded in the 20th century. It underwent retrofitting from 2002-2004 to reinforce it and sustain its life in response to changing design standards.
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.
Retrofitting case study of RCC structureManish Sharma
This document discusses several case studies of seismic retrofitting techniques used to improve the performance of vulnerable or earthquake damaged reinforced concrete buildings. It describes the features and damage observed in five buildings from earthquakes in Mexico and Turkey. For each building, it outlines the retrofitting techniques employed such as adding concrete shear walls, bracing, jacketing of columns and beams, and infilling frame bays with shear walls. The expected performance of the retrofitted buildings, based on analytical modeling, was improved seismic resistance and reduced vibration periods.
Comparison of Different Retrofitting Techniques for Masonry BuildingsNitin Kumar
The document compares different retrofitting techniques for masonry buildings, including jacketing using steel wire meshing, GI welded wire meshing, and polypropylene bands, as well as splint and bandage techniques using RCC and GI welded wire meshing. It provides details on the retrofitting process using polypropylene bands, which involves fixing vertical and horizontal bands to the walls with welding and wires, and connecting them to roof and floor elements. It also describes the retrofitting process using wire mesh, which involves removing plaster, raking mortar joints, drilling walls, and applying concrete in layers with embedded reinforcement. The document aims to present comparative results of various retrofitting techniques.
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
Seismic retrofit for rcc structureslocal global consequencesHashim k abdul azeez
This document discusses various schemes for retrofitting reinforced concrete structures to improve their seismic performance. It begins by outlining the objectives and framework for rehabilitation, including setting performance targets based on acceptable damage levels. It then describes several local and global intervention methods. Local methods include injecting cracks, using shotcrete, steel plate adhesion, steel jacketing, and externally bonded fiber-reinforced polymers. Global methods involve overall structural modification through techniques like base isolation or supplemental damping. The document stresses the importance of considering both structural and non-structural elements as well as foundation systems when selecting rehabilitation strategies.
This document discusses retrofitting techniques for masonry buildings to strengthen them against earthquakes. It describes various structural and member retrofitting methods such as adding shear walls, jacketing beams and columns. Failure mechanisms of masonry buildings are outlined, including out-of-plane failure, in-plane failure and connection failure. Repair techniques like jacketing are explained. The document also references Indian codes for earthquake design and concludes that retrofitting is an effective technology for protecting structures, but expertise is still needed at the basic level.
Seismic Retrofitting of RC Buildingwith Jacketing and Shear Wall Seismic Ret...Bala murali
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.
The document discusses seismic retrofitting of buildings to make them more resistant to earthquakes. It describes how seismic retrofitting includes strengthening structural elements like connections, walls, and foundations. It outlines several methods for retrofitting such as adding new structural elements like walls, using innovative materials like fiber reinforced plastics, implementing base isolation systems, and supplemental energy dissipation. The document provides details on evaluating seismic vulnerability and the need for retrofitting to improve building safety, reduce hazards, and limit losses from earthquakes.
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.
Helen McHugh, Head of Sustainable Technology at ebm-papst - Retrofitting Case...Global Business Events
This document discusses how upgrading building fans with EC (electronically commutated) technology can significantly reduce energy consumption and costs. It provides case studies showing energy savings of 51-78% from retrofitting air handling units, fan coils, data center cooling units, and condensers with EC fans. EC fans are more efficient than standard AC fans due to integrated speed control and ability to continuously modulate fan speed to match demand. This saves energy compared to standard on/off fan operation.
Final presentations lxb123530 attempt_2014-05-06-22-47-10_20140506 retrofitti...designprince
This document discusses retrofitting an outdated suburban retail development from the 1950s in Austin, Texas. The existing development, a shopping center called Alamo Drafthouse, suffers from poor urban design with a single commercial use, large surface parking lots, low density, and an emphasis on cars over pedestrians. The document evaluates two approaches to retrofitting the site: standard urban infill, which would increase density, mix uses, add walkability and green space; and a pattern language approach, which provides a framework of design patterns to create a more identifiable neighborhood with a mix of uses and a network of paths. Both approaches are compared as alternatives to retrofit the outdated shopping center development.
DESIGN AND ANALYSIS OF MULTI STORIED STRUCTURES USING STATIC NON LINEAR ANALYSISIjripublishers Ijri
In plan during the seismic excitation using nonlinear static analysis (pushover) have been performed on the
same structure. The literature pertaining to pushover analysis is reviewed. The pushover analysis adopted
in the present study is on similar lines with the procedure presented by Ashraf Habibullah and Stephen
Pyle using ETABS V 9.7 structural analysis software. The effect of earthquake force in a idealized G+4 story
building under maximum earthquake zone, with the help of pushover analysis has been investigated and
the results were compared in terms of base shear, displacement, spectral acceleration, spectral displacement
and effective damping and effective time period .to strengthen the symmetric and un symmetric RCC
framed buildings` steel braces are included by using retrofitting method.
The document discusses reinforced hollow concrete block masonry (RHCBM) as a construction method that can effectively resist seismic forces. RHCBM involves reinforcing hollow concrete blocks with vertical and horizontal steel reinforcement. It provides benefits like increased strength, ductility, cost-effectiveness, and faster construction compared to other methods. For existing non-engineered masonry structures, retrofitting techniques like grouting and wire meshing can be used to enhance earthquake resistance. Experimental results show RHCBM panels have higher ultimate load capacity and displacement ductility than conventional masonry.
seismic retrofitting using precast elementsdiscorajan
This document discusses methods for seismic retrofitting of existing buildings using precast concrete elements. There are three main methods - increasing lateral load capacity through the installation of precast concrete frames, braces, or armature cross walls. Precast concrete frames can be installed as an outer frame or parallel unit frames attached to new or existing foundations. Precast concrete braces are assembled off-site from precast leg and central units connected by pre-stressing cables. Armature cross walls involve replacing timber walls with precast wall panels connected by pins and light grouting.
This document outlines basic principles for designing earthquake-resistant buildings. It discusses how earthquakes cause buildings to vibrate and experience large internal forces, potentially leading to damage or collapse. Earthquakes represent the most significant natural risk worldwide in terms of loss of life and economic costs. While seismic risk is often seen as concentrated in areas of high seismicity, regions of low-to-moderate seismicity also face risk due to lack of preventive measures, resulting in high vulnerability. The document presents principles for conceptual design and detailing of structural and non-structural elements to improve earthquake resistance without large additional costs.
This document presents a thesis on retrofitting existing buildings in Bangladesh to improve seismic performance. It begins with an introduction to earthquakes and Bangladesh's seismic environment due to its location between tectonic plates. The objective is to evaluate an existing building using static analysis and design software to determine demand-capacity ratios of members under seismic loads. Beams exceeding capacity will be retrofitted with steel plating and columns with concrete jacketing. Dynamic time history analysis will also be performed and results compared to static analysis. The methodology, building model, load calculations, software analysis, retrofitting designs, and planned comparisons are described over several chapters.
Standard Penetration Test & Liquid Limit,Plasticity Limitgurjapsinghsomal
This document describes the procedure for conducting a standard penetration test (SPT). The SPT is commonly used to determine the properties of cohesionless soils that cannot be easily sampled. It involves driving a split spoon sampler into the ground using a 63.5 kg hammer dropped from a height of 0.75 m. The number of blows required to drive the sampler each 150 mm provides the standard penetration resistance value (N), which can indicate the relative density, shear strength, and compressibility of the soil. Corrections may be applied to N for certain soil types.
METHODS OF RETROFITTING EARTHQUAKE DAMAGESUmer Farooq
The primary purpose of earthquake retrofitting is to keep a home from being displaced from its concrete foundation. Retrofitting means making improvements to an existing building. The purpose is to make the building safer and less prone to major structural damage during an earthquake. Existing homes need to be retrofitted because our understanding of the effects of earthquakes as well as construction techniques have improved after the homes were built. The terms house bolting, foundation bolting and cripple wall bracing are often used synonymously with earthquake retrofitting
This document discusses repairs, rehabilitation, and retrofitting of structures. It begins by defining repair, rehabilitation, and retrofitting. Repair returns a structure to its previous condition without improving strength. Rehabilitation considers strength by repairing damage. Retrofitting modifies existing structures to increase resistance to hazards like earthquakes. It provides examples of each process. The document outlines evaluation and quality control methods for repairs. It also discusses materials and techniques used for crack repair in structures, including epoxy injection grouting. Overall, the document provides an overview of restoring and upgrading structures through various repair, rehabilitation, and retrofitting methods.
This document provides information on the standard penetration test (SPT), including the instruments, procedures, corrections, and applications. It describes that the SPT is commonly used to evaluate the in-situ properties of cohesionless soils. The key instruments are a split spoon sampler, drive-weight assembly with a 63.5 kg hammer, and cathead. The procedure involves drilling a borehole, driving the sampler with the hammer, and recording the number of blows to penetrate each 15 cm interval. Corrections are made to account for overburden pressure, dilatancy effects, and hammer energy efficiency. The SPT provides useful correlations to estimate properties like relative density, friction angle, and strength.
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
ANALYSIS OF REINFORCED CONCRETE FRAMED STRUCTURE(G+15) WITH STEEL BRACING SYS...IRJET Journal
This document summarizes the analysis of a reinforced concrete framed structure (G+15 building) with steel bracing systems using ETABS software. The building was modeled in three configurations - without bracing/shear walls, with various bracing systems, and with shear walls. Bracings and shear walls were placed at the center bays. The models were analyzed for seismic forces in various seismic zones using ETABS. Story displacement and story shear values were compared for models with V-bracing and chevron bracing. It was found that chevron bracing performed better in Zones II&III while V-bracing was better in Zones IV&V.
seismic response of multi storey building equipped with steel bracingINFOGAIN PUBLICATION
1) The document analyzes the seismic response of a multi-storey reinforced concrete building equipped with different steel bracing systems.
2) A 7-storey building model was created and linear analysis was conducted to compare the responses of an unbraced building model and models with X, V, and inverted V bracing systems.
3) The results showed that all bracing systems reduced displacement, drift, shear forces, and bending moments compared to the unbraced building, with the X bracing system providing the largest reductions in structural response.
Analysis and Optimum Design for Steel Moment Resisting Frames to Seismic Exci...IJCMESJOURNAL
The essential purpose of this wander is to develop an Interior Penalty Function (IPF) based estimation to multi-storey steel traces for slightest weight of frames. The frames are proposed for contradicting even impact in view of seismic stacking close by gravity forces. Various structural stems are used for restricting seismic (lateral) forces; however steel moment resisting frames (MRFs) are considered for the present work. The framework solidifies codal courses of action of IS 800-2007, as needs be gets the edges with perfect weight for in-plane moments with lateral support of beam element. Strength and buckling criteria are considered as direct goals close by side constraints in formulating optimization problem. A Software program is made that uses an interior penalty function (IPF) for weight minimization of two-dimensional moment restricting steel encompassed structures. The program uses MATLAB, performs one dimensional interest, and structural design in an iterative technique. The design cases have exhibited that the proposed estimation gives a beneficial instrument to the practicing fundamental algorithm. The program is associated with 6 and 9 storey (4 bays) moment resisting frames (MRFs). The program showed its capacity of optimizing the largeness of two medium size frames. To get part obliges in frames an examination technique must be associated. In the present work Equivalent Lateral Force framework (ELF) and material nonlinear time history analysis (NTH) are associated and perfect qualities gained from both the examinations are contemplated.
Analysis and Optimum Design for Steel Moment Resisting Frames to Seismic Exci...IJCMESJOURNAL
The essential purpose of this wander is to develop an Interior Penalty Function (IPF) based estimation to multi-storey steel traces for slightest weight of frames. The frames are proposed for contradicting even impact in view of seismic stacking close by gravity forces. Various structural stems are used for restricting seismic (lateral) forces; however steel moment resisting frames (MRFs) are considered for the present work. The framework solidifies codal courses of action of IS 800-2007, as needs be gets the edges with perfect weight for in-plane moments with lateral support of beam element. Strength and buckling criteria are considered as direct goals close by side constraints in formulating optimization problem. A Software program is made that uses an interior penalty function (IPF) for weight minimization of two-dimensional moment restricting steel encompassed structures. The program uses MATLAB, performs one dimensional interest, and structural design in an iterative technique. The design cases have exhibited that the proposed estimation gives a beneficial instrument to the practicing fundamental algorithm. The program is associated with 6 and 9 storey (4 bays) moment resisting frames (MRFs). The program showed its capacity of optimizing the largeness of two medium size frames. To get part obliges in frames an examination technique must be associated. In the present work Equivalent Lateral Force framework (ELF) and material nonlinear time history analysis (NTH) are associated and perfect qualities gained from both the examinations are contemplated.
Dynamic Response of High Rise Structures Under The Influence of Shear WallsIJERA Editor
This study presents the procedure for seismic performance estimation of high-rise buildings based on a concept of the capacity spectrum method. In 3D analytical model of thirty storied buildings have been generated for symmetric buildings Models and analyzed using structural analysis tool ETABS. The analytical model of the building includes all important components that influence the mass, strength, stiffness and deformability of the structure. To study the effect of concrete core wall & shear wall at different positions during earthquake, seismic analysis using both linear static, linear dynamic and non-linear static procedure has been performed. The deflections at each storey level has been compared by performing Equivalent static, response spectrum method as well as pushover method has also been performed to determine capacity, demand and performance level of the considered building models. From the below studies it has been observed that non-linear pushover analysis provide good estimate of global as well as local inelastic deformation demands and also reveals design weakness that may remain hidden in an elastic analysis and also the performance level of the structure. Storey drifts are found within the limit as specified by code (IS: 1893-2002) in Equivalent static, linear dynamic & non-linear static analysis.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
EFFECT OF SEISMIC LOAD ON REINFORCED CONCRETE MULTISTORY BUILDING FROM ECONOM...IAEME Publication
This paper aims at studying the effect of earthquake loading on the constructional
design of a 20-storey reinforced concrete residential building from economical point
of view. This type of loading should be taken into considerations now in Iraq
especially after the earthquake of 7.3 magnitude that occurred in November 2017 near
the city of Halabja by about 31 kilometers. The same reinforced concrete multistory
building was designed twice; once with traditional gravity dead and live loading and
the second with adding earthquake loading in order to discuss the difference from
structural and economical points of view. A commercial package ETABS2018 was
used to analyze this 60-meter-high building. The building was analyzed according to
the American code ASCE7-10, while it was designed according to ACI 318-14. A huge
increase in the steel reinforcement amounts in columns, beams, slabs and shear walls
were recorded due to taking the seismic load into considerations. More specifically,
the reinforcing steel amounts increased by about 327%, 165%, 40% and 91.3% for
columns, beams, slabs and shear walls, respectively. Therefore, cost was raised by
about 328%, 165%, 40% and 91.3% for columns, beams, slabs and shear walls,
respectively. It is worth to mention here that the maximum increase in main
reinforcement of beams was observed on the storey 10. Whereas, in slabs, the
maximum increase that was recorded in main steel reinforcement was happened from
the storey 8 to the building top. In columns, the main reinforcement increase was seen
on the 9th, 10th and 11th storeys. Finally, in shear walls, the main reinforcement
increase was seen in the 1
st
, 2
nd
and 3
rd
storey due to effect lateral shear forces
This research introduces a new simple, efficient, and practical procedure to design
the reinforced concrete (RC) circular slabs which have large diameters. The principal
idea of this paper concerns to use the isotropic perpendicular RC straight joists to
resist the external load. The yield-line theory was adapted to analysis the circular
waffle slabs. The steps of design were according to the ACI Code provisions. Fixed
and simply supported circular slabs were presented. Closed form equations have been
driven by author for the purposes of analysis and design this type of slabs by the
present procedure. Uniformly distributed load was considered, that represent almost
practical cases. Useful illustration example is presented in this study according to the
available materials in Iraq to facilitate the job of designers. The good performance of
RC circular slab which design by the present procedure proved clearly the efficiency
of this technique.
IRJET- Dynamic Analysis of Tall Tubular Steel Structures for Different Geomet...IRJET Journal
This document analyzes the dynamic behavior of tall tubular steel structures with different geometric configurations (square, rectangular, triangular, hexagonal) using computer modeling and simulation. Modal analysis showed hexagonal structures have the longest period and lowest frequency, indicating greater stability. Earthquake and wind analyses found hexagonal structures experienced the highest displacements and drift. In general, tubular structures performed better than conventional steel frames. Future work could optimize hexagonal designs using additional structural systems or analyze complex tube-in-tube configurations.
Seismic Behavior Of Double Steel Plate Composite Wall Under Cyclic LoadingIRJET Journal
This document analyzes the seismic behavior of double steel plate composite walls (DSPCWs) under cyclic loading through finite element analysis. Six DSPCW models were developed varying the aspect ratio (length to width ratio) and tie stud spacing. Lower aspect ratios and smaller tie stud spacings improved the wall's energy dissipation, ductility, and resistance to strength and stiffness degradation under cyclic loads. The analysis found the aspect ratio and tie stud spacing significantly impacted the wall's hysteretic response, failure mechanism, strength deterioration, and stiffness. Walls with lower aspect ratios or smaller tie stud spacings exhibited greater seismic resistance and deformation capacity.
This document summarizes a dissertation analyzing the seismic performance of an irregular 11-story building with AAC blocks using the response spectrum method in ETABS. The objectives were to analyze and design the building economically according to codes while studying the effects of earthquake and wind loads. The methodology involved defining materials, loads, response spectra, and mass/diaphragm in ETABS to analyze and design the building. Results showed maximum displacements of 25.95mm, story shear of 3.138kN, and overturning moment of 75.980kNm. Reinforcement percentages ranged from 3.76% at the base to 0.8% in upper stories. The study concluded the AAC blocks provided a lighter and more econom
This document summarizes a study that tested reinforced concrete beam-column connections under cyclic loading to evaluate their seismic performance. A 1/3 scale beam-column specimen was designed and constructed based on analysis of a 4-story building frame. The specimen was tested under reversed cyclic loading with increasing displacements up to failure while monitoring response through instruments. Cracks initially formed in flexure and progressed to shear cracks. Analysis of load-displacement hysteresis loops provided information on ductility, energy dissipation, strength degradation, and stiffness degradation to evaluate the seismic performance of the connection.
Optimisation of earth quake response of tall building by using different fram...eSAT Journals
Abstract In India reinforced concrete structures are mostly used since this is the most convenient & economic system for low-rise buildings. However, for medium to high-rise buildings this type of structure is no longer economic because of increased dead load, less stiffness, span restriction and hazardous formwork. So the Structural engineers are facing the challenge of striving for the most efficient and economical design solution. Also Earthquake engineering should be extended to the design of earthquake sensitive tall buildings. Use of composite material is of particular interest, due to its significant potential in improving the overall performance through rather modest changes in manufacturing and constructional technologies. In India, many consulting engineers are reluctant to accept the use of composite steel-concrete structure because of its unfamiliarity and complexity in its analysis and design. But literature says that if properly configured, then composite steel-concrete system can provide extremely economical structural systems with high durability, rapid erection and superior seismic performance characteristics. This paper discusses Optimization of Earth quack response of tall building by using different types of framing system over the height of the building . So to optimize the earth quack response, a Ten story Combined model ( R.C.C, Composite and Steel frames) is developed and analyzed by using ETABS ; it proves that the combined model is better option. Key Words: Composite structure, Tall Building and Steel structures
IRJET- Dynamic Analysis of Tall Tubular Steel Structures of Hexagon Configura...IRJET Journal
This document discusses the dynamic analysis of tall tubular steel structures with hexagonal configurations. It aims to understand the behavior of such structures compared to traditional steel beam-column frames. Models of an 88-story office building are created in ETABS with different structural systems - a steel moment frame, hexagonal tubular frame, and hexagonal frame with diagonal bracing. The models are analyzed under wind, gravity, and earthquake loads. Results for base shear, displacements, drifts and frequencies are compared between the systems. The study aims to determine the optimal geometric configuration for tall tubular steel structures.
Study of Wind Loads on Steel Building with and Without Different Braced Syste...IRJET Journal
This document summarizes a study analyzing the performance of a 40-story steel building under wind loads using different bracing systems in Tekla Structures software. The building was modeled without bracing and with V-bracing, X-bracing, and chevron bracing. Parameters like natural period, story drift, and displacement were compared. The results showed that the chevron bracing design provided the best structural performance with the shortest natural periods and lowest displacements and drifts. Thus, chevron bracing was the most effective at reducing a building's motion under wind loads compared to the other bracing configurations studied.
Out of Plane Behavior of Contained Masonry Infilled Frames Subjected to Seism...paperpublications3
The document discusses the out-of-plane behavior of reinforced concrete (RC) frames with contained masonry infill subjected to seismic forces. It presents results from a finite element analysis of RC frames with different configurations: bare frames, frames with plain masonry infill, and frames with contained masonry infill wrapped in steel wires. The analysis determined the natural frequencies of the frames under different configurations and aspect ratios. It found that frames with contained masonry infill had the highest natural frequencies, followed by frames with plain masonry infill, with bare frames having the lowest natural frequencies.
SEISMIC EVALUATION OF RETROFITING TO REINFORCED CONCRETE BUILDINGSIRJET Journal
This document summarizes a research study on seismic evaluation and retrofitting of existing reinforced concrete buildings. The study analyzed a typical existing hostel building using pushover analysis to evaluate the performance of the bare reinforced concrete frame and infilled frame. The analysis identified weaknesses in the bare frame where beams would fail first during an earthquake. Retrofitting methods using fiber reinforced polymer composites were used to strengthen weak structural members. The study concluded that columns in existing buildings need to be retrofitted to have adequate strength to prevent premature collapse at the performance point during an earthquake.
STRUCTURAL PERFORMANCE OF INNOVATIVE FABRICATED COUPLED COMPOSITE COLUMN IN M...IRJET Journal
This document summarizes a research paper that analyzes the structural performance of an innovative fabricated coupled composite column system for multi-story buildings. The system uses closely spaced double small-section concrete filled steel tubes connected by steel connector beams. Buckling load analysis was performed by varying the number of connectors, column cross-section size, and concrete grade. Seismic analysis was then conducted by replacing conventional columns in a 10-story building model with the coupled composite columns under different parametric conditions. Results for base shear, story displacement, and drift were compared to the conventional building model. The coupled composite column system was found to improve seismic performance parameters compared to conventional steel columns.
A THEORETICAL STUDY ON COLLAPSE MECHANISM AND STRUCTURAL BEHAVIOR OF MULTI-ST...nhandoan10
This document presents a theoretical study on the collapse mechanism and structural behavior of multi-story reinforced concrete (RC) frames subjected to earthquake loading. A nonlinear finite element analysis was utilized to investigate the behavior and collapse mechanism. Plastic hinges were assumed to occur when steel yields or concrete reaches ultimate strength. The behavior of RC frames was investigated focusing on propagation of plastic hinges with varying numbers of stories, concrete grades, and reinforcement ratios, under three earthquake motions. Parameters like member rotations, hinge formation times, maximum shear and displacements were examined. Several conclusions were drawn regarding plastic hinge behavior and design of RC frames under seismic loads.
Similar to Seismic Retrofitting of a RC Building by Adding Steel Plate Shear Walls (20)
This document provides a technical review of secure banking using RSA and AES encryption methodologies. It discusses how RSA and AES are commonly used encryption standards for secure data transmission between ATMs and bank servers. The document first provides background on ATM security measures and risks of attacks. It then reviews related work analyzing encryption techniques. The document proposes using a one-time password in addition to a PIN for ATM authentication. It concludes that implementing encryption standards like RSA and AES can make transactions more secure and build trust in online banking.
This document analyzes the performance of various modulation schemes for achieving energy efficient communication over fading channels in wireless sensor networks. It finds that for long transmission distances, low-order modulations like BPSK are optimal due to their lower SNR requirements. However, as transmission distance decreases, higher-order modulations like 16-QAM and 64-QAM become more optimal since they can transmit more bits per symbol, outweighing their higher SNR needs. Simulations show lifetime extensions up to 550% are possible in short-range networks by using higher-order modulations instead of just BPSK. The optimal modulation depends on transmission distance and balancing the energy used by electronic components versus power amplifiers.
This document provides a review of mobility management techniques in vehicular ad hoc networks (VANETs). It discusses three modes of communication in VANETs: vehicle-to-infrastructure (V2I), vehicle-to-vehicle (V2V), and hybrid vehicle (HV) communication. For each communication mode, different mobility management schemes are required due to their unique characteristics. The document also discusses mobility management challenges in VANETs and outlines some open research issues in improving mobility management for seamless communication in these dynamic networks.
This document provides a review of different techniques for segmenting brain MRI images to detect tumors. It compares the K-means and Fuzzy C-means clustering algorithms. K-means is an exclusive clustering algorithm that groups data points into distinct clusters, while Fuzzy C-means is an overlapping clustering algorithm that allows data points to belong to multiple clusters. The document finds that Fuzzy C-means requires more time for brain tumor detection compared to other methods like hierarchical clustering or K-means. It also reviews related work applying these clustering algorithms to segment brain MRI images.
1) The document simulates and compares the performance of AODV and DSDV routing protocols in a mobile ad hoc network under three conditions: when users are fixed, when users move towards the base station, and when users move away from the base station.
2) The results show that both protocols have higher packet delivery and lower packet loss when users are either fixed or moving towards the base station, since signal strength is better in those scenarios. Performance degrades when users move away from the base station due to weaker signals.
3) AODV generally has better performance than DSDV, with higher throughput and packet delivery rates observed across the different user mobility conditions.
This document describes the design and implementation of 4-bit QPSK and 256-bit QAM modulation techniques using MATLAB. It compares the two techniques based on SNR, BER, and efficiency. The key steps of implementing each technique in MATLAB are outlined, including generating random bits, modulation, adding noise, and measuring BER. Simulation results show scatter plots and eye diagrams of the modulated signals. A table compares the results, showing that 256-bit QAM provides better performance than 4-bit QPSK. The document concludes that QAM modulation is more effective for digital transmission systems.
The document proposes a hybrid technique using Anisotropic Scale Invariant Feature Transform (A-SIFT) and Robust Ensemble Support Vector Machine (RESVM) to accurately identify faces in images. A-SIFT improves upon traditional SIFT by applying anisotropic scaling to extract richer directional keypoints. Keypoints are processed with RESVM and hypothesis testing to increase accuracy above 95% by repeatedly reprocessing images until the threshold is met. The technique was tested on similar and different facial images and achieved better results than SIFT in retrieval time and reduced keypoints.
This document studies the effects of dielectric superstrate thickness on microstrip patch antenna parameters. Three types of probes-fed patch antennas (rectangular, circular, and square) were designed to operate at 2.4 GHz using Arlondiclad 880 substrate. The antennas were tested with and without an Arlondiclad 880 superstrate of varying thicknesses. It was found that adding a superstrate slightly degraded performance by lowering the resonant frequency and increasing return loss and VSWR, while decreasing bandwidth and gain. Specifically, increasing the superstrate thickness or dielectric constant resulted in greater changes to the antenna parameters.
This document describes a wireless environment monitoring system that utilizes soil energy as a sustainable power source for wireless sensors. The system uses a microbial fuel cell to generate electricity from the microbial activity in soil. Two microbial fuel cells were created using different soil types and various additives to produce different current and voltage outputs. An electronic circuit was designed on a printed circuit board with components like a microcontroller and ZigBee transceiver. Sensors for temperature and humidity were connected to the circuit to monitor the environment wirelessly. The system provides a low-cost way to power remote sensors without needing battery replacement and avoids the high costs of wiring a power source.
1) The document proposes a model for a frequency tunable inverted-F antenna that uses ferrite material.
2) The resonant frequency of the antenna can be significantly shifted from 2.41GHz to 3.15GHz, a 31% shift, by increasing the static magnetic field placed on the ferrite material.
3) Altering the permeability of the ferrite allows tuning of the antenna's resonant frequency without changing the physical dimensions, providing flexibility to operate over a wide frequency range.
This document summarizes a research paper that presents a speech enhancement method using stationary wavelet transform. The method first classifies speech into voiced, unvoiced, and silence regions based on short-time energy. It then applies different thresholding techniques to the wavelet coefficients of each region - modified hard thresholding for voiced speech, semi-soft thresholding for unvoiced speech, and setting coefficients to zero for silence. Experimental results using speech from the TIMIT database corrupted with white Gaussian noise at various SNR levels show improved performance over other popular denoising methods.
This document reviews the design of an energy-optimized wireless sensor node that encrypts data for transmission. It discusses how sensing schemes that group nodes into clusters and transmit aggregated data can reduce energy consumption compared to individual node transmissions. The proposed node design calculates the minimum transmission power needed based on received signal strength and uses a periodic sleep/wake cycle to optimize energy when not sensing or transmitting. It aims to encrypt data at both the node and network level to further optimize energy usage for wireless communication.
This document discusses group consumption modes. It analyzes factors that impact group consumption, including external environmental factors like technological developments enabling new forms of online and offline interactions, as well as internal motivational factors at both the group and individual level. The document then proposes that group consumption modes can be divided into four types based on two dimensions: vertical (group relationship intensity) and horizontal (consumption action period). These four types are instrument-oriented, information-oriented, enjoyment-oriented, and relationship-oriented consumption modes. Finally, the document notes that consumption modes are dynamic and can evolve over time.
The document summarizes a study of different microstrip patch antenna configurations with slotted ground planes. Three antenna designs were proposed and their performance evaluated through simulation: a conventional square patch, an elliptical patch, and a star-shaped patch. All antennas were mounted on an FR4 substrate. The effects of adding different slot patterns to the ground plane on resonance frequency, bandwidth, gain and efficiency were analyzed parametrically. Key findings were that reshaping the patch and adding slots increased bandwidth and shifted resonance frequency. The elliptical and star patches in particular performed better than the conventional design. Three antenna configurations were selected for fabrication and measurement based on the simulations: a conventional patch with a slot under the patch, an elliptical patch with slots
1) The document describes a study conducted to improve call drop rates in a GSM network through RF optimization.
2) Drive testing was performed before and after optimization using TEMS software to record network parameters like RxLevel, RxQuality, and events.
3) Analysis found call drops were occurring due to issues like handover failures between sectors, interference from adjacent channels, and overshooting due to antenna tilt.
4) Corrective actions taken included defining neighbors between sectors, adjusting frequencies to reduce interference, and lowering the mechanical tilt of an antenna.
5) Post-optimization drive testing showed improvements in RxLevel, RxQuality, and a reduction in dropped calls.
This document describes the design of an intelligent autonomous wheeled robot that uses RF transmission for communication. The robot has two modes - automatic mode where it can make its own decisions, and user control mode where a user can control it remotely. It is designed using a microcontroller and can perform tasks like object recognition using computer vision and color detection in MATLAB, as well as wall painting using pneumatic systems. The robot's movement is controlled by DC motors and it uses sensors like ultrasonic sensors and gas sensors to navigate autonomously. RF transmission allows communication between the robot and a remote control unit. The overall aim is to develop a low-cost robotic system for industrial applications like material handling.
This document reviews cryptography techniques to secure the Ad-hoc On-Demand Distance Vector (AODV) routing protocol in mobile ad-hoc networks. It discusses various types of attacks on AODV like impersonation, denial of service, eavesdropping, black hole attacks, wormhole attacks, and Sybil attacks. It then proposes using the RC6 cryptography algorithm to secure AODV by encrypting data packets and detecting and removing malicious nodes launching black hole attacks. Simulation results show that after applying RC6, the packet delivery ratio and throughput of AODV increase while delay decreases, improving the security and performance of the network under attack.
The document describes a proposed modification to the conventional Booth multiplier that aims to increase its speed by applying concepts from Vedic mathematics. Specifically, it utilizes the Urdhva Tiryakbhyam formula to generate all partial products concurrently rather than sequentially. The proposed 8x8 bit multiplier was coded in VHDL, simulated, and found to have a path delay 44.35% lower than a conventional Booth multiplier, demonstrating its potential for higher speed.
This document discusses image deblurring techniques. It begins by introducing image restoration and focusing on image deblurring. It then discusses challenges with image deblurring being an ill-posed problem. It reviews existing approaches to screen image deconvolution including estimating point spread functions and iteratively estimating blur kernels and sharp images. The document also discusses handling spatially variant blur and summarizes the relationship between the proposed method and previous work for different blur types. It proposes using color filters in the aperture to exploit parallax cues for segmentation and blur estimation. Finally, it proposes moving the image sensor circularly during exposure to prevent high frequency attenuation from motion blur.
This document describes modeling an adaptive controller for an aircraft roll control system using PID, fuzzy-PID, and genetic algorithm. It begins by introducing the aircraft roll control system and motivation for developing an adaptive controller to minimize errors from noisy analog sensor signals. It then provides the mathematical model of aircraft roll dynamics and describes modeling the real-time flight control system in MATLAB/Simulink. The document evaluates PID, fuzzy-PID, and PID-GA (genetic algorithm) controllers for aircraft roll control and finds that the PID-GA controller delivers the best performance.
Literature Review Basics and Understanding Reference Management.pptxDr Ramhari Poudyal
Three-day training on academic research focuses on analytical tools at United Technical College, supported by the University Grant Commission, Nepal. 24-26 May 2024
Embedded machine learning-based road conditions and driving behavior monitoringIJECEIAES
Car accident rates have increased in recent years, resulting in losses in human lives, properties, and other financial costs. An embedded machine learning-based system is developed to address this critical issue. The system can monitor road conditions, detect driving patterns, and identify aggressive driving behaviors. The system is based on neural networks trained on a comprehensive dataset of driving events, driving styles, and road conditions. The system effectively detects potential risks and helps mitigate the frequency and impact of accidents. The primary goal is to ensure the safety of drivers and vehicles. Collecting data involved gathering information on three key road events: normal street and normal drive, speed bumps, circular yellow speed bumps, and three aggressive driving actions: sudden start, sudden stop, and sudden entry. The gathered data is processed and analyzed using a machine learning system designed for limited power and memory devices. The developed system resulted in 91.9% accuracy, 93.6% precision, and 92% recall. The achieved inference time on an Arduino Nano 33 BLE Sense with a 32-bit CPU running at 64 MHz is 34 ms and requires 2.6 kB peak RAM and 139.9 kB program flash memory, making it suitable for resource-constrained embedded systems.
Redefining brain tumor segmentation: a cutting-edge convolutional neural netw...IJECEIAES
Medical image analysis has witnessed significant advancements with deep learning techniques. In the domain of brain tumor segmentation, the ability to
precisely delineate tumor boundaries from magnetic resonance imaging (MRI)
scans holds profound implications for diagnosis. This study presents an ensemble convolutional neural network (CNN) with transfer learning, integrating
the state-of-the-art Deeplabv3+ architecture with the ResNet18 backbone. The
model is rigorously trained and evaluated, exhibiting remarkable performance
metrics, including an impressive global accuracy of 99.286%, a high-class accuracy of 82.191%, a mean intersection over union (IoU) of 79.900%, a weighted
IoU of 98.620%, and a Boundary F1 (BF) score of 83.303%. Notably, a detailed comparative analysis with existing methods showcases the superiority of
our proposed model. These findings underscore the model’s competence in precise brain tumor localization, underscoring its potential to revolutionize medical
image analysis and enhance healthcare outcomes. This research paves the way
for future exploration and optimization of advanced CNN models in medical
imaging, emphasizing addressing false positives and resource efficiency.
ACEP Magazine edition 4th launched on 05.06.2024Rahul
This document provides information about the third edition of the magazine "Sthapatya" published by the Association of Civil Engineers (Practicing) Aurangabad. It includes messages from current and past presidents of ACEP, memories and photos from past ACEP events, information on life time achievement awards given by ACEP, and a technical article on concrete maintenance, repairs and strengthening. The document highlights activities of ACEP and provides a technical educational article for members.
International Conference on NLP, Artificial Intelligence, Machine Learning an...gerogepatton
International Conference on NLP, Artificial Intelligence, Machine Learning and Applications (NLAIM 2024) offers a premier global platform for exchanging insights and findings in the theory, methodology, and applications of NLP, Artificial Intelligence, Machine Learning, and their applications. The conference seeks substantial contributions across all key domains of NLP, Artificial Intelligence, Machine Learning, and their practical applications, aiming to foster both theoretical advancements and real-world implementations. With a focus on facilitating collaboration between researchers and practitioners from academia and industry, the conference serves as a nexus for sharing the latest developments in the field.
Presentation of IEEE Slovenia CIS (Computational Intelligence Society) Chapte...University of Maribor
Slides from talk presenting:
Aleš Zamuda: Presentation of IEEE Slovenia CIS (Computational Intelligence Society) Chapter and Networking.
Presentation at IcETRAN 2024 session:
"Inter-Society Networking Panel GRSS/MTT-S/CIS
Panel Session: Promoting Connection and Cooperation"
IEEE Slovenia GRSS
IEEE Serbia and Montenegro MTT-S
IEEE Slovenia CIS
11TH INTERNATIONAL CONFERENCE ON ELECTRICAL, ELECTRONIC AND COMPUTING ENGINEERING
3-6 June 2024, Niš, Serbia
Electric vehicle and photovoltaic advanced roles in enhancing the financial p...IJECEIAES
Climate change's impact on the planet forced the United Nations and governments to promote green energies and electric transportation. The deployments of photovoltaic (PV) and electric vehicle (EV) systems gained stronger momentum due to their numerous advantages over fossil fuel types. The advantages go beyond sustainability to reach financial support and stability. The work in this paper introduces the hybrid system between PV and EV to support industrial and commercial plants. This paper covers the theoretical framework of the proposed hybrid system including the required equation to complete the cost analysis when PV and EV are present. In addition, the proposed design diagram which sets the priorities and requirements of the system is presented. The proposed approach allows setup to advance their power stability, especially during power outages. The presented information supports researchers and plant owners to complete the necessary analysis while promoting the deployment of clean energy. The result of a case study that represents a dairy milk farmer supports the theoretical works and highlights its advanced benefits to existing plants. The short return on investment of the proposed approach supports the paper's novelty approach for the sustainable electrical system. In addition, the proposed system allows for an isolated power setup without the need for a transmission line which enhances the safety of the electrical network
CHINA’S GEO-ECONOMIC OUTREACH IN CENTRAL ASIAN COUNTRIES AND FUTURE PROSPECTjpsjournal1
The rivalry between prominent international actors for dominance over Central Asia's hydrocarbon
reserves and the ancient silk trade route, along with China's diplomatic endeavours in the area, has been
referred to as the "New Great Game." This research centres on the power struggle, considering
geopolitical, geostrategic, and geoeconomic variables. Topics including trade, political hegemony, oil
politics, and conventional and nontraditional security are all explored and explained by the researcher.
Using Mackinder's Heartland, Spykman Rimland, and Hegemonic Stability theories, examines China's role
in Central Asia. This study adheres to the empirical epistemological method and has taken care of
objectivity. This study analyze primary and secondary research documents critically to elaborate role of
china’s geo economic outreach in central Asian countries and its future prospect. China is thriving in trade,
pipeline politics, and winning states, according to this study, thanks to important instruments like the
Shanghai Cooperation Organisation and the Belt and Road Economic Initiative. According to this study,
China is seeing significant success in commerce, pipeline politics, and gaining influence on other
governments. This success may be attributed to the effective utilisation of key tools such as the Shanghai
Cooperation Organisation and the Belt and Road Economic Initiative.
Optimizing Gradle Builds - Gradle DPE Tour Berlin 2024Sinan KOZAK
Sinan from the Delivery Hero mobile infrastructure engineering team shares a deep dive into performance acceleration with Gradle build cache optimizations. Sinan shares their journey into solving complex build-cache problems that affect Gradle builds. By understanding the challenges and solutions found in our journey, we aim to demonstrate the possibilities for faster builds. The case study reveals how overlapping outputs and cache misconfigurations led to significant increases in build times, especially as the project scaled up with numerous modules using Paparazzi tests. The journey from diagnosing to defeating cache issues offers invaluable lessons on maintaining cache integrity without sacrificing functionality.
Introduction- e - waste – definition - sources of e-waste– hazardous substances in e-waste - effects of e-waste on environment and human health- need for e-waste management– e-waste handling rules - waste minimization techniques for managing e-waste – recycling of e-waste - disposal treatment methods of e- waste – mechanism of extraction of precious metal from leaching solution-global Scenario of E-waste – E-waste in India- case studies.
Harnessing WebAssembly for Real-time Stateless Streaming PipelinesChristina Lin
Traditionally, dealing with real-time data pipelines has involved significant overhead, even for straightforward tasks like data transformation or masking. However, in this talk, we’ll venture into the dynamic realm of WebAssembly (WASM) and discover how it can revolutionize the creation of stateless streaming pipelines within a Kafka (Redpanda) broker. These pipelines are adept at managing low-latency, high-data-volume scenarios.
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Seismic Retrofitting of a RC Building by Adding Steel Plate Shear Walls
1. IOSR Journal of Mechanical and Civil Engineering (IOSR-JMCE)
e-ISSN: 2278-1684,p-ISSN: 2320-334X, Volume 7, Issue 2 (May. - Jun. 2013), PP 49-62
www.iosrjournals.org
www.iosrjournals.org 49 | Page
Seismic Retrofitting of a RC Building by Adding Steel Plate Shear
Walls
M.A. Ismaeil1
,A.E.Hassaballa3
1 King Khalid University, KSA. On Leave from Sudan University of Science and Technology, Khartoum, Sudan.
3 Jazan University, KSA. On Leave from Sudan University of Science and Technology, Khartoum, Sudan.
Abstract: This paper deals with the step-by-step retrofitting of buildings by using steel plate shear walls
(SPSWs) with the aid of SAP2000 programme. One type of reinforced concrete building is selected for
evaluation. This building represents the most used forms of residential buildings in the Sudan, in terms of
geometric form, and dimensions. This paper uses the equivalent static method provided in the regulations
proposed by the Egyptian Society for Earthquake Engineering. One typical model was selected from the existing
residual buildings in Khartoum city, as a case study. The proposed methodology that has been used to evaluate
the seismic resistance of chosen building is done through the design of the structural elements of the buildings
before and after adding the seismic forces. The retrofitting of building was done by using steel plate shear walls
with thicknesses of 5mm, 7mm and 10mm. From the results obtained, it was found that the use of two additional
SPSWs with 7 mm thickness placed at the internal frame of the existing system, resulted in a reduction of
bending moments in the columns and beams. The increase of thickness has a clear effect on the bending moment
of the columns, but has little effects on the bending moments of the beams.
Keywords- Retrofitting, SAP2000, Steel Plate Shear Walls (SPSWs), the Sudan
I. Introduction
This paper discusses Seismic retrofitting of a typical residential building in the Sudan which have been
designed and constructed without any seismic provisions. Seismic retrofitting is a modification of the structural
and /or non-structural components in a building that aims to improve the building's performance in future
earthquakes. Adding structural walls is one of the most common structure-level retrofitting methods to
strengthen existing structures. This approach is effective for controlling global lateral drifts and for reducing
damage in frame members. In this paper the seismic retrofitting of existing reinforced concrete RC buildings by
means of steel shear walls is examined.
1.1 The main function of steel plate shear walls
The main function of a steel plate shear wall (SPSW) is to resist horizontal story shear and overturning
moment due to lateral loads. In general, steel plate shear wall system consists of a steel plate wall, two boundary
columns and horizontal floor beams , fig.1, and 2 show samples of steel plate shear wall systems [1].
Figure 1. Coupled steel plate shear wall [1]
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Figure 2. A view of building with steel plate shear walls and a close-up of the walls [1]
1.2 The construction of steel plate shear walls
Steel plate shear wall systems that can be constructed with shop welded-field bolted elements can make
the steel plate shear walls more efficient than the traditional systems Fig .3 show the Steel Frame – RC
Structure Connections .
(a)
(b)
Figure 3. The steel frame – RC structure connections [2]
II. Case Study
2.1 Description of the Building
A three-story RC residential building, representing the majority of domestic buildings in Sudan, was
selected for this research. The studied frame is an existing building located in Khartoum city zone 2A [8]. The
structure system is a moment resisting RC frame with a 200 mm thickness flat slab, situated .The analysis is
carried out using SAP2000 FEA programm [3]. The structural members are made of in-situ reinforced concrete
.The overall plan dimension is 18 mx24 m. the height of the building is 9.6 m .The rectangular shape was used
for the columns. Columns and beams sizes along the building height are listed in Tables 1 and 2.Figs. 4, 5, and 6
show detailed information on the structural and architectural layout of the building.
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Figure 4. Section x-x
Figure 5.Foundations and columns plan
Figure 6. Plan of residual building considered
Table 1. The cross sections of columns
The cross sections of columnsStory No.
250x500Ground floor
250x500First floor
250x500Second floor
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Table 2. The cross sections of beams
The cross sections of beamsStory No.
300x500Ground floor
300x500First floor
300x500Second floor
IV. Structural Modeling
Numerical models for the case has been prepared using SAP2000 version 14 (Computers and
Structures) [3]. Beams and columns are modeled as frame elements while walls and slabs are modeled as shell
elements. In this paper the seismic performance of the considered residual building will be evaluated using the
linear static analysis procedure. .Fig. 7 shows the models for the three-story building. The label of columns is
shown in Fig. 8.
Figure 7. Three –dimension view of the initial structure.
Figure 8. Label of columns
4.1 Modeling of steel shear walls in Analysis
The steel plate shear walls can be modeled using full shell elements and isotropic material. It is
suggested that the wall panel be modeled using at least 16 shell elements (4x4 mesh) per panel [11]. The lateral
force resisting system consists of moment resisting frames with steel plate shear walls. The thickness of steel
shear wall panels is taken variable between 5mm-10 mm [4].
V. Analysis of Original Building
The internal forces obtained from the computer analysis program SAP2000 [3] are used to design the
reinforced concrete sections of the structural elements of the residual building using the (BS 8110, 1997) [5]
,and the limit state design method (Mosley and Bungey, 1997) [6]. It has been found that the existing design of
columns under the effect of gravity loads is adequate for the study case. As for the design of columns a
computer program called ISACOL (Shehata, 1999) [7] has been used. The paper studied four columns for the
evaluation. Table 3 shows the Straining action for the four columns due to gravity load and Table 4 shows the
present design compared with the original design of critical columns for the studied case. It is clear that the
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original design of these columns exceeds the present design which means that it is satisfactory for gravity loads.
It is worthy to mention that internal forces in beams of the study case have been calculated under gravity loads.
Then the (BS 8110, 1997) [5] has been used to check the existing design. It has been found that the existing
design is adequate for the case.
Table 3.Straining action for the four columns due to gravity loads
Columns
No.
Load Case N Mx My
C12 ULTIMATE 904.74 9.40 47.73
C20 ULTIMATE 1181.41 2.39 -9.22
C14 ULTIMATE 1357.83 1.07 -2.03
C22 ULTIMATE 1358.37 8.83 1.55
Where :
N: is the axial load in the column due to due to forces.
Mx : is the bending moment at the column due to forces applied in x- direction .
My : is the bending moment at the column due to forces applied in y- direction.
5.1 Design of some columns due to gravity loads only (C22):
Figure 9. ISACOL Program result for design of column No, C22 due to gravity loads
Table 4. Comparison between original and present design for gravity loads
Column
No.
Original Design Present Design
Section* Reinf. Section* Reinf.
C12 250x500 8 Φ 16 250x400 8 Φ 16
C20 250x500 8 Φ 16 250x400 8 Φ 16
C14 250x500 8 Φ 16 250x400 8 Φ 16
C22 250x500 8 Φ 16 250x400 8 Φ 16
* Section dimensions are in mm.
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VI. Check of Design Considering Earthquake and Wind Loads
The moments obtained from earthquake and wind loads are shown in .Tables4 and 5. It has been found
that the effect of seismic load is much more than the effect of wind load. Fig. 12 and fig. 13 show the
comparison between moments in columns due to earthquake and wind loads.
6.1 Wind loads
The British Standard Code gives methods for determining the gust peak wind loads on buildings and
components thereof that should be taken into account in design using equivalent static procedures. Wind loads
according to British Standard Code (BSI) were calculated by using SAP2000, and Wind speed factors according
to BSI, cp3: chapter V: part 2: 1972 [4] .The basic wind speed V for Khartoum is given by 44.4 m/sec [8] .
Table 5. The Staining actions (Mx) due to Wind loads (ENVWX) and Seismic loads (ENVEQX)
Column
No.
Wind-ENVWX Seismic-ENVEQX
Mx Mx
C12 9.40 9.40
C20 4.26 2.47
C14 1.09 1.09
C22 11.78 8.84
Table 6. The Staining actions (My) due to Wind loads (ENVWX) and Seismic loads (ENVEQX)
Column No.
Wind-ENVWX Seismic-ENVEQX
My My
C12 47.63 47.63
C20 -9.26 -9.26
C14 -2.00 -2.00
C22 1.52 1.52
Table 7. The Staining actions (Mx) due to Wind loads (ENVWY) and Seismic loads (ENVEQY)
Column No.
Wind-ENVWY Seismic-ENVEQY
Mx Mx
C12 43.77 83.43
C20 34.46 71.64
C14 30.88 66.33
C22 41.80 80.28
Table 8. The Staining actions (MY) due to Wind loads (ENVWY) and Seismic loads (ENVEQY)
Column
No.
Wind+ENVWY Seismic+ENVEQY
My My
C12 51.80 50.51
C20 -8.97 -9.26
C14 -2.00 -2.00
C22 4.91 13.74
Where, ENVEQX are envelope of Load Combination for seismic loads in direction x, ENVEQY: are
envelope of Load Combination for seismic loads in direction in direction Y.
Figure 10.Comparison between My due to Wind loads and My due to Seismic loads
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Figure 11.Comparison between Mx due to Wind loads and Mx due to Seismic loads
In all directions the effect of seismic loads is govern so, the paper concentrated in the effect of seismic
loads only
6.2 Earthquake loads
It is well known that the Sudan has no regulations for the seismic design of buildings. Therefore, in the
present paper earthquake loads are calculated following the rules which are given in the Regulations for
earthquake resistant design of buildings in Egypt, (ESEE, 1988) [9]. These regulations have been prepared by
the Egyptian Society for Earthquake Engineering (ESEE). In order to apply the ESEE regulations a seismic map
for the Sudan is required to determine the site seismicity factor. In 2002, Eissa et al . Developed a new seismic
hazard maps and seismic zoning map for the Sudan (Eissa et al , 2002) [8] , as shown in Fig.12.
Figure 12. Seismic Zoning Map of the Sudan (Eissa et al , 2002) [8]
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Figure 13. Seismic Hazard Map of the Sudan (Hassaballa et al , 2010) [10].
VII. Seismic Assessment by the ESEE. 1988
The total design seismic base shear force is estimated using the static equivalent force procedure
(ESEE, 19880) [9]. Four our case study, distribution of the lateral seismic loads is shown in fig 16 , for both
directions.
7.1 Calculation of base shear
The total weight is given by equation (1) :
Wi = Di + PLi (1)
Where, p is the incidence factor and is equal to p = 0.25. After analysis for gravity loads, the total floor weight
will be as follows: 8955 KN.The equivalent lateral force procedure of (ESEE 1988) was used to calculate the
design base shear. The resulting seismic coefficient, Cs, was determined to be 0.125 and the corresponding base
shear was approximately 1120 KN.from equation (2):
V = Cs*Wt (2)
7.2 Distribution of horizontal seismic force
The period of the building is the same in both directions. Hence, the load in the E-W direction are the
same as those for the N-S direction as shown Fig 14.
Figure 14.Distribution of horizontal seismic force
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7.3 Check of seismic design for study case
Numerical analysis for the study case has been performed using SAP2000 (Computers and Structures)
[3] and the reinforced concrete columns are designed according to the (BS 8110, 1997) [5] using the limit state
design method (Mosley and Bungey, 1997) [6].Table 9 and 10 show the Straining action (moments) for the ten
columns due to seismic load, and the seismic design compared with the original design of that columns which
are chosen respectively. It is clear that most of columns are unsafe due to seismic loads. Therefore, a
strengthening scheme is needed for the residual building in order to resist earthquake forces.
Table 9.Straining action for the same four columns due to seismic loads
Column No. Load Case N Mx My
C12 ENVEQY 904.60 83.43 50.51
C20 ENVEQY 1181.39 71.64 -9.26
C14 ENVEQY 1357.73 66.33 -2.00
C22 ENVEQY 1358.28 80.28 13.74
7.3.1 Design of some columns due to gravity and seismic loads (C22):
Figure 15.ISACOL Program result for Design of Column No, C22due to seismic loads
Table 10. Comparison between Original and Present Design Including Seismic Loads
Column
No.
Original Design Present Design
Section* Reinf. Section* Reinf.
C12 250x500 8 Φ 16 250x550 10 Φ 16
C20 250x500 8 Φ 16 250x500 10 Φ 16
C14 250x500 8 Φ 16 250x500 10 Φ 16
C22 250x500 8 Φ 16 250x600 10 Φ 16
* Section dimensions are in mm.
VIII. Suggesting of Retrofitting
8.1 Type of retrofitting
There are many seismic retrofit techniques available, depending on the purpose needed from
strengthening, types and conditions of structures. Seismic retrofitting is the modification of existing structures
to make them more resistant to seismic ground motion, or soil failure due to earthquakes .
There are two ways to enhance the seismic capacity of existing structures. The first approach is a structure-level
retrofit, which involves global modifications to the structural system. Common global modifications include the
addition of structural walls, steel braces, or base isolators. The second approach is a member-level retrofit. In
this approach, the ductility of components with inadequate capacities is increased to satisfy their specific limit
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states. The member-level retrofit includes methods such as the addition of concrete, steel, or fiber reinforced
polymer (FRP) jackets to columns for confinement [11] .Fig. 16-18 show some technique using to retrofit
existing structures.
Figure 16. Retrofitted with RC Wing Wall
Figure 17. School building retrofitted with shear walls
Figure 18. Retrofitting with RC Column Jacketing [12]
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8.2 suggestion of strengthening
There are different methods for seismic strengthening of existing buildings. However, social and
economic conditions should be considered to choose the appropriate method. Adding structural walls is one of
the most common structure-level retrofitting methods to strengthen existing structures. This approach is
effective for controlling global lateral drifts and for reducing damage in frame members [5]. Structural walls
may be either reinforced concrete or steel plate. In this paper new SPSWs with 5 mm, 7 mm, and 10 mm
thickness were added in (y) direction along the height of the structure. Fig. 20, 21 , and 22 show the suggested
strengthening of the structure with the new SPSWs.
Figure 20. The SPSWs 5 mm
Figure 21. The SPSWs 7 mm
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Figure 22. The SPSWs 10 mm
Figure 23. Modeling of shear wall in y directions [14]
IX. Analysis of Retrofitted Structure
The strengthened structure was reanalyzed using the same procedure. The proposed method increased
the performance of the structure in both directions either for strength, displacement and ductility capacity.
Table. 11 show straining action for the four columns that which is chosen due to seismic load before and after
strengthening. It has been found that all columns in the study case became safe after strengthening.
Table 11. Straining action for the four columns that which are chosen due to seismic load before and after
strengthening.
Column
No.
Gravity Seismic+Column
SPSW
5mm
SPSW
7mm
SPSW
10mm
C12 9.40 83.43 35.09 29.96 25.26
C20 2.39 71.64 56.63 53.27 49.66
C14 1.07 66.33 24.94 20.50 16.41
C22 8.83 80.28 41.19 36.46 31.86
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Figure 24.Straining action Mx for the four columns which are chosen due to seismic load before and after
strengthening.
Table 12. Straining action My for the four columns that which are chosen due to seismic load before and after
strengthening.
Columns
No.
Gravity Seismic+Column SPSW 5mm SPSW 7mm
SPSW
10mm
My My My My My
C12 47.73 50.51 54.24 53.83 53.06
C20 -9.22 -9.26 -9.68 -9.74 -9.80
C14 -2.03 -2.00 -2.75 -2.88 -3.01
C22 1.55 13.74 15.87 15.39 14.61
Figure 25.Straining action My for the four columns which are chosen due to seismic load before and after
strengthening.
Table 13. Comparison between Original and Strengthened Design for Study Case .
Column No.
Original Design After Strengthening
Section* Reinf. Section* Reinf.
C12 250x500 8 Φ 16 250x400 8 Φ 16
C20 250x500 8 Φ 16 250x400 8 Φ 16
C14 250x500 8 Φ 16 250x400 8 Φ 16
C22 250x500 8 Φ 16 250x400 8 Φ 16
* Section dimensions are in mm
X. Conclusion
One of the most difficult problems of strengthening of existing buildings is how to find the adequate
solution that satisfies both economical and technical aspects.
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This study presents guidelines to investigate the seismic resistance of buildings in Sudan.? The present
paper proposes a simple procedure to check the seismic resistance and retrofit of such buildings. The obtained
results emphasize the following conclusions: (1) Current design of residual buildings in the Sudan does not
consider earthquake loads,(2) It has been found that the current design of buildings in the Sudan is not safe for
the current seismicity of the Sudan,(3) A proposed methodology has been presented for evaluation of seismic
resistance of existing buildings in the Sudan, and (4) A strengthening technique for existing buildings in the
Sudan has been presented. (5) with the use of 7 mm thickness steel plate shear wall inserted in the building, a
reduction of bending moments in the columns and beams was observed. (6) The increase of thickness has a clear
effect on the bending moment of the columns, and has little effects on the bending moment of the beams.
It is recommended that, since this retrofitting method showed a great improvement in the capacity of the
building, it should be adopted as a suitable strategy for this case to reduce the seismic vulnerability of exiting
RC buildings in Sudan.
References
[1]. Abolhassan, P.E. ,Seismic Behaviour and Design of Steel Shear Walls.(ASI, Steel TIPS, First Print, California,2001).
[2]. Astaneh-Asl, A., Steel Plate Shear Walls, Proceedings, U.S.-Japan Partnership for Advanced Steel Structures, U.S.-Japan
Workshop on Seismic Fracture issues in Steel Structure, San Francisco,February 2000.
[3]. Computers and Structures. SAP2000: Three Dimensional Static and Dynamic Finite Element Analysis and Design of Structures,
Computers and Structures Inc., Berkeley, California, U.S.A. 2001.
[4]. Ismaeil, M. A., and Sobaih, M.E, A Proposed Methodology for Seismic Evaluation and Strengthening of Existing School
Buildings in The Sudan., 15th WCEE, Portugal, September, 2012. Paper No.0 571.
[5]. BS 8110. The Structural Use of Concrete, British Standard Institution, London. 1997.
[6]. Mosley, W. H. and Bungey, J. H. ,Reinforced Concrete Design (BS 8110:Part 1, 2nd Ed. Macmillan , London. 1997).
[7]. A .Y. Shehata, Information Systems Application on Reinforced Concrete Columns., M.Sc. Thesis, Faculty of Engineering,
Department of Structural Engineering, Cairo University, Giza, Egypt, 1999.
[8]. A .A. Eissa, Towards a Sudanese Code of Practice for Earthquake Design., M.Sc. Thesis., Faculty of Engineering, Department of
Structural Engineering, Khartoum University, Khartoum, Sudan. 2002.
[9]. Egyptian Society for Earthquake Engineering (ESEE) ,Regulations for Earthquake-Resistance Design of Buildings in Egypt.,Cairo
,Egypt.,(1988).
[10]. Hassaballa, A. E , Sobaih, M. E & A. R. A. Mohamed ,Sensitivity Analysis in Estimating Seismic Hazard for Sudan., Proc., 14th
European Conference on Earthquake Engineering, 30 Aug.-3 Sept., 2010, Ohrid, Republic of Macedonia.
[11]. Jong-Wha Bai, Seismic Retrofit for Reinforced Concrete Building Structures , Final Report ,. Consequence-Based Engineering
(CBE) Institute,. Texas ,2003.
[12]. Murty .C. V. R . , The Seismic Performance of Reinforced Concrete Frame Buildings with Masonry Infill Walls ,A Tutorial
Developed by a Committee of the World Housing Encyclopedia,(First Edition ,Publication Number WHE,2006).
[13]. Sobaih, M. E ;Hassaballa, A. E , & Ismaeil, M. A. ,Assessment of Seismic Performance and Strengthening of Existing School
Buildings in the Sudan, International Journal of Engineering Research &Technology (IJERT),ISSN:2278-0181, 2(6), 2013.
[14]. Ismaeil, M. A., and Sobaih, M.E, A Proposed Methodology for Seismic Evaluation and Strengthening of Existing School
Buildings in The Sudan., 15th WCEE, Portugal, September, 2012. Paper No.0 571.