This document describes a 4-storey reinforced concrete test building with unreinforced masonry infill walls that will be used to test different seismic retrofit schemes. An analysis found the building has weak columns that are susceptible to sidesway collapse. The masonry infill provides much more shear strength than the bare concrete frame but at a smaller drift. Three retrofit schemes are proposed: 1) Replace masonry with damped bracing, 2) Jacket columns and some masonry with composite material to improve ductility, 3) Strengthen columns and add steel bracing. The effectiveness of each scheme will be tested using full-scale dynamic tests.
In last decades steel structures has played an impo rtant role in construction industry. Providing strength,stability and ductility are major purpose s of seismic design. It is necessary to design a structure to perform well under seismic loads. Stee l braced frame is one of the structural systems used to resist earthquake loads in structures. Stee l bracing is economical,easy to erect,occupies less space and has flexibility to design for meetin g the required strength and stiffness. Bracing can be used as retrofit as well. There are various type s of steel bracings such as Diagonal,X,K,V,inverted V type or chevron and global type concentr ic bracings. In the present study,it was shown that modeling of the G+4 steel bare frame with vari ous bracings (X,V,inverted V,and Knee bracing) by computer software SAP2000 and pushover analysis results are obtained. Comparison between the seismic parameters such as base shear,roof displacement,time period,storey drift,performance point for steel bare frame with differe nt bracing patterns are studied. It is found that the X type of steel bracings significantly contribu tes to the structural stiffness and reduces the maximum interstate drift of steel building than oth er bracing systems.
Lateral Load Analysis of Shear Wall and Concrete Braced Multi-Storeyed R.C Fr...ijsrd.com
Generally RC framed structures are designed without regards to structural action of masonry infill walls present. Masonry infill walls are widely used as partitions. These buildings are generally designed as framed structures without regard to structural action of masonry infill walls. They are considered as non- structural elements. RC frame building with open first storey is known as soft storey, which performs poorly during strong earthquake shaking. Past earthquakes are evident that collapses due to soft storeys are most often in RC buildings. In the soft storey, columns are severely stressed and unable to provide adequate shear resistance during the earthquake. . In this study, 3D analytical model of twelve storeyed buildings have been generated for different buildings Models and analyzed using structural analysis tool 'ETABS'. To study the effect of infill, ground soft, bare frame and models with ground soft having concrete core wall and shear walls and concrete bracings at different positions during earthquake; seismic analysis using both linear static, linear dynamic (response spectrum method) has been performed. The analytical model of the building includes all important components that influence the mass, strength, stiffness and deformability of the structure.
Comparitive study on rcc and composite (cft) multi storeyed buildingseSAT 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. 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. Steel-concrete composite columns are used extensively in modern buildings. Extensive researches on composite columns in which structural steel section are encased in concrete have been carried out. In-filled composite columns, however have received limited attention compared to encased columns. In this study E-Tabs nonlinear software is used for simulation of steel concrete composite (CFT) with steel reinforced concrete structures (RCC) of G+14, G+19 and G+24 stories each are considered for comparative study. Comparison of parameters like time period, storey displacement and storey drift is done. Keywords: Composite CFT columns, bracings, shear wall, time period, storey displacement and storey drift.
In last decades steel structures has played an impo rtant role in construction industry. Providing strength,stability and ductility are major purpose s of seismic design. It is necessary to design a structure to perform well under seismic loads. Stee l braced frame is one of the structural systems used to resist earthquake loads in structures. Stee l bracing is economical,easy to erect,occupies less space and has flexibility to design for meetin g the required strength and stiffness. Bracing can be used as retrofit as well. There are various type s of steel bracings such as Diagonal,X,K,V,inverted V type or chevron and global type concentr ic bracings. In the present study,it was shown that modeling of the G+4 steel bare frame with vari ous bracings (X,V,inverted V,and Knee bracing) by computer software SAP2000 and pushover analysis results are obtained. Comparison between the seismic parameters such as base shear,roof displacement,time period,storey drift,performance point for steel bare frame with differe nt bracing patterns are studied. It is found that the X type of steel bracings significantly contribu tes to the structural stiffness and reduces the maximum interstate drift of steel building than oth er bracing systems.
Lateral Load Analysis of Shear Wall and Concrete Braced Multi-Storeyed R.C Fr...ijsrd.com
Generally RC framed structures are designed without regards to structural action of masonry infill walls present. Masonry infill walls are widely used as partitions. These buildings are generally designed as framed structures without regard to structural action of masonry infill walls. They are considered as non- structural elements. RC frame building with open first storey is known as soft storey, which performs poorly during strong earthquake shaking. Past earthquakes are evident that collapses due to soft storeys are most often in RC buildings. In the soft storey, columns are severely stressed and unable to provide adequate shear resistance during the earthquake. . In this study, 3D analytical model of twelve storeyed buildings have been generated for different buildings Models and analyzed using structural analysis tool 'ETABS'. To study the effect of infill, ground soft, bare frame and models with ground soft having concrete core wall and shear walls and concrete bracings at different positions during earthquake; seismic analysis using both linear static, linear dynamic (response spectrum method) has been performed. The analytical model of the building includes all important components that influence the mass, strength, stiffness and deformability of the structure.
Comparitive study on rcc and composite (cft) multi storeyed buildingseSAT 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. 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. Steel-concrete composite columns are used extensively in modern buildings. Extensive researches on composite columns in which structural steel section are encased in concrete have been carried out. In-filled composite columns, however have received limited attention compared to encased columns. In this study E-Tabs nonlinear software is used for simulation of steel concrete composite (CFT) with steel reinforced concrete structures (RCC) of G+14, G+19 and G+24 stories each are considered for comparative study. Comparison of parameters like time period, storey displacement and storey drift is done. Keywords: Composite CFT columns, bracings, shear wall, time period, storey displacement and storey drift.
Seismic Retrofitting of a RC Building by Adding Steel Plate Shear WallsIOSR Journals
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.
STUDY ON SEISMIC EFFECT OF HIGH RISE BUILDING SHEAR WALL/WALL WITHOUT SHEAR WALLIAEME Publication
Objective: In this paper the analytical study on the lateral behaviour of the structure is mainly concentrated and how it is varying in the different zones of zone II and zone III with different storey heights of a 6storey, 11storey, and 16storey structure. The study also involves the orientation of shear wall. Method in this study the behaviour of lateral displacements induced on or after earthquakes. Concrete shear walls are used to resist the lateral displacement owing to earthquake vibrations. Shear walls can be placed around the building as periphery walls, around the lift and beside the staircase. Filing the buildings are modelled with floor area of 32mx28m. with 8 bays along 32m span and 7 bays along 28m and apiece bay width of 4m .the lateral displacement of the structure is compared in OMRF &SMRF and the lateral displacement values of current floor level to another floor level should reach storey drift, the analysis is done in staadprov8i.findingthe lateral displacements of the structure is compared in OMRF & SMRF and it is found that lateral displacement is less in SMRF compare with OMRF.
EFFECT OF SHEAR WALL AREA ON SEISMIC BEHAVIOR OF MULTI STORIED BUILDINGS WITH...Ijripublishers Ijri
The advances in three-dimensional structural analysis and computing resources have allowed the efficient
and safe design of increasingly taller structures. These structures are the consequence of increasing urban
densification and economic viability. The trend towards progressively taller structures has demanded a shift
from the traditional strength based design approach of buildings to a focus on constraining the overall motion
of the structure. Structural engineers have responded to this challenge of lateral control with a myriad
of systems that achieve motion control while adhering to the overall architectural vision.
Reinforced Concrete (RC) wall-frame buildings are widely recommended for urban construction in areas
with high seismic hazard. Presence of structural walls imparts a large stiffness to the lateral-force resisting
system of the building. Proper detailing of walls can also lead to ductile behavior of such structures during
strong earthquake shaking. One of the major parameters influencing the seismic behavior of wall-frame
buildings is the wall-area ratio. Thus shear wall area ratio is set as a key parameter which needs to be investigated
in this analytical study.
Analysis of precast shear wall connection state of the art revieweSAT Journals
Abstract The behavior of precast members in whole structure is different than cast in situ member due to their joints condition. So it is important to study the behavior of precast concrete member and its joints for whole structural configuration and loading condition. The precast concrete shear wall system is very important for construction due to economical advantages speed of construction. The connections between panels are extremely important since they affect both the speed of erection and the overall integrity of the structure. Comprehensive review reveals the significance of detailed analysis required for stress distribution form the precast member to the structural system to encounter the shear stresses generated during an earthquake event.
Keywords: Precast, shear wall, connection, cyclic loading
Lateral Load Analysis of Shear Wall and Concrete Braced Multi-Storeyed R.C Fr...ijsrd.com
Generally RC framed structures are designed without regards to structural action of masonry infill walls present. Masonry infill walls are widely used as partitions. These buildings are generally designed as framed structures without regard to structural action of masonry infill walls. They are considered as non- structural elements. RC frame building with open first storey is known as soft storey, which performs poorly during strong earthquake shaking. Past earthquakes are evident that collapses due to soft storeys are most often in RC buildings. In the soft storey, columns are severely stressed and unable to provide adequate shear resistance during the earthquake. . In this study, 3D analytical model of twelve storeyed buildings have been generated for different buildings Models and analyzed using structural analysis tool 'ETABS'. To study the effect of infill, ground soft, bare frame and models with ground soft having concrete core wall and shear walls and concrete bracings at different positions during earthquake; seismic analysis using both linear static, linear dynamic (response spectrum method) has been performed. The analytical model of the building includes all important components that influence the mass, strength, stiffness and deformability of the structure.
Seismic Retrofitting of a RC Building by Adding Steel Plate Shear WallsIOSR Journals
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.
STUDY ON SEISMIC EFFECT OF HIGH RISE BUILDING SHEAR WALL/WALL WITHOUT SHEAR WALLIAEME Publication
Objective: In this paper the analytical study on the lateral behaviour of the structure is mainly concentrated and how it is varying in the different zones of zone II and zone III with different storey heights of a 6storey, 11storey, and 16storey structure. The study also involves the orientation of shear wall. Method in this study the behaviour of lateral displacements induced on or after earthquakes. Concrete shear walls are used to resist the lateral displacement owing to earthquake vibrations. Shear walls can be placed around the building as periphery walls, around the lift and beside the staircase. Filing the buildings are modelled with floor area of 32mx28m. with 8 bays along 32m span and 7 bays along 28m and apiece bay width of 4m .the lateral displacement of the structure is compared in OMRF &SMRF and the lateral displacement values of current floor level to another floor level should reach storey drift, the analysis is done in staadprov8i.findingthe lateral displacements of the structure is compared in OMRF & SMRF and it is found that lateral displacement is less in SMRF compare with OMRF.
EFFECT OF SHEAR WALL AREA ON SEISMIC BEHAVIOR OF MULTI STORIED BUILDINGS WITH...Ijripublishers Ijri
The advances in three-dimensional structural analysis and computing resources have allowed the efficient
and safe design of increasingly taller structures. These structures are the consequence of increasing urban
densification and economic viability. The trend towards progressively taller structures has demanded a shift
from the traditional strength based design approach of buildings to a focus on constraining the overall motion
of the structure. Structural engineers have responded to this challenge of lateral control with a myriad
of systems that achieve motion control while adhering to the overall architectural vision.
Reinforced Concrete (RC) wall-frame buildings are widely recommended for urban construction in areas
with high seismic hazard. Presence of structural walls imparts a large stiffness to the lateral-force resisting
system of the building. Proper detailing of walls can also lead to ductile behavior of such structures during
strong earthquake shaking. One of the major parameters influencing the seismic behavior of wall-frame
buildings is the wall-area ratio. Thus shear wall area ratio is set as a key parameter which needs to be investigated
in this analytical study.
Analysis of precast shear wall connection state of the art revieweSAT Journals
Abstract The behavior of precast members in whole structure is different than cast in situ member due to their joints condition. So it is important to study the behavior of precast concrete member and its joints for whole structural configuration and loading condition. The precast concrete shear wall system is very important for construction due to economical advantages speed of construction. The connections between panels are extremely important since they affect both the speed of erection and the overall integrity of the structure. Comprehensive review reveals the significance of detailed analysis required for stress distribution form the precast member to the structural system to encounter the shear stresses generated during an earthquake event.
Keywords: Precast, shear wall, connection, cyclic loading
Lateral Load Analysis of Shear Wall and Concrete Braced Multi-Storeyed R.C Fr...ijsrd.com
Generally RC framed structures are designed without regards to structural action of masonry infill walls present. Masonry infill walls are widely used as partitions. These buildings are generally designed as framed structures without regard to structural action of masonry infill walls. They are considered as non- structural elements. RC frame building with open first storey is known as soft storey, which performs poorly during strong earthquake shaking. Past earthquakes are evident that collapses due to soft storeys are most often in RC buildings. In the soft storey, columns are severely stressed and unable to provide adequate shear resistance during the earthquake. . In this study, 3D analytical model of twelve storeyed buildings have been generated for different buildings Models and analyzed using structural analysis tool 'ETABS'. To study the effect of infill, ground soft, bare frame and models with ground soft having concrete core wall and shear walls and concrete bracings at different positions during earthquake; seismic analysis using both linear static, linear dynamic (response spectrum method) has been performed. The analytical model of the building includes all important components that influence the mass, strength, stiffness and deformability of the structure.
LATERAL LOAD ANALYSIS OF SOFT STORY BUILDING AND IMPORTANCE OF MODELING MASON...ijsrd.com
Generally Masonry infills are considered as non-structural elements and their stiffness contributions are generally ignored in practice. But they affect both the structural and non-structural performance of the RC buildings during earthquakes. RC frame building with open first storey is known as soft storey, which performs poorly during strong earthquake shaking. A similar soft storey effect can occur if first and second story used as service story. Hence a combination of two structural system components i.e. Rigid frames and RC shear walls leads to a highly efficient system in which shear wall resist the majority of the lateral loads and the frame supports majority of the gravity loads. To study the effect of masonry infill with different soft storey level, 7 models of Reinforced Concrete framed building were analyzed with two types of shear wall when subjected to earthquake loading. The results of bare frame and other building models have been compared, it is observed that model with swastika and L shape shear wall are showing efficient performance and hence reducing the effect of soft storey in model 3, model 4 and model 5.
Stiffness degradation behavior of retrofitted rc infilled frame under cyclic ...eSAT Journals
Abstract The present study was to evaluate the load carrying capacity of retrofitted 3-bay 4-storey brick infill R.C frame using Ferro cement under cyclic loading. Generally bricks will not be considered as a structural element, but by an effective strengthening technique infill walls and RC frame elements can be kept together and forcing them to work as a whole until the end of the ground motion. The effectiveness of the retrofitted frame under cyclic load was investigated in terms of displacement, stiffness and load carrying capacity. Keywords: Retrofit, Ferro cement, R.C frame, brick infill, cyclic loading, stiffness degradation
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
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.
Influence of Modeling Masonry Infill on Seismic Performance of Multi-Storeyed...ijsrd.com
Masonry infilled RC frames are the most common type of structures used for multi-storeyed constructions in the developing countries, even in those which are located in seismically active regions also. Masonry infill walls are mainly used to increase the stiffness and strength of R C framed buildings. R C framed building with open first storey is known as soft storey, which performs poorly during earthquakes. A similar soft storey effect can also appear top storey level if it is used as service storey. The soft storey located in the upper part of the multistorey building does not significantly affect. To observe the effect of masonry infill panel, it is modeled as an equivalent double diagonal strut. In this study 7 models are taken were analyzed with two different techniques of modelling of masonry infill wall with L type of shear wall when subjected to earthquake loading. The results of masonry infill show more stiffness than the strut modeling technique. It is observed that, providing infill wall and shear wall improves earthquake resistant behavior of the structure and also the effect of water pressure, an attempt is made to develop relationship between strength and stiffness ratios for linear trend line.
Neuro-symbolic is not enough, we need neuro-*semantic*Frank van Harmelen
Neuro-symbolic (NeSy) AI is on the rise. However, simply machine learning on just any symbolic structure is not sufficient to really harvest the gains of NeSy. These will only be gained when the symbolic structures have an actual semantics. I give an operational definition of semantics as “predictable inference”.
All of this illustrated with link prediction over knowledge graphs, but the argument is general.
Builder.ai Founder Sachin Dev Duggal's Strategic Approach to Create an Innova...Ramesh Iyer
In today's fast-changing business world, Companies that adapt and embrace new ideas often need help to keep up with the competition. However, fostering a culture of innovation takes much work. It takes vision, leadership and willingness to take risks in the right proportion. Sachin Dev Duggal, co-founder of Builder.ai, has perfected the art of this balance, creating a company culture where creativity and growth are nurtured at each stage.
Slack (or Teams) Automation for Bonterra Impact Management (fka Social Soluti...Jeffrey Haguewood
Sidekick Solutions uses Bonterra Impact Management (fka Social Solutions Apricot) and automation solutions to integrate data for business workflows.
We believe integration and automation are essential to user experience and the promise of efficient work through technology. Automation is the critical ingredient to realizing that full vision. We develop integration products and services for Bonterra Case Management software to support the deployment of automations for a variety of use cases.
This video focuses on the notifications, alerts, and approval requests using Slack for Bonterra Impact Management. The solutions covered in this webinar can also be deployed for Microsoft Teams.
Interested in deploying notification automations for Bonterra Impact Management? Contact us at sales@sidekicksolutionsllc.com to discuss next steps.
Smart TV Buyer Insights Survey 2024 by 91mobiles.pdf91mobiles
91mobiles recently conducted a Smart TV Buyer Insights Survey in which we asked over 3,000 respondents about the TV they own, aspects they look at on a new TV, and their TV buying preferences.
Connector Corner: Automate dynamic content and events by pushing a buttonDianaGray10
Here is something new! In our next Connector Corner webinar, we will demonstrate how you can use a single workflow to:
Create a campaign using Mailchimp with merge tags/fields
Send an interactive Slack channel message (using buttons)
Have the message received by managers and peers along with a test email for review
But there’s more:
In a second workflow supporting the same use case, you’ll see:
Your campaign sent to target colleagues for approval
If the “Approve” button is clicked, a Jira/Zendesk ticket is created for the marketing design team
But—if the “Reject” button is pushed, colleagues will be alerted via Slack message
Join us to learn more about this new, human-in-the-loop capability, brought to you by Integration Service connectors.
And...
Speakers:
Akshay Agnihotri, Product Manager
Charlie Greenberg, Host
JMeter webinar - integration with InfluxDB and GrafanaRTTS
Watch this recorded webinar about real-time monitoring of application performance. See how to integrate Apache JMeter, the open-source leader in performance testing, with InfluxDB, the open-source time-series database, and Grafana, the open-source analytics and visualization application.
In this webinar, we will review the benefits of leveraging InfluxDB and Grafana when executing load tests and demonstrate how these tools are used to visualize performance metrics.
Length: 30 minutes
Session Overview
-------------------------------------------
During this webinar, we will cover the following topics while demonstrating the integrations of JMeter, InfluxDB and Grafana:
- What out-of-the-box solutions are available for real-time monitoring JMeter tests?
- What are the benefits of integrating InfluxDB and Grafana into the load testing stack?
- Which features are provided by Grafana?
- Demonstration of InfluxDB and Grafana using a practice web application
To view the webinar recording, go to:
https://www.rttsweb.com/jmeter-integration-webinar
State of ICS and IoT Cyber Threat Landscape Report 2024 previewPrayukth K V
The IoT and OT threat landscape report has been prepared by the Threat Research Team at Sectrio using data from Sectrio, cyber threat intelligence farming facilities spread across over 85 cities around the world. In addition, Sectrio also runs AI-based advanced threat and payload engagement facilities that serve as sinks to attract and engage sophisticated threat actors, and newer malware including new variants and latent threats that are at an earlier stage of development.
The latest edition of the OT/ICS and IoT security Threat Landscape Report 2024 also covers:
State of global ICS asset and network exposure
Sectoral targets and attacks as well as the cost of ransom
Global APT activity, AI usage, actor and tactic profiles, and implications
Rise in volumes of AI-powered cyberattacks
Major cyber events in 2024
Malware and malicious payload trends
Cyberattack types and targets
Vulnerability exploit attempts on CVEs
Attacks on counties – USA
Expansion of bot farms – how, where, and why
In-depth analysis of the cyber threat landscape across North America, South America, Europe, APAC, and the Middle East
Why are attacks on smart factories rising?
Cyber risk predictions
Axis of attacks – Europe
Systemic attacks in the Middle East
Download the full report from here:
https://sectrio.com/resources/ot-threat-landscape-reports/sectrio-releases-ot-ics-and-iot-security-threat-landscape-report-2024/
Software Delivery At the Speed of AI: Inflectra Invests In AI-Powered QualityInflectra
In this insightful webinar, Inflectra explores how artificial intelligence (AI) is transforming software development and testing. Discover how AI-powered tools are revolutionizing every stage of the software development lifecycle (SDLC), from design and prototyping to testing, deployment, and monitoring.
Learn about:
• The Future of Testing: How AI is shifting testing towards verification, analysis, and higher-level skills, while reducing repetitive tasks.
• Test Automation: How AI-powered test case generation, optimization, and self-healing tests are making testing more efficient and effective.
• Visual Testing: Explore the emerging capabilities of AI in visual testing and how it's set to revolutionize UI verification.
• Inflectra's AI Solutions: See demonstrations of Inflectra's cutting-edge AI tools like the ChatGPT plugin and Azure Open AI platform, designed to streamline your testing process.
Whether you're a developer, tester, or QA professional, this webinar will give you valuable insights into how AI is shaping the future of software delivery.
GraphRAG is All You need? LLM & Knowledge GraphGuy Korland
Guy Korland, CEO and Co-founder of FalkorDB, will review two articles on the integration of language models with knowledge graphs.
1. Unifying Large Language Models and Knowledge Graphs: A Roadmap.
https://arxiv.org/abs/2306.08302
2. Microsoft Research's GraphRAG paper and a review paper on various uses of knowledge graphs:
https://www.microsoft.com/en-us/research/blog/graphrag-unlocking-llm-discovery-on-narrative-private-data/
DevOps and Testing slides at DASA ConnectKari Kakkonen
My and Rik Marselis slides at 30.5.2024 DASA Connect conference. We discuss about what is testing, then what is agile testing and finally what is Testing in DevOps. Finally we had lovely workshop with the participants trying to find out different ways to think about quality and testing in different parts of the DevOps infinity loop.
Elevating Tactical DDD Patterns Through Object CalisthenicsDorra BARTAGUIZ
After immersing yourself in the blue book and its red counterpart, attending DDD-focused conferences, and applying tactical patterns, you're left with a crucial question: How do I ensure my design is effective? Tactical patterns within Domain-Driven Design (DDD) serve as guiding principles for creating clear and manageable domain models. However, achieving success with these patterns requires additional guidance. Interestingly, we've observed that a set of constraints initially designed for training purposes remarkably aligns with effective pattern implementation, offering a more ‘mechanical’ approach. Let's explore together how Object Calisthenics can elevate the design of your tactical DDD patterns, offering concrete help for those venturing into DDD for the first time!
Elevating Tactical DDD Patterns Through Object Calisthenics
2327
1. 2327
1
The University of Adelaide, Adelaide, Australia
2
European Commission, Joint Research Centre, Ispra Italy
SEISMIC RETROFIT OF REINFORCED CONCRETE BUILDINGS - A REVIEW
AND CASE STUDY
M C GRIFFITH1
And A V PINTO2
SUMMARY
In this paper, the specific details of a 4-storey, 3-bay reinforced concrete frame test structure with
unreinforced brick masonry (URM) infill walls are described along with estimates of its likely
weaknesses with regard to seismic loading. The construction details for this building are typical of
construction more than 40 years old in Mediterranean European countries. The concrete frame is
shown to be essentially a “weak-column strong-beam frame” which is likely to exhibit poor post-
yield hysteretic behaviour. Based on the results of an extensive literature review, the building is
expected to have maximum lateral deformation capacities corresponding to about 2% lateral drift.
The unreinforced masonry infill walls are likely to begin cracking at much smaller lateral drifts, of
the order of 0.3%, and to completely lose their load carrying ability by drifts of between 1% and
2%. Three seismic retrofit schemes were identified, based on the literature review, for further
study. The effectiveness of each retrofit scheme will be tested using full-scale pseudo-dynamic
tests at the European Laboratory for Structural Assessment (ELSA) at the European Commission’s
Joint Research Centre in Ispra, Italy. The results of the detailed analyses and tests will be reported
elsewhere.
INTRODUCTION
There has been much research on the topic of seismic retrofit of structures in recent years. Attention has been
focussed world-wide on both building and bridge structures and with the widespread damage to older structures
in the relatively recent Loma Prieta, Northridge, and Kobe earthquakes, owners are increasingly taking action to
prevent similar damage to existing structures in future earthquakes.
The purpose of the present study was to investigate possible seismic retrofit options for use in a project using
full-scale pseudo-dynamic tests at the European Laboratory for Structural Assessment (ELSA) at the European
Commission’s Joint Research Centre in Ispra, Italy. This project is being conducted as part of the overall
European effort to develop seismic retrofit guidelines in the form of Part 1-4 of Eurocode 8 (CEN, 1998). To
that end, the present study investigated potential seismic retrofit techniques for use in a “typical” reinforced
concrete frame building with brick masonry infill walls. While the building was designed according to the state-
of-the-art over 40 years ago, it does not meet the present day seismic design requirements. The building is
representative of many other buildings of its era constructed in European Mediterranean countries such as
Greece, Italy and Portugal.
LITERATURE REVIEW
In the course of this investigation, a review of the broader literature in the area of seismic rehabilitation was
undertaken (Griffith and Pinto, 1999). Over 200 papers, mainly journal articles and World Earthquake
Engineering Conference papers and European Conference on Earthquake Engineering papers, published since
1980 were reviewed as part of this project. In the interest of space, only a brief summary is given here.
A review of the current EC8 practice in repair and strengthening of concrete structures in Europe (Elnashai and
Pinho, 1998) discussed the need for the design philosophy underpinning the assessment and strengthening of
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buildings to be consistent with that for new buildings. While different design target performance limits may be
allowed for new and existing construction, the basic design philosophy should be consistent. It was concluded
that there is a need to explicitly include deformation-related performance objectives in retrofit design guidelines
in view of the trend towards deformation-based seismic design of new structures. Consequently, the lateral drifts
and structural deformations reported for concrete frames and masonry infill are specifically summarised here.
Considering first the concrete frame on its own, it may be expected that it will withstand a lateral drift of the
order of 1.5% to 2% before the beam-column joints and/or columns fail (Beres et al, 1992a). The maximum
base shear strength for the concrete frame will likely be of the order of 15% of its weight and occur at roughly
1% drift (Bracci et al, 1995a,b).
As for the masonry, the ultimate strength of the masonry infill may be estimated using a value for the maximum
shear strength of URM of MPaMPau 2.04.0 ±=τ . There is a wide range in the values reported in the literature
for the shear strain (or lateral drift angle) at which the maximum shear stress occurs. Nevertheless, based on the
literature it appears that this maximum stress may be estimated to occur at a lateral drift angle of approximately
0.3% (see for example Pires and Carvalho, 1992; Valiasis et al, 1993; Fardis and Calvi, 1995; Zarnic and Gostic,
1997; Schneider et al, 1998).
Turning to failure modes, a recent review by Dyngeland (1998) found that the most common failure mechanisms
for concrete buildings due to seismic loading are: (1) beam-column joint failures; (2) column failure due to
inadequate flexural or shear strength; (3) shear wall failure; or (4) infill wall failure due to inadequate shear
strength or inadequate out-of-plane flexural strength. Bruneau (1994) provides a similar overview of the seismic
vulnerability of masonry (brick and concrete block) buildings and their most common failure mechanisms. Of
particular interest to this project are those due to in-plane forces.
Many of the structural failures during earthquakes in the early 1970s were due to inadequate shear strength
and/or lack of confinement in concrete columns. Hence, early column strengthening procedures typically
involved increasing the concrete column’s cross-section. The main problem with this approach is that it often
unacceptably increases the dimension of the column, rendering the retrofit impractical. The use of thin carbon
fibre composite sheets avoids this problem and has consequently gained acceptance over the past 10 years. It
was noted that steel and composite jacketing was particularly useful for correcting inadequate lap splice
problems and that anchor bolts can be used to improve confinement away from the corners of rectangular
columns (eg, Priestley et al, 1994; Saadatmanesh et al, 1997). Nevertheless, concrete jacketing of concrete
columns has been shown to be very effective in improving strength and ductility and converting strong-beam
weak-column buildings into buildings with a strong-column weak-beam mechanism (Choudhuri et al, 1992;
Rodriguez and Park, 1994; Bracci et al, 1997; Bush et al, 1990).
Where the masonry infill is susceptible, it can be retrofit in a wide variety of ways. Crack injection grouting is
often used to return a masonry wall to its “original” condition whereas the use of so-called “jacketing”
techniques adds both strength and stiffness to the infill. In this context, jacketing consists of encasing the
existing element by an additional structural component. For masonry infill walls, jacketing can take the form of:
• shotcreting – the application by spraying a thin layer of concrete onto the face of the brickwork.
Reinforcement may or may not be attached to the brickwork before spraying;
• prefabricated reinforced concrete panels attached, normally, with dowels through the brickwork;
• steel plates or fibre composite sheets glued/bonded onto the brickwork; or
• steel strip bracing attached to the brickwork using either through-bolting or some form of chemical
bonding agent.
While recent research has focussed on the use of advanced fibre composites, energy dissipation and seismic
isolation devices for the seismic retrofit of buildings, the more traditional methods should not be overlooked
when considering which system(s) to employ. In practice, the optimal scheme will depend upon many factors,
some of which are non-technical such as aesthetics and the level of disruption to occupants (Jirsa, 1994).
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DESCRIPTION OF ELSA TEST BUILDING
The ELSA test building is a 4-storey, 3-bay reinforced concrete frame with unreinforced brick masonry infill
walls. The concrete frame was designed for gravity loads and a nominal lateral load of 8% of its weight, W
(Carvalho, 1998). The reinforcement details were specified to be representative of buildings constructed over 40
years ago in European Mediterranean countries such as Italy, Portugal and Greece. In the following sections, the
building is described and the results of a preliminary assessment of its likely seismic behaviour are presented.
Frame Geometry, Section Details and Material Properties
The dimensions of the building and section details are shown in Figures 1 – 3. It can be seen in the elevation and
plan drawings (Figure 1) that the storey heights are 2.7m and there are two 5m span bays and one 2.5m span bay.
Brick masonry infill (200mm thick) is contained within each bay. The left-hand bay contains a window (1.2 x
1.1m) at each of the 4 levels. The central bay contains a doorway (2.0 x 1.9m) at ground level and window
openings (2.0 x 1.1m) in each of the upper 3 levels of the building. The right-hand (2.5m span) bay contains
solid infill. The beam reinforcement details are shown in Figure 2. It should be noted that the longitudinal
reinforcing steel consists of smooth round bars which are terminated with 180° bends. All beams in the direction
of loading are 250mm wide and 500mm deep. The transverse beams are 200mm wide and 500mm deep. The
concrete slab thickness is 150mm. The column reinforcement details are shown in Figure 3. The column stirrup
detail with a 90° curtailment bend should be noted in particular. Preliminary calculations have been carried out
in order to establish which failure mechanisms are most likely to occur under seismic loading. In order to do
this, the mean values for the respective material strengths shown in Table 1 were used.
Table 1 – Material properties (mean values).
Steel MPafsy 235= , MPaxEst
3
10200=
Concrete MPafc 24=′ , 003.0=cuε , MPaxEc
3
1020=
Brick Masonry MPau 4.0=τ , 003.0=uγ
Figure 1 – Plan and elevation views of concrete frame plus masonry infill building.
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Figure 2 – Beam reinforcement details.
Figure 3 – Column reinforcement details.
Frame Sidesway Potential and Column Shear Strength
The ultimate moment capacity, uM , was first calculated for each beam and column cross-section using
conventional rectangular stress-block theory and the mean values for the respective steel yield and concrete
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compression strength properties shown in Table 1. In order to assess whether a column sidesway mechanism
was likely to occur, the sum of the moment capacities of the columns at each level were divided by the sum of
the moment capacities of the beams at each level using equation (1).
∑
∑
beamsu
columnsu
M
M
,
,
(1)
Even though the slab contribution to the beam capacity was ignored, the value given by equation (1) was still
less than one for each level of the structure, indicating that the structure is highly susceptible to column sidesway
collapse. (Note: in practice, the value given by equation (1) should be markedly greater than 1, say 1.4 for
example, to ensure that a column sidesway mechanism is not likely to occur.)
The shear capacity of each column, uV , was then estimated to determine whether the columns were likely to
suffer shear failure before reaching their maximum flexural strength. These calculations indicated that no
columns are expected to suffer premature shear failure.
Masonry Infill and Concrete Frame Shear Strength and Stiffness
Next, the relative shear strength of the masonry infill walls were estimated and compared to the estimated
ultimate shear strength for each storey of the bare concrete frame. The values suggest that the ultimate strength
of the brick walls is approximately four times that of the bare frame. Of course, the column storey shears will
not achieve their maximum at the same lateral drift as will the masonry since the lateral stiffness of the
brickwork is also much greater than that for the frame. The retrofit scheme therefore needs to be capable of
accommodating the differences in both strength and stiffness. It should also be noted that the shear strength of
the concrete frame above level 2 is only 60% of the frame’s shear strength below level 2.
Section and Joint Details
There are two main aspects of concern for the beam-column details shown in Figures 2 and 3. The first is related
to the possibility of premature joint failure due to poor anchorage of the bottom beam steel that terminates in the
beam-column joint region. The behaviour of smooth round bars with 180° bends in the joint region is likely to
be better than the behaviour observed by Beres et al (1992) who tested joints with deformed bars which
terminated in the joint region without any bends. In those tests, exterior joints failed at lateral drifts of between
1.5% and 2% of the storey height. Interior joints failed at lateral drifts between 2% and 2.5%. Therefore, it is
expected that the joints in the test building will perform adequately, at least up to drifts of 2% to 2.5%.
However, the use of the 90° stirrup “overlapping details” (Figure 3) in the curtailment of the shear reinforcement
for the beams and, more particularly, for the columns is another matter. Experience has shown that columns will
collapse if their stirrups are not located sufficiently close to confine the concrete core and prevent buckling of the
longitudinal steel. The stirrup spacing used in this project is 150mm in all columns ( bds 10= or bd5.12 ) and
either 100mm or 200mm in the beams ( bds 3.8= or bd7.16 ). These are remarkably close spacings in view of
the age of the design. Nevertheless, the stirrup detail shown in Figure 3 is not expected to withstand repeated
large cycles of lateral loading once concrete crushing has occurred.
Summary
In summary, the main issues to be addressed by potential seismic retrofit schemes are:
• The large difference in strength and stiffness between the concrete frame and the brick masonry infill.
For example, the bottom storey of masonry infill is estimated to reach its ultimate shear strength of
about 660kN at a storey deformation approximately 0.3% drift. On the other hand, the bottom storey of
the frame is estimated to reach its ultimate strength of 150kN at a drift of between 1% and 2%.
• The large change in strength and stiffness of the frame at level 2. The strength of the bare concrete
frame above level 2 is estimated to be only 60% of the strength of the frame below level 2. Similarly,
the lateral shear stiffness for the frame storeys above level 2 are estimated to be 65% of the stiffness for
the frame storeys below level 2.
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• The seismic behaviour of the bare concrete frame is likely to be that of a “weak-column, strong-beam”
mechanism under ultimate deformation conditions.
• The stirrup curtailment detail (Figure 3) which uses 90° hooks is unlikely to withstand repeated cycles
of large deformation (say ±2% drift).
RETROFIT STRATEGIES
In this section a number of seismic retrofit strategies are discussed. Each has its relative merits. For example,
the retrofit choice will depend to a large extent upon the seismic performance level that is required during the
design basis earthquake (DBE). Predominately elastic response so that the masonry infill walls are protected
during the DBE will require a much different retrofit than if the walls are allowed to fail to permit ductile
moment or braced frame behaviour. Hence, several retrofit options were considered for this project.
Option 1: Replacement of URM infill with damped bracing
In this option, the URM infill would be replaced with K-bracing in the 2.5m span bay at each level of the
building. The bracing would incorporate energy dissipation devices that would help reduce the seismic demands
from the levels corresponding to the 5% damped design spectrum for the DBE. With the addition of the damped
bracing, the frame can be designed to provide more uniform storey stiffnesses and strengths and the energy
dissipation devices can be designed to “yield” at appropriate force amplitudes. In this way, ductile bracing can
limit the forces that they attract and help limit the maximum base shear reaction. In practice, any retrofit
solution that increases the base shear reaction will incur additional expenses due to the need to improve the
building’s foundation.
Option 2: Composite jacketing of columns and selected masonry infill
Composite jacketing can be used to strengthen the columns and infill walls and to improve the ductility of the
columns and the post-cracking behaviour of the URM infill walls. However, this retrofit option will cause a
modest increase in the lateral strength and stiffness of the building. If the consequences of this are acceptable
(e.g. foundation strengthening) then the composite jackets should be easily capable of addressing the potential
column stirrup weakness and the poor post-cracking behaviour of the masonry infill. Since the jacketed infill
would be able to carry sizeable loads after cracking, the change in strength and stiffness of the concrete frame
itself would not be critical and probably need not be specifically modified.
Option 3: Retrofit of concrete frame elements only
In this option, only the concrete frame elements would be repaired. The masonry infill would essentially be
ignored. The assumption being that the deformations in the building during the DBE would be between 1.5%
and 3% drift and that the URM would have completely failed at that point. The likely maximum sustainable
drift for the concrete frame was estimated to be approximately 2%. With this in mind, the column hinge zones
would need to be confined (composite or concrete jacketing) to maintain confinement during large reversals of
displacement (in excess of 1.5% drift). Furthermore, the change in strength and stiffness at level 2 must be
addressed in this option.
Summary
In summary, three retrofit options have been briefly discussed in this section. Each of the options has its merits
and all can be made to “work”. The “best” scheme can be decided only after considering the costs and benefits
of each scheme. Hence, more refined analyses of the seismic behaviour of the “as-is” building and evaluation of
the test results of the ELSA test structure with the various retrofit options are required.
CONCLUSIONS
In summary, a comprehensive literature review was performed in order to gain a better insight into the key issues
relevant to seismic retrofit of concrete frame buildings with unreinforced masonry infill walls. Based on this
review, it was concluded that buildings having details typical of construction of more than 40 years ago in
Mediterranean European countries are likely to have maximum lateral deformation capacities corresponding to
about 2% lateral drift. The unreinforced masonry infill walls are likely to begin cracking at much smaller lateral
drifts, of the order of 0.3%, and to completely lose their load carrying ability by drifts of between 1% and 2%.
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In this paper, the specific details of a 4-storey, 3-bay reinforced concrete frame test structure with unreinforced
brick masonry (URM) infill walls were described and estimates of its likely weaknesses with regard to seismic
loading were outlined. The concrete frame was shown to be essentially a “weak-column strong-beam frame”
which is likely to exhibit poor post-yield hysteretic behaviour. To make matters worse, there is a decrease in
strength and stiffness of the concrete frame of the order of 35-40% at level 2. This particular problem is not
critical as long as the URM infill retains its load-carrying capacity since the strength and stiffness of the URM
infill is estimated to be much larger than that of the frame. However, even if the infill were designed to respond
elastically in the DBE its ductility is much worse and in the event of a larger than expected earthquake the infill
strength is likely to be lost. Hence, three retrofit options were selected for further detailed investigation.
The effectiveness of the retrofit schemes eventually selected from among the options discussed here will be
tested using full-scale pseudo-dynamic tests at the European Laboratory for Structural Assessment (ELSA) at the
European Commission’s Joint Research Centre in Ispra, Italy. The results of the detailed analyses and tests will
be reported in future publications.
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