Load testing of reinforced concrete bridges in the NetherlandsEva Lantsoght
As the bridge stock in The Netherlands and Europe is ageing, various methods to analyze existing bridges are being studied. Load testing of bridges is an option to study the capacity when crucial information about the structure is lacking. This information could be related to the material (for example, the effect of ASR on the capacity) as well as to the structural system (for example, the effect of restraints at the supports or transverse redistribution capacity).
When it is decided to load test a bridge, the question arises which maximum load should be attained during the experiment to approve the capacity of the bridge, and which criteria, based on the measurements during the test, would indicate that the test needs to be aborted before reaching the maximum desired load (the “stop criteria”).
A number of reinforced concrete slab bridges have been load tested over the course of the past few years. These load tests were pilot cases, in which the bridges were heavily equipped with sensors, to study the bridges’ behavior at critical positions for bending moment and shear. The test results were then extensively analyzed, and compared to the stop criteria available in the currently used codes and guidelines.
As a result of the analysis and experiments, recommendations are given for proof loading of bridges. These recommendations are important, since they will form the basis of a guideline for proof loading of existing concrete bridges that is under development in The Netherlands.
Application of Modified Bond Model to the capacity of Ruytenschildt BridgeEva Lantsoght
The Ruytenschildt bridge in Friesland is a continuously supported concrete slab bridge, and was tested in two spans to failure in August 2014. The results of this experiment are valuable for the analysis of existing slab bridges and for analyzing the moment and shear capacity of reinforced concrete slabs and slab bridges.
Earlier analyses found that a large number of existing slab bridges in The Netherlands rate as insufficient for shear. However, these analyses did not take into account the beneficial effect of transverse load redistribution. Therefore, the Modified Bond Model was developed. This model covers beam shear, punching shear and flexure for reinforced concrete slabs.
The test results are now to compare to the predictions with the Modified Bond Model. Since the Modified Bond Model is independent of the failure mode, the maximum load that is found can be directly correlated to the maximum tandem load in the experiment. Comparing the test results on the bridge with the predictions based on the Modified Bond Model shows good correspondence. The results are also compared to a new proposal for vmin, the minimum shear stress at which shear failure takes place. For smaller value, a moment failure takes place.
While the presented results only show a comparison between 2 tests on an existing bridge and the proposed Modified Bond Model, the results indicate that the Modified Bond Model can become a useful tool for design and analysis of reinforced concrete slabs based on the principles of the theory of plasticity.
Load testing of reinforced concrete bridges in the NetherlandsEva Lantsoght
As the bridge stock in The Netherlands and Europe is ageing, various methods to analyze existing bridges are being studied. Load testing of bridges is an option to study the capacity when crucial information about the structure is lacking. This information could be related to the material (for example, the effect of ASR on the capacity) as well as to the structural system (for example, the effect of restraints at the supports or transverse redistribution capacity).
When it is decided to load test a bridge, the question arises which maximum load should be attained during the experiment to approve the capacity of the bridge, and which criteria, based on the measurements during the test, would indicate that the test needs to be aborted before reaching the maximum desired load (the “stop criteria”).
A number of reinforced concrete slab bridges have been load tested over the course of the past few years. These load tests were pilot cases, in which the bridges were heavily equipped with sensors, to study the bridges’ behavior at critical positions for bending moment and shear. The test results were then extensively analyzed, and compared to the stop criteria available in the currently used codes and guidelines.
As a result of the analysis and experiments, recommendations are given for proof loading of bridges. These recommendations are important, since they will form the basis of a guideline for proof loading of existing concrete bridges that is under development in The Netherlands.
Application of Modified Bond Model to the capacity of Ruytenschildt BridgeEva Lantsoght
The Ruytenschildt bridge in Friesland is a continuously supported concrete slab bridge, and was tested in two spans to failure in August 2014. The results of this experiment are valuable for the analysis of existing slab bridges and for analyzing the moment and shear capacity of reinforced concrete slabs and slab bridges.
Earlier analyses found that a large number of existing slab bridges in The Netherlands rate as insufficient for shear. However, these analyses did not take into account the beneficial effect of transverse load redistribution. Therefore, the Modified Bond Model was developed. This model covers beam shear, punching shear and flexure for reinforced concrete slabs.
The test results are now to compare to the predictions with the Modified Bond Model. Since the Modified Bond Model is independent of the failure mode, the maximum load that is found can be directly correlated to the maximum tandem load in the experiment. Comparing the test results on the bridge with the predictions based on the Modified Bond Model shows good correspondence. The results are also compared to a new proposal for vmin, the minimum shear stress at which shear failure takes place. For smaller value, a moment failure takes place.
While the presented results only show a comparison between 2 tests on an existing bridge and the proposed Modified Bond Model, the results indicate that the Modified Bond Model can become a useful tool for design and analysis of reinforced concrete slabs based on the principles of the theory of plasticity.
Defining loading criteria for proof loading Eva Lantsoght
As the bridge stock in The Netherlands and Europe is ageing, various methods to analyse existing bridges are being studied. Proof loading of bridges is an option to study the capacity when crucial information about the structure is lacking. This information could be related to the material (for example, the effect of alkali-silica reaction on the structural capacity) as well as to the structural system (for example, the effect of restraints at the supports or transverse redistribution capacity). When it is decided to proof load a bridge, the question arises which maximum load should be attained during the experiment to approve the capacity of the bridge, and which criteria, based on the measurements during the test, would indicate that the proof loading needs to be aborted before reaching the maximum desired load (the so-called stop criteria). To define the required loading criteria, a review of the literature has been made, finite element models of existing viaducts have been made, and on these viaducts, proof loading tests have been carried out. These bridges were heavily instrumented, with a goal of learning as much as possible about the structural behaviour during proof loading. As a result of the analysis and experiments, recommendations are given for proof loading of bridges with respect to the required maximum load and the stop criteria.
These recommendations are important, since they form the basis of a guideline for proof loading of existing concrete bridges that is under development in The Netherlands.
Reliability index after proof load testing: viaduct De BeekEva Lantsoght
Proof load tests can be used for a field assessment of the bridge under study. This paper addresses the determination of the reliability index of an existing bridge by means of proof loading through the case study viaduct De Beek. The information of this bridge is used to determine the updated reliability index after proof load testing. A sensitivity study is carried out to identify the effect of the assumptions with regard to the coefficient of variation on the resistance and load effects. In the current practice of proof load testing with vehicles, it can typically only be demonstrated that a certain vehicle type can cross the bridge safely. The results in this paper provide a new insight on the updating of the reliability index after proof load testing. Consensus on the coefficients of variation that need to be used on the resistance and load effects, is still missing.
Recommendations for proof load testing of reinforced concrete slab bridges - ...Eva Lantsoght
Proof loading of existing bridges is an option to study the capacity when crucial information about
the structure is lacking. To define the loading criteria for proof load testing, a review of the
literature has been made, finite element models of existing viaducts have been made, and on
these viaducts, proof loading tests have been carried out. These bridges were heavily
instrumented, to learn as much as possible about the structural behaviour during proof loading.
Additional laboratory experiments have been used to develop controlled loading protocols, and to
identify which stop criteria can be used for which case. As a result of the analysis and experiments,
recommendations are given for proof loading of bridges with respect to the required maximum
load and the stop criteria. These recommendations have resulted in a guideline for proof loading
of existing reinforced concrete slab bridges for The Netherlands.
The Application of WIM data for probabilistic bridge assessmentRoberta Keaney
Best Presentation Winner at the 8th International Conference on Weigh-In-Motion, which took place in Prague in May 2019.
Authors: Lorcan Connolly, Roisin Donnelly, Alan O'Connor, Eugene O'Brien
Bridges are vulnerable to extreme events such as natural disasters in addition to hazards stemming from negligence and improper maintenance, overloading, collisions, intentional acts of vandalism, and terrorist attacks. These structures must be protected but the current approach to risk is not always rational. Sensitivity analysis will be performed to relate the reliability of bridges and reliability of the transportation network.
Proof load testing of the viaduct De BeekEva Lantsoght
Proof load testing can be a suitable method to show that a bridge can carry the required loads
from the code without distress. This paper addresses the preparation, execution, and analysis of a
proof load test on a four-span reinforced concrete solid slab bridge, viaduct de Beek. The bridge
has one lane in each direction, but was restricted to a single lane, since an assessment showed
that the capacity is not sufficient to allow both lanes. For this proof load test, the bridge was
heavily equipped with sensors, so that early signs of distress can be seen. The difficulty in this test
was that, for safety reasons, only the first span could be tested, but that the lowest ratings were
found in the second span. A direct approval of the viaduct by proof loading was thus not possible,
and an analysis was necessary after the field test. The result of this analysis is that only by allowing
6.7% of plastic redistribution in the second span, sufficient capacity can be demonstrated.
Applying Experimental Results to the Shear Assessment Method for Solid Slab B...Eva Lantsoght
The combination of increased live loads and a more conservative shear capacity in the recently implemented Eurocodes, resulted in a large number of existing solid slab bridges in the Netherlands being shear-critical upon assessment. However, an enhancement of the shear capacity can occur in slabs under concentrated wheel loads due to transverse load redistribution. To quantify this effect, a comprehensive series of experiments on slabs and slabs strips under a concentrated load near to the support and under a combination of a concentrated and a line load was carried out. The experiments show the difference in behaviour for slabs, carrying the load in a two-dimensional way, as compared to beams in shear. The results from the laboratory research are used to develop recommendations, that are easily used in combination with the codes. These recommendations are implemented in a spreadsheet-based first-level assessment tool, the Quick Scan method. The assessment with this tool of selected cases of existing solid slab bridges shows that applying the experimental results into the assessment practice leads to an improved selection ability of the Quick Scan method.
Defining loading criteria for proof loading Eva Lantsoght
As the bridge stock in The Netherlands and Europe is ageing, various methods to analyse existing bridges are being studied. Proof loading of bridges is an option to study the capacity when crucial information about the structure is lacking. This information could be related to the material (for example, the effect of alkali-silica reaction on the structural capacity) as well as to the structural system (for example, the effect of restraints at the supports or transverse redistribution capacity). When it is decided to proof load a bridge, the question arises which maximum load should be attained during the experiment to approve the capacity of the bridge, and which criteria, based on the measurements during the test, would indicate that the proof loading needs to be aborted before reaching the maximum desired load (the so-called stop criteria). To define the required loading criteria, a review of the literature has been made, finite element models of existing viaducts have been made, and on these viaducts, proof loading tests have been carried out. These bridges were heavily instrumented, with a goal of learning as much as possible about the structural behaviour during proof loading. As a result of the analysis and experiments, recommendations are given for proof loading of bridges with respect to the required maximum load and the stop criteria.
These recommendations are important, since they form the basis of a guideline for proof loading of existing concrete bridges that is under development in The Netherlands.
Reliability index after proof load testing: viaduct De BeekEva Lantsoght
Proof load tests can be used for a field assessment of the bridge under study. This paper addresses the determination of the reliability index of an existing bridge by means of proof loading through the case study viaduct De Beek. The information of this bridge is used to determine the updated reliability index after proof load testing. A sensitivity study is carried out to identify the effect of the assumptions with regard to the coefficient of variation on the resistance and load effects. In the current practice of proof load testing with vehicles, it can typically only be demonstrated that a certain vehicle type can cross the bridge safely. The results in this paper provide a new insight on the updating of the reliability index after proof load testing. Consensus on the coefficients of variation that need to be used on the resistance and load effects, is still missing.
Recommendations for proof load testing of reinforced concrete slab bridges - ...Eva Lantsoght
Proof loading of existing bridges is an option to study the capacity when crucial information about
the structure is lacking. To define the loading criteria for proof load testing, a review of the
literature has been made, finite element models of existing viaducts have been made, and on
these viaducts, proof loading tests have been carried out. These bridges were heavily
instrumented, to learn as much as possible about the structural behaviour during proof loading.
Additional laboratory experiments have been used to develop controlled loading protocols, and to
identify which stop criteria can be used for which case. As a result of the analysis and experiments,
recommendations are given for proof loading of bridges with respect to the required maximum
load and the stop criteria. These recommendations have resulted in a guideline for proof loading
of existing reinforced concrete slab bridges for The Netherlands.
The Application of WIM data for probabilistic bridge assessmentRoberta Keaney
Best Presentation Winner at the 8th International Conference on Weigh-In-Motion, which took place in Prague in May 2019.
Authors: Lorcan Connolly, Roisin Donnelly, Alan O'Connor, Eugene O'Brien
Bridges are vulnerable to extreme events such as natural disasters in addition to hazards stemming from negligence and improper maintenance, overloading, collisions, intentional acts of vandalism, and terrorist attacks. These structures must be protected but the current approach to risk is not always rational. Sensitivity analysis will be performed to relate the reliability of bridges and reliability of the transportation network.
Proof load testing of the viaduct De BeekEva Lantsoght
Proof load testing can be a suitable method to show that a bridge can carry the required loads
from the code without distress. This paper addresses the preparation, execution, and analysis of a
proof load test on a four-span reinforced concrete solid slab bridge, viaduct de Beek. The bridge
has one lane in each direction, but was restricted to a single lane, since an assessment showed
that the capacity is not sufficient to allow both lanes. For this proof load test, the bridge was
heavily equipped with sensors, so that early signs of distress can be seen. The difficulty in this test
was that, for safety reasons, only the first span could be tested, but that the lowest ratings were
found in the second span. A direct approval of the viaduct by proof loading was thus not possible,
and an analysis was necessary after the field test. The result of this analysis is that only by allowing
6.7% of plastic redistribution in the second span, sufficient capacity can be demonstrated.
Applying Experimental Results to the Shear Assessment Method for Solid Slab B...Eva Lantsoght
The combination of increased live loads and a more conservative shear capacity in the recently implemented Eurocodes, resulted in a large number of existing solid slab bridges in the Netherlands being shear-critical upon assessment. However, an enhancement of the shear capacity can occur in slabs under concentrated wheel loads due to transverse load redistribution. To quantify this effect, a comprehensive series of experiments on slabs and slabs strips under a concentrated load near to the support and under a combination of a concentrated and a line load was carried out. The experiments show the difference in behaviour for slabs, carrying the load in a two-dimensional way, as compared to beams in shear. The results from the laboratory research are used to develop recommendations, that are easily used in combination with the codes. These recommendations are implemented in a spreadsheet-based first-level assessment tool, the Quick Scan method. The assessment with this tool of selected cases of existing solid slab bridges shows that applying the experimental results into the assessment practice leads to an improved selection ability of the Quick Scan method.
Como evaluar la capacidad de puentes de hormigón existentes?Eva Lantsoght
Después de la expansión de la red vial del país, la comunidad de ingenieros civiles y el gobierno tienen un número mayor de puentes existentes a manejar. En el futuro, esos puentes necesitaran mantenimiento y adopciones a los cambios en términos de las cargas vivas. En ese artículo vamos a ver como en Europa y América del Norte se está evaluando la capacidad de puentes de hormigón existentes. Típicamente, la evaluación es primero analítico, y después, dependiendo de la necesidad, experimental. En caso de concluir que no hay capacidad suficiente, diseñamos un refuerzo estructural para el puente. Revisaremos diferentes métodos de cálculo, inspección, pruebas de carga, y reforzamiento para puentes de hormigón existentes.
Stop criteria for proof load tests verified with field and laboratory testing...Eva Lantsoght
As the existing bridge stock is aging, improved assessment methods such as proof load testing become increasingly important. Proof load testing involves large loads, and as such the risk for the structure and personnel can be significant. To capture the structural response, extensive measurements are applied to proof load tests. Stop criteria, based on the measured quantities, are used to identify when further loading in a proof load test is not permitted. For proof load testing of buildings, stop criteria are available in existing codes. For bridges, recently stop criteria based on laboratory tests on beams reinforced with plain bars have been proposed. Subsequently, improved stop criteria were developed based on theoretical considerations for bending moment and shear. The stop criteria from the codes and the proposed stop criteria are compared to the results from field testing to collapse on the Ruytenschildt Bridge, and to the results from laboratory tests on beams sawn from the Ruytenschildt Bridge. This comparison shows that only a small change to the stop criteria derived from laboratory testing is necessary. The experimental evidence strengthens the recommendation for using the proposed stop criteria in proof load tests on bridges for bending moment, whereas further testing to confirm the stop criteria for shear is necessary.
Recommendations for proof load testing of reinforced concrete slab bridges - ...Eva Lantsoght
Proof loading of existing bridges is an option to study the capacity when crucial information about
the structure is lacking. To define the loading criteria for proof load testing, a review of the
literature has been made, finite element models of existing viaducts have been made, and on
these viaducts, proof loading tests have been carried out. These bridges were heavily
instrumented, to learn as much as possible about the structural behaviour during proof loading.
Additional laboratory experiments have been used to develop controlled loading protocols, and to
identify which stop criteria can be used for which case. As a result of the analysis and experiments,
recommendations are given for proof loading of bridges with respect to the required maximum
load and the stop criteria. These recommendations have resulted in a guideline for proof loading
of existing reinforced concrete slab bridges for The Netherlands.
Extended Strip Model for slabs subjected to a combination of loadsEva Lantsoght
Reinforced concrete slab bridges are assessed for a combination of loads that include self-weight, superimposed loads, and distributed and concentrated live loads. The shear capacity of reinforced concrete slabs subjected to a combination of loads is thus an important topic for the assessment of existing bridges. Currently, a plastic model exists for the assessment of reinforced concrete solid slabs subjected to a concentrated load: the Extended Strip Model, based on the Strip Model for concentric punching shear. To apply this model to slabs subjected to a combination of loads, the model needs to be adapted based on theoretical principles. The results are then compared with the results from experiments on half-scale slab bridges subjected to a combination of a concentrated load close to the support and a line load. The result of this comparison is that the proposed method is suitable to find a safe estimate of the maximum concentrated load on the slab. The implication of this development is that an improved tool is available to estimate the maximum load of a truck that can be placed on a reinforced concrete bridge, thus improving the current assessment.
Determination of loading protocol and stop criteria for proof loading with be...Eva Lantsoght
Proof loading of existing bridges is an interesting option when insufficient information about a bridge is available. To safely carry out a proof loading test, high loads are placed on the bridge. To avoid permanent damage to the structure, a controlled loading protocol needs to be described, and the measurements need to be closely monitored to identify the onset of distress. The criteria from existing codes and guidelines to evaluate the measurements, called stop criteria, are not universally applicable. To develop recommendations for proof loading of reinforced concrete solid slab bridges, beam experiments were analysed. The beams were heavily instrumented to evaluate the existing stop criteria, and possibly develop new stop criteria. The result of these experiments is the development of a standard loading protocol for the proof loading of reinforced concrete slab bridges. Recommendations for the use of the stop criteria are also formulated. These insights are used to develop a new guideline for the proof loading of reinforced concrete slab bridges in the Netherlands.
Shear capacity of the ruytenschildt bridge Eva Lantsoght
In August 2014, the Ruytenschildt Bridge, a reinforced concrete solid slab bridge (reinforced with plain bars) in the Friesland province in the Netherlands was tested until failure. One of the goals of proof loading and testing this bridge to failure, was to study the failure mode of existing slab bridges. The combination of smaller shear capacities as prescribed by the Eurocode in combination with the heavier live load models, has raised concerns with regard to a number of existing slab bridges in the Netherlands. As the shear capacity of existing bridges is under study, the results of testing an actual slab bridge until failure are used to compare to the results of testing half-scale slab specimens in the laboratory, and the conclusions resulting from those experiments. In this paper, the results of the predictions based on the first order of approximation rating procedure from the Netherlands for shear, the Quick Scan method, as well as based on predictions of the failure mode and the average predicted capacity are compared to the experimental results. The predictions show a possibility of shear failure in the second span of the bridge. The experiment showed that both spans of the bridge failed in flexure. The observed failure mode is important, as some of the results indicate that the solid slab bridges, currently under discussion with regard to their shear capacity, fail in flexure in reality. Flexural failure is considered a ductile failure compared to the brittle failure mode in case of a shear failure.
Bridging the gap between one way and two-way shear in slabsEva Lantsoght
The shear capacity of slabs under concentrated loads is particularly of interest for bridge decks under concentrated live loads. Often, one-way shear will be analyzed by considering the slab as a wide beam (without taking advantage of the transverse load redistribution capacity of the slab) and two-way shear by considering the punching area around the load. Since experiments showed that the failure mode of slabs under concentrated loads is a combination of one-way and two-way shear as well as two-way flexure, a method was sought that bridges the gap between traditional one-way and two-way shear approaches. The proposed method is a plasticity-based method. This method is based on the Strip Model for concentric punching shear and takes the effects of the geometry into account for describing the ultimate capacity of a slab under a concentrated load. The model consists of “strips” that work with arching action (one-way shear) and slab “quadrants” that work in two-way shear. As such, the resulting Extended Strip Model is suitable for the design and assessment of elements that are in the transition zone between one-way and two-way shear.
Observability Concepts EVERY Developer Should Know -- DeveloperWeek Europe.pdfPaige Cruz
Monitoring and observability aren’t traditionally found in software curriculums and many of us cobble this knowledge together from whatever vendor or ecosystem we were first introduced to and whatever is a part of your current company’s observability stack.
While the dev and ops silo continues to crumble….many organizations still relegate monitoring & observability as the purview of ops, infra and SRE teams. This is a mistake - achieving a highly observable system requires collaboration up and down the stack.
I, a former op, would like to extend an invitation to all application developers to join the observability party will share these foundational concepts to build on:
GridMate - End to end testing is a critical piece to ensure quality and avoid...ThomasParaiso2
End to end testing is a critical piece to ensure quality and avoid regressions. In this session, we share our journey building an E2E testing pipeline for GridMate components (LWC and Aura) using Cypress, JSForce, FakerJS…
How to Get CNIC Information System with Paksim Ga.pptxdanishmna97
Pakdata Cf is a groundbreaking system designed to streamline and facilitate access to CNIC information. This innovative platform leverages advanced technology to provide users with efficient and secure access to their CNIC details.
Encryption in Microsoft 365 - ExpertsLive Netherlands 2024Albert Hoitingh
In this session I delve into the encryption technology used in Microsoft 365 and Microsoft Purview. Including the concepts of Customer Key and Double Key Encryption.
UiPath Test Automation using UiPath Test Suite series, part 6DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 6. In this session, we will cover Test Automation with generative AI and Open AI.
UiPath Test Automation with generative AI and Open AI webinar offers an in-depth exploration of leveraging cutting-edge technologies for test automation within the UiPath platform. Attendees will delve into the integration of generative AI, a test automation solution, with Open AI advanced natural language processing capabilities.
Throughout the session, participants will discover how this synergy empowers testers to automate repetitive tasks, enhance testing accuracy, and expedite the software testing life cycle. Topics covered include the seamless integration process, practical use cases, and the benefits of harnessing AI-driven automation for UiPath testing initiatives. By attending this webinar, testers, and automation professionals can gain valuable insights into harnessing the power of AI to optimize their test automation workflows within the UiPath ecosystem, ultimately driving efficiency and quality in software development processes.
What will you get from this session?
1. Insights into integrating generative AI.
2. Understanding how this integration enhances test automation within the UiPath platform
3. Practical demonstrations
4. Exploration of real-world use cases illustrating the benefits of AI-driven test automation for UiPath
Topics covered:
What is generative AI
Test Automation with generative AI and Open AI.
UiPath integration with generative AI
Speaker:
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
GraphSummit Singapore | The Future of Agility: Supercharging Digital Transfor...Neo4j
Leonard Jayamohan, Partner & Generative AI Lead, Deloitte
This keynote will reveal how Deloitte leverages Neo4j’s graph power for groundbreaking digital twin solutions, achieving a staggering 100x performance boost. Discover the essential role knowledge graphs play in successful generative AI implementations. Plus, get an exclusive look at an innovative Neo4j + Generative AI solution Deloitte is developing in-house.
Essentials of Automations: The Art of Triggers and Actions in FMESafe Software
In this second installment of our Essentials of Automations webinar series, we’ll explore the landscape of triggers and actions, guiding you through the nuances of authoring and adapting workspaces for seamless automations. Gain an understanding of the full spectrum of triggers and actions available in FME, empowering you to enhance your workspaces for efficient automation.
We’ll kick things off by showcasing the most commonly used event-based triggers, introducing you to various automation workflows like manual triggers, schedules, directory watchers, and more. Plus, see how these elements play out in real scenarios.
Whether you’re tweaking your current setup or building from the ground up, this session will arm you with the tools and insights needed to transform your FME usage into a powerhouse of productivity. Join us to discover effective strategies that simplify complex processes, enhancing your productivity and transforming your data management practices with FME. Let’s turn complexity into clarity and make your workspaces work wonders!
Maruthi Prithivirajan, Head of ASEAN & IN Solution Architecture, Neo4j
Get an inside look at the latest Neo4j innovations that enable relationship-driven intelligence at scale. Learn more about the newest cloud integrations and product enhancements that make Neo4j an essential choice for developers building apps with interconnected data and generative AI.
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/
Removing Uninteresting Bytes in Software FuzzingAftab Hussain
Imagine a world where software fuzzing, the process of mutating bytes in test seeds to uncover hidden and erroneous program behaviors, becomes faster and more effective. A lot depends on the initial seeds, which can significantly dictate the trajectory of a fuzzing campaign, particularly in terms of how long it takes to uncover interesting behaviour in your code. We introduce DIAR, a technique designed to speedup fuzzing campaigns by pinpointing and eliminating those uninteresting bytes in the seeds. Picture this: instead of wasting valuable resources on meaningless mutations in large, bloated seeds, DIAR removes the unnecessary bytes, streamlining the entire process.
In this work, we equipped AFL, a popular fuzzer, with DIAR and examined two critical Linux libraries -- Libxml's xmllint, a tool for parsing xml documents, and Binutil's readelf, an essential debugging and security analysis command-line tool used to display detailed information about ELF (Executable and Linkable Format). Our preliminary results show that AFL+DIAR does not only discover new paths more quickly but also achieves higher coverage overall. This work thus showcases how starting with lean and optimized seeds can lead to faster, more comprehensive fuzzing campaigns -- and DIAR helps you find such seeds.
- These are slides of the talk given at IEEE International Conference on Software Testing Verification and Validation Workshop, ICSTW 2022.
Sudheer Mechineni, Head of Application Frameworks, Standard Chartered Bank
Discover how Standard Chartered Bank harnessed the power of Neo4j to transform complex data access challenges into a dynamic, scalable graph database solution. This keynote will cover their journey from initial adoption to deploying a fully automated, enterprise-grade causal cluster, highlighting key strategies for modelling organisational changes and ensuring robust disaster recovery. Learn how these innovations have not only enhanced Standard Chartered Bank’s data infrastructure but also positioned them as pioneers in the banking sector’s adoption of graph technology.
Securing your Kubernetes cluster_ a step-by-step guide to success !KatiaHIMEUR1
Today, after several years of existence, an extremely active community and an ultra-dynamic ecosystem, Kubernetes has established itself as the de facto standard in container orchestration. Thanks to a wide range of managed services, it has never been so easy to set up a ready-to-use Kubernetes cluster.
However, this ease of use means that the subject of security in Kubernetes is often left for later, or even neglected. This exposes companies to significant risks.
In this talk, I'll show you step-by-step how to secure your Kubernetes cluster for greater peace of mind and reliability.
Enchancing adoption of Open Source Libraries. A case study on Albumentations.AIVladimir Iglovikov, Ph.D.
Presented by Vladimir Iglovikov:
- https://www.linkedin.com/in/iglovikov/
- https://x.com/viglovikov
- https://www.instagram.com/ternaus/
This presentation delves into the journey of Albumentations.ai, a highly successful open-source library for data augmentation.
Created out of a necessity for superior performance in Kaggle competitions, Albumentations has grown to become a widely used tool among data scientists and machine learning practitioners.
This case study covers various aspects, including:
People: The contributors and community that have supported Albumentations.
Metrics: The success indicators such as downloads, daily active users, GitHub stars, and financial contributions.
Challenges: The hurdles in monetizing open-source projects and measuring user engagement.
Development Practices: Best practices for creating, maintaining, and scaling open-source libraries, including code hygiene, CI/CD, and fast iteration.
Community Building: Strategies for making adoption easy, iterating quickly, and fostering a vibrant, engaged community.
Marketing: Both online and offline marketing tactics, focusing on real, impactful interactions and collaborations.
Mental Health: Maintaining balance and not feeling pressured by user demands.
Key insights include the importance of automation, making the adoption process seamless, and leveraging offline interactions for marketing. The presentation also emphasizes the need for continuous small improvements and building a friendly, inclusive community that contributes to the project's growth.
Vladimir Iglovikov brings his extensive experience as a Kaggle Grandmaster, ex-Staff ML Engineer at Lyft, sharing valuable lessons and practical advice for anyone looking to enhance the adoption of their open-source projects.
Explore more about Albumentations and join the community at:
GitHub: https://github.com/albumentations-team/albumentations
Website: https://albumentations.ai/
LinkedIn: https://www.linkedin.com/company/100504475
Twitter: https://x.com/albumentations
Threats to mobile devices are more prevalent and increasing in scope and complexity. Users of mobile devices desire to take full advantage of the features
available on those devices, but many of the features provide convenience and capability but sacrifice security. This best practices guide outlines steps the users can take to better protect personal devices and information.
National Security Agency - NSA mobile device best practices
Load rating using load testing: introducing the new bridge load testing e-circular
1. Jan 13th 2020
Challenge the future
Delft
University of
Technology
Load Rating using Load Testing:
Introducing the New Bridge Load Testing E-Circular
Sreenivas Alampalli, Dan M. Frangopol, Jesse Grimson, David Kosnik,
Marvin Halling, Eva O.L. Lantsoght, Jeff S. Weidner, David Y. Yang, Y. Edward Zhou
2. 2Load Rating using Load Testing: Introducing the New Bridge Load Testing E-Circular
• 1998 Manual for Bridge Rating
through Load Testing
• Basis for AASHTO Manual for
Bridge Evaluation
• Need to include current state-
of-the-practice
Introduction:
Why an e-circular on load testing?
NCHRP, Manual for Bridge Rating through Load Testing. 1998: Washington, DC. p. 152.
3. 3Load Rating using Load Testing: Introducing the New Bridge Load Testing E-Circular
Introduction to e-circular
Contents of e-circular
Chapter Title
1 Introduction
2 General Considerations
3 General load test preparation
4 Diagnostic load tests
5 Proof load tests
6 Estimating the reliability index and remaining service life
7 Illustrative examples
4. 4Load Rating using Load Testing: Introducing the New Bridge Load Testing E-Circular
Introduction to e-circular
Objectives of a load test (1)
Diagnostic load testing Proof load testing
Lantsoght, E. O. L., Bonifaz, J., Sanchez, T. A. and Harris, D. K., 2019, "Chapter 8:
Methodology for diagnostic load testing," Load Testing of Bridges: Current practice and
Diagnostic Load Testing, Lantsoght, E. O. L., ed., Taylor & Francis, Structures and
Infrastructures, Series Editor: D.M. Frangopol.
Lantsoght, E. O. L., Koekkoek, R. T., Hordijk, D. A. and De Boer, A., 2017, "Towards
standardization of proof load testing: pilot test on viaduct Zijlweg," Structure and
Infrastructure Engineering, pp. 16.
5. 5Load Rating using Load Testing: Introducing the New Bridge Load Testing E-Circular
Introduction to e-circular
Objectives of a load test (2)
Diagnostic load testing
• known load, fraction of design live
load
• compare analytical response to
experimental response
• develop field-validated model
• load rating based on improved
model
Proof load testing
• apply factored live load
• direct proof that bridge can carry
loads
• evaluate long-term reliability of
load-carrying mechanisms
• careful execution
6. 6Load Rating using Load Testing: Introducing the New Bridge Load Testing E-Circular
Introduction to e-circular
Application of load tests
• Current load rating close to 1
• Multi-girder bridges
• Slab bridges
• Bridges with deterioration or damage
• Planless bridges
• Arch bridges
Lantsoght, E. O. L., Bonifaz, J., Sanchez, T. A. and Harris, D. K., 2019,
"Chapter 8: Methodology for diagnostic load testing," Load Testing of
Bridges: Current practice and Diagnostic Load Testing, Lantsoght, E. O. L.,
ed., Taylor & Francis, Structures and Infrastructures, Series Editor: D.M.
Frangopol.
7. 7Load Rating using Load Testing: Introducing the New Bridge Load Testing E-Circular
Scope:
• Preparation
• Execution
• Analysis of load tests
Long-span bridges outside of scope
But elements can be tested according to
e-circular
Introduction to e-circular:
Scope
Lantsoght, E.O.L., et al., Proof load testing of reinforced concrete slab
bridges in the Netherlands. Structural Concrete, 2017. 18(4): p. 597-
606.
8. 8Load Rating using Load Testing: Introducing the New Bridge Load Testing E-Circular
• Diagnostic load tests
• Parameter-specific tests
• Proof load tests
• Dynamic load allowance estimation
• Vibrational methods
General considerations:
Types of load tests
9. 9Load Rating using Load Testing: Introducing the New Bridge Load Testing E-Circular
• Rating factor according to MBE
• Diagnostic load test: identify
LL more accurately
• Proof load test: RF entirely
• Load rating:
• diagnostic load test: with field-
verified model, adjusted for
rating
• proof load test: based on
rating vehicle weight LR and
maximum proof load LP
General considerations:
Rating Factor and Load Testing for Load Rating
10. 10Load Rating using Load Testing: Introducing the New Bridge Load Testing E-Circular
• Gather available documentation
• Field inspection according to
MBE
• section losses
• deterioration
• Preliminary calculations
• load rating
• expected capacity
• material parameters
• analytical model
• NDE to improve model
Load testing preparation:
Preliminary structural investigation
Lantsoght, E.O.L., et al., Towards standardization of proof load testing: pilot
test on viaduct Zijlweg. Structure and Infrastructure Engineering, 2017: p. 16.
11. 11Load Rating using Load Testing: Introducing the New Bridge Load Testing E-Circular
• Site-specific limitations
inspection
• instrumentation plan
• load application
• site-specific safety concerns
• Preparation test objectives
• Include interpretation of
responses
• Safety and risk analysis plan
• Planning of on-site activities
Load testing preparation:
Planning and preparation of load tests
Planning of on-site activities
12. 12Load Rating using Load Testing: Introducing the New Bridge Load Testing E-Circular
• Instrumentation plan:
• sensor layout
• data collection plan
• mounting & wiring details
• Parameters to measure
• Include redundancy
• Data acquisition and
visualization
• Personnel requirements local
agencies’ requirements
• Requirements for test vehicles
Load testing preparation:
Loading and instrumentation
Lantsoght, E.O.L., et al., Pilot Proof-Load Test on Viaduct De
Beek: Case Study. Journal of Bridge Engineering, 2017. 22(12):
p. 05017014.
13. 13Load Rating using Load Testing: Introducing the New Bridge Load Testing E-Circular
Effect of temperature and humidity
• on structural response
• on sensor
Structural response:
• reference (dummy) sensor
• “no load” cases
Sensor:
• sensor selection, small sensitivity
• corrections provided by manufacturer
Load testing preparation:
Environmental effects
Koekkoek, R.T., E.O.L. Lantsoght, and D.A. Hordijk, Proof loading of the
ASR-affected viaduct Zijlweg over highway A59. 2015, Delft University of
Technology: Delft, The Netherlands. p. 180.
14. 14Load Rating using Load Testing: Introducing the New Bridge Load Testing E-Circular
Steel bridges
• strain profiles – composite action
• strains: design assumptions, or
performance over time
Concrete bridges
• avoid risk of brittle failure
• strain profile: (un)cracked cross-
section
• larger gages, smeared cracking
• prestressed: cfr. steel bridges
Load testing preparation:
Structure type considerations (1)
Yarnold, M., T. Golecki, and J. Weidner, Identification of Composite Action
Through Truck Load Testing. Frontiers in Built Environment, 2018. 4(74).
15. 15Load Rating using Load Testing: Introducing the New Bridge Load Testing E-Circular
Arch bridges
• stone, masonry, unreinforced concrete
• 3D load-carrying behavior
• analytical model: 3D as well
Timber bridges
• special attention to condition assessment
Long-span and signature
• more detailed preparation
Load testing preparation:
Structure type considerations (2)
Wipf, T.J., M.A. Ritter, and D.L. Wood, Evaluation and Field Load
Testing of Timber Railroad Bridge. Transportation Research
Record, 2000. 1696(Structures): p. 323-333.
16. 16Load Rating using Load Testing: Introducing the New Bridge Load Testing E-Circular
Diagnostic load testing
Procedures (1)
17. 17Load Rating using Load Testing: Introducing the New Bridge Load Testing E-Circular
Diagnostic load testing
Procedures (2)
18. 18Load Rating using Load Testing: Introducing the New Bridge Load Testing E-Circular
Diagnostic load testing
Procedures (3)
19. 19Load Rating using Load Testing: Introducing the New Bridge Load Testing E-Circular
20. 20Load Rating using Load Testing: Introducing the New Bridge Load Testing E-Circular
Proof load testing
Procedures (1)
21. 21Load Rating using Load Testing: Introducing the New Bridge Load Testing E-Circular
Proof load testing
Procedures (2)
22. 22Load Rating using Load Testing: Introducing the New Bridge Load Testing E-Circular
Proof load testing
Procedures (3)
23. 23Load Rating using Load Testing: Introducing the New Bridge Load Testing E-Circular
Proof load testing
Stop criteria
• No nonlinearity
• Define stop criteria prior to test
• Depends on
• structure type
• material
• expected failure mode
• For recommendations: refer to
literature
Lantsoght, E. O. L., Yang, Y., van der Veen, C., Hordijk, D. A. and de Boer, A.,
2019, "Stop Criteria for Flexure for Proof Load Testing of Reinforced Concrete
Structures," Frontiers in Built Environment, V. 5, No. 47, 2019-April-05.
24. 24Load Rating using Load Testing: Introducing the New Bridge Load Testing E-Circular
Estimating reliability index and remaining service
life (1)
25. 25Load Rating using Load Testing: Introducing the New Bridge Load Testing E-Circular
Estimating reliability index and remaining service
life (2)
26. 26Load Rating using Load Testing: Introducing the New Bridge Load Testing E-Circular
Estimating reliability index and remaining service
life (3)
27. 27Load Rating using Load Testing: Introducing the New Bridge Load Testing E-Circular
Estimating reliability index and remaining service
life (4)
28. 28Load Rating using Load Testing: Introducing the New Bridge Load Testing E-Circular
Estimating reliability index and remaining service
life (5)
29. 29Load Rating using Load Testing: Introducing the New Bridge Load Testing E-Circular
Examples
• Full example of diagnostic load test
• Full example of proof load test
• Summarized case studies (3)
• List of suggested further reading
30. 30Load Rating using Load Testing: Introducing the New Bridge Load Testing E-Circular
Summary and conclusions
New e-circular: Primer on Bridge Load Testing
Practical document
Advice on load testing:
• Preparation
• Execution
• Analysis
& new concepts:
• Field-verified analytical model
• Rating after proof load testing
• Determination of reliability index
31. 31Load Rating using Load Testing: Introducing the New Bridge Load Testing E-Circular
Contact:
Eva Lantsoght
E.O.L.Lantsoght@tudelft.nl
elantsoght@usfq.edu.ec