1) The document discusses continuous welded rail (CWR) structures and the interaction between railway tracks and bridges. CWR reduces impact forces in the rails, increasing lifespan and improving ride quality.
2) Key considerations for CWR include buckling from high temperatures and fracture from low temperatures. Track-bridge interaction is also analyzed under various loads like temperature, traction, braking, and train forces.
3) Design requirements specify allowable stresses and displacements. Models are created to analyze stress and displacement considering load combinations through computational methods like finite element analysis.
Workshop under the Capacity Building Programme of the Southern Road Connectivity Project / Expressway Connectivity Improvement Plan Project, March 2016
Grillage Analysis of T-Beam bridge, Box culvert and their Limit State Design; components of Bridges and loads acting on bridges are presented in this slide.
ANALYSIS OF FRAMES USING SLOPE DEFLECTION METHODSagar Kaptan
slope deflection equations are applied to solve the statically indeterminate frames without side sway. In frames axial deformations are much smaller than the bending deformations and are neglected in the analysis.
Workshop under the Capacity Building Programme of the Southern Road Connectivity Project / Expressway Connectivity Improvement Plan Project, March 2016
Grillage Analysis of T-Beam bridge, Box culvert and their Limit State Design; components of Bridges and loads acting on bridges are presented in this slide.
ANALYSIS OF FRAMES USING SLOPE DEFLECTION METHODSagar Kaptan
slope deflection equations are applied to solve the statically indeterminate frames without side sway. In frames axial deformations are much smaller than the bending deformations and are neglected in the analysis.
Types of Pavements, Layers present in the pavements, Stresses on the rigid pavements, wheel load, repetitions etc.. and Indian Standard Method of design of Rigid Pavements.
Bridges and its Types & Components by Chetan BishtChetanBisht16
This is very Useful for Fresher Civil engineers and also for Student of Civil Engineering . This Slide show almost cover the Basic Knowledge about Bridges
Larsen and Toubro (Lucknow Metro Project) Summer Internship PresentationShuBham RaNa
Hello Friends Myself SHUBHAM RANA . I am pursuing B.Tech in Civil Engineering from IIT ROORKEE. This is the glimpse of my work and basic aspects which I learned while doing my Internship in Larsen and Toubro Heavy Civil Infra IC. Thank You :)
Design and Analysis of Pre Stressed I Girders by Midas Civil Softwareijtsrd
Today the construction of bridges has gained worldwide importance. Bridges are an important feature of all road networks and the use of pre stressed bridges is increasingly popular in the construction of bridges due to their better stability, service friendliness, economy and durability, beauty and appearance of the building. Reinforced concrete construction, steel or steel construction using composite construction. In the case of high spaces, reinforced concrete construction makes no money due to the large space. cross section is used more effectively than cross section of reinforced concrete. Prefabricated concrete is used for long bridges with a length of more than 10 meters. Typically, when bridges are calculated, the superstructure and substructure are analyzed separately. The supernatural structure is usually a grid made of large strips, a shortcut membrane and a desk slab. vertical grid Columns of large girders with anchors. The superstructure is tested according to IRC 62014 and according to IRC 182000 with unimaginable gravity loads and loads of moving vehicles. Reduced stress and deviation rates compared to a straightforward tender profile. Rishabh Singh | A. K. Jha | R. S. Parihar "Design and Analysis of Pre-Stressed I-Girders by Midas Civil Software" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-6 | Issue-5 , August 2022, URL: https://www.ijtsrd.com/papers/ijtsrd50694.pdf Paper URL: https://www.ijtsrd.com/engineering/civil-engineering/50694/design-and-analysis-of-prestressed-igirders-by-midas-civil-software/rishabh-singh
Bridge Bearings has been considered as of huge importance in civil engineering. It plays a significant role in the structure of bridges. This presentation covers the complete study of Bridge Bearings.
Innovation in Civil Engineering and their Impact on Communities .
Civil Engineering Innovations,. in the Bandra - Worli Sea Link Project , Mumbai .Technical Instances of the Duttabad Constraint .
Types of Pavements, Layers present in the pavements, Stresses on the rigid pavements, wheel load, repetitions etc.. and Indian Standard Method of design of Rigid Pavements.
Bridges and its Types & Components by Chetan BishtChetanBisht16
This is very Useful for Fresher Civil engineers and also for Student of Civil Engineering . This Slide show almost cover the Basic Knowledge about Bridges
Larsen and Toubro (Lucknow Metro Project) Summer Internship PresentationShuBham RaNa
Hello Friends Myself SHUBHAM RANA . I am pursuing B.Tech in Civil Engineering from IIT ROORKEE. This is the glimpse of my work and basic aspects which I learned while doing my Internship in Larsen and Toubro Heavy Civil Infra IC. Thank You :)
Design and Analysis of Pre Stressed I Girders by Midas Civil Softwareijtsrd
Today the construction of bridges has gained worldwide importance. Bridges are an important feature of all road networks and the use of pre stressed bridges is increasingly popular in the construction of bridges due to their better stability, service friendliness, economy and durability, beauty and appearance of the building. Reinforced concrete construction, steel or steel construction using composite construction. In the case of high spaces, reinforced concrete construction makes no money due to the large space. cross section is used more effectively than cross section of reinforced concrete. Prefabricated concrete is used for long bridges with a length of more than 10 meters. Typically, when bridges are calculated, the superstructure and substructure are analyzed separately. The supernatural structure is usually a grid made of large strips, a shortcut membrane and a desk slab. vertical grid Columns of large girders with anchors. The superstructure is tested according to IRC 62014 and according to IRC 182000 with unimaginable gravity loads and loads of moving vehicles. Reduced stress and deviation rates compared to a straightforward tender profile. Rishabh Singh | A. K. Jha | R. S. Parihar "Design and Analysis of Pre-Stressed I-Girders by Midas Civil Software" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-6 | Issue-5 , August 2022, URL: https://www.ijtsrd.com/papers/ijtsrd50694.pdf Paper URL: https://www.ijtsrd.com/engineering/civil-engineering/50694/design-and-analysis-of-prestressed-igirders-by-midas-civil-software/rishabh-singh
Bridge Bearings has been considered as of huge importance in civil engineering. It plays a significant role in the structure of bridges. This presentation covers the complete study of Bridge Bearings.
Innovation in Civil Engineering and their Impact on Communities .
Civil Engineering Innovations,. in the Bandra - Worli Sea Link Project , Mumbai .Technical Instances of the Duttabad Constraint .
Engineering the future means tackling the problems today…
This report is part of the 4th semester Architectural Technology and Construction Management education. The summer of 2011 was the starting point for my interest regarding floating constructions. It started with a book, named FLOAT (by Koen Olthuis and David Keuning). I was very interested about this technology, and the book proved to be a good starting point to find out more about it. During 3rd semester I had the opportunity to make a report about this theme and so I combined my learning goals with personal interests and decided to find out more.
Now, studying in the 4th semester I have decided to continue writing about floating constructions, and the main subject for this report is a floating city. Many say it is impossible, or even pointless. Advances in material science, nautical design and maritime constructions could not only make the floating city possible but it may also be an essential asset in the near future. Can we build it? YES, WE CAN! It is not a question of whether we can do it…but how we do it.
I would like to thank the people who supported me in doing this report. Many thanks to my guiding teacher Mihoko Goto Brethvad who accepted the problem statement of a floating city and many thanks as well to architect journalist David Keuning for the interview, and last but not least, many thanks to Koen Olthuis for sharing his ideas regarding building on water worldwide.
This ppt presentation may be very useful who wants to present himself on the topic such as steel bridge girders and prestressed concreting and the psc slabs
THE various rocks are classified as according to rock mass classification system as it is used for used for various engineering design and stability analysis of underground structures.
Public sector innovation is both an imperative and an opportunity for governments today. This OECD conference brought together public sector practitioners, researchers, civil society and businesses to discuss how innovation can help solve today's complex challenges.
For more information: https://www.oecd.org/governance/observatory-public-sector-innovation/events/
Comparative study of results obtained by analysis of structures using ANSYS, ...IOSR Journals
The analysis of complex structures like frames, trusses and beams is carried out using the Finite
Element Method (FEM) in software products like ANSYS and STAAD. The aim of this paper is to compare the
deformation results of simple and complex structures obtained using these products. The same structures are
also analyzed by a MATLAB program to provide a common reference for comparison. STAAD is used by civil
engineers to analyze structures like beams and columns while ANSYS is generally used by mechanical engineers
for structural analysis of machines, automobile roll cage, etc. Since both products employ the same fundamental
principle of FEM, there should be no difference in their results. Results however, prove contradictory to this for
complex structures. Since FEM is an approximate method, accuracy of the solutions cannot be a basis for their
comparison and hence, none of the varying results can be termed as better or worse. Their comparison may,
however, point to conservative results, significant digits and magnitude of difference so as to enable the analyst
to select the software best suited for the particular application of his or her structure.
Behaviour of the track in hot weather. Rail thermal forces for jointed and CW...Constantin Ciobanu
Permanent Way Institution - West of England Section Meeting - 28.02.2017
The speaker presented the main parameters that influence the track response to temperature variations and the means to evaluate and control the rail thermal forces. It was discussed the theoretical background and practical elements of managing the track in hot weather for jointed and CWR track, on plain line and S&C.
https://www.thepwi.org/calendar/event/view?id=677
This is a release note for midas NFX 2015, finite element analysis software focusing on accuracy and flexibility.
New features and improvement are presented in detail. Multi-media resources, such as video demo and online trying module, are included. For more information about midas NFX and this release, please visit: www.midasNFX.com
Civil 2014 (v2.1) is released now. The following features have been newly implemented.
Improvements in Eurocode Moving Load Analysis
- Centrifugal Forces
- Eccentricity of Vertical Loads of Rail Traffics
- Concurrent Stresses
- User-defined Railway Traffic Loads
- User-defined Permit Truck Loads
- Concurrent Reactions
Simultaneous Display of Top and Bottom Stress Diagram in Bridge Girder Diagram
Auto-calculation of Effective Slab Width as per Eurocode
Update Geometry of Analysis Model using Buckling Mode Shape
Easy and Fast Generation of Strands/Tendons
For details, please refer to the attached Civil 2014 (v2.1) Release Note.
Slides version for NFX 2013 Online Release Seminar. This webinar Introduces and demonstrates enhancements of NFX's new updates: such as Mid-Surface Extraction, Implicit Nonlinear Dynamic Analysis, Transient Nonlinear Heat Stress, Optimization....
NFX is a FEA generalist software committing to make your FEA work efficient and cost effective. Go achieve this goal, NFX carries 3 most distinguishable characteristics:
1) CAE/CFD solution-in-one interface: This makes NFX more multidisciplinary, and seriously saves your effort to switch between platforms.
2) Intuitive workflow and GUI: NFX is designed to carry out complicated tasks in headache-free ways. Consistent feedbacks about “fast learning curve” and “junior engineer friendly” make us confident to claim for the best in this one.
3) High-end analysis capacity with affordable price: provides total solutions from high-end structural analysis functions such as contact analysis, nonlinear analysis, explicit dynamic analysis and fatigue analysis in addition to high-end fluid analysis functions such as moving mesh, free surface analysis and mass transfer analysis.
Generative AI Deep Dive: Advancing from Proof of Concept to ProductionAggregage
Join Maher Hanafi, VP of Engineering at Betterworks, in this new session where he'll share a practical framework to transform Gen AI prototypes into impactful products! He'll delve into the complexities of data collection and management, model selection and optimization, and ensuring security, scalability, and responsible use.
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.
Communications Mining Series - Zero to Hero - Session 1DianaGray10
This session provides introduction to UiPath Communication Mining, importance and platform overview. You will acquire a good understand of the phases in Communication Mining as we go over the platform with you. Topics covered:
• Communication Mining Overview
• Why is it important?
• How can it help today’s business and the benefits
• Phases in Communication Mining
• Demo on Platform overview
• Q/A
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.
GraphSummit Singapore | The Art of the Possible with Graph - Q2 2024Neo4j
Neha Bajwa, Vice President of Product Marketing, Neo4j
Join us as we explore breakthrough innovations enabled by interconnected data and AI. Discover firsthand how organizations use relationships in data to uncover contextual insights and solve our most pressing challenges – from optimizing supply chains, detecting fraud, and improving customer experiences to accelerating drug discoveries.
GDG Cloud Southlake #33: Boule & Rebala: Effective AppSec in SDLC using Deplo...James Anderson
Effective Application Security in Software Delivery lifecycle using Deployment Firewall and DBOM
The modern software delivery process (or the CI/CD process) includes many tools, distributed teams, open-source code, and cloud platforms. Constant focus on speed to release software to market, along with the traditional slow and manual security checks has caused gaps in continuous security as an important piece in the software supply chain. Today organizations feel more susceptible to external and internal cyber threats due to the vast attack surface in their applications supply chain and the lack of end-to-end governance and risk management.
The software team must secure its software delivery process to avoid vulnerability and security breaches. This needs to be achieved with existing tool chains and without extensive rework of the delivery processes. This talk will present strategies and techniques for providing visibility into the true risk of the existing vulnerabilities, preventing the introduction of security issues in the software, resolving vulnerabilities in production environments quickly, and capturing the deployment bill of materials (DBOM).
Speakers:
Bob Boule
Robert Boule is a technology enthusiast with PASSION for technology and making things work along with a knack for helping others understand how things work. He comes with around 20 years of solution engineering experience in application security, software continuous delivery, and SaaS platforms. He is known for his dynamic presentations in CI/CD and application security integrated in software delivery lifecycle.
Gopinath Rebala
Gopinath Rebala is the CTO of OpsMx, where he has overall responsibility for the machine learning and data processing architectures for Secure Software Delivery. Gopi also has a strong connection with our customers, leading design and architecture for strategic implementations. Gopi is a frequent speaker and well-known leader in continuous delivery and integrating security into software delivery.
In his public lecture, Christian Timmerer provides insights into the fascinating history of video streaming, starting from its humble beginnings before YouTube to the groundbreaking technologies that now dominate platforms like Netflix and ORF ON. Timmerer also presents provocative contributions of his own that have significantly influenced the industry. He concludes by looking at future challenges and invites the audience to join in a discussion.
zkStudyClub - Reef: Fast Succinct Non-Interactive Zero-Knowledge Regex ProofsAlex Pruden
This paper presents Reef, a system for generating publicly verifiable succinct non-interactive zero-knowledge proofs that a committed document matches or does not match a regular expression. We describe applications such as proving the strength of passwords, the provenance of email despite redactions, the validity of oblivious DNS queries, and the existence of mutations in DNA. Reef supports the Perl Compatible Regular Expression syntax, including wildcards, alternation, ranges, capture groups, Kleene star, negations, and lookarounds. Reef introduces a new type of automata, Skipping Alternating Finite Automata (SAFA), that skips irrelevant parts of a document when producing proofs without undermining soundness, and instantiates SAFA with a lookup argument. Our experimental evaluation confirms that Reef can generate proofs for documents with 32M characters; the proofs are small and cheap to verify (under a second).
Paper: https://eprint.iacr.org/2023/1886
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.
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:
Pushing the limits of ePRTC: 100ns holdover for 100 daysAdtran
At WSTS 2024, Alon Stern explored the topic of parametric holdover and explained how recent research findings can be implemented in real-world PNT networks to achieve 100 nanoseconds of accuracy for up to 100 days.
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.
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.
UiPath Test Automation using UiPath Test Suite series, part 5DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 5. In this session, we will cover CI/CD with devops.
Topics covered:
CI/CD with in UiPath
End-to-end overview of CI/CD pipeline with Azure devops
Speaker:
Lyndsey Byblow, Test Suite Sales Engineer @ UiPath, Inc.
UiPath Test Automation using UiPath Test Suite series, part 5
Rail bridge and composite girder bridge analysis
1. 111-1
M I D A S I T
Bridging YourInnovations to Realities
2. Bridging Your Innovations to Realitiesmidas Civil
2
Rail Structure Interaction
Overview
1) Definition of Continuous Welded Rail (CWR)
Rails are continuously welded and thus, the length of one rail is longer than 200m.
ex > standard length rail (L=25m), longer rail (L=25~200m)
2) Necessity of Continuous Welded Rail
Time[ms]
Dynamicamplification
Q
Q
6
5
4
3
2
1
0
16 18 20 221412108642
Wheel/rail impact forces
Wheel impact
forces occur
- The reduced impact force in the rails increases the life span of the rails and improves the ride quality.
- The decreasing noise and vibration by the reduced impact force is less impeding the ambient environment.
3) Check Points for Continuous Welded Rail
- When temperature rises: track deformation
(buckling of rail)
- When temperature drops: fracture failure
3. Bridging Your Innovations to Realitiesmidas Civil
3
Rail Structure Interaction
Traction/Braking loads
abutment pier
Longitudinal displacements
at top surface of deck end
Temperature Train vertical loads
Track-BridgeInteraction
4. Bridging Your Innovations to Realitiesmidas Civil
4
Rail Structure Interaction
Track-BridgeInteraction
1) Axial Forcesin a ContinuouslyWeldedRail Track on Embankment
(Thermal Load on the Rail)
2) Axial Forcesin a ContinuouslyWeldedRail Track on Bridge
(Thermal Load on the Bridge)
Axial forces in the track on embankment
under thermal loading
Track/bridge interaction due to
thermal loading
Fixed end Movable end
Continuous welded rail
Additional rail
stresses
Axial forces
in the rails
Distance (m)
Displacementintherails(mm)
Resistance
TAEF ∆×××= α
5. Bridging Your Innovations to Realitiesmidas Civil
5
Rail Structure Interaction
Design Requirementsfor Track/Bridge Interaction Analysis
Design Standards: UIC774-3, EN 1991-2
Item Loads
DesignCriteria
Gravel ballast bed Concrete bed
Additional rail
stress
Compressive stress Thermal loads
Traction/braking loads
Train vertical loads
R≥1500: 72N/mm2
R≥700: 58N/mm2
R≥600: 54N/mm2
R≥300: 27N/mm2
92N/mm2
Tensile stress 92N/mm2 92N/mm2
Longitudinal relative displacement in
bridge deck
Traction/braking loads
<5mm
<30mm (when rail
expansion device at both
ends)
Check the stability (the
uplift force and
compression) of rail
fastener
longitudinal displacement due to rotation
of the deck end between deck and deck or
between deck and pier
Train vertical loads <8mm
Check the stability (the
uplift force and
compression) of rail
fastener
Opening displacement when split web at
rail end takes place (applying cable
signaling system or zero-longitudinal
resistance rail (ZLR) fastener)
Thermal loads D=√(R2-(R-δ)2)
Same as the gravel track
6. Bridging Your Innovations to Realitiesmidas Civil
6
Rail Structure Interaction
Design Loads
- If all of the spans in the bridge consist of a continuous welded rail, thermal loads are applied to the bridge and rails or the
rails only.
- If rail expansion joints are present on the bridge, thermal loads are applied to both the bridge and the rails.
- Temperature variations in the rails and bridge are as follows:
. Rails: in summer=+40℃, in winter=-50℃
. Bridge: concrete structures=±25℃, steel structures= normal temperature area ±35℃, cold temperature area ± 45℃
1) Thermal Loads
2) Traction/Braking Loads
- Traction/braking loads are uniformly distributed and applied to the two front positions of the rails. The magnitude
of load and the loaded length are as follows:
- For the cases such as an exclusive subway track, light rail transit, etc where the design loads are different,
transformed uniform loads which correspond to ¼ of the rail axial loads are used. The loaded length is equal to
one maximum coach.
- Traction/braking loads are applied concurrently with the associated vertical loads.
- Traction/braking loads are applied to the positions that will cause the most unfavorable rail stresses or bridge
deformations.
Type of Track
Tractionloads braking loads
Magnitude of Load Loadedlength Magnitude of Load Loadedlength
High-speedrailway 33kN/m/track 33m 20kN/m/track 400m
Normal railway 24kN/m/track 33m 12kN/m/track 300m
7. Bridging Your Innovations to Realitiesmidas Civil
7
Rail Structure Interaction
Design Loads
-For a high-speed railway, HL load does not include
an impact factor. For a passenger locomotive, HL
load can have a uniform load of 60kN/m.
- For a normal railway, LS load and an equivalent load
can be applied and an impact factor is not
considered.
- For an exclusive subway track, EL-18 load or an equivalent
uniformly distributed load can be applied.
- For a double or more track bridge, only two tracks will be
loaded with train vertical loads.
- For a multi-span continuous bridge, only the deck near the
critical positions will be loaded.
3) Train Vertical Loads
(b) Equivalent HL load
(a) HL load
(b) Equivalent LS load
(a) LS load (L-load)
95kN/m
74kN/m
8. Bridging Your Innovations to Realitiesmidas Civil
8
Rail Structure Interaction
Load Combinations
- Load combinations used for computing the rail stresses and the longitudinal loads acting on bearings
- When computing the stresses and displacements in the rails for a continuous or simply supported bridge deck:
α,β,γ=1
- When using the computational analysis method, the interaction due to traction/braking loads and train vertical
loads can be separately computed.
ƩR = αR (Thermal loads) + βR(Traction/braking loads)+γR(Train vertical loads)
9. Bridging Your Innovations to Realitiesmidas Civil
9
Rail Structure Interaction
1) Establishment of Criteria for Construction of Rail Expansion Joint on BridgeSection
RailExpansion Joint
Countermeasure
The limits to the axial force and displacement
of a continuous welded rail on bridge are exceeded
bridge
track
Support layout
Span composition
Stiffness of deck
Use zero-longitudinal resistance
rail fasteners
Economicefficiency
Compare the maintenance cost forrail
expansion joints with the cost of bridge
construction
Conditions for building rail expansion joints
Minimum separated distance between expansion joints
Separation distance from a turnout
Separation distance from the terminus for a transition
curve
Separation distance from the terminus for a bell curve
Requirements for building the bridge deck
10. Bridging Your Innovations to Realitiesmidas Civil
10
Rail Structure Interaction
2) Flowchart
RailExpansion Joint
Check the axial force
and displacement in
the rails
Modify the support placement
Check the axial force
and displacement in
the rails
Modify the span composition
Check the axial force
and displacement in
the rails
Modify the stiffness of deck
Check the axial force
and displacement in
the rails
Use a zero-longitudinal resistance rail fastener
Check the axial force
and displacement in
the rails
Consider building REJ (rail expansion joint)
Analyze the economical
efficiency
Submit the report
Allow the constructionof rail
expansion joint
ContinueOK
OK
OK
OK
OK
OK
NG
NG
NG
NG
NG
NG
NG
NG
NG
NG
11. Bridging Your Innovations to Realitiesmidas Civil
11
Rail Structure Interaction
1) Computational Analysis
- Considerations for modeling
• Placement of bearings, the dimensions and properties of the deck and pier, the bending stiffness and the height of deck,
the neutral axis of deck, and the lateral and bending stiffness of foundation.
- Finite elements
• Rail and bridge: Beam elements
• Ballast or pad: nonlinear spring elements
- Modeling method
• Element length: 1~2m is recommended
상판중립축
궤도중심선
Rigid Link
Rigid Link
Track-BridgeInteraction Analysis
Embankment section
Bridge deck
Springfor the longitudinal
resistance of ballast (Bilinear)
Rail
Rail expansion joint
Neutral axis of bridge deck
Centerline of track
Bearing
Longitudinal displacement of the rail
1. Observed data
2. Idealized bilinear curve (under train loading)
3. Bilinear curve when train loading is not applied
Longitudinal
resistance of
the roadbed
12. Bridging Your Innovations to Realitiesmidas Civil
12
Rail Structure Interaction
- The accuracy depends on the computational analysis methods.
- The following two computational analysis methods are available:
. Separate analysis: thermal loading, traction/braking loading and train vertical
loading are separately considered.
. Complete Analysis: thermal loading, traction/braking loading and train vertical
loading are concurrently applied.
- Depending on the global structural system, the separate analysis is more likely to
producethe greater axial forcesthan the staged analysis.
AnalysisMethods
13. Bridging Your Innovations to Realitiesmidas Civil
13
Rail Structure Interaction
Simplified Separate Analysis Complete Analysis
AnalysisMethods
14. Bridging Your Innovations to Realitiesmidas Civil
14
Rail Structure Interaction
RailTrack AnalysisModel Wizard (Layout)
Advanced:define the fixedendsfreelyand
adjustthe spanlength
ZLR: Specifythe zero-longitudinalresistance rail
fastener(the resistance of ballastissetto zerofor
the specifiedsections.)
REJ: Place the rail expansionjointforeachtrack
ex ) 4@50,70:four decks with the length of 50m and
a deck with the length of 70m. The total length of
bridge section is 270m.
15. Bridging Your Innovations to Realitiesmidas Civil
15
Rail Structure Interaction
TaperedSectionAssignment
Sectionsat 0.1 of the total span length:Span_2
Sectionsat 0.5 of the total span length:Span
Sectionsat 0.9 of the total span length:Span_2
TaperedOption
Start 0.1~Start 0.5: Z Axis CurvedType (Quadratic) , From (J-end)
Start 0.5~Start 0.9: Z Axis CurvedType (Quadratic) , From (I-end)
Define TaperedSection
RailTrack AnalysisModel Wizard (Section)
16. Bridging Your Innovations to Realitiesmidas Civil
16
Rail Structure Interaction
1 . Lateral Resistance Data
- Enter gravel ballast data and concrete ballast data.
- For gravel ballast,the resistance of ballast isdifferentbetweenthe stress
checkand the displacementcheck.
2. Define Condition
- Selecteithergravel ballastor concrete ballast for the entire section.
- Via the ‘Advanced’function,selecteithergravel ballast or concrete ballastby
sections(Forundefinedsections,gravel ballastisused).
3. Boundary Types
Spring Type Bearing Type
1
23
RailTrack AnalysisModel Wizard (Boundaries)
17. Bridging Your Innovations to Realitiesmidas Civil
17
Rail Structure Interaction
4. ModelingbySections
1) Embankment section
5. Boundary ConditionsTaking into Account the Effective Length
The resistance ofballast enteredshouldbe in kN/m and islongitudinal resistance.
The resistance multipliedbythe effective lengthwill be usedin the model.
2) Section connecting embankment and deck start point 3) Section connecting deck start and end points
RailTrack AnalysisModel Wizard (Boundaries)
18. Bridging Your Innovations to Realitiesmidas Civil
18
Rail Structure Interaction
1. Accelerating/braking/vertical train loadscan be freelyenteredbysectionsin a tabular format.
The length and magnitude of load can be enteredwithreference tothe leftendof the model.
-RunningDirection:the direction in which the train runs.Define either‘KeepRight’or ‘KeepLeft’.
-TrainSection: Train sectionis recognizedwhenavertical load is entered. Whenavertical Load is excluded,define TrainSectionandapply Loaded
Condition.
- Load Type:For single track, in general,applyeitheraccelerating loadsor brakingloads. Fordouble track, apply acceleratingloads andbraking loads
foreachtrack. Asfar as train vertical loads are concerned, variousuniformloadscan be appliedby sectionsandtherefore HLload, which is most
frequentlyused,canbe easilyrepresented.
2. Filesare added for the moving load analysis
- Number ofTrack LoadingLocations: the numberof movingtimesof train load.If “n” is entered,nfilesare added.
- Location Incrementfor eachModel:the incrementof moving load pertrack. If “n” is entered,the trainmovesbyn and the boundaryconditions
are assignedtothe sectionto which the train load is applied.
ex> If “Number of Track Loading Locations” is 3 and “Location Increment for Track” is 10, the train moves forward by 10m, 20m and 30m and three files are added.
Case 1: Single Track Case 2: Double Track
RailTrack AnalysisModel Wizard (Load)
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RailTrack AnalysisModel Wizard
1 .StressCheck Model Option
Thisoptioncreatesa file to checkthe additionalstresses.
-SimplifiedSeparate AnalysisModel
-Complete Analysis
2. DisplacementCheckModel Option
Thisoptioncreatesa file to checkthe displacements. Inthisfile,the resistance of ballast applied at UnloadedConditionisdifferentforthe case of
gravelballast.In addition, this file is available only for SimplifiedSeparate AnalysisModel.
- Relative LongitudinalDisplacementComponentdue toAccelerationandBrakingAlone
- Relative LongitudinalDisplacementComponentdue toVerticalEffects
-Relative LongitudinalDisplacementComponentatRailExpansionJoints
- Rail Break GapSize
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CaseStudies
Forthe case of a high-speedrailwaywithgravel ballast and double track,the following propertiesare definedforrail, ballast and horizontal
alignment:
Track Item Property Unit Value Remark
Rail
UIC60
Cross-sectionalarea A m2 7.669E-3
Moment of inertia Iyy m4 30.363E-6
Ballast
Gravelballast
Longitudinal resistance (Unloaded) kN/m 12.0~20.0 Stress check: 20.0
Displacement check: 12.0
Longitudinal resistance (Loaded) kN/m 60.0
Limit displacement mm 2.0
Horizontal
alignment
Tangent section
Girder Type
Span Length
Equivalent Modulus
of Elasticity
Cross-
sectional Area
Moment of Inertia
Neutral Axis
(Girder Reference
Location)
Main Girder Height
( m ) ( E : N/m2 ) ( A : m2 ) ( Iyy : m4 ) ( Izz : m4 ) ( d : m ) ( H : m )
PC Box 40 2.8 x 1010 12.0 20.0 165.0 1.11 3.5
PCBox girder bridge is chosenfor the high-speedrailwaytrack.
The dimensionsof girderandthe geometricrelationbetweenthe girderandtrack are definedasfollows:
The longitudinalresistance of deckis setto 1.5 x 10
6
kN/m.
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Rail Structure Interaction
Forthe case of a high-speedrailwaywithgravel ballast and double track,the rail, ballast and horizontal alignmentare definedasfollows:
Simple bridge type
Continuousbridge type
CaseStudies
40m 40m 40m 40m 40m 40m 40m 40m 40m 40m
80m 80m 80m 80m 80m
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Rail Structure Interaction
Axial stressby temperature load (Simple spanbridge)
Axial stressby temperature load (Continuousbridge)
Because the simple bridge type gives the smaller additional stress than the continuous bridge type, the simple bridge type is adopted.
CaseStudies
-26.6 MPa
-44.1MPa
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Rail Structure Interaction
CaseStudies
Axial stressby temperature (+25°C) at UnloadedCondition
Axial stressby temperature,traction and vertical train loads at LoadedCondition
-35.6MPa
-26.6 MPa
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Rail Structure Interaction
CaseStudies
Axial stressby temperature,braking and vertical train loadswith differenttrain position
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Rail Structure Interaction
CheckDisplacements
- Restrict the deformations of the deck and the track to prevent the excessive relaxation of ballast.
- Limits to the relative lateral displacements between the bridge deck and rails under traction/braking loads: 4mm or less
- Exceptions are made for the cases where the zero-longitudinal resistance rail fastener is used and the special treatment is
done for the contact underneath the rails.
2) Limits to the RelativeLongitudinal Displacements in the Bridge Deck
3) Limits to the Longitudinal Displacements in the Deck End due to the Angle of Rotation
- Limits to the longitudinal displacements in the deck end due to the rotation of the deck end under train vertical
loads: 8mm or less
1) RelativeDisplacements between the Rails and Bridge
- Limits to the absolute longitudinal displacements between the bridge deck and pier or between the bridge deck
and deck under traction/braking loads: 5mm or less
Limits to relative longitudinal displacements Limits to displacements due to rotation of deck end
abutment pier
Longitudinal displacements
at top surface of deck end
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Rail Structure Interaction
Japanese Shinkansen Railway Structure Design Standard
Conditions
Allowable opening
displacements
-rail: 60kg
-buckling strength of rail:
100tonf/rail
69mm
ACI Manual of Concrete Practice
Wheel radius
Allowable opening
displacements
16 in. (0.4m) or less 2in.(50mm)
16 in. or higher 4in.(100mm)
CheckDisplacements
4) AllowableOpening Displacements when Opening Gap at Rail End takes place .
- Allowable Opening Displacements According to International Standards
- Allowable Opening Displacements According to Korean Standards
. Railway Design Manual (Volume Track)
1) Limits to the opening displacements, d, when the split web at rail
end takes place due to thermal loads in case of using cable
signaling system (not track circuit system):
2 2
( )d R R δ= − − 3
2
xP
e x
EI
β
δ β
β
−
= 4
4
k
EI
β =
2) Restrict the opening displacements of (1) when a
zero-longitudinal resistance rail fastener is built
Wheel loadP
Center of wheel O
Vehicle velocity V
Wheel radius R
Vertical displacement δBending stiffness of rail EI
Bearing stiffness of trackK
Opening displacement d
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Relative Longitudinal Displacementbytraction loads
CaseStudies
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Rail Structure Interaction
CaseStudies
Tip> If the deck is defined by Center-Top, the nodal displacements at deck top are produced and
these include the nodal displacements due to rotational angle. If the deck is defined by centroid,
the nodal displacements at deck top can be computed using the following equation:
Relative displacement due to rotation of the end
= displacement Dx at neutral axis + distance from centroid to deck top x sin(Rot Ry)
Relative Longitudinal Displacementbyvertical train loads
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FactorsAffecting the Axial Forcesin Track (1)
1) Longitudinal Resistanceof Track
Longitudinal resistance of trackvs. longitudinal
displacement of rail
Bi-Linear behavior of longitudinal resistance of track
Allowable longitudinal resistance of track
Note 1: Apply 20.0kN/m when checking the rail stresses and apply 12.0kN/m when checking the displacements in the structure
Note 2: In the case when tests for longitudinal resistance are conducted, values derived from tests can be used.
Type of Track Load Case
Limit displacement
(mm)
Longitudinal
resistance of track
(kN/m)
Remark
Gravel track
Loaded Case 2.0 12.0~20.0 Note 1
Unloaded Case 2.0 60.0
Concrete track or frozen
ballast track
Loaded Case 0.5 40.0 Note 2
Unloaded Case 0.5 60.0
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FactorsAffecting the Axial Forcesin Track (1)
Axial stresses of Ballast Bed in the longitudinal direction
Axial stresses of Concrete Bed in the longitudinal direction
Unloaded Condition (underthermal loads)
Loaded Condition
(traction/brakingloads and vertical loads added)
Unloaded Condition (underthermal loads)
Loaded Condition
(traction/brakingloads and vertical loads added)
Longitudinal axial stress is about 30% less in the ballast track than in the concrete track under the same conditions.
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2) Zero-Longitudinal Resistance Rail (ZLR) Fastener inthe BridgeSection
Characteristic behavior of zero-longitudinal resistance rail fastener
- The zero-longitudinal resistance rail fastener behaves similarly to the conventional rail fastener for the gravity
load but generates a gap between the rail and the rail fastener not to introduce longitudinal resistance.
<Gap between rail fastener and rail base> <Downslide of rigid body of rail fastener> <Vertical load-displacement diagram>
FactorsAffecting the Axial Forcesin Track (2)
Installing ZLR fastener can reduce about 29% of the axial stress.
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1) Expansion Length
- Maximum expansion length recommended by UIC774-3 for a single deck railway bridge with gravel ballast not needing
REJ (rail expansion joint)
. 60m: Steel structure with gravel ballast track (the maximum length is 120m when a support exists in the middle)
. 90m: Steel or concrete bridge with gravel ballast track and concrete slab
(the maximum length is 180m when a support exists in the middle)
. For the ballastless track, detailed analysis should be conducted.
- Illustrations of expansion lengths
L 2L
FactorsAffecting the Axial Forcesin Bridge (1)
- Type 1 - Type 2
- Type 3 - Type 4
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FactorsAffecting the Axial Forcesin Bridge (1)
- Type 1
-Unloaded Condition : 26.48 MPa -Loaded Condition : 32.86 MPa
-Unloaded Condition : 11.45 MPa -Loaded Condition : 14.07 MPa
- Type 2
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FactorsAffecting the Axial Forcesin Bridge (1)
- Type 3
-Unloaded Condition : 26.52 MPa -Loaded Condition : 42.05 MPa
-Unloaded Condition : 21.12 MPa -Loaded Condition : 26.43 MPa
- Type 4
Axial stresses in the longitudinal direction under the same conditions:
Type 2 (14.07 MPa) < Type 4 (26.43 MPa) < Type 1 (32.86 MPa) < Type 3 (42.05 Mpa)
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FactorsAffecting the Axial Forcesin Bridge (2)
2) Span length
3) Bending stiffness of the deck and the deck height
- Train vertical loads can cause the longitudinal deformations in the girder, and the span length is the factor
causing the track/bridge interaction.
- Because of the bending of deck, train vertical loads on bridge can cause interactions.
- The bending of deck induces longitudinal deflections at top surface of the deck end and therefore causes the
relaxation of gravel track.
-The effect of bending in deck end
1.0 EI 1.5 EI 2.0 EI
0
-5
-10
-15
-20
-25
-30
-35
0.1 Ko
0.5 Ko
1.0 Ko
2.0 Ko
10 Ko
RailStress(MPa)
2@40M_FMM_Vertical Load
Stiffness of Deck
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Rail Structure Interaction
FactorsAffecting the Axial Forcesin Bridge (3)
4) Support stiffness
K: Total stiffness of support
: relative displacement between the upperand lower parts of bearing
-Factors affecting the support stiffness K
Bending ofPier Rotation ofFoundation Displacement of Foundation
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FactorsAffecting the Axial Forcesin Bridge (4)
5) Effects of support layout of bridge
Axial forces by FF-MM type Axial forces by FM type
-Types of bearing
FFFF type
FM type
FMMF type
FMM type
MFM type
MFMM type
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FactorsAffecting the Axial Forcesin Bridge (4)
Cases illustratingthe effects ofsupport layout ofbridge
- Case1: Simple bridge ( 1@30 8 Span)
Axial force is about 26% less for MFFM type (28.12 MPa) than in the FMFM type (38.08 MPa) when other conditions are identical.
- Case 2: 2 span continuous bridge (2@30 4 Span)
Axial force is about 45% less for MFM type (29.77 MPa) than in the FMM type (54.20 MPa) when other conditions are identical.
FMFM type MFFM type
MFM type FMM type
38.1 MPa 28.1 MPa
29.8 MPa 54.2 MPa
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FactorsAffecting the Axial Forcesin Bridge (4)
6) Axial forces affected by span composition
Case 1 : 78.75 MPa > Case 2 : 60.63 MPa > Case 3 : 59.72 MPa
Axial force is 24.2% less for Case 3 than in Case 1.
78.7 MPa 60.6MPa
59.7 MPa
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1) Verificationof computational analysis
- A computer program that performs the track/bridge interaction should be validated against the test cases specified in the
Appendix 1.7.1 of UIC774-3. Percentage errors may be up to 10% and up to 20% for safety side.
Standard dimensions recommended by UIC774-3
Result table for a simple span bridge specified in UIC774-3
Track-BridgeInteraction Verification
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2) Validation against UIC774-3
Resultdue to temperature 35 degreescentigrade onbridge deck:
-30.47 Mpa
UIC774-3 recommendation:-30.67 MPa
Resultdue to temperature 35 degreescentigrade onbridge deckand
50 degreescentigrade onrails: -150.17 Mpa
UIC774-3 recommendation:156.67 MPa
Validation of the maximum additional stresses due to train moving loads
Validation of thermal loads
Additional stressat 0 pointfrom right pierdue to train loading:181.38 Mpa
UIC774-3 recommendation:182.4 MPa
Maximumadditional stressesdue to train moving
loads:-195.05 MPa
Track-BridgeInteraction Verification