The document discusses the analysis and design of pre-stressed concrete sleepers used in railways. It covers the general functions of sleepers in providing support and transferring loads to the ballast bed. The most common types of pre-stressed sleepers are then described, including twin-block, longitudinal, and mono-block sleepers. Finally, the key design considerations for sleepers are outlined, such as loads from static and dynamic wheel forces, distribution of loads to the rail seat and ballast, and moments and stresses experienced by the sleeper.
Permanent Way of Railway & Components ?(part -1,2,3,4,5)RAMPRASAD KUMAWAT
Permanent Way Components: , Selection of Alignment, Ideal Permanent Ways and Cross-sections in different conditions, Salient Features and types of Components viz.
Rails, Sleepers, Ballast, Rail Fastenings.
Types and Selection of Gauges
Railway secondary part of the transportation . Railway use of maximum materials transport of one place to other place. Particular time of number of trains are move of particular junction so these part are used of points and crossing.
Best helpful of these ppt of railway track and design purposes.
Permanent Way of Railway & Components ?(part -1,2,3,4,5)RAMPRASAD KUMAWAT
Permanent Way Components: , Selection of Alignment, Ideal Permanent Ways and Cross-sections in different conditions, Salient Features and types of Components viz.
Rails, Sleepers, Ballast, Rail Fastenings.
Types and Selection of Gauges
Railway secondary part of the transportation . Railway use of maximum materials transport of one place to other place. Particular time of number of trains are move of particular junction so these part are used of points and crossing.
Best helpful of these ppt of railway track and design purposes.
A stressed ribbon bridge (also stress-ribbon bridge or catenary bridge) is a tension structure (similar in many ways to a simple suspension bridge). The suspension cables are embedded in the deck which follows a catenary arc between supports. Unlike the simple span, the ribbon is stressed in traction, which adds to the stiffness of the structure (simple suspension spans tend to sway and bounce).
what is a ribbon bridge
stress ribbon pedestrian bridges
cancer symbols and colors
bridge materials for sale
materials used to build bridges
used bridge
material used in construction
interesting civil engineering topics
civil engineering topics for presentation
seminar topics pdf
best seminar topics for civil engineering
civil seminar topics ppt
civil engineering seminar topics 2019
seminar topics for mechanical engineers
mechanical engineering seminar topics 2018
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.
Significance of Road, Rail, Air and Water transports - Coordination of all modes to achieve sustainability - Elements of permanent way – Rails, Sleepers, Ballast, rail fixtures and fastenings, - Track Stress, coning of wheels, creep in rails, defects in rails – Route alignment surveys, conventional and modern methods- - Soil suitability analysis - Geometric design of railways, gradient, super elevation, widening of gauge on curves- Points and Crossings
Railway construction and maintenance - Railways, airports, docks and harbour ...Shanmugasundaram N
RAILWAY CONSTRUCTION AND MAINTENANCE
Earthwork – Stabilization of track on poor soil - Track drainage – Calculation of Materials required for track laying - Construction and maintenance of tracks – Railway Station and yards and passenger amenities-Signalling
Types of Failures in Rigid Pavements Joint Spalling in Rigid Pavements. Excessive compressive stress causes deterioration in the joints,... Faulting in Rigid Pavements. The difference in elevation between the joints is called as faulting. Polished Aggregate in Rigid Pavements. The repeated traffic ...
rigid pavement pdf
rigid pavement and flexible pavement
rigid pavement design
rigid pavement construction
flexible pavement versus rigid pavement
aashto rigid pavement design
aashto rigid pavement calculator
rigid pavement pdf
rigid pavement and flexible pavement
rigid pavement design
rigid pavement construction
flexible pavement versus rigid pavement
aashto rigid pavement design
The branch of Civil Engineering which deals with the design, construction and maintenance of the railway tracks for safe and efficient movements of trains is called Railway Engineering
BALLAST
RAILS
SLEEPERS
POINTS OF CROSSINGS
POINTS OF SWITCH
The rolled steel sections laid
end to end in two parallel lines
over sleepers to form a railway
track are known as RAILS The rails used in the construction of railway track can be divided into the following three types :
(1) Double Headed Rails (D.H. Rail)
(2) Flat Footed Rails (F.F. Rail)
(3) Bull Headed Rails (B.H. Rail)
A stressed ribbon bridge (also stress-ribbon bridge or catenary bridge) is a tension structure (similar in many ways to a simple suspension bridge). The suspension cables are embedded in the deck which follows a catenary arc between supports. Unlike the simple span, the ribbon is stressed in traction, which adds to the stiffness of the structure (simple suspension spans tend to sway and bounce).
what is a ribbon bridge
stress ribbon pedestrian bridges
cancer symbols and colors
bridge materials for sale
materials used to build bridges
used bridge
material used in construction
interesting civil engineering topics
civil engineering topics for presentation
seminar topics pdf
best seminar topics for civil engineering
civil seminar topics ppt
civil engineering seminar topics 2019
seminar topics for mechanical engineers
mechanical engineering seminar topics 2018
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.
Significance of Road, Rail, Air and Water transports - Coordination of all modes to achieve sustainability - Elements of permanent way – Rails, Sleepers, Ballast, rail fixtures and fastenings, - Track Stress, coning of wheels, creep in rails, defects in rails – Route alignment surveys, conventional and modern methods- - Soil suitability analysis - Geometric design of railways, gradient, super elevation, widening of gauge on curves- Points and Crossings
Railway construction and maintenance - Railways, airports, docks and harbour ...Shanmugasundaram N
RAILWAY CONSTRUCTION AND MAINTENANCE
Earthwork – Stabilization of track on poor soil - Track drainage – Calculation of Materials required for track laying - Construction and maintenance of tracks – Railway Station and yards and passenger amenities-Signalling
Types of Failures in Rigid Pavements Joint Spalling in Rigid Pavements. Excessive compressive stress causes deterioration in the joints,... Faulting in Rigid Pavements. The difference in elevation between the joints is called as faulting. Polished Aggregate in Rigid Pavements. The repeated traffic ...
rigid pavement pdf
rigid pavement and flexible pavement
rigid pavement design
rigid pavement construction
flexible pavement versus rigid pavement
aashto rigid pavement design
aashto rigid pavement calculator
rigid pavement pdf
rigid pavement and flexible pavement
rigid pavement design
rigid pavement construction
flexible pavement versus rigid pavement
aashto rigid pavement design
The branch of Civil Engineering which deals with the design, construction and maintenance of the railway tracks for safe and efficient movements of trains is called Railway Engineering
BALLAST
RAILS
SLEEPERS
POINTS OF CROSSINGS
POINTS OF SWITCH
The rolled steel sections laid
end to end in two parallel lines
over sleepers to form a railway
track are known as RAILS The rails used in the construction of railway track can be divided into the following three types :
(1) Double Headed Rails (D.H. Rail)
(2) Flat Footed Rails (F.F. Rail)
(3) Bull Headed Rails (B.H. Rail)
EU: Railway or Tramway Sleepers (Cross-Ties) of Wood – Market Report. Analysi...IndexBox Marketing
IndexBox Marketing has just published its report: “EU: Railway or Tramway Sleepers (Cross-Ties) of Wood - Market Report. Analysis And Forecast To 2020”. This report focuses on the EU wooden railway sleeper market, providing a comprehensive analysis and the most recent data on its market size and volume, EU trade, price dynamics, domestic production, and turnover in the industry. The market trends section reveals the main issues and uncertainties concerning the industry, while the medium-term outlook uncovers market prospects. The attractivity index (IB Index) summarizes the source of existing opportunities as they appear in this market, as well as an interpretation of the trade figures.
Testing of 50 year old prestressed concrete railway sleepersDan Dwyer
This was a final year undergraduate civil engineering degree project which undertook testing to determine the remaining strength in old railway sleepers. Testing was done on concrete compressive strength and static bending test.
This presentation gives an overview of rail related problems ESTEQ can help to solve. It is a combination of work from MSC Software, VI-Grade and ESTEQ
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Design of Beam- RCC Singly Reinforced BeamSHAZEBALIKHAN1
Concrete beams are an essential part of civil structures. Learn the design basis, calculations for sizing, tension reinforcement, and shear reinforcement for a concrete beam.
An investigation of structural integrity of chassis mounted platform subjecte...Dr.Vikas Deulgaonkar
The present work deals with the investigation of strength of a specialized chassis mounted platform/structure designed to carry concentrated load. This work deals with the mathematics behind braking through shear and bending diagrams analysis processes. The perceptible loading case in the present analysis comprises braking load and its effect on the platform/structure by usage of simple shear force & bending moment diagrams. These diagrams reveal the distribution of shearing force during braking for typical Indian truck. Present analysis accentuates on the design stage aspects of the platform as this research is a step in doctoral study. Effect of load during braking for an atypical type of combination of longitudinal and cross members in platform/frame design is formulated. This paper provides a new technique for computation of strength using shear and bending diagrams. Peculiarity of this analysis is the usage of combined section modulus of three members for computation of stress.
Stress and fatigue analysis of landing gear axle of a trainer aircrafteSAT Journals
Abstract The undercarriage or landing gear of an aircraft is the structure that supports an aircraft on the ground and allows it to taxi, takeoff and land. Among the various parts of landing gear, axle is the most critical component where the loads (landing and ground loads) act on the axle first, then transferred to the structure. In this study stress and fatigue analysis of the axle is performed to meet the strength and life requirements. The modeling of the axle is done using UniGraphics (UG) software. Stress analysis is carried out using MSC Patran (pre-processing and post-processing)/Nastran (solver) for different landing loads (spin up, spring back, maximum vertical and drift) and ground handling loads (braking, taxing and turning). Stress analysis was carried out by both classical and FEM approaches and by comparing the results it was obvious that they were in correlation with one another. Fatigue analysis was also carried out for the axle using landing spectrum and ground handling spectrum to estimate the fatigue life. By the iteration process, the requirement of 10000 landings was satisfied. Keywords: Static, Fatigue, Axle, Fatigue life, UniGraphics, MSC Patran, MSC Nastran
Transcript: Selling digital books in 2024: Insights from industry leaders - T...BookNet Canada
The publishing industry has been selling digital audiobooks and ebooks for over a decade and has found its groove. What’s changed? What has stayed the same? Where do we go from here? Join a group of leading sales peers from across the industry for a conversation about the lessons learned since the popularization of digital books, best practices, digital book supply chain management, and more.
Link to video recording: https://bnctechforum.ca/sessions/selling-digital-books-in-2024-insights-from-industry-leaders/
Presented by BookNet Canada on May 28, 2024, with support from the Department of Canadian Heritage.
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.
Alt. GDG Cloud Southlake #33: Boule & Rebala: Effective AppSec in SDLC using ...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.
State of ICS and IoT Cyber Threat Landscape Report 2024 previewPrayukth K V
The IoT and OT threat landscape report has been prepared by the Threat Research Team at Sectrio using data from Sectrio, cyber threat intelligence farming facilities spread across over 85 cities around the world. In addition, Sectrio also runs AI-based advanced threat and payload engagement facilities that serve as sinks to attract and engage sophisticated threat actors, and newer malware including new variants and latent threats that are at an earlier stage of development.
The latest edition of the OT/ICS and IoT security Threat Landscape Report 2024 also covers:
State of global ICS asset and network exposure
Sectoral targets and attacks as well as the cost of ransom
Global APT activity, AI usage, actor and tactic profiles, and implications
Rise in volumes of AI-powered cyberattacks
Major cyber events in 2024
Malware and malicious payload trends
Cyberattack types and targets
Vulnerability exploit attempts on CVEs
Attacks on counties – USA
Expansion of bot farms – how, where, and why
In-depth analysis of the cyber threat landscape across North America, South America, Europe, APAC, and the Middle East
Why are attacks on smart factories rising?
Cyber risk predictions
Axis of attacks – Europe
Systemic attacks in the Middle East
Download the full report from here:
https://sectrio.com/resources/ot-threat-landscape-reports/sectrio-releases-ot-ics-and-iot-security-threat-landscape-report-2024/
Smart TV Buyer Insights Survey 2024 by 91mobiles.pdf91mobiles
91mobiles recently conducted a Smart TV Buyer Insights Survey in which we asked over 3,000 respondents about the TV they own, aspects they look at on a new TV, and their TV buying preferences.
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
PHP Frameworks: I want to break free (IPC Berlin 2024)Ralf Eggert
In this presentation, we examine the challenges and limitations of relying too heavily on PHP frameworks in web development. We discuss the history of PHP and its frameworks to understand how this dependence has evolved. The focus will be on providing concrete tips and strategies to reduce reliance on these frameworks, based on real-world examples and practical considerations. The goal is to equip developers with the skills and knowledge to create more flexible and future-proof web applications. We'll explore the importance of maintaining autonomy in a rapidly changing tech landscape and how to make informed decisions in PHP development.
This talk is aimed at encouraging a more independent approach to using PHP frameworks, moving towards a more flexible and future-proof approach to PHP development.
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.
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.
SAP Sapphire 2024 - ASUG301 building better apps with SAP Fiori.pdfPeter Spielvogel
Building better applications for business users with SAP Fiori.
• What is SAP Fiori and why it matters to you
• How a better user experience drives measurable business benefits
• How to get started with SAP Fiori today
• How SAP Fiori elements accelerates application development
• How SAP Build Code includes SAP Fiori tools and other generative artificial intelligence capabilities
• How SAP Fiori paves the way for using AI in SAP apps
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.
1. ANALYSIS AND DESIGN OF
PRE-STRESSED CONCRETE SLEEPERS
BY
YUSUF M. HASHIM,
HASSANABBAMUSA
M.TECH. STRUCTURAL ENGINEERING, SHARDA UNIVERSITY
AT
2.
3. the ballast and the subgrade. Prestressed concrete sleepers
are supplied ready for laying straight from the factory,
meaning that all the reinforcing has been built into the
sleeper and prestressed in accordance with the standards.
They were first of all used in France round about in 1914
but are common since 1950 and later developed and used
by the British and German federal railways after the Second
World War.
4. GENERAL FUNCTIONS AND
REQUIREMENTS OF SLEEPERS
• To provide support and fixing possibilities for the rail
foot and fastenings.
• To sustain rail forces and transfer them as uniformly as
possible to the ballast bed.
• To preserve track gauge and rail inclination.
• To provide adequate electrical insulation between both
rails.
• To be resistant to mechanical influences and weathering
over a long time period.
5. TYPES OF PRESTRESSED SLEEPERS
The most commonly used Pre-stressed sleepers which have
been adopted by the railways of various countries are:
1. Twin-block sleepers: These are connected by a coupling
rod or pipe filled with concrete and containing high-tensile
bars for compressing the concrete in the blocks as
illustrated in fig. 1
2. Longitudinal sleepers located continuously under the rails
and connected by flexible tie bars for gauge retention as
illustrated in fig 2
6. 3. Mono-block sleepers: These are Beam-type single-piece
prestressed concrete sleepers, and have roughly the same
dimensions as timber sleepers.
The advantages of the twin-block sleeper over the mono-block
sleeper are: well-defined bearing surfaces and also high lateral
resistance in the ballast bed. The advantages of beam-type
sleepers are their lower cost and high flexural stiffness. They also
provide greater measure of rigidity to the track if the rails are
tightly fastened to the sleepers, preventing rotations at the seating
and buckling of the rails.
7. DESIGN CONSIDERATIONS OF SLEEPERS
The principal function of rail road tie is to distribute the wheel
loads carried by the rails to the ballast. Although the sleeper
is a simple determinate structural element, it is not possible
to precisely evaluate the loads to which a concrete sleeper is
subjected to during its service life, due to the various
uncertainties and complexities inherent in the variables
involved, together with the inadequate knowledge of the
dynamics of the track structure.
8. The various factors influencing the design of sleepers are;
1. The static and dynamic loads imposed on rail seats which
depend upon;
• The type of track (straight or curved)
• It’s construction and standard of maintenance
• The axle load and their spacing
• The running characteristics, speed and standard of
maintenance of vehicles.
9. 2. The ballast reaction on the sleeper, which is influenced
by;
• The shape of the sleeper.
• It’s flexibility and spacing.
• The unit weight of the rail.
• The standard on maintenance of the track.
• The characteristics of the ballast.
END OF FIRST PRESENTER
10. The “permissible stress” method is currently most commonly used to
design sleepers. However, the permissible stress principle does not
consider the ultimate strength of materials, probabilities of actual loads,
and the risks associated with failure, all of which could lead to the
conclusion of cost-ineffectiveness and over design of current pre-stressed
concrete sleepers.
Recently, the limit states design method, which appeared in the last
century and has been already proposed as a better method for the design of
pre-stressed concrete sleepers. The limit states design has significant
advantages compared to the permissible stress design, such as the
utilisation of the full strength of the member, and a rational analysis of the
probabilities related to sleeper strength and applied loads.
First Concept
DESIGN OF PRE-STRESSED CONCRETE SLEEPERS
introduction
11. Codes of practice for design of pc sleepers
Indian standard (IS: 12269 – 1987) with amendment No.6 of June 2000,
Specification for 53-S grade cement for manufacture of concrete sleepers.
Indian Railway Standard Specification for Pre-tensioned Pre-stressed
Concrete Sleepers, For Broad Gauge And Metre Gauge , Serial No. T-39-
85 (Fourth Revision – Aug’ 2011).
Australian Standard (AS 1085.14-2003), Railway track material Pre-
stressed concrete sleepers
design of pc sleepers
(A) - GENERAL CONDITION
1. TYPE AND SPACING
The sleepers shall be pre-stressed concrete sleepers intended for track
designs using centre-to-centre spacings of sleepers of 500 mm to 750 mm.
The sleepers are designed as fully prestressed sections where the limiting
stresses are based on the fatigue resistance of the concrete.
12. 2. SHAPE AND DIMENSIONS
The depth and width of the sleeper may vary throughout its length. The
minimum length of the sleeper shall be determined by the bond development
requirements of the pre-stressing tendons, and the base width shall then be
determined by the allowable bearing pressure.
3. CLEAR TENDON COVER
Minimum clear concrete cover to tendons at the soffit of the sleeper shall
be 35 mm. Elsewhere, the minimum clear concrete cover to tendons
generally shall be 25 mm with the exception that the tendon may be exposed
at the end faces.
(B) - DESIGN FORCES
1. VERTICAL WHEEL LOAD
The design static wheel load shall be specified by the purchaser. NOTE: For
information about dynamic effects on wheel loads and sleepers, See Appendix
2. QUASISTATIC LOAD
The Quasistatic load is the sum of the static load and the effect of the static
load at speed. It includes the effects of the geometrical roughness of the track
on vehicle response and the effect of unbalanced superelevation.
13. The dynamic load is the load due to high frequency effects of the wheel/rail
load interaction and track component response. A minimum allowance of 150
percent of static wheel load shall be used.
3. DYNAMIC LOAD
The combined quasistatic and dynamic design load is the sum of the static
load, the allowance for the effects of the static load at speed and the allowance
for dynamic effects and shall be not less than 2.5 times the static wheel load.
Therefore, the combined quasistatic and dynamic design load factor (j) shall be
not less than 2.5.
4. COMBINED VERTICAL DESIGN LOAD FACTOR (J)
FIGURE 4.1 AXLE LOAD DISTRIBUTION FACTOR (DF)
14. The proportion of vertical load taken by a single sleeper resulting from
a single wheel may be determined from the following equation provided the
values used in the equation can be determined:
where
Qx = the load carried by any sleeper, per rail, in kilonewtons, for a single wheel at
distance x
x = distance from the sleeper to the wheel load, in metres
zx = rail deflection at distance x from a point load
s = sleeper spacing, in metres
Q = static wheel load, in kilonewtons
λ = (k/4EI)0.25
k = track modulus, in megapascals
E = Young's modulus for the rail steel, in megapascals
I = second moment of area for the rail section, in metres
15. RAIL SEAT LOAD
The value of the rail seat load (R) shall be based on the impact and load
distribution factors determined in accordance with Clauses 4.2.1 and 4.2.2 and
shall be calculated as follows:
R = jQ DF/100 .
BALLAST AND BALLAST PRESSURE
The maximum ballast pressure shall be determined from loading conditions similar
to those for the maximum positive bending moment at the rail seat (see Clause
4.3.2.1 and Table 4.1). This maximum ballast pressure )( ab p is based on a
uniform pressure distribution beneath each rail seat and is calculated using the
appropriate equation from Table 4.1.
Table 4.1 maximum ballast pressure
16. LATERAL LOADS
In order to prevent gauge-widening under traffic, fastenings shall restrain
the rail from lateral movement when a lateral load is applied at the rail head
in addition to vertical wheel load as specified in Clause 4.2.1.1. AS 1085.19
provides requirements for resilient fastenings (see Section 5).
LONGITUDINAL LOADS
The rail shall be restrained to avoid excessive longitudinal movement. A minimum
longitudinal restraint force of 10 kN per rail seat shall be allowed. Maximum movement of
the rail relative to the rail seat under such a load shall not exceed the values given in
AS 1085.19 (see Section 5).
17.
18. RAIL SEAT NEGATIVE DESIGN BENDING MOMENT
The rail seat negative design bending moment (MR−) shall be not less than 67 percent of
the rail seat positive design bending moment or 14 kNm, whichever is greater.
19. MOMENTS AT CENTRE
CENTRE POSITIVE DESIGN BENDING MOMENT
The maximum positive bending moment of the sleeper shall be based on a
pressure distribution beneath each rail seat, similar to that shown in Figure 4.2(a).
The length of the ballast pressure distribution beneath each rail seat and the centre
positive design bending moment (MC+) shall be calculated from the appropriate
equation given in Table 4.3.
20. CENTRE NEGATIVE DESIGN BENDING MOMENT
The maximum negative bending moment shall be taken to occur at the centre of
the sleeper, under partially or totally centrebound conditions producing tensile stress
at the top and compressive stress at the underside of the sleeper.
The value of the centre negative design bending moment (MC−) for track gauge of
1600 mm and greater is based on a ballast pressure distribution as shown in Figure
4.2(b) and is calculated as follows:
The value of the maximum centre negative bending moment (MC−) for track gauge of
1435 mm is based on a uniform distribution of ballast pressure on the sleeper soffit
and is calculated as follows:
21.
22.
23. LOSS OF PRESTRESS
The loss of pre-stress shall be determined by the methods specified in AS
3600. For preliminary design, a value of 25 percent may be assumed.
NOTE: A lower value of total loss may be considered if it can be proven by
testing (see Paragraph E7, Appendix E).
DEVELOPMENT LENGTH AND END ZONE
The development lengths of tendons shall comply with AS 3600. Bursting
and spalling forces shall be assessed and reinforcement provided if needed.