Vibration isolation performance of floating slab track used. The design procedure separately incl udes determining thickness of slab under wall load. Vibration isolation performance of floating slab track. In the subsequent section the main parts of the assessment procedure are described.
Network standards have been referenced where appropriate. Floating slab track adds the highest possible mass above the track spring to form a system with a very low resonance frequency. The slab track should allow for adjustments in the vertical and lateral directions to account for deformations of the subbase. Construction the track slab uses a suitably prepared formation. Contribution of dynamic slab track design dr prof mirjana tomicic torlakovic, dipl. Essentially, a slab track consists of a concrete slab placed on a subbase over a prepared subgrade. Ballastless track of the type low vibration track in a turnout in the gotthard base tunnel s faido multifunction station. Design methodology of slab track systems request pdf.
Repair and replacement slab s design allows track level adjustment and total replacement in case of damage or emergency. There is no longer need to waste space and money on massive and bulky concrete slabs requiring spacious and expensive tunnels. Recent modifications to slab track include use of vibration reducing grooved slab mat under the track slab. Rheda track types, the concrete mix design of rheda 2000 has now reached a very high degree of perfection. Due to the high degree of prefabrication the construction method requires less labour and reworking.
Capacity4rail public page 26 due to a rigid track foundation on tunnels, not only the thickness of slab track can be reduced, the reinforcement can be also optimized. Quality of slab track construction track alignment design. The most known tracks with precast slabs are shinkansen line in japan and max bogl slab track designed in germany. The reinforced concrete design manual sp1711 is intended to provide guidance and assistance to professionals engaged in the design of castinplace reinforced concrete structures.
This pdf file contains a chapter of 23 pages with various aspects of flat slabs including four example of flat slab design. Over the last 20 years, there has been an increase in the use of concrete slab technology for transit, commuter, and highspeed train applications. Definition slab track is defined as a type of track where the sleepers and ballast are replaced by a concrete or ashphalt layer history of slab track in the late 20th century slab track started to appear, especially in tunnels, where the floor of the tunnel would be a single slab. As well as the greater construction cost of the track form itself, great expense can come from any increase in the diameter of the tunnel that has to be made to. Transition design railway track slab mat stiffness mnm3 track stiffness mnm track modulus mpa fixed slab track 6 92 track transition 1 150 96 58 2 70 77 44 3 40 63 33 4 30 56 28 5 24 50 24 floating slab track 20 46 22 0 50 100 150 200 250 0 40 80 120 160 floating slab track fixed slab track fixed slab track track stiffness knmm. The variations of this design are shown in figure 1 for open. Design requirements and improved guidelines for design track. Advances in design theories of highspeed railway ballastless tracks the load stress of the track slab or bed slab and the baseplate or supporting layer in the longitudinal and lateral directions can be obtained by exerting a vertical train load on the rail. Intense teamwork and strong cooperation between civil engineers and geotechnical engineers is required in order to obtain a reliable design of the slab track systems.
Introduction since the middle of the 20th century, several countries across the world have adopted and developed the use of ballastless slabtrack systems. International journal of emerging technology and advanced engineering analysis and design of ballastless track slab. Floating slab track an overview sciencedirect topics. Concrete slab track state of the practice semantic scholar. The track slab for the shinkansen is 2340 mm 92 in wide, 4930 mm 16.
A holistic design approach for high speed railway lines with a velocity of up to 300 kmh, slab track systems provide good performance and durable riding quality. Assessing the sustainability of design and maintenance. Consider all wheels in a truck and proximity of adjacent cars. Monitoring of the structure described in this article is focused on the transition areas between standard structure with ballast and slab track construction. Pdf concrete slab track state of the practice researchgate. This booklet is the combination of a series of design lectures given by me over the past ten years. In this scope, the main objective of this paper is to develop a numerical tool that, after being properly validated and tested, enables the 4 and 5 that use rail sections are squared estimation of the static response of a slab track system stedeftm with the purpose of optimizing its structural design behaviour.
Ballasted track varies considerably, with rail pad stiffness being a key parameter. Track structure design chapter 2 documents the types and magnitudes of loads transferred from the vehicle wheel to the rail. The first reinforced concrete design manual formerly titled aci design handbook was developed in accordance with the design provisions of 1963 aci 318 building code by aci committee 340, design. How is that known unless an onsite investigation has been done. Slab track railway design combines superior stability with an almost complete absence of deformation. Select a track modulus, u or k, based on desired design deflection 3. Sustainable development, global change and ecosystems 2. After experimentation, a slab track design, referred to as slab track type a, was selected for routine use for tunnels and viaducts. Ballastless track slab is a continuous slab of concrete in which the rails are supported directly on the upper surface by using resilient pad. Advances in design theories of highspeed railway ballastless. The approach is based on the dynamic analysis of a slab track and a number of performance factors calculated on the basis of the results of the dynamic simulations. The track consists of a low viaduct consisting of a piled concrete slab, with on top a separate slab with rheda 2000 track. Kolkata metro introduction ballast has been an integral part of railway track and an economical medium providing an elastic support to it for many years. The design procedure includes determini ng slab thickness based on moving live loads and then checking adequacy of slab thickness for stationary live load.
Slab design reading assignment chapter 9 of text and, chapter of aci31802 introduction aci318 code provides two design procedures for slab systems. Therefore, slab track design incurs significantly lower maintenance. Foreword the reinforced concrete design manual sp1711 is intended to provide guidance and assistance to professionals engaged in the design of castinplace reinforced concrete structures. Tip5ct2006031415 innotrack integrated project ip thematic priority 6. A max design is supposedly a design for the maximum soil condition in the area.
Pdf cantilever slab design ramjan shehzaad academia. The newer lines include a higher percentage up to 96 %. The most significant slab track systems are analysed in detail and compared. Though the material is locally available, but ballasted track calls for frequent maintenance attention, and periodical screening. In addition, slab track sections are in service on the canadian pacific railway, the long island railroad and in the eurotunnel under the english channel. These are the basic elements upon which track design is built. Japan, ballastless track always consists of prefabricated slabs just under 5 m long. In the optimized design the mobility was kept low by positioning the webs of the box girder directly under the. The variations of this design are shown in figure 1. The rails may be directly fastened to the concrete slab. The percentage of ballastless track varies considerably from line to line. The rail, pad and shell are held by special alignment frames and. Select design wheel load based on most common, heaviest car and desired track speed.
This paper presents the analysis and design of ballastless track slab for 17t railway loading. Most of the slab track designs are analyzed in details providing information concerning their geometry, structural behavior and in many cases their construction methods. With such systems the emissions can be reduced far below the level of ballasted track systems even with subballast mats. For 1m slab width, moment, shear force, oneway continuous slab for continuous slab, moment and shear force can be obtained from table 3.
Repair and replacement slabs design allows track level adjustment and total replacement in case of damage or emergency. The design procedure separately includes determining thickness of slab under wall load. It causes dust pollution hence efforts are always being made in the search of. Design and layout of ballastless track systems using. Structure of slab tracks a slab track means a reinforced concrete rc slab laid on a viaduct or other rugged bed, and secured to the bed using cement asphalt figure 5. Up to now continuously reinforced concrete pavements crcp with free or controlled transversal cracking in combination with a cement or bituminous treated base layer or asphalt pavements had been chosen for the multilayered ballastless track design. The track slabs are made of precast reinforced concrete or prestressed concrete.
Request pdf on aug 1, 2008, s tsoukantas and others published design methodology of slab track systems find, read and cite all the research you need on researchgate. For continuous slab track, both the top and bottom beams of the unit are joined endtoend. Dynamic design of track transition between two different. Pdf international journal of emerging technology and. Slab track designs have significant advantages comparing to ballasted tracks. Design requirements and improved guidelines for design. The mitigation of noise and vibration increases the costs of the slab track construction significantly. Both supporting structure and rheda slab are dilated at intervals of 35 m to limit the longitudinal forces in the concrete and the displacements at the end of the structure. The design procedure includes determining slab thickness based on moving live loads and then checking adequacy of slab thickness for stationary live load. Rail is supplied in long or short lengths for aluminothermic or flash butt welding. Concrete floor slabs on grade are subjected to a variety of loads and loading conditions. This paper also includes design recommendations for addressing soils investigation, concrete slab, direct fixation fasteners and noise. Pdf railway track technology has evolved over a period of 150 years since the. After experimentation, a slab track design, referred to as slab track type a.
Concrete floor slabs on grade are subjected to a varie ty of loads and loading conditions. The low fastener stiffness on slab track is the main reason for its higher noise levels, with absorption of sound by the ballast accounting for only about 1db. Development of slab tracks began in 1965 and, after. The slab track superstructure design without ballast is a perspective construction especially for building tunnels and bridges in the modernized sections of railway tracks in slovakia. Ballastless tracks track rail transport rapid transit. The rail must support the vehicle and the resulting loads by absorbing some of the impact and shock and transferring some forces back into the vehicle via the wheels. Some of this trackage included the floating slab design as used for the washington, dc metro tunnel system. In the fourth chapter a comparison between the various slab track systems is taking place in. In order to feed the design with cuttingtheedge knowledge on railway infrastructure, three.
The concrete slab is cast insitu, slip formed or precast with slots for the sub system. Dynamic design of track transition between two different slab. Defination components of slab track types of slab track advantages conclusion. Ballastless tracks free download as powerpoint presentation. Slab track design railway track laying by stabirail. Hence, when attempting to design a slab track structure. Figure 3 illustrates the principle of the repeating unit method. The most significant are the high stability of the track, the almost nonexistent need for maintenance. Sections are also included on switch and crossing geometry, clearances and track survey requirements. Chapter 18 concrete slab structures january 2019 188 18. Oneway simply supported slab analysis and design of the slab similar to design of simply supported beam as indicate in the previous chapter. T railway technology today 2 edited by kanji wako the. Element package abaquscae is used to model a 3d slab track design under.
After experimentation, a slab track design, referred to as slab track type a, was selected for routine use for tunnels and viaduc ts. What remains true is that the performance of the slab is influenced primarily by the underlying soil. Recent modifications to slab track include use of vibration reducing. Construction during track shutdowns is possible using earlystrength scc.
This paper provides a summary of several types of slab track used today and discusses slab track design and construction methods. Tm 580912 concrete floor slabs on grade subjected to. Treatments for noise from slab track include absorptive panels and rail dampers. Extensive calculations were carried out leading to optimization of the concrete box girder design, see figure 11. The main parameters that are considered to evaluate the dynamic performance of each of the studied.
Following are the rcc slab design and detailing guidelines. The barriers were designed around the dutch national structure gauge and came to a height of 0. Stabirails new ballastless track construction system has proven to be the most efficient method for laying railway track in concrete beds. A guide to permanent way design permanent way institution. Track layout parameters in existing lines with slab track. The nonprestressed reinforcement biblock sleeper, with op. The intention was to provide the beginner novice with simple guidelines to give an appreciation of the basics elements of track design starting with horizontal and vertical design.
Dynamic comparison of different types of slab tracks and. Chapter track structure design table of contents 4. The details of this method are given in forrest 1997, so only a brief description is given here. Ballastless track construction system superior stability, the absence of deformation and a shallower construction height are just some of the advantages slab track, also known as ballastless track. Overlayunbonded, bonded, asphalt concrete ac overlays transition. The aim of this paper is to analyse a ballastless standard rail track using staad pro and to obtain maximum design moments as contours from staad pro. Slab track design lacks the necessity for underlying ballast because the rails are anchored directly to a concrete slab.
Gerb floating slab track systems make a classical heavy massspringsystem look old. Concrete slab track and rail pads dampen some noise frequencies but may reflect other frequencies and this should be addressed in the design and maintenance of slab track di mino et al. Design requirements for street track 4 features of uk second generation track designs 7 systems with insitu embedment 7 systems using precast embedment 9 generic problems with concrete slab construction 10 generic problems with floating rail construction 11. Ballastless track design offers many advantages compared to its traditional counterpart.
A ballastless track or slab track is a type of railway track infrastructure in which the traditional elastic combination of tiessleepers and ballast is replaced by a rigid construction of concrete or asphalt. Flat slab analysis, design and detailing pdf civil engineering. The slab track design has remained virtually unchanged since the first sections were laid in 1972. The slab track was also tested in configurations with a layer of absorptive material on top of the track slab, with integral absorptive minibarriers and with both. The first reinforced concrete design manual formerly titled aci design handbook was developed in. Reinforced concrete slab design and detailing guidelines for depth of slab, loads on slab, reinforcement guide for oneway and twoway slabs as per is 456. The barriers were designed around the dutch national structure gauge and came to a. Quality of slab track construction track alignment. Reinforced concrete slab design and detailing guide is456.