Introduction since the middle of the 20th century, several countries across the world have adopted and developed the use of ballastless slabtrack systems. 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. 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. Oneway simply supported slab analysis and design of the slab similar to design of simply supported beam as indicate in the previous chapter. It causes dust pollution hence efforts are always being made in the search of. Rheda track types, the concrete mix design of rheda 2000 has now reached a very high degree of perfection. In the optimized design the mobility was kept low by positioning the webs of the box girder directly under the. Defination components of slab track types of slab track advantages conclusion. 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. After experimentation, a slab track design, referred to as slab track type a. The barriers were designed around the dutch national structure gauge and came to a height of 0. Concrete floor slabs on grade are subjected to a variety of loads and loading conditions. Pdf international journal of emerging technology and. Following are the rcc slab design and detailing guidelines.
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. Network standards have been referenced where appropriate. 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. Slab track design railway track laying by stabirail. A guide to permanent way design permanent way institution. Slab design reading assignment chapter 9 of text and, chapter of aci31802 introduction aci318 code provides two design procedures for slab systems. The track slab for the shinkansen is 2340 mm 92 in wide, 4930 mm 16. The slab track should allow for adjustments in the vertical and lateral directions to account for deformations of the subbase. 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. Japan, ballastless track always consists of prefabricated slabs just under 5 m long.
Ballastless tracks free download as powerpoint presentation. Repair and replacement slab s design allows track level adjustment and total replacement in case of damage or emergency. Development of slab tracks began in 1965 and, after. Recent modifications to slab track include use of vibration reducing. 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. The first reinforced concrete design manual formerly titled aci design handbook was developed in. Floating slab track an overview sciencedirect topics. 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. 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. Assessing the sustainability of design and maintenance. Most of the slab track designs are analyzed in details providing information concerning their geometry, structural behavior and in many cases their construction methods. Due to the high degree of prefabrication the construction method requires less labour and reworking. Figure 3 illustrates the principle of the repeating unit method. Monitoring of the structure described in this article is focused on the transition areas between standard structure with ballast and slab track construction.
Extensive calculations were carried out leading to optimization of the concrete box girder design, see figure 11. Floating slab track adds the highest possible mass above the track spring to form a system with a very low resonance frequency. 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. In order to feed the design with cuttingtheedge knowledge on railway infrastructure, three. Repair and replacement slabs design allows track level adjustment and total replacement in case of damage or emergency. Consider all wheels in a truck and proximity of adjacent cars. Recent modifications to slab track include use of vibration reducing grooved slab mat under the track slab. The percentage of ballastless track varies considerably from line to line. Dynamic design of track transition between two different. The rail, pad and shell are held by special alignment frames and. Contribution of dynamic slab track design dr prof mirjana tomicic torlakovic, dipl. Treatments for noise from slab track include absorptive panels and rail dampers.
Ballastless track design offers many advantages compared to its traditional counterpart. 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. The details of this method are given in forrest 1997, so only a brief description is given here. In the subsequent section the main parts of the assessment procedure are described. Ballastless track slab is a continuous slab of concrete in which the rails are supported directly on the upper surface by using resilient pad. 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. Design requirements and improved guidelines for design track. 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.
The design procedure includes determining slab thickness based on moving live loads and then checking adequacy of slab thickness for stationary live load. 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. Stabirails new ballastless track construction system has proven to be the most efficient method for laying railway track in concrete beds. Track layout parameters in existing lines with slab track. After experimentation, a slab track design, referred to as slab track type a, was selected for routine use for tunnels and viaducts.
The variations of this design are shown in figure 1. International journal of emerging technology and advanced engineering analysis and design of ballastless track slab. Select design wheel load based on most common, heaviest car and desired track speed. The reinforced concrete design manual sp1711 is intended to provide guidance and assistance to professionals engaged in the design of castinplace reinforced concrete structures. 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. Hence, when attempting to design a slab track structure. Tip5ct2006031415 innotrack integrated project ip thematic priority 6. Ballastless track of the type low vibration track in a turnout in the gotthard base tunnel s faido multifunction station. The design procedure separately incl udes determining thickness of slab under wall load. Some of this trackage included the floating slab design as used for the washington, dc metro tunnel system. The newer lines include a higher percentage up to 96 %. Vibration isolation performance of floating slab track. Essentially, a slab track consists of a concrete slab placed on a subbase over a prepared subgrade. 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.
Sections are also included on switch and crossing geometry, clearances and track survey requirements. 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. The main parameters that are considered to evaluate the dynamic performance of each of the studied. The variations of this design are shown in figure 1 for open. There is no longer need to waste space and money on massive and bulky concrete slabs requiring spacious and expensive tunnels. The nonprestressed reinforcement biblock sleeper, with op.
Vibration isolation performance of floating slab track used. The track slabs are made of precast reinforced concrete or prestressed concrete. Construction the track slab uses a suitably prepared formation. Concrete slab track state of the practice semantic scholar. The most significant slab track systems are analysed in detail and compared. After experimentation, a slab track design, referred to as slab track type a, was selected for routine use for tunnels and viaduc ts. Though the material is locally available, but ballasted track calls for frequent maintenance attention, and periodical screening. Pdf concrete slab track state of the practice researchgate. Over the last 20 years, there has been an increase in the use of concrete slab technology for transit, commuter, and highspeed train applications. The rails may be directly fastened to the concrete slab. Therefore, slab track design incurs significantly lower maintenance. The most known tracks with precast slabs are shinkansen line in japan and max bogl slab track designed in germany. Chapter 18 concrete slab structures january 2019 188 18. 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.
Quality of slab track construction track alignment design. Slab track designs have significant advantages comparing to ballasted tracks. 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. How is that known unless an onsite investigation has been done. A max design is supposedly a design for the maximum soil condition in the area. Gerb floating slab track systems make a classical heavy massspringsystem look old. For 1m slab width, moment, shear force, oneway continuous slab for continuous slab, moment and shear force can be obtained from table 3. 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. Track structure design chapter 2 documents the types and magnitudes of loads transferred from the vehicle wheel to the rail.
Ballasted track varies considerably, with rail pad stiffness being a key parameter. The most significant are the high stability of the track, the almost nonexistent need for maintenance. Element package abaquscae is used to model a 3d slab track design under. Quality of slab track construction track alignment. 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. 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. Sustainable development, global change and ecosystems 2. 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. 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 track design lacks the necessity for underlying ballast because the rails are anchored directly to a concrete slab.
The mitigation of noise and vibration increases the costs of the slab track construction significantly. Rail is supplied in long or short lengths for aluminothermic or flash butt welding. These are the basic elements upon which track design is built. Design requirements and improved guidelines for design. In the fourth chapter a comparison between the various slab track systems is taking place in. Flat slab analysis, design and detailing pdf civil engineering. Construction during track shutdowns is possible using earlystrength scc. Slab track railway design combines superior stability with an almost complete absence of deformation. Advances in design theories of highspeed railway ballastless. The slab track design has remained virtually unchanged since the first sections were laid in 1972. Dynamic design of track transition between two different slab. Design and layout of ballastless track systems using. Concrete floor slabs on grade are subjected to a varie ty of loads and loading conditions. It fulfils even the most stringent demands for durability and reliability under a great variety of climatic conditions and applicable concrete standards.
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. 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. The barriers were designed around the dutch national structure gauge and came to a. Reinforced concrete slab design and detailing guide is456. 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. Chapter track structure design table of contents 4. This pdf file contains a chapter of 23 pages with various aspects of flat slabs including four example of flat slab design. Design methodology of slab track systems request pdf. Overlayunbonded, bonded, asphalt concrete ac overlays transition. This paper presents the analysis and design of ballastless track slab for 17t railway loading. The design procedure separately includes determining thickness of slab under wall load.
Pdf railway track technology has evolved over a period of 150 years since the. Pdf cantilever slab design ramjan shehzaad academia. Dynamic comparison of different types of slab tracks and. The use of floating slab track assisted in this but the bridge structure itself had to be designed carefully. This booklet is the combination of a series of design lectures given by me over the past ten years. T railway technology today 2 edited by kanji wako the. With such systems the emissions can be reduced far below the level of ballasted track systems even with subballast mats.
Select a track modulus, u or k, based on desired design deflection 3. This paper provides a summary of several types of slab track used today and discusses slab track design and construction methods. 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. Tm 580912 concrete floor slabs on grade subjected to. The concrete slab is cast insitu, slip formed or precast with slots for the sub system. This paper also includes design recommendations for addressing soils investigation, concrete slab, direct fixation fasteners and noise. Ballastless tracks track rail transport rapid transit. 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.