الفهرس 
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Abstract
CHAPTER 1
INTRODUCTION
The increased speeds, higher traffic densities, and larger heavier cars now being used on railroads have led to new requirements for improved stability and durability of rail track support. The impact of research and development in the area of track structure design and maintenance couid be large; the costs associated with the replacement and upkeep of railroad fills are too much every year for railroads alone. A large portion of this cost is due to geotechnical problems
To reduce these costs, the rail track structure must be improved so as to minimize misalignments, permanent settlement and in the same time a high elastic deformation is wanted. The solution of this problem depends on a large number of variables. These include, for example, the rail size, tie spacing, the type of ballast, the dimensions of various layers, type of sub-ballast, type of subgrade, the magnitude and speed of wheel loads, and tie type of the track construction.
One approach to better understanding of the behaviour of the rail track structure is the use of sophisticated analytical techniques to model the structure. This provides the engineer with a means of studying various stresses and deflections that affect the behaviour of the track system.
The function of any movement support system is to provide the support, the guideway, and the surface conditions necessary for the safe, economical, and comfortable operation of vehicles using the support system, with due consideration to the operational characteristics of these vehicles and such other constrains as may exist. The movement support system is vital part of any transportation mode.