Indian Railway Standards:-
A railway track may be defined as a composite structure consisting of Rails ,Rail-joints, Fish plates and Bolts, Sleepers, Rail to ‘Sleeper fastenings’, Ballast and other track-fittings. This composite structure acts as an integrated unit and transfers the loads coming on to it from rails to the formation
These “transmitted stresses should not exceed the permissible stresses of various track components and bearing pressure of soil – sub grade below”. Since this track structure is not directly embedded into the ground unlike another civil engineering structures so it acts as floating structure (super structure) over the sub-grade foundation and its design is based on ‘theory of ELASTICITY’.
Railway Track Structures:-
the structure Basically Comprises the following track Components
3.Rail to sleeper-fastenings
The standards for various track components in India have been laid on the basis of permissible speed criteria and traffic density for :1.Broad gauge 2.Meter gauge
*Broad gauge has been classified into 5 groups namely : A,B,C,D and E routes.
*Meter gauge has been classified into 3 groups namely : Q,R and S routes.
Track standards for B.G Routs:-
1.Rails:The rail section of 60kg/m and 52kg/m will only be used on B.G routs. However,90R(90lbs/yd) rails when ever existing may be permitted as an interim measure for speeds not exceeding 130km/hr .
Sleepers and Sleeper Fastenings:-
these are given in following figure table
Track Standards For M.G routs:-
The track structure for different categories of M.G routes has to be accordance with the track standards given below: