For calculating the invert arch length of horse shoe
shape tunnel , most of the time we depend on Auto Cad, as well as
various hectic calculations.
From my past experiences and as per knowledge, the short-cut
calculation has been developed, called as CBS
FACTOR, the calculation has been
shown below……..
INVERT ARCH LENGTH OF HORSE SHOE SHAPE TUNNEL = d X CBS FACTOR
|
Where,
d = Dia. Of horse shoe shape tunnel
CBS FACTOR = 0.8481
From above formula, we can calculate Ivert Arch length
instantly with simple multiplication.
For example….
For a 6mt. dia tunnel, the Arch length has been calculated…
Invert Arch length = d x 0.8481
6 x
0.8481 -> 5.0886 m
The above calculation can be verified using Auto-Cad or any
mathematical technique