Page 81 - GM E-BOOKLET 2022

Point no 7B in AMQ yard has been shifted by 8m length inview of
increase of speed on loop lines to 30kmph in AMQ station.

AMQ

3.1.11. YARD IMPROVEMENTS:
Improvements to yards have been done to 9 nos of yards i.e PPY, GUU,
SNF, HYB, RGP, IPG, NSKL, MCI, MMZ during the year till Oct’22.

3.1.12. IMPROVEMENTS TO MARGUTTI TUNNEL:
It is a D-shaped tunnel of diameter 4.92 m at the face and height of 6.70
m at crown level (from RL). The length of the tunnel is 1.645 km, out of

which 200 m length Gulbarga end and 25 m towards BIDR end with cut
and cover method. The tunnel has been lined for the length of 1200 m
and balance 400m is unlined portion. The maximum over burden
available is 25m. The tunnel approaches towards Gulbarga end are
made with five benches and normal cutting of 9-10m at BIDR end. The
catch water drain has been provided at the bottom bench for Gulbarga
end. During the heavy rain on 06.10.2019, the tunnel at KM 60/2-58/6
(BIDR-Gulbarga section) face wall & cutting collapsed.
REASON FOR THE COLLAPSE:
 Gulbarga end: while making the cut and cover portion the cutting made

is much lower than normal hillock. The catch water provided with CC
walls only upto the centre of the tunnel balance portion up to disposable
point was not done, this resulted in stagnation of water in the entire 200 m
length and suddenly gushed the face wall which is built with normal stone
masonry wall and entire masonry of 10m length along with boulders, filled
material laying over cut and cover portion came on to the track.
 BIDR end: The catch water drains provided are become defunct the rain

water entered into the cutting and the weathered rock and some portion
of the slopes which are with normal earth fallen on to the track. The
retaining wall constructed was sunk for a length of 10 m.

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