These cross-passages are being constructed to attach each the tunnels based mostly on New Australian Tunneling Technique (NATM) know-how.
Within the underground portion of the RRTS corridor, two parallel tunnels are being constructed for the motion of trains on every route.
Additionally, provision of 1 cross passage has been made in these tunnels at a distance of each 250 metres.
Cross-passage is a component between the 2 tunnels which allows motion of individuals from one tunnel to a different in case of necessity or emergency.
These cross-passages are useful in the operation of trains and the safety of passengers in case of emergency in the underground part.
In case of an emergency, if practice operations in one tunnel cease attributable to any unexpected causes, by these cross-passages, commuters could be evacuated from the opposite tunnel.
For the development of the cross-passage by NATM method, sequential excavation technique is adopted.
First, an interior line is drawn on the soil with the assistance of metal plate, girder and wire mesh, i.e. the world the place the excavation needs to be made for the cross-passage is marked.
Then, the soil is excavated with the assistance of small machines operated by hand.
Rock bolts are used to stabilize the soil.
Throughout this building course of, the soil stress and its impact on the floor are constantly checked by devices.
With the development of the cross-passage, it’s strengthened with concrete, then tunnel rings are put in to provide it extra power and stability.
The NATM technique is efficient for tunnel building or cross passage in small and curved locations.
A complete of six tunnels are being constructed in Meerut on the Delhi-Ghaziabad-Meerut corridor, in which a complete of cross-passages will probably be constructed. A complete of six cross-passages in two-km-long parallel tunnels are being constructed between Bhainsali to Meerut Central; a complete of two cross-passages in one-km-long parallel tunnels between Bhainsali to Begumpul and one cross-passage between about 700 m lengthy parallel tunnels between Gandhi Bagh to Begumpul.
Then again, a complete of 4 tunnels are to be constructed on the RRTS corridor in Delhi, in which a complete of 12 cross-passages will probably be constructed.
A complete of eight cross-passages will probably be constructed in each the three-km-long parallel tunnels below building between New Ashok Nagar and Anand Vihar and a complete of 4 cross-passages will probably be constructed in the two-km-long parallel tunnels below building between Anand Vihar to Sahibabad.
It could be famous that about 90-meter-long Sudarshan (tunnel boring machine) is being used for tunnelling in the RRTS challenge.
This Sudarshan strikes ahead by reducing the soil and putting in the tunnel rings.
On this approach, the tunnel building retains progressing because it strikes ahead.
Tunnelling with the assistance of a TBM is without doubt one of the most superior methods.
For the primary time in any city mass transit challenge in India, tunnel of a 6.5 meter diameter is being constructed.
Provision of varied safety measures has additionally been made to make sure the safety of the passengers in the underground portion.
The development of the cross-passage is one such provision.
Other than this, air flow ducts are being constructed to make sure the air circulation in the RRTS tunnel.
Additionally, a aspect walkway of 60-90 cm vast are being constructed in the tunnels, which is not going to solely help in upkeep actions however may even assist in case of emergencies.
The RRTS challenge is being applied as per the stipulated time-frame.
NCRTC goes to operationalise the 17-km-long precedence part between Sahibabad and Duhai quickly, a lot earlier than its schedule.
Then again, the whole corridor from Delhi to Meerut is focused to be open for the general public in the 12 months 2025.