Lucknow: The Lucknow Metro Rail Corporation (LMRC), today, achieved a historic milestone as the Tunnel Boring Machines (TBMs) – ‘GANGA’ and ‘GOMTI’ simultaneously broke through the ground face to reach the Hussainganj underground Metro Station after completing their third and final drive between the Charbagh and the Hussainganj underground Metro stretch. Earlier also, these two TBMs had completed the tunneling drives between the Sachivalaya – Hazratganj and the Sachivalaya- Hussainganj Metro stretch in record time.
This now marks the completion of tunneling works for the 3.67 km long Charbagh-Hazratganj underground Metro stretch of the Lucknow Metro Rail Project Phase I-A in a record time of approximately 15 months – two months ahead of schedule. LMRC had started its first tunneling drive from the Sachivaalaya Metro station on 18th January, 2017 and tunneling for the whole section was scheduled to be completed by June, 2018 but it has been completed two months ahead of the schedule.
The fact that the tunnelling work was completed two months ahead of schedule inspite of enormous technical and logistical challenges made the moment even sweeter for engineers of LMRC and the Gulermak-TPL JV (the contractor). It is indeed a moment of triumph and pride for the entire team of engineers and officials associated with the tunneling work who could successfully construct the 3.67 km twin tunnels in just about fifteen months in one of the most challenging and demanding urban conditions.
Tunnelling through the heart of the Lucknow city posed an enormous engineering challenge as the route passed beneath highly congested areas and basements of commercial establishments. Realizing the enormity of the technical challenge, engineers working on the project carefully planned each and every step involved in tunneling operation .The final drive from Charbagh to Hussainganj was the most challenging wherein TBMs had to pass just 1m below the bed of Haider Canal in the vicinity of highly populated area with dilapidated hutments on weak foundations.
Another major technical challenge during the final drive was the encounter of very hard strata which significantly reduced the TBMs advancement rate and also posed a critical challenge towards the safety of TBMs itself
The state of the art onboard computerized tunnel guidance system provided in TBMs ensured that the tunneling was done as per the designed alignment to the highest level of accuracy. Extensive instrumentation was done throughout the underground stretch and continuous online and real time monitoring was done by a team of dedicated experts to ensure safety during TBM operations.