The Rs 7,000-crore-missing link tunnel linking Mumbai and Pune has failed the monsoon tests. Traffic through the link was disrupted after a slab at the entrance of the tunnel caved in after a landslide caused by heavy rains in the Lonavala-Khopoli stretch within 66 days of opening the stretch.
Traffic movement has been disrupted since the incident on Monday. Travellers had to go back to the hazardous ghat section to reach either Mumbai or Pune. Potholes were seen in the Missing Link stretch a few days ago.
The Maharashtra State Road Development Corporation (MSRDCL) implemented the Missing Link project, and the tunnel section of the link was built by Hyderabad-based Navayuga Engineering Company.
These five-lane twin tunnels are part of the six-lane, 94-km Yashwantrao Chavan Mumbai-Pune Expressway and the Missing Link reduced travel time between Mumbai and Pune by 30 minutes. It cut the travel distance by 6 km.
Navyuga had claimed a world record for building the world’s widest twin tunnels (23.33 metres wide) and the longest in Asia (10.67 km). The Mumbai-Pune Expressway Missing Link spans 13.3 kms.
Navayuga Engineering did not offer any comment on this incident. Maharashtra Chief Minister, Devendra Fadnavis, said around 100 tonnes of debris had landed in the tunnel. Till late evening, they had managed to remove around 70 tonnes and were working on restoring the connectivity, the CM said.
The section had earlier developed potholes. Fadnavis downplayed the potholes and called it an engineering marvel, as it was built over a dam.
Chinta Sridhar, managing director of Navayuga Engineering Company, had said at the tunnel that it was a statement of what India can build. “Delivering the widest underground tunnel through the challenging basalt terrain of the Sahyadris reflects our ability to execute complex, design-led infrastructure at a global scale,” Sridhar had said.
According to Ramesh Singooru, senior vice president and regional head of Navayuga Engineering, the tunnel was constructed beneath a large water body. The project also involved extensive rock excavation of around 65 lakh tonnes, large-scale concrete works, and the integration of viaduct structures across an 180-metre valley.
“Construction utilised 7,600 tonnes of steel, reinforcing the structural strength of the tunnels. Over 1.1 lakh cubic metres of concrete were deployed for shotcrete, enhancing structural stability and durability; an additional 2.2 lakh cubic metres of concrete were used for PQC (Pavement Quality Concrete), ensuring long-term road performance, Singooru had said at the launch.
The responsibility of maintaining the tunnel is with Navayuga, along with a defect liability obligation.