Additional rockfall protection work on the Pune-Mumbai Expressway’s Connecting Link is now expected to be completed by November, with the earlier September-end deadline pushed back due to persistent monsoon conditions.
The reinforcement measures were recommended by IIT-Bombay after a major landslide on July 6 caused extensive disruption on the busy expressway. The incident resulted in a traffic jam that lasted around 20 hours and sent large boulders onto the carriageway near the entrance of Tunnel 2.
Officials from the Maharashtra State Road Development Corporation (MSRDC) said work on the additional protection system is currently around 30% complete. The project involves installing high-tensile steel mesh and steel barriers along vulnerable portions of the hillside to prevent rocks and boulders from reaching the road.
Measures Designed to Protect Carriageway
The July landslide brought down boulders estimated to weigh between 17 and 20 tonnes, with some damaging a temporary frame installed near the tunnel entrance. Water from newly formed channels on the slope also flowed onto the Mumbai-bound carriageway.
A senior MSRDC official said, “But the steel mesh, procured from Switzerland, has been designed to contain loose rock and prevent them from reaching the road. The steel barriers will provide an additional line of defence against larger rocks that could dislodge from higher elevations of the hill”
The damaged frame has since been restored as part of the immediate measures taken following the landslide.
“The short-term measures are being sped up, but mesh installation will need time,” another senior MSRDC official said.
Monsoon Slows Installation
Officials said construction has progressed more slowly because the work requires suitable weather conditions. Drilling, anchoring and fixing the protective mesh are difficult during periods of heavy rainfall.
“Drilling, anchoring and mesh installation require relatively dry conditions. With the monsoon easing, rest of the work is being accelerated and is expected to be completed by Nov,” the official said.
Protection Designed for Extreme Weather
Following the landslide, a geotechnical and engineering team from IIT-Bombay inspected the hillside and recommended multiple measures to strengthen sections considered vulnerable.
The revised protection system is being designed to withstand an extreme weather event with a 1-in-1,000-year probability. This is a higher design benchmark than the 1-in-100-year standard used for the original rockfall protection system on the ₹6,695-crore Connecting Link.
The additional works are intended to provide another layer of protection against rockfalls and slope instability while improving safety for motorists using the expressway.
November Now the Target
The extension of the deadline means the safety works will continue through the post-monsoon period. With rainfall expected to ease, MSRDC officials said the pace of construction would be increased.
The Connecting Link is a major component of the Pune-Mumbai road network, and the latest reinforcement programme highlights the engineering challenges involved in building and maintaining transport infrastructure through steep and geologically sensitive terrain.
Completion of the additional mesh and barrier system by November is now the key target as authorities work to strengthen the hillside and reduce the risk of another major rockfall disrupting traffic on one of Maharashtra’s busiest expressway corridors.
Source: Times of India
