Mumbai-Pune Expressway: Rains an ‘act of God’, landslide not a construction flaw, says authority

The corporation said the tunnel had not suffered any structural damage and defended the work carried out on the project. (Express Photo by Narendra Vaskar)

After a monsoon-triggered landslide partially paralysed the newly inaugurated Rs 6,695-crore Mumbai-Pune Expessway ‘missing link’ project today, the Maharashtra State Road Development Corporation (MSRDC) blamed it on nature and described it as an “act of God”. “This is not the contractor’s fault; it is nature at play,” said Anilkumar Gaikwad, vice chairman, MSRDC.

Mitigation measures and designs were in place to counteract the landslides, but only to an extent, the corporation said.

Terming it an “act of God”, another MSRDC official said, “Rock fall mitigation measures are in place, vetted by IIT-Bombay. This includes rock boulting mesh up to a height of 15 meters on the mountain over the tunnel. That is still intact. But the boulders falling down are coming from a height of around 150m. Such heavy rainfall is akin to an act of God, with little that can be done to prevent it.”

“After the rains clear, we will inspect the rock and see if extending the mesh to an even greater height is feasible, although that will be an expensive affair and will go over forest land,” the official said.

Mumbai-Pune Expressway: How it happened

The landslide occurred early Monday, July 6, at around 3:30am. Officials said the landslide took place near the end of the first tunnel on the Pune-to-Mumbai carriageway of the ‘missing link’, damaging a retaining wall and rendering the route unsafe for traffic.

Anilkumar Gaikwad said that some boulders slid from the top due to the heavy rain, blocking the mouth of tunnel 2.

He said, “Due to the intense rain, boulders from the top fell at the mouth of tunnel 2. The tunnel structure has not been affected, but the false frame – which is an external structure built at the edges of tunnels – has been damaged.”

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The corporation said the tunnel had not suffered any structural damage and defended the work carried out on the project, saying the contractor had followed all prescribed safety measures.

Senior MSRDC officials said the slope above the tunnel had been stabilised using rock bolts, steel mesh and other rockfall protection measures after detailed studies that were vetted by IIT Bombay.

A waterlogged stretch on Narangi Bypass Road in Virar West following heavy monsoon rains. (Express photos by Akash Patil)

However, the boulders that came down on Monday morning had originated from nearly 150 metres above the protected portion of the slope.

“The protection measures extend up to about 15 metres above the tunnel portal and they remain intact. The rocks that fell came from much higher up the hillside. When rainfall is this intense, there is only so much engineering can do,” an official said.

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On Sunday, some potholes surfaced on the ‘missing link’ road, giving ammunition to the Opposition to target the Bharatiya Janata Party-led state government. Chief Minister Devendra Fadnavis, however, played it down saying it was a small incident.

Major tragedy averted?

Officials said the protection systems did help reduce the impact of the rockfall, adding that the fallout from the falling boulders could have been worse had the protective barries not been in place.

“The barriers slowed the boulders and prevented them from crashing directly onto vehicles. Had these measures not been in place, the consequences could have been far more serious,” the official said.

The corporation said it would carry out a fresh geological assessment after the monsoon to determine whether the rockfall protection could be extended further up the slope. “We will examine whether additional mesh can be installed higher on the hillside. But that would involve substantial cost and work inside forest land, so the feasibility will have to be studied,” the official said.

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The landslide led to the closure of the Pune-to-Mumbai carriageway of the 13.3-km ‘missing link’ early Monday. Traffic on the Mumbai-to-Pune carriageway was restored, but vehicles travelling towards Mumbai continued to be diverted via the old Mumbai-Pune Highway (NH-48) as debris removal continued. The clearance work is being carried out by Navayuga Engineering Company.