Officials say they will be implementing the precast technique, used by MMRDA to build the underpass for Sahar elevated road below WEH, to extend the Adoshi, Khandala tunnels on the Mumbai-Pune Expressway
In the wake of back-to-back landslides occurring within a fortnight on the Mumbai-Pune Expressway, the Maharashtra State Road Development Corporation (MSRDC) has decided to increase the length of Adoshi and Khandala tunnels.
Repair work being carried out on the Mumbai-Pune Expressway last month, after the landslide. File pic
MSRDC officials said the technique that will be used to extend the tunnels will be the same as the one implemented by the Mumbai Metropolitan Region Development Authority (MMRDA) while constructing the underpass for the Sahar elevated road below the Western Express Highway (WEH).
Besides lengthening these tunnels, the MSRDC will be installing electronic sensors in the ghat section of the expressway to trace loose boulders, enabling officials to take immediate action to prevent landslides.
Sources claimed that a team comprising members of the Geological Survey of India, an IITian and an expert from Italy recently surveyed both the tunnels and informed the authorities that the area near Khandala tunnel was very prone to landslides because the rock in this section was fractured.
The team stated that boulders would keep falling even if the outer layer was removed and suggested that the extension of the Khandala and Adoshi tunnels was the best solution to prevent loss of life in case of a landslide.
“Rocks and boulders near the Khandala tunnel are very loose, so we have decided to increase the length of the tunnel. Precasts will be used to extend both the tunnels. These are made of steel and can bear more than 100 tonnes of weight, which is very effective during a landslide.
While the Adoshi tunnel will be increased by 100 metres, another 320 to 340 metres will be added to the Khandala one. MMRDA has used this technique (precast) for constructing the underpass for the Sahar elevated road below the WEH,” said Anil Diggikar, MSRDC managing director and vice-chairperson.