The IIT Roorkee Report

The IIT Roorkee team which studied the horizontal and vertical forces on the Mullaperiyar dam found that an earthquake in the area would produce a Peak Ground Acceleration of 0.21 g at the site (where “g” is a unit of gravitational acceleration), which worsens fears over the safety of the 114-year-old structure. It was also found that the tensile strength of the dam was the lower side, making it unlikely that the dam would withstand seismic forces.

Besides, the dam not being made of homogenous material, would behave strangely in the event of an earthquake. The forces on the lime-surkhi-concrete structure will be different at different locations. The compression strength of the dam is also just one third of what is now used for concreting buildings.

The dam, built much before engineers became aware of the effect of earthquakes on dams, is structurally deficient, says the report. This is the second report by experts from an IIT that has said that the dam is structurally unsafe. Earlier, internationally accepted hydrologists Dr A K Gosain and Dr Subash Chander of IIT Delhi had submitted a report that that stated that with its existing spillway capacity, the Mullaperiyar dam could not withstand any floods and that it was “hydrologically unsafe”. This analysis, as opposed to the static analysis done by the Central Water Commission, found that the dam was structurally unstable.

Posted in: Mullaperiyar