Report blames rats for flyover wall collapse

Harshraj Singh

Tribune News Service

Ludhiana, June 18

About a month after the collapse of retaining wall under the Gill Chowk flyover, the inquiry report by the four-member committee has blamed rats for the damage. A portion of the retaining wall collapsed on the night of May 13. While the damaged side of the flyover has been closed to traffic, repair work is still going on.

The inquiry has been conducted by the committee comprising ADC (Development) Shena Aggarwal, MC Executive Engineer Rahul Gagneja, PWD Executive Engineer Rakesh Garg and GLADA Executive Engineer Ranbir Singh.

The committee is of the opinion that the cause of failure of RE (reinforced earth) wall is weakening of reinforcing geogrid net, which is laid during the construction of the bridge, by rats.

“During inspection, it was observed that the reinforcing geogrid was eaten by rats at many places and there were big holes in it. The RE wall panels are held in position by the geogrid net only. After the net was cut by rats, it lost strength required for holding the RE wall panels. This led to the failure of RE wall,” the report reads.

The committee also observed: “The earth retaining wall is a reinforced earth (RE) wall. Concrete panels supporting the earth are tied with geogrid net. The concrete panels of the abutment side wall had fallen off and the geogrid was torn off. The approach slab was intact but the lean concrete below approach slab has settled. Many rat burrows were found in the earth under the bridge portion and all around the RE wall. The span adjoining the collapsed wall was being used as a garbage dump, which had been cleared."

When the retaining wall collapsed, MC officials had also put the entire blame on rats. However, private engineers had accused the contractor concerned of using substandard material, which lead to the collapse of retaining wall. The Council of Engineers (a private organisation) had also alleged poor workmanship in the construction of retaining wall. Ravneet Singh Bittu, MP, visited the site on May 14 and ordered an inquiry. The panel has submitted its report to him, said Deputy Commissioner Pradeep Kumar Agrawal. Meanwhile, MC Superintending Engineer Dharam Singh said repair work would be completed this week

What report says

During inspection, it was observed that the reinforcing geogrid was eaten by rats at many places and there were big holes in it. The RE wall panels are held in position by the geogrid net only. After the net was cut by rats, it lost strength required for holding the RE wall panels. This led to the failure of RE wall

Suggestions by the committee 

• Ensure safety of other bridges in the city
• Garbage dumps near or under the bridges should be immediately shifted
• Rat burrows around bridges should be located and pressure-grouted
• Wherever the RE wall panels are bulging out or have reverse slope, these should be strengthened by providing reinforcing steel strand anchoring.