‘Excavation site lacked lateral support’

JNTU submits inspection report on Madhapur soil collapse incident.

By Author   |   Published: 14th Mar 2017   11:33 pm
Movement of heavy vehicles very close to the excavated portion aggravated the situation, says NV Ramana Rao, professor at JNTU.

Hyderabad: Lack of retaining arrangements, heavy surcharge load and the impact of reinforcement placed on the road led to the collapse of a huge lump of soil at the Madhapur construction site, resulting in the death of two women on Monday, according to a preliminary report by experts.

A team of experts from the Jawaharlal Nehru Technological University (JNTU) submitted the report to Greater Hyderabad Municipal Corporation (GHMC) on Tuesday, in which they said the excavation site was very close to the road and no arrangements were made at the site to retain the deep excavated portion. The excavation was totally vertical without any lateral support leading to movement of soil mass, said NV Ramana Rao, Civil Engineering professor at JNTU, who led the team.

This apart, movement of heavy vehicles was very close the excavated portion and this aggravated the situation, said Rao, who had visited the site based on a request from the GHMC.

In his observations, he said a 10.5-metre deep cellar floor was dug up for the proposed multi-storey building. The excavation was being carried out very closely to the road almost abetting it with no or little setback. Construction of retaining wall was in progress and was at the foundation level only, he said.

The team has also made a few recommendations to improve lateral stability in areas where slope stability is at risk and excavation is done close to the property line without maintaining any setbacks on all sides. These include stopping traffic on roads adjacent to the deep excavation, no dumping of heavy loads close to the excavations, and that the excavated portion should be stabilised temporarily by a “grouted soil anchor/nail with pad system” with proper design and execution.