NGRI hands over SLBC tunnel safety survey report to Uttam

The NGRI has submitted a detailed survey report on the Srisailam Left Bank Canal (SLBC) tunnel to Irrigation Minister N Uttam Kumar Reddy. The report highlights stress zones, seepage patterns, and factors behind the February 2025 roof collapse.

Hyderabad: The National Geophysical Research Institute (NGRI) submitted a comprehensive survey report on the structural integrity assessment and subsurface conditions of the ongoing Srisailam Left Bank Canal (SLBC) tunnel works to Irrigation Minister N Uttam Kumar Reddy.

NGRI officials highlighted observations on stress zones, seepage patterns, and tunnel roof stability. They also explained factors behind the February 22, 2025 roof collapse. The report was formally handed over by NGRI Chief Scientist, HVS Satyanarayana, to the Minister during a review meeting on Friday.

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The NGRI has employed advanced geophysical techniques such as seismic imaging and electrical resistivity tomography to detect anomalies invisible to conventional inspections.

Uttam Kumar Reddy emphasised the government’s commitment to ensuring the safety of workmen, noting that scientific inputs from NGRI would be crucial in making informed decisions on tunnel completion.

The Minister appreciated NGRI’s work and sought its active involvement in the ongoing soil investigations into the Medigadda, Annaram, and Sundilla barrages of the Kaleshwaram Lift Irrigation Project, where rehabilitation works are being planned. The report would be thoroughly examined, and necessary measures would be initiated based on its recommendations, he said.

The Minister asked the irrigation officials to expedite works on the SLBC tunnel project by mobilising necessary equipment and machinery from agencies within the country in addition to the machinery being procured overseas.

Ever since the works were resumed on the tunnel, a progress of 151.50 metres was achieved. In a month’s time, the works would gather pace to complete 200 metres of tunnel excavation from each side per month, officials said.