Ayodhya: Earthquake hazard tests for Ram Mandir matched those for big dams & nuclear power plants

Ayodhya-NGRI: Hyderabad-based National Geophysical Research Laboratory, a 1961-founded research laboratory of the Council of Scientific and Industrial Research, did the seismic hazard analysis of the Ram Mandir construction site in December 2020.

Three years ago, a team of scientists from the Hyderabad-based National Geophysical Research Laboratory (NGRI) landed in Ayodhya for a study that they generally reserve for big bridges, dams and even nuclear power plants.

The scientists from NGRI, a 1961-founded research laboratory of the Council of Scientific and Industrial Research (CSIR) under the Union Ministry of Science and Technology, arrived in Ayodhya in November 2020 for a visit to the construction site of the Ayodhya Ram temple.

The Shri Ram Janmabhoomi Teerth Kshetra had contacted NGRI to seek its expertise in conducting research in the highly complex structure, and on processes of the earth system and its extensively interlinked subsystems to help in the construction of the Ram Mandir in Ayodhya.

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The following month, more than 25 scientists and technical officers of NGRI were on the ground in Ayodhya carrying out various experiments to determine seismic hazards posed to the temple, to be built on the site after the Supreme Court verdict in November 2019.

"We did our work in December 2020 and compiled a report in early January 2021," recalls Anand Kumar Pandey, chief scientist at the NGRI, who led the team of scientists from the renowned institute that has provided seismic hazard analysis for many major national infrastructure projects in the country.

Weeks-long tests conducted by NGRI scientists on the soil under the site of the Ram Mandir used radars and crane-mounted giant generators for a range of experiments using geology, geomorphology and remote sensing.

One of them was the Ground Penetration Radar study in which electro-magenic pulse was applied on the earth at the site to learn about the broad soil layers and their moisture content and if there is any discontinuity in the natural fabric of the soil layer.

It is a study that is generally used in large infrastructure projects like dams and bridges.

- Anand Kumar Pandey, who was NGRI's coordinator of the Ayodhya project.

Among other experiments were Deep Resistivity Sounding and Electrical Resistivity and IP Tomography to understand general moisture content and properties of soil and rock up to a depth of more than 100 metres, and Acceleration and Displacement Response Spectra to learn how the soil would behave in the event of an earthquake.

The on-site studies were followed by the building of models in the institute's laboratory in Hyderabad based on the findings. Finally, one model was created based on the site's response to the studies. The construction companies, too, had their own models for seismic risks.

The seismic hazard analysis by NGRI scientists, to determine the engineering properties, resistance, load bearing, moisture bearing capacity and liquefaction of the underground soil, considered resistance to a possible earthquake of magnitude 8 on the Richter scale.

The NGRI's report was first submitted to independent experts before it was presented to the Shri Ram Janmabhoomi trust. "These were national-level experts in engineering and geology," says Pandey. After the approval by the independent experts, NGRI scientists did a presentation of the final report before the Shri Ram Janmabhoomi trust in early January 2021. "All the stakeholders of the Ram Mandir construction were present on the occasion," he adds.

The seismic hazard analysis by NGRI suggested removal of top soil at the temple site by 15-20 metres.

They did multiple excavations to remove the soil and create a compact, engineered, layer by layer of pressed structure in its place.

- Pandey, referring to the work by the companies constructing the temple following the report by NGRI.