Multi-storey temples highly vulnerable to quakes: Study

Kathmandu, June 5:

Ancient multi-storey temples in different parts of the country are highly vulnerable to earthquakes because of their structure, a recent study has revealed.

The study conducted by Dr Bijaya Jaishi of the Department of roads and Prof Prem Nath Maskey of the Institute of Engineering (IoE) on earthquake resistance capacity of such temples found out that the multi-storey structure of the temples with thick bases prevent them from collapsing.

They will instead break or bend from the middle due to tension or compression during quakes.

The study found out that the loose joints, free walls and pillars and a large number of windows have made the temples highly fragile.

The study was primarily conducted in Nyatapola temple, the temple of Yechheswor and the Salan Ganesh in Bhaktapur, all three with completely different structures and sizes.

Sensory tests were conducted to find out their natural time period (movement of the structure in one second), Dr Jaishi said. “We found out that our temples have a natural time period of 0.6 seconds that prevents the temples from immediate collapse.”

The researchers have also come up with a mathematical formula to calculate the earthquake resistance capacity of all the temples.

According to Jaishi, renovation of the ancient structures could help them from being damaged during earthquakes. “We cannot afford to adopt expensive technologies like base isolation or the use of energy dissipating techniques, but based on the findings of the research, we could easily repair the highly vulnerable parts.”

Risk could be minimised by building walls in the pillars, making the joints of the temples stronger and configuring the wooden pillars appropriately, Jaishi added.

The findings of the study have been published in Engineering Structures, a journal published from the United Kingdom, he said.