Syed Akbar
Hyderabad, March 5: The imposing minarets of the historic Jama Masjid in Delhi as also
the domes of the mosque will receive the maximum stress in case an earthquake strikes the
national capital region or northern parts of India.
In a first-ever earthquake model for the Jama Masjid, India’s biggest mosque built by
Moghul Emperor Shah Jahan during 1644-1658 CE, the city-based International Institute of
Information Technology (IIIT-Hyderabad) has noticed that the stress concentration at the
centre of the minarets is more. When earthquake occurs, mainly the minarets are prone to
damage. Jama Masjid falls under earthquake zone IV.
A student of IIIT-H, Mr Prasanna Kumar under the guidance of Dr D Neelima Satyam,
assistant professor, has developed three-dimensional numerical model of this historical
structure by considering actual material properties.
The vulnerability of the structure is assessed considering site-specific properties of
the strata. The peak ground acceleration at the surface has been estimated using finite
fault simulation technique and dynamic analysis is done considering 2001 Bhuj earthquake
(7.7 magnitude) data as the input.
The effects of local soils were also considered and detailed soil structure interaction
analysis has been carried out. The IIIT-H team also found that stress concentration near
top and base of the minarets is more. The stress concentration is more on left edge of
middle dome and on the left edges of two small domes. In the model plan, area of the
Masjid is taken as 80mx27m and three domes were modeled, while each minaret is taken as
41m.
The results obtained predicted the stress concentration, cracks propagation or damage
under seismic loads. Such studies are essential to estimate the structural health and for
adopting retrofitting procedures.
Jama Masjid, originally called Masjid-e-jahan-numa (mosque commanding view of the world)
is one of the last architectural works of the Shah Jahan. The Masjid has three great
gates, four towers and two 40 m-high minarets constructed of strips of red sandstone and
white marble.
The mosque is about 261 feet (80 m) long and 90 feet (27 m) wide, and its roof is covered
with three domes with alternate stripes of black and white marble, with its topmost parts
covered with gold. Two lofty minarets, 130 feet (41 m) high, and containing 130 steps,
longitudinally striped with white marble and red sandstone, flank the domes on either
side.
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