Microzonation and Site Specific Ground Motion Modelling of Delhi City
IR@C-MMACS: CSIR-Centre for Mathematical Modelling and Computer Simulation, Bangalore
View Archive Info| Field | Value | |
| Title |
Microzonation and Site
Specific Ground Motion
Modelling of Delhi City
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| Creator |
Parvez, Imtiyaz A
Jade, Sridevi Gaur, V K |
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| Subject |
Computational Seismology
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| Description |
Delhi – the capital of India is a fast growing megacit y that influences the
economic and industrial developments of much of the country. This region has
experienced many earthquakes since ancient times and faces severe seismic threats
from the Central Himalayan seismic gap just 250-300 km north of it. The objective
of this project is to investigate the detailed site specific ground motion modelling
and to prepare the Microzonation maps of Delhi City in terms of peak ground
motion amplitudes and spectral amplifications. A first order microzonation map will
also be prepared using microtremor measurements. Strong ground motion mapping
due to the earthquakes originating in a given seismogenic zone can be accomplished
using, either recorded seismic signals or simulated ones. The former requires a
dense set of recording instruments triggered by strong earthquake. Simulated
signals can be theoretically computed based on our knowledge of the physics of the
seismic source and of wave propagation. In practice, however, the availability of
adequately spaced strong motion database is rather rare. An alternative is to use the
theoretical approach, based on computer codes, developed from a detailed
knowledge of the seismic source processes and of the propagation of seismic waves
and simulate the ground motion associated with the given earthquake scenario (Fäh
et al., 1993a, 1993b).
The other method which may be used to prepare a first order quick
microzonation maps of Delhi City is that due to Nakamura (1989) technique. This
technique measures the three components of background noise at a site and, from
these, computes the site-specific resonant frequency. This method involves
computing the spectral ratio of each of the horizontal components (E-W and N-S) of
ground motion relative to the vertical component. It gives the better results in
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estimating the dominant period of a site compared with results obtained from the
analysis of actual earthquake data. The Nakamura method yields the site frequency
response estimate better available at the moment and also provides some indication
of the amplification to be expected at a site.
At the conclusion of the project, maps of various seismic hazard
parameters, directly measured or numerically modelled, notably of peak ground
velocity and acceleration, that from the basic quantities for the design of
earthquake-resistant structures will be produced. These numbers together with
available geological and geotechnical information pertaining to Delhi City can
fortunately be used to construct high resolution microzonation maps using a low
cost parametric analysis.
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| Publisher |
CSIR Centre for Mathematical Modelling and Computer Simulation
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| Date |
2001-05
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| Type |
Monograph
NonPeerReviewed |
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| Format |
application/pdf
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| Identifier |
http://cir.cmmacs.ernet.in/228/1/PP%20CM%200102.pdf
Parvez, Imtiyaz A and Jade, Sridevi and Gaur, V K (2001) Microzonation and Site Specific Ground Motion Modelling of Delhi City. Other. CSIR Centre for Mathematical Modelling and Computer Simulation , C-MMACS,Bangalore 560037,India. (Unpublished) |
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| Relation |
http://cir.cmmacs.ernet.in/228/
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