CASE STUDY OF SITE CHARACTERISATION FOR SEISMIC MICROZONATION OF BHOPAL
Kapil Sharma, Prof. Praveen Sing Tomar, Dr. Prakash Porey
Seismic microzonation, Seismic hazard and Risk Microzonation. Peak ground acceleration (PGA), Multichannel analysis of surface wave (MASW), Soil liquefaction.
The capital of Madhya Pradesh, falls in the zone II of the seismic hazard zonation map. Earthquakes of intensity up to VI or higher and Bhopal magnitude between 5.0 or more have occurred here in the past in the vicinity of Bhopal i.e. at Jabalpur, Umaria, Gwalior and Seoni are the sensitive areas as they are comes under the Narmada and Son valley. According the census of 2011, the population of Bhopal is 17.95 million. After independence, there has been a tremendous growth in the population and industrial activity in and around Bhopal. Hence, even a earthquake of magnitude 4 or 5 can cause widespread devastation here. In this light we need to carry out microzonation of the city, because it is well known that damage due to an earthquake may vary even within a few meters, because of variation in local site conditions such as thickness of soil layer and type of soil. The basis of microzonation is to model the rupture mechanism at the source of an earthquake, evaluate the propagation of waves through the earth to the top of bed rock, determine the effect of local soil profile and thus develop a hazard map indicating the vulnerability of the area to potential seismic hazard. Seismic microzonation will also help in designing buried lifelines such as tunnels, water and sewage lines, gas and oil lines, and power and communication lines.