SEISMIC DAMAGE ASSESSMENT FOR R.C. BUILDINGS IN DELHI

Abstract

During the Recent few years, India has faced enormous destruction of large number of modern building structures generally having 4 to 10 storyes. It has been observed that Reinforced Concrete buildings on soft or loose soil deposits have severely been affected and more damages were noticed comparing with buildings on fairly good soil conditions - such as stiff soil. Considering the typical examples of Ahmedabad (epicentral distance, 250 km) and Rajkot (e.d = 200 km) having the soil characterization discussed as above. The total number of buildings in Ahmedabad (e.d 250 km) that have been found damaged 120 Nos. and most of them were G+4 (117 Nos.) and G+10 (3 Nos.) having utilized the ground floor as parking. i.e., soft openings. It may also be mentioned here that probably the foundations of these buildings were laid in soft clay or loose sand soil deposits and adequate attention towards soil etc. before initiating the construction has not been paid. Thus, such a divasting loss to the property and life has been experienced during the Bhuj Earthquake of year 2001.0n the other hand Rajkot despitd of having less e.d = 200 km (even less than Ahmedabad) seen more damages due to earthquake forces, were found safe compared to damages in other cities of Gujarat including Ahmedabad. The reason for very less damage (almost negligible to buildings) the availability of rocky/stiff soil in the Rajkot area. In order to assess the influence of earthquake loads on site soil conditions for calculating the horizontal Seismic coefficient defined by Ah (Indian standards) and also CA and C'v (US code) a case study of Delhi has been carried out Actual soil data for two different areas of Delhi namely, Shahadra to Tis Hazari having fairly firm soil and Trans Yamuna area (Noida) having loose/alluvium Soil deposits have been considered along with the information of Standard practice adopted in IS:1893 and ATC-40 for this purpose. Through the present study, an attempt to make a comparison between the two was made and is presented in the subsequent sections of the thesis report. The calculations have been carried out using MS-Excel.