ISSN (e): 2250 – 3005 || Volume, 06 || Issue, 04||April – 2016 || International Journal of Computational Engineering Research (IJCER) www.ijceronline.com Open Access Journal Page 23 Probabilistic Seismic Hazard Analysis Of Dehradun City , Uttrakhand Ashutosh Gupta 1 , Sana Zafar 2 1 P.G. Student, Department of Civil Engineering, MMM University of Technology, Gorakhpur, Uttar Pradesh, India 2 Assistant Professor, Department of Civil Engineering, MMM University Of Technology, Gorakhpur, Uttar Pradesh, India I. Introduction Dehradun city has been subjected to frequent earthquakes of moderate intensities and about once i a century to disastrous earthquake of higher magnitude . Greatest earthquake recorded in Dehradun region on September 1 , 1803. The magnitude of this earthquake was about 9.0. Magnitude-Frequency data on earthquakes in Dehradun and its surrounding region is given below. EARTHQUAKES OF MAGNITUDES IN RICHTER SCALE 5 TO 6 6 TO 7 7 TO 7.5 7.5 TO 8 >8 NO. OF EVENTS 36 11 2 1 2 RECURRENCE INTERVAL IN YEARS 2 5 10 31 190 TABLE 1 : Earthquakes in Dehradun and its surrounding region Recent earthquake near Dehradun city are shown in figure 1 : FIG 1 : Recent earthquakes near Dehradun ABSTRACT Dehradun is very old city and also rapidly growing urban area located in valley at foothills of Garhwal Himalayas. Dehradun city and adjoining region in western Himalayas is a is a very active seismic region of Himalayan belt , stretching from Pamir - Hindukush to Arkans in Burma.According to seismic zoning map of India , Dehradun city lies in Zone 4 and expected MSK intensity 8 .Dehradun city is located in the vicinity of twenty four independent seismic source zones which in reality are active faults. This creates uncertainties in size , location and the rate of recurrence of earthquakes. Probabilistic seismic hazard analysis provides a framework in which these uncertainties can be identified , quantified and combined in a rational manner to provide a more complete picture of the seismic hazard . This study presents a PSHA of the Dehradun city using the attenuation relationship given by Cornell et al (1979) in order to determinate various levels of earthquake-caused ground motion that will be exceeded in a given future time period. Keywords: seismic source zones , active faults , attenuation relationship , recurrence of earthquakes , seismic hazard , fault length , uncertainties