Investigating the Seismic Risk in New Majlesi City

جغرافیاوتوسعه ناحیه ای

Articles in Press, Accepted Manuscript, Available Online from 15 February 2025

Document Type: Research

DOI: 10.22067/jgrd.2025.85337.1358

Authors

Ghazaleh Razaghian^{* 1}; Ali beitollahi²; negar soodmand³; fateme Dehghan Farouji⁴

¹Department of Geology, Damavand Branch, Islamic Azad University, Damavand, Iran Earthquake and Natural Disaster Research Center, Damavand Branch, Islamic Azad University, Damavand, Iran

²Assistant Professor, Department of Seismology Engineering and Risk, Road, Housing and Urban Development Research Center

³PhD student, Department of Geophysics, Faculty of Basic Sciences, Islamic Azad University, North Tehran Branch, Tehran, Iran

⁴Instructor, Department of Seismology Engineering and Risk, Road, Housing and Urban Development Research Center, Tehran, Iran

Abstract

The formation and construction of a new city is aimed at reducing vulnerability and improving the standard of living. The formation of the new Majlesi city and its development also makes the evaluation of seismic risk parameters in this area significant. Seismicity studies and earthquake risk analysis will play an important role in the design of engineering structures and thus reduce risks and damages in urban areas. This city is located on Quaternary sediments, and the North Rukh and Mubarakeh faults pass near Majlisi city. The occurrence of large earthquakes and a large number of instumental earthquakes indicate that the region is seismically active, the density of these small earthquakes is higher in the southwest of the region. According to the Gutenberg-Richter relationship, the seismicity coefficients for the area of Majlesi city are equal to b=0.7 and a=4.73, and the seismicity rate is equal to 1.28 for earthquakes greater than 4. The bedrock acceleration zoning map shows 4 zones with different accelerations, the rate of change of ground acceleration in urban areas is between 0.182 g and 0.193 g. The most dangerous part of the urban area is in the north, and the least dangerous part is in the southwestern part of the urban area. Based on borehole data, Majlesi city is located on dense sand and sand with low density in some parts, With the effect of the magnification factor, the acceleration on the ground surface is estimated to be 0.213 g to 0.226 g. Along with these data, uniform risk spectrum diagrams have been prepared, which will play an important role in future studies and reducing possible risks.

Keywords

Majlesi city; earthquake risk analysis; fault; acceleration

References