Analysis of Location of Villages in Relation to Rupture Zone (Case Study: North Qazvin Fault)

This paper studies the shear zone of North Qazvin fault and investigates the location of rural settlements in this area. In selected sections, the presence of transverse valleys along the fault made it possible to investigate the evidence of shear zones in which we can see severe crushing in igneous rocks of andesitic and trachyandesitic type, and cataclastic. Moreover, traces of faulted and fractured zones (Damage zone) including fractures and small and minor faults were observed. The study also found Intact green tuffs at the end of the shear zone of the North Qazvin fault, which was considered as the healthy wall next to the shear zone. According to the field studies and observations of the shear zone of the North Qazvin fault in this section, the width of the shear zone was measured at 320 m on the hanging wall of the fault. After that, we used common software to compare the location of villages with the rupture zone of ​​the North Qazvin fault. The results showed that the villages of Barajin, Hesamabad, Kherman-Sokhteh, Dastjerd-e Olia, Ahvarak, Khoran, Tazarkesh, Kikhanan, Najmabad, Razjerd, Qutbi Miyan, Sperno, Ange, Mazraeh Lat and Mazraeh Kharmanlough are located on the rupture zone of the North Qazvin fault. Moreover, 45 villages are located less than 2 km away from the North Qazvin fault. Therefore, it is necessary to relocate the villages that are on the rapture zone or change the direction of future developments of these villages outward, away from the rupture zone. For those villages that are located less than 2 km away from the North Qazvin fault, with regard to the acceleration of earthquakes around the fault and the phenomenon of rock fall in villages, the study proposes retrofitting in future construction.