Investigation of rock quality of Shirinrud dam site by engineering seismology

Abstract

At this paper, we studied about the rock quality of Shirinrud dam site by engineering seismology. Shirinrud dam site is located 80 km far from Kerman and 18 km far from Hojadk village. The dam and its constructions are established in the Bidu Formation which consists of seven rock units, and the refraction profiles were surveyed on Jb3/2, Jb4, and Jb5 rock units. To evaluate the rock mass quality and basement topography at this site, nine refraction seismic profiles by primary waves and two refraction seismic profiles by secondary waves were surveyed. We used some methods such as Palmer method, the reciprocal method, plus-minus method, etc. to process and interpret data. Based on investigations, primary wave velocity in unit Jb3/2 varies between 2,100 and 2,200 m/s, in unit Jb4 is between 2,100 and 4,200 m/s, and in unit Jb5 is between 2,500 and 3,000 m/s. The Q values on these three units are 0. 05, 1. 2, and 1. 9, and the rock mass rating (RMR) values are 27. 1, 40. 5, and 33. 5, respectively. With respect to wave velocity, Q, and RMR values, the units Jb3/2, Jb4, and Jb5 are evaluated as very weak, intermediate, and weak, respectively. © 2011 Saudi Society for Geosciences.