Evaluation of geological and engineering geological properties of Cheshmeh-Asheq dam site

Abstract

This paper describes the results of the engineering geological investigations and geotechnical studies carried out in the Cheshmeh-Asheq dam site. This study is based on field and laboratory investigations, surface discontinuity surveying, drilled borehole data and permeability and groutability of dam foundation. The present studies include the evaluation of the dam foundation by water pressure tests (WPT). The water pressure tests indicate the necessity to provide a grout curtain below the dam foundation. The rock mass quality of the test section obtained from secondary permeability index (SPI) completed with the degree of jointing of the drill core acts as a useful reference for ground treatment design. The rock mass qualities and classifications of the dam site is assigned using the rock mass rating (RMR) and the geological strength index (GSI) classification systems. Results of the studies indicate that except of some cases, there is a reasonable correlation between SPI and RQD values. According to these results, type and composition of grout is suggested for construction of the grout curtain. © 2012 ejge.