The proposed Kangir dam site is located in western Iran, Elam province, and will impound flow of the Kangir River. The foundation rocks comprise some limestones (Asamri Formation) and, to a greater extent, the marls, gypsum-bearing-marls, and gypsum strata of the Gachsaran Formation. To characterize the rock masses investigated at the dam site, rock mass classification systems such as rock mass rating, Q-tunneling index, rock quality designation, dam mass rating, geological strength index and rock mass index were all used. These classifications provide the basis for estimating deformation and strength properties, for supplying quantitative data to the design engineer, and they also present a platform for communication between exploration, design and construction groups. The results obtained from the comprehensive rock mass studies at the proposed dam site are presented and discussed in this article.
Water is a rare and vital commodity in Iran; the west of Iran can be described as semi-arid mount-ainous region that suffers from water shortages, periodic droughts, and a limited water supply which constrains development activities. Owing to the increasing demand for water in the western provinces of Iran, the Ministry of Energy has selected a number of sites that may be suitable for the construction of storage dams to be used mainly for the domestic recharge of groundwater and for irrigation. This paper highlights the engineering geological characterization of the rock masses exposed at the dam abutments and foundation area at the proposed Kangir dam site. This site is located in western Iran in Elam province, and will impound flow from the Kangir River. The study area is part of the folded Zagros area, a well-known tectonic belt which stretches from NW to S and SE of Iran. The foundation rocks comprise some limestones and to a greater extent strata comprising marl, gypsiferous marl, and gypsum. Karstification is widespread in the limestone and gypsum units. In order to achieve a geotechnical characterization of the rock masses, a comprehensive engineering geology and rock mechanics study was conducted in the study area. The physical and geomechanical properties of the different rock types exposed in the study area were determined in the laboratory based on ASTM standards and ISRM suggested methods. To characterize the rock masses investigated at the dam site, rock mass classification systems such as rock mass rating (RMR), Q-tunneling index, rock quality designation (RQD), dam mass rating (DMR), geological strength index (GSI) and rock mass index (RMi) were used. These classifications provide the basis for estimating deformation and strength properties, for supplying qualitative and quantitative data to the design engineering team, and constitute a platform for clear communication between exploration, design and construction groups. The rock mass constants mb, s and a, GSI values, UCS and tensile strength, cohesion, internal friction angle, global strength and the Young's modulus of each rock unit at the dam site were determined from GSI values using RocLab freeware.