Engineering Classify and Estimation of the Geomechanical Parameters of Rock Masses at the Chamshir Dam Site

The basic aim of this study is to identify geo mechanical parameters of rock mass of Jam Shir dam site in the Gachsaran in Kahkoulooie and Bouyerahmad province. Utilizing water resources of Zohreh river is main goal of constructing of mentioned dam to supply 110 thousands hectare of agricultural area of south of Iran and to supply necessity electricity of adjacent regions. Jam Shir dame with approximately 140 meters height and 1,700,000,000 cubic meters volume is created as roller weighted concrete dam. During accomplishing engineering projects, in addition to descriptive and qualitative information that was gathered using field investigation and underground exploration, quantitative data for intrinsic characteristics of materials is needed. Hence, the rock in the area under in-situ situation is tested in the laboratory. The goal of these examinations is to identify and classify the rocks and demonstrating relationships among different properties of material. Precise investigations in this stage can refuse some difficulties in accomplish and working stage of dam. Jam Shir dam is located in Structural -erosive valley and U-shaped in stretch of an syncline. Rock masses of dam structure encompass 4 rock units( from surface to underground respectively) above Mishan, middle Mishan, transition region and below Mishan.in this study, by acquired result from exploration borehole, field observations, in-situ tests and laboratory studies, geo mechanical , geo technical and hydraulic parameters of rock mass of jam shir dam different units included Compressive strength, angle of friction, cohesion, permeability, deformability module and etc. were evaluated and relationships of these parameters for different units were examined .in final , by comparing obtained parameters with geo mechanical parameters in several constructed dam site in exterior and interior of country indicate that Jam Shir dam site is suitable for constructing weighted concrete dam regarding to geo mechanical, geo technical and hydraulic parameter.