Pumped storage reservoirs are one of the newest systems in saving electricity. According to importance of convey water for placed the turbine and knowing that, almost of instability of underground area is for ignorance in some engineering geology parameters, we have decided to investigate this parameters. In this research we have been studied the engineering geology parameters along tunnel, changing in some of these parameters are shown in Rockwork 2008. After all with the new classification called IRMR the engineering geology parameters of rock mass have been studied, compare the result with classic classification, RMR and GSI shown that the outlet and entrance of tunnel are under bad situation. At the next, studied of joint for recognized the wedge base on finite element method have been investigate. Eventually with emphasis on rock bursting, squeezing and geomechanic studied the admissible advancement step for two section of tunnel base on FLAC 3D have been carried out. Using such studied make safety in services and reduce the spent-time.

Based on the extensive studies which have been done، undoubtedly، the role of the wave velocity data of rocks in hydrocarbon reservoir evaluation is absolutely vital. Within، it is important to study the wave velocities in the Dolomites، which often make up one of the best parts of hydrocarbon reservoirs in the carbonate system. Certainly، the texture of rocks، mineralogical composition، grain size، percent of quartz in rocks، and many microstructure properties affect the Engineering and Physical Behavior of rocks. According with previous studies and to better understanding this relationship، a comprehensive program of tests on the three categories of dolomite with fine، medium and coarse grained were designed. In this paper، the results related to the measurement of compressive (Vp) and shear wave velocity (Vs) for 32 samples are given. According to the results، with increasing in grain size، density of rock decreases. The compressive and shear wave velocity for fine grain and coarse grain samples were found to be %9 and %12 lower، respectively، than those for the medium grain samples. The results showed that for fine، medium and coarse grain samples; moreover، the ratio of Vp/Vs is 1. 78، 1. 81، and 1. 77 respectively. It was also observed that the dynamic Young› s modulus for the medium grain samples approximately 15% of the fine grain samples and approximately 27% of the coarse grain samples is more. In addition، it was found that a significant change does not occur in Poisson› s ratio of the studied rocks with an increase in grain size.

There are many researches and contributions on stress analysis of tunnel’ s roof and wall. But there is not enough research on invert stress analysis, especially in soft grounds. In this paper it has been tried to introduce an analytical model for prediction and calculation of invert up-lift pressure in soil and very poor quality rock mass. Figure 1 shows the problem under tunnel’ s structures. When the pressure is high tunnel designer must be considered an invert structure for control of instability under tunnel lining. The pressure can be occurred by swelling process in some rocks and soils with high value clay content when there is a variation in moisture. But this research has been focused on invert up-lift pressure just by field stress and geomechanics conditions. Stress concentration and pore pressure have been considered in the equilibrium limit analysis and Mohr-Columb failure criterion has been applied as a linear well-known formulation for soils and very jointed rock masses behavior.

Wellbore instability is a quite common event during drilling, and causes many problems such as stuck pipe and lost circulation. It is primarily due to the inadequate understanding of the rock properties, pore pressure, and earth stress environment prior to well construction. This study aims to use the existing relevant logs, drilling, and other data from offset wells to construct a precise mechanical earth model (MEM) describing the pore pressure, stress magnitudes and orientations, and formation mechanical properties of South Pars Gas field. Since the core test data, MDT/XPT data, and LOT/XLOT data were not available to calibrate the developed model, each component of the model was determined using a range of existing methods and relations, and then the wellbore instability was analyzed based on the developed MEM and the Mogi-Coulomb failure criterion. The predicted incidents such as the lost circulation and tight hole were then compared with the caliper log and reported drilling events to determine the consistency of the model. Since the stability analysis based on the developed MEM had the most agreement with the caliper log and reported drilling events, the equations presented by Eaton and Zoback had good estimations of the pore pressure and rock strengths. Also the estimated horizontal stresses were precise enough to enable the constructed MEM to predict the wellbore instabilities. The stress regime in the field of study was strike-slip, which is frequently specified in the industrial technical reports of the studied field. Finally, it was concluded that the Mogi-Coulomb failure criterion minimized the conservative nature of the mud pressure prediction due to the consideration the strengthening effect of the intermediate stress.

Aggregates are materials which are used extensively in construction industry such as concrete constructions, road base and subbase and rail ways. Hamedan province has extensive sources of limestones, so it is essential to evaluate the limestone characteristics for their applications in different civil projects. In this study, Hamedan limestones are classified based on their applications in projects with different sensetivites by considering aggregate parameters (Aggregate impact value, Aggregate crushing value, Los Angeles aggregate abrasion value) and petrography investigations. This classification is called aggregate index (AI). Then, this index is divided to P wave velocity called aggregate adjusted index (AAI). Finally, this parameter has been estimated by simple and multiple (by using best subsets) regression methods, based on physical and mechanical properties of studied rocks. In simple regression, Schmit hammer rebound is the only parameter which has a determination coefficient less than 50% and it is not suitable for estimation, while in multiple regression the best parameters (e. g. P wave velocity, uniaxial compressive strength, tensile strength and dry density) have been chosen and unfavorable parameters have been ignored which finally leads to a relaible equation with 99% significant level.