Layer | Fill | Outline |
---|
Map layers
Theme | Visible | Selectable | Appearance | Zoom Range (now: 0) |
---|
Fill | Stroke |
---|---|
Collaborating Authors
Results
Abstract Rock Mechanics and Rock Engineering was established as a new scientific and engineering discipline in Lisbon in 1966. Since then, this discipline expanded the initial topics of interest and it has become a major discipline of science and engineering. The recent activities of this discipline involved the nuclear waste disposal problem. However, the decrease of constructions in civil engineering and closure of mines due to environmental concerns worldwide resulted in the decrease of interest to Rock Mechanics and Rock Engineering. Although this discipline is not restricted to purely engineering works and activities, it is experiencing a hard time. This article presents a brief overview of various aspects of this discipline and it discusses the present circumstances and bottlenecks that this discipline is now facing. And then, an outline of Geomechanics and Geoengineering as the new directions of rock mechanics and rock engineering is given and possible extensions to new and existing problems and scientific and engineering applications are pointed out. Introduction Rock Mechanics was born as a new discipline in 1962 in Salzburg, Austria and officially endorsed in the first congress of International Society for Rock Mechanics in Lisbon in 1966 [1]. When one looks at the content of the proceedings of the first Congress, the spectrum of Rock Mechanics and Rock Engineering (RMRE) is very wide compared to that these days. In other words, the more emphasis is given to the applications in civil and mining engineering and the relation of rock mechanics with earth science or geosciences is almost non-existent in the last three decades. The recent decrease of civil engineering constructions and mining activities due to economical reasons and environmental concerns in many countries resulted in the decrease of the interest of academia and engineering community in RMRE. The over-emphasis on the nuclear waste disposal problems, which are only relevant to a limited number of countries worldwide, causes further decreases of the interest of academia and engineering community in RMRE. Rock is the main constituent of the crust of the Earth and its behaviour is the most complex one among all materials in geo-sphere to be dealt by mankind. Furthermore, it contains various discontinuities, which make the thermo-hydromechanical mechanical behaviour of rocks more complex. These simply require higher level of knowledge and intelligence in the community of the RMRE. However, one can find numerous oversimplified procedures handling the various aspects of RMRE and they probably cause the obstruction of the advancement in RMRE. Furthermore, the commercialism of some softwares as an ultimate level of advancement undoubtedly resulted in a further loss of interest of academia and engineering community in RMRE. This article is written with a sole purpose of pointing out some shortcomings, bottlenecks and new directions in RMRE. In other words, the self-criticism in RMRE is now required if this discipline is desired to exist among other major disciplines in decades to come.
- North America > United States (1.00)
- Europe > Portugal > Lisbon > Lisbon (0.44)
- Asia > Middle East > Turkey (0.29)
- Geology > Structural Geology > Tectonics > Plate Tectonics > Earthquake (1.00)
- Geology > Geological Subdiscipline > Geomechanics (1.00)
- Water & Waste Management > Solid Waste Management (1.00)
- Energy > Oil & Gas > Upstream (1.00)
- Energy > Power Industry > Utilities > Nuclear (0.69)
The Application Of Digital Image Processing To Estimate The Joint Volumetric Distribution
Serajian, Vahid (Department of mining & metallurgical engineering, Amirkabir University of Technology (AUT)) | Salari-Rad, Hossein (Assistant Professor, Department of mining & metallurgical engineering, Amirkabir University of Technology)
ABSTRACT The purpose of this study is to estimate the volumetric distribution of discontinuities in jointed rock exposures using "Digital Image Processing (DIP)" methods. In this study, various Pre-Processing, Segmentation and Recognition methods have been applied on images of a jointed slope. Among pre-processing and segmentation algorithms, respectively, "Median Filtering" and "Niblack local binarization" method with K coefficient between -0.7 to -0.9 indicated better results. On the other hand, using "Trace Angle- Trace Quantity" histogram and engineering judgment, the value of Representative Angle (RA), Alternative Angle Limit (AAL) and Joint Set Number (JSN) can be evaluated. Similar traces are separated using mentioned parameters for spacing calculations and the rest will be classified as random joints. Applying the equation proposed by Palmstrom and using the data achieved from DIP, the Volumetric Joint Count (Jv) can be measured. Eventually, the proposed algorithms were applied on images of a jointed rock mass with known geometrical parameters. The results, obtained from DIP methods indicate proper correlation with manually surveyed parameters. Introduction In Rock Engineering, obtaining accurate data from discontinuity traces in rock exposures play a vital role in "Engineering Judgment" and "Rock Mass Characterization". Review of different Rock Mass Characterization methods (RQD, RSR, RMR, Q, etc.) indicates that in all of them, the geometrical conditions of rock mass should be determined. Conventional data acquisition methods in are prone to different kinds of errors. Thus, during data acquisition process, new and improved methods have always been considered as a solution to emit such errors. In addition to the importance of accurate discontinuity trace map construction in rock mass characterization, precise outputs from digital imaging methods can be implemented as an input for numerical analysis softwares such as UDEC, FLAC and so on. Digital Image Processing (DIP) is one of the new techniques that despite being developed in electrical and computer engineering, but has vastly been implemented in other fields. Reid and Harrison (2000) proposed a semiautomatic method for line reconstruction whereby an operator selects a seed pixel at one of the extremities of every perceived discontinuity.[1] Kemeny et al (2003) proposed new methods using DIP and differential evolution algorithm.[2] Hadjigeorgiou et al (2003) discussed about different Line and Edge detection methods suitable for discontinuity trace map construction.[3] Moreover, Lemy and Hadjigeorgiou (2003), reviewed the general procedure to construct discontinuity map using digital imaging methods.[4] In comparison with conventional data acquisition methods in rock exposures, the new method developed by DIP has advantages as follows:In dangerous face conditions, such as faces with unstable blocks or falling rocks, or conditions in which for any reason, lack of time for manual discontinuity mapping is inevitable, acquisition and interpretation of discontinuity network using digital images can be a great step forward. Digital imaging algorithms can assist us in 1500 heavily jointed rock masses where distinguishing between measured and nonmeasured traces by conventional methods may be troublesome, applying DIP can avoid"Censoring" and "Truncating" biases
ABSTRACT Rock mass consists of distinct blocks produced by discontinuities. The geometry and orientation of pre-existing discontinuities show a larger impact on the behavior of slopes that is often used to describe the measurement of the steepness, incline, gradient, or grade of a straight line. There are numerous analytical methods for the rock slope stability including limit equilibrium, stress analysis and stereographic methods. This paper has tried to explore the effects of forces due to water pressure on discontinuity surfaces in plane failure through applying the improved equations by Hoek & Bray, Goodman & Shi, Priest & Vutukuri and Katsuyama. It has studied the effect of water flow velocity on sliding surfaces in safety factor, as well. New equations for consideration water velocity (fluid dynamics) are presented. The suggested equations have higher validity rate comparing to the current equations. 1. Introduction Rock mass classification system was proposed about 60 years ago for tunneling with steel support but later developed for non-steel support underground excavation, slope and foundation engineering. So far as slope stability is concerned, it is an extreme consideration by Priest (1976) [1], Hoek & Bray (1981) [2], Goodman & Shi (1985) [3] and Vutukuri & Katsuyama (1994) [4]. Problem of slope stability is an important issue in soil and rock engineering and therefore, much works have been done to solve this problem by employing different methods such as limit equilibrium using slices, limit analysis, method of characteristics, and more recently, the finite element technique [5]. Slope stability is usually assessed under the framework of limiting equilibrium [6], an analysis that is a simplification of the more rigorous limit theory, and has become the most preferred method for routine slope stability analysis in rock and soil mechanics. In this particular analysis, an assumption of the slip-line field is made, usually, as a geometrically fairly simple failure surface [7]. However, none of the basic equations of continuum mechanics regarding equilibrium, deformation and constitutive behavior are satisfied completely. Safety factors, in these methods, are calculated using one or more of the equations of static equilibrium applied to material bounded by an assumed potential slip surface and surface of slope. Limit equilibrium method is based on efficient force condition on slip surface. Two major categories can be identified as follow: a. Forces that cause failure, and b. Forces that resist failure. In equilibrium conditions, ratio of these forces is an equivalent one. Due to inaccurate estimation and determination, the ratio of resisting forces to slip forces is mostly considered bigger than one. In this research firstly equilibrium equation is studied then the effect of forces due to water pressure on discontinuity in two cases of static and fluid dynamics are discussed. 2. Equilibrium Equation Many of the limit equilibrium methods such as ordinary method of slices, simplified Bishop [8] and Spencer [9] are considered static equilibrium by dividing the soil or rock mass above an 1218 assumed slip surface into a finite number of vertical slices.
- North America > United States (0.48)
- Asia > Middle East > Iran (0.15)
Abstract Basaltic rock masses are a consequence of solidification of crust surface lava flows trough intermittent events that result in superposition of different flows giving rise to relevant discontinuities in the contacts between the flows. These discontinuities strongly condition water seepage mechanisms which are fundamental issues for the dam stability. This paper discusses seepage aspects within basaltic rocks and the use of drainage and grouting for control, as well as some design aspects related to uplift pressures and its influence in dam construction. 1. Introduction Since the 60's many of the innumerous dams in Brazil have been built in basaltic formations which led to the development of important concepts related to seepage forces acting in the foundations and to the use of cement grouting and drainage systems to assure sliding stability safety. The typical basaltic sequence of flows has sub-horizontal contacts and large scale joints and breccias representing preferential flow paths. These sub-horizontal features became of fundamental importance in the stability analysis of concrete dams, whose technology is being used as a reference for new projects. In view of the experience accumulated in the Parana Sedimentary Basin, where most of dams built in basalt are located, the technological development of dam design and construction led the authors to concentrate on water seepage evaluation techniques as tools for assessing dam sliding stability. 2. Geological Background The Parana Basin (Figure 1) has an area larger than 1 million km formed by a series of continental deposits with some few intercalations of marine deposits. In the upper part there is a Triassic sandstone layer covered by basaltic lava flows (Cretaceous). The thickness of each basalt layer varies from few to tens of meters and the total basalt package may be thicker than 1km (Figure 2). Each layer may include a sequence of basaltic breccia, vesicular basalt and dense basalt in the middle of the flow pack representing 2/3 of the flow thickness. For designing the main important design features are: - discontinuities along flow contacts having influence on the sliding stability of the dam structures: with both shear strength and stiffness of low magnitude and high permeability; This feature often exceeds the project scale. - discontinuities within the lava flow: very large and having sub-horizontal dip. - high residual stresses-mainly sub-horizontal stresses remaining from tectonic events or erosional processes: difficult excavation procedures and the construction of underground structures. 3. Design Considerations The design deals with the sliding stability of concrete structures founded on basaltic rocks. Although stress and strain field analyses have been performed for many of the projects, the final decision has been supported by the fulfillment of the limit equilibrium relation Eq. In this equation, Fv is the orthogonal force on the surface under analysis, U is the corresponding uplift pressure, C is the cohesion available in the area S, ö is the friction angle, ãö 621 and ãc are the corresponding partial safety reduction factors established in the design criteria and Fh is the driving force parallel to the surface.
Abstract The discontinues deformation analysis (DDA) is a powerful tool to predict and describe the slope failure of fractured rock. An important feature in DDA is the contact detection between different blocks. In this paper first of all a brief introduction on the basic principles of contact detection is presented. Then a new method is proposed that consider the influence of the total forces direction acting on rock. Finally the slope failure is simulated using this method. The results imply the advantages of applying this new method to present the mechanism of rock slop failure. 1. Introduction Many materials and structures have a blocky nature, being formed by components that may undergo different movements. The blocks, interact through the joints or interfaces between them. For example, rock masses are divided into discrete units by joint and faults. Soils are composed of small particles. Stones and bricks form the fabric of masonry structures. A contact of blocks may consist of a material, such as mortar in masonry, or it may be plain interactions of solid objects, such as joints in rock. The explicit modeling of these contacts, represented as structural discontinuities, is outside the capability of continuum idealization, is outside the capability of continuum idealizations, which generally underlie standard finite element models [1]. Discrete element models are very appropriate tools to represent blocky structures. In rock slope engineering, it is well known that the behavior of a slope failure is strongly affected by its discontinuities (Goodman 1976 [2]). Ohnishi et al. (1995) [3] demonstrated the applicability of the original 2D discontinuous deformation analysis (Shi and Goodman 1988 [4]; Shi 1989 [5]; Jing 1998 [6]) to a slope failure simulation. However, the DEM has to use contact damping to diminish the unexpected forces and vibrations when blocks are in contact with one another, but this contact damping lacks physical meaning in the computations (Chen et al. 2002 [7]). In addition, the input value of the contact damping affects the correct contact forces and the contact period during computation. However, DDA does not need damping to keep the computation convergent in this situation and as a result can simulate the contact with more physical meaning than the DEM. DDA has the following major characteristics (Sasaki et al. 1994 [8]): 1.The principle of minimum total potential energy is used to calculate an approximate solution similar to FEM. 2. Dynamic and static problems can be solved by applying the same formulations. 3. Any constitutive law can be incorporated. 4. Any contact criterion (i.e., Mohr-Coulomb criterion), boundary conditions (i.e., constraint displacement), and loading conditions (i.e., initial stress, inertia force, volume force, etc.) can be modeled. In view of these characteristics, this study 584 aims at extending contact detection algorithm and developing necessary implementation. The developed code is then applied to the slop as a validation of the present approach.
- Asia > Japan (0.48)
- Asia > Middle East > Iran (0.15)
Abstract The usual way to carry out rock slope stability analyses is:to make a rock mass discontinuity pole counting to identify the predominant directions of rock discontinuities; with strength data for the discontinuities, to carry on plane, wedge and toppling failure analyses for the slopes involved. Although pole counting analyses are very useful and they always should be done, they do not insure that the actual failure plane or planes are identified, i.e. the plane in a predominant direction is not necessarily the weakest plane. To try to overcome this difficulty, the Author has developed a simple DOS based FORTRAN program: ALLWEDGE (50kB), which identifies all kinematically possible wedges for a rock slope and analyzes them with Mohr- Coulomb strength parameters (c´ and φ´) for the discontinuities and the Hoek and Bray (1977) complete method of wedge analysis without a tension crack. The program allows to process up to 400 discontinuities (theoretically 79,800 wedges for each slope) and 30 slopes, common rock unit weight, slope water conditions and earthquake horizontal and vertical accelerations. It also allows to include for each slope: external forces, maximum width (which limits wedge height) and to list only the wedges with a factor of safety less than a predetermined value. It also can calculate the stabilizing tension and its direction to reach a predetermined factor of safety. Output files could be very large. An example is presented for both the traditional method and the all-wedge method and conclusions are derived. 1. Usual procedure for rock slopestability analyses and difficulties The usual procedure to carry out rock slope stability analyses is:to make a rock mass discontinuity pole counting to identify the predominant directions of rock discontinuities. with strength data for the discontinuities, to carry on plane, wedge and toppling failure analyses for the slopes involved. Although pole counting analyses are very useful and they always should be done, they do not insure that the actual failure plane or planes are identified, i.e. the plane in a predominant direction is not necesarily the weakest plane. The Author has analyzed actual wedge and plane rock slope failures in which the actual failure planes were not the ones with the predominant direction, due to the fact that either the discontinuity field survey was not as complete as required or that the critical discontinuities were not easily detected in these field surveys. 2. Proposed procedure for rock slopewedge and plane failure stability analyses In view of these difficulties, the Author proposes the following procedure for rock slope wedge and plane failure stability analyses:to identify from the discontinuity survey the discontinuities that should not intersect (which can be called "genetic"): i.e. bedding planes in sedimentary rocks. with all the discontinuities, carry on wedge kinematic analyses to identify all possible wedges for a slope. with all identified kinematically possible wedges, carry on stability analyses and obtain factors of safety.
- Geology > Structural Geology > Tectonics > Plate Tectonics > Earthquake (0.55)
- Geology > Rock Type > Sedimentary Rock (0.49)
- Geology > Geological Subdiscipline > Stratigraphy (0.35)
A New Empirical Criterion For Prediction Of The Shear Strength Of Natural Infilled Rock Joints Under Constant Normal Load (CNL) Conditions
Zare, M. (Faculty of Mining, Petroleum & Geophysics, Shahrood University of Technology ) | Kakaie, R. (Faculty of Mining, Petroleum & Geophysics, Shahrood University of Technology ) | Torabi, S.R. (Faculty of Mining, Petroleum & Geophysics, Shahrood University of Technology ) | Arif, I. (Faculty of Mining, Petroleum & Geophysics, Shahrood University of Technology ) | Jalali, S.M.E. (Faculty of Mining, Petroleum & Geophysics, Shahrood University of Technology )
Abstract The Shear strength properties of rock discontinuities depend upon whether they are clean and closed, or open and filled with various infill materials. The most obvious effect of a filling material is to separate the discontinuity walls and reduce the rock-torock contact, which influences the joint shear strength. The aim of this paper is to investigate the influence of infill materials on the shear strength of natural rock joints. For this purpose, laboratory tests have been carried out in constant normal load (CNL) conditions and the output of the analyses has been conducted to propose an empirical criterion for prediction of the shear strength of the natural infilled rock joints. Finally, this empirical criterion has been validated based on the experimental method. The results show that this criterion can perform the predictions with an acceptable confidence level. 1. Introduction Rock mass is characterized by joints, fractures and other planes of weakness that reduce the shear strength [1,2]. When an excavation is carried out, primary rock movements take place along the existing joints due to stress relief and associated stress re-distribution. Therefore, it is important to quantify the shear strength of discontinuities in the design and construction of surface and underground rock structures as well as in mining operations. Over many years, fine sediments resulting from weathering and other surface processes could subsequently ingress to rock joints, reducing the overall shear strength of the joint surface. The jointed rock mass often fails due to these infilled joints because they are often the weakest planes initiating sliding [3]. Despite their frequent natural occurrence, filled discontinuities have been studied much less systematically, perhaps because of the difficulties arising from the increased number of variable parameters. The most important effect of filling material is to separate the discontinuity walls and thereby reduce rock-rock contact, but shear strength will also be influenced by the nature of the filling material itself the characteristics of the wall-fill interfaces. Because of the lack of reliable and realistic theoretical or empirical relations and the difficulties in obtaining and testing representative samples, engineers generally rely on judgment, often considering the shear strength of the infill itself to be conservative. In critical cases, in situ tests may be carried out to provide site specific design criteria, but invariably amount of testing that can be undertaken precludes the establishment of fundamental relations. Besides, all of the experimental studies performed in the literature, have used modeled joints or replicas for numerous testing programs. In this paper, a comprehensive statistical analysis has been applied on a series of data obtained from comprehensive test program on natural infilled rock joints. The output of this analysis has been conducted to propose an empirical criterion for prediction of the shear strength of the natural infilled rock joints.
- Research Report > New Finding (0.54)
- Research Report > Experimental Study (0.54)
ABSTRACT 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. 1. Introduction 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.
- Geology > Geological Subdiscipline > Geomechanics (1.00)
- Geology > Mineral > Sulfate > Gypsum (0.99)
- Geology > Rock Type > Sedimentary Rock > Carbonate Rock > Limestone (0.68)
Abstract The behavior of joints and intact rock is characterized by some parameters which have interactive effects on rock mass problems. Moreover, some of these parameters are not easily measured and they may be variable in the region of the problem. Joint normal and shear stiffness are the mechanical parameters which can be assessed in distinct element modeling. Knowing that the strength conditions of discontinuities are determined by the stress distribution through the model and along discontinuities, this paper is concerned on the effect of selected stiffness values on Distinct Element Method (DEM) computed stresses in the rock masses. 1. Introduction Development of distinct element method (DEM) has been a significant step to identify the behavior of fractured rock masses. The behavior of joints and intact rock is defined by some parameters which have interactive effects on problems. Some of these parameters are not easily measured and furthermore may be variable in the region of the problem. Thus it is momentous to recognize the influence of variation of these parameters and their interactive effects on reliability of modeling results. Joint normal and shear stiffness are the mechanical parameters which can be evaluated by distinct element modeling. It sounds to be essential to know the effects of selected stiffness values on the obtained results. 2. Estimation of Joint Stiffness Joint stiffness is not an easily measured or well known parameter. Methods of estimating joint stiffness have been derived. Two possible methods are presented here. One is based on the deformation properties of the rock mass and the intact rock; the other is adopted from the properties of the joint infilling material. 2.1. Stiffness estimated from rock mass properties Approximate stiffness values can be backcalculated from information on the deformability and joint structure in the jointed rock mass and the deformability of the intact rock. If the jointed rock mass is assumed to have the same deformational response as an equivalent elastic continuum, then relations can be derived between jointed rock properties and equivalent continuum properties. For uniaxial loaded rock containing a single set of uniformly spaced joints oriented normal to the direction of loading, the following relation applies. 2.2. Stiffness estimated from joint infill properties Another approach for estimating joint stiffness assumes that a joint has an infill material with known elastic properties. The stiffness of a joint can be evaluated from the thickness and modulus of the infilling material by the following equations. 3. Empirical Relation of Joint StiffnessValues Values for normal and shear stiffness of rock joints typically can range from roughly 10 to 100 MPa/m (for joints with soft clay infilling), to over 100 GPa/m (for tight joints in granite and basalt). Published data on stiffness properties for rock joints are limited; summaries of data can be found in Kulhawy [5], Rosso [6] and Bandis et al. [7].
Evaluation Of Stress Mode In The Hydropower Station Of Bakhtyari Dam, Iran
Hosseinizadeh, S. (Shahid Bahonar University of Kerman, Mining Engineering Department) | Jalalifar, H. (Shahid Bahonar University of Kerman, Mining Engineering Department) | Nasab, S. Karimi (Assistant Professor, Shahid Bahonar University of Kerman, Mining Engineering Department)) | Radman, A.M. (Kavoshgaran Consulting Engneering Co.)
ABSTRACT Dominant geological structures and joint sets are the main and important factors which change the direction and magnitude of in situ stresses. Their importance and role have been examined in this research and finally the direction of stresses has been predicted in the area of Bakhtyari Dam. Studying the manner of geology evolution in the area, the following three main structures within the boundary of underground powerhouse of Bakhtyari Dam were identified: reverse fault F1–3, Siyah kooh anticline and the right hand strike-slip fault F2. Reverse fault F1–3 has become inactive as a result of folding and erosion. Therefore, the present stress field induced by this fault doesn't follow the direction of stresses that have created it. Borehole slotter test proved this issue to be correct. The strike-slip fault F2 has no impact on the direction of in situ stress due to its being far away from powerhouse caverns. Therefore, this fault has not been able to cause any joint or fracture neither to open discontinuities in powerhouse caverns area. Consequently, regarding the extension of joints resulted from folds throughout the area of underground powerhouse. 1. Introduction Below the ground, elements of rock materials have been affected by existing stresses. These stresses either follow the gravity rules and the side pressures or generally are influenced by structural tectonic stresses. Therefore, underground structures can be designed and constructed if the stress conditions and origins are known. Many researchers have studied this subject and determined stress direction and stress magnitude with regard to the structures all around the world (e.g. Hoek [1], Hoek and Brown [2], Hoek and Moy [3], McCutchen [4] etc.). In these researches, theories of stress direction related to structures are predicted. Bakhtyari dam with the height of 315 meters is the highest concrete two-arch dam in the world rank. This dam will be constructed on the Bakhtyari river which is a main branch of Dez river. The dam is located 570 km southwest of Tehran in Lorestan province of Iran. This area is situated in Zagros folded belt and consists of Sarvak formation whose rocks prominently belong to the Cretaceous period. Parallel to this project, a hydropower station with the capacity of 1600 MW electricity will be constructed. It is an underground structure and is about 500 m downstream of the dam axis, near the left bank of the river. This powerhouse includes two caverns, one for generators and one for transformers [5]. 2. Geological Settings The studied site is located in northwest of Zagros folded belt which is composed of numerous high anticlines with steep slopes and deep valleys oriented parallel to Za extending from Bandar Abbas in the south to Naft Shahr in the west [5]. The regional geology involves Garu, Sarvak, Gurpi, Amiran, Tale-Zang and Kashkan formations. Most of the project and the whole parts of dam and hydropower station are located in Sarvak formation [5].
- Asia > Middle East > Iran > Tehran > Tehran (0.25)
- Asia > Middle East > Iran > Hormozgan > Bandar Abbas (0.24)
- Geology > Geological Subdiscipline > Geomechanics (1.00)
- Geology > Structural Geology > Tectonics > Compressional Tectonics > Fold and Thrust Belt (0.62)
- Geology > Structural Geology > Fault > Dip-Slip Fault > Reverse Fault (0.56)
- Geology > Structural Geology > Fault > Strike-Slip Fault (0.46)
- Energy > Oil & Gas > Upstream (1.00)
- Energy > Renewable > Hydroelectric (0.81)
- Energy > Power Industry > Utilities (0.81)
- Asia > Azerbaijan > Aran Region > Middle Caspian Basin > Yevlakh-Aghjabady Depression > Muradkhanli-Jafarli-Zardab Block > Jafarli Field > J-2 Well (0.93)
- Africa > Middle East > Libya > Murzuq District > Murzuq Basin > Block NC 186 > Well J-1 (0.93)
- Reservoir Description and Dynamics > Reservoir Characterization > Reservoir geomechanics (1.00)
- Reservoir Description and Dynamics > Reservoir Characterization > Faults and fracture characterization (1.00)
- Reservoir Description and Dynamics > Reservoir Characterization > Exploration, development, structural geology (1.00)