This study has been executed aiming at identifying, classifying and investigating the environmental effects of Lorestan’s Roodbaar Dam during its exploitation phase through utilizing MIKE11 software and LINMAP technique. Lorestan’s Roodbaar Dam is located in Lorestan Province, 100 kilometers to the South of Alugoodarz Town on Roodbaar River (from branches of Eastern Dez River), within the area of Zagros Mountains in the West of Iran. It is crucial not to consider merely one parameter when using the evaluation methods, on the contrary, the mutual effects of all parameters and their consequent effects must be taken into account. The immediately- affected area was located through collecting data from the environmental conditions of the area and from the technical information on Roodbaar Dam using MIKE 11 software. The positive and negative effects of the dam were eventually prioritized using LINMAP mathematical model. Prioritizing the positive effects of the project indicated that (income) ranked 0.0507, following that (services, industry, commercial) ranked 0.0480 and was placed in the second place. Two villages will go under water with the construction of this dam. This will lead to the mentioned villagers moving and their resettlement. Therefore (moving) ranked 0.3452 and it earned first place among the negative effects of the dam and (erosion) (sedimentation within the dam’s container), (the endangered plant species within the area) all ranked 0.2959 and were placed second within the prioritization. At the end proper approaches were presented for the exploitation stage of Lorestan’s Roodbar Dam taking into consideration the results obtained from prioritizing the effects.

The current study aims at assessing the risks of Roodbar Dam using Multi Attribute Decision Making and RAM-D Model. First, a list of environmental risks was provided and placed at disposal of experts who are aware in the fields of dam and environment. Consequently, 33 risk factors were identified. The results of the questionnaire were analyzed and prioritized using TOPSIS Method. Based on the noted method, three risks including impact on landscape and tourism, waste disposal and impact on habitats which obtained the scores equal to 0.739, 0.667 and 0.66 respectively were considered the most important risks. Afterwards, by means of AHP Method and Expert choice Software, the risks were assessed and analyzed in the form of 6 risk groups based on the intensity and probability of occurrence. At the next step, considering the varied results between the methods; TOPSIS and AHP, the results were unified using the integrated methods. Finally, 10 risks were determined for Roodbar Dam in construction phase. Then, by means of RAM-D the risks were assessed. Based on the results of the method, land use change, impact on habitats and influence on aquatics with the scores of 9, 6.75 and 4.5 were determined the most signification risks of Roodbar Dam in construction phase. The risks are consequences of the destruction of the forest cover of oak species, the change of the main land use in the area and the activities of the construction phase of dam on Roodbar River. At the end, to mitigate the obtained risks, managerial andcorrective measures were recommended.

Dams are mainly constructed of earth and rock-fill materials and hence they are generally referred to as embankment dams orfill-type dams. The role of drainage system is also vital as it shifts the phreatic surface ensuring the safety of downstreamtoe. This paper presents the results of seepage analyses of the considered earth dam using finite element method. Slide software is one of geotechnical program that is based on the finite element and canconsider analysis like stress-strain, seepage, slope stability, dynamic analysis and also fast water drop inreservoir. In this research seepage analysis in Roudbar Lorestan dam has been done by Slide software. In orderto evaluate the type and size of mesh size on the total flow rate and total head through the dam cross section,four mesh size such as coarse, medium, fine and unstructured mesh is considered. Result showed that averageflow rate of leakage under the different mesh size for Roudbar Lorestan dam equal 629584 m3 per year for the entire lengthof the dam.

Stress analysis and stability control in tunnel intersections is a very complicated issue due to stress concentration and three-dimensional situation. During tunnel construction, increase in load on support, extra tunnel deformations and disordering in rock around of intersection zone is unique and instability may be occur in this sections. In order to control extra deformation and stress, these sections need stronger support system than other sections. Extra deformations and stress values in Y shaped intersections influenced by tunnel intersection angle. The effect of intersection angle on length of extra support has been studied in this paper by three-dimensional modeling of penstock tunnel intersection of Rudbar Dam in FLAC3D. Numerical analysis results for three intersection angles of 60, 75 and 90 show an increase in length of extra support by decreasing in intersection angle.

Probabilistic slope stability analysis provides a tool for considering uncertainty of the soil parameters in design. In this paper, using Slide software, the Monte Carlo simulation is used as an analytical method to develop probabilistic models of slope stability based on equilibrium methods. The limit equilibrium methods are the most popular approaches in slope stability analysis. These methods are well known to be a statically indeterminate problem, and assumptions on the inter-slice shear forces are required to render the problem statically determinate. In modeling using this methodology, the selected stochastic parameters are internal friction angle, cohesion and unit weight of soil, which are modeled using a truncated normal probability density function (pdf). In this research, the abilities offered using models were presented by using field data obtained from Roudbar Lorestan dam in Iran. The results obtained show that the hybrid Monte Carlo simulation and equilibrium methods can be used successfully for slopes stability assessment.

Rudbar Lorestan dam is constructed on Abrudbar River, 100 km south of Aligudarz city. There is a segment of Main Recent Fault(MRF) called Saravand – Baznavid Fault(SBF) at 1.6 km south of dam site. Using Automatic Extraction Method, based on STA Algorithm, lineaments were extracted from sattelite images and Shaded Relif Model. For detailed structural analysis, the study area was divided into three zones based on geological map. In Eslamabad Fault zone, Eslamabad fault is the main structural element, that is likely of P-type fractures. The main structure in the SBF zone is Saravand – Baznavid active Fault, which caused the drainage to be displaced as much as 500–1000m in the northern height of study area. In the Dam axis zone, the main structure is F1 fault. This fault is about 150 meters in length with right lateral strike slip component. Thermoluminescence dating, sence of movement, dominant slikenside, and the orientation of groove marks on the fault plane indicate this fault to be active. Large dicplacements along with strike- slip faults in the study area, such as F1 fault, have been considered using shear zone and enechelon models. However, the main faults in the study area is SBF, that is relate in an enechelon pattern to seismic Dourud fault and has the right potential to movement in the future

Rudbar Lorestan Dam and Power Plant locates on the High Zagros structural zone, according to the geological map of Iran. The Dalan Formation, Permian age, forms the geological structure of dam body foundation and a portion of its reservoir. Meanwhile, outcrops of an Upper Cretaceous formation, called Sarvak Formation, is exposed out beside the Dalan Formation, due to effect of thrust faults. The main sources of Rudbar Lorestan river are precipitation and drainage of groundwater. The karstification process in carbonate sediments at the site was expected to be expanded well, due to geological and climate conditions. However, based on the evidences of karstic features, which could make a drainage network, have not seen. Both confined and unconfined aquifers present in the site. In this regard, presence of artesian boreholes is a good evidence for confined aquifer. The dominant types of ground water are calcic bicarbonate and sulfate, based on chemical analysis of 22 samples, collected from six sources of water at the site, In this manner, the types of water of the Rudbar river, Kish spring and outlet of access tunnel T2 are calcic bicarbonate, because of recharge from unconfined aquifers and short residence time. However, the type of water of artesian boreholes, i.e. TG-4 and RB-8, and inlet of the access tunnel T2, are calcic sulfate, based on contact of water with sulfate minerals and long residence time in confined aquifers.

Accurate determination of geotechnical and geological parameters of rock mass was performed using geotechnical exploration results including, the laboratory and in situ tests, empirical relations, geological surveys and field observations. The rock masses along penstock tunnels of Rudbar-Lorestan have a complex geology and consist of Dalan, Hormoz and Mila formations, mostly composed of shale, marl, marly limestone to limestone and dolomite. In this study, based on the measured data, the rock masses along penstock tunnels were classified by engineering classification systems of RMR, Q and GIS. And, a new relationship between RMR and Q for the studied area was presented. There were various empirical relations between RMR, Q and GIS, that were used for estimating geotechnical parameters. It must be noted that each of the empirical relations found may produce proper results for special regions. In this paper, the deformation modulus, cohesion and friction angle of Dalan formation were evaluated using the results of in situ dilatometer tests, laboratory tests, and findings of more than 25 geotechnical exploration boreholes in Dalan formation. Afterwards, by calibrating the empirical equations through the measured data, the geotechnical parameters of Mila and Hormuz formations were accurately estimated.

Summary In this research, stability of penstock tunnels bifurcation with headrace tunnel of Rudbare-Lorestan dam powerhouse was studied. Due to the weak rock masses at the bifurcation area, the numerical modeling using FLAC3D was performed. According to the results of numerical modeling and determination of plastic zone and the empirical methods, the temporary support system consists of shotcrete and rock bolt with adequate length are suggested. Based on laboratory and in situ tests, the geomechanical parameters are determined.
Introduction Today, large underground structures are constructed in order to transfer the water, oil and gas storage, underground power plants, radioactive waste repositories and etc. With the development and upgrade of infrastructures, tunnel construction is increasing all over the world and tunnel engineers are more aware of the importance of the safety and economics of tunnel construction. Stability of underground structures depend on size and geometry of construction, excavation technique, in situ stress conditions and support system and its installation time.
Methodology and Approaches In order to estimate the deformation modulus of the rack mass in the headrace tunnel, in situ tests including of plate loading and dilatometer tests were performed. Then elasto-plastic behavior was defined for the rock mass by mohr-columb criterion and model was executed numerically to reach static stability. The Bifurcation cavern have been excavated by heading and benching method that is executed through drill and blasting technique.
Results and Conclusions The empirical method suggest shotcrete with rock bolts to support weak rock masses. Also the numerical analysis demonstrate the installation of rock bolts with shotcrete as a temporary support system. Due to the large plastic zone caused by excavation processes, the value of the advancing step 0.8 m was determined. Also, the analysis of rock mass plastic zone in bifurcation area determined a suitable length of 6 meters for rock bolts. During the excavating of rock pillars, the value of change in the axial force acting on the rock bolt in the right wall of the tunnel No. 1, was increased. Also, the excavation of tunnel No. 2 at a distance of 11 meters from the tunnels No. 1, No. 4 and No. 5, was shown the less influence on the value of axial forces applied to the rock bolts. After the 16 stages of excavation advancement steps and installation of support systems, the maximum values of displacement in the roof, floor and walls of the bifurcation, were respectively 2.8, 3.67 and 1.5 cm

The importance and necessity of using underground spaces in the present era is not overlooked. Caverns are used as an important bunch of underground spaces for the storage of radioactive waste, hydrocarbons, and hydroelectric power plant projects. Construction of caverns has particular complexity and water seepage into the caverns is one of the most important problems. The purpose of the present study was to investigate the 3D modeling of the fracture network of a cavern for the pumped storage power plant of Rudbar Lorestan dam by using DFN method and 3DEC software and then determining the tensor of hydraulic conductivity by using the model. To achieve the goal, statistical analyses were performed on the in situ data extracted from the area. Power law distribution was determined as a suitable statistical distribution proportional to the data. Then, the DFN model was created and validated using the Watson-Williams test. In the following, a block model of DFN made from the fractures was constructed to determine the Representative Elementary Volume for different dimensions from 1 to 12 m. It was found that a 7-meter model was appropriate. Furthermore, the tensor of hydraulic conductivity was determined by using a hydraulic head on a generated REV.