The present thesis is to focus on the two head race tunnels within the Melado HPP, Chile. The upstream tunnel is called Castillo 7800 m long and the downstream tunnel is called Vallical 8800 m long.The feasibility study of this project was carried in 2010. The resulting report from this study was used as a basis for this thesis. Along with all the background information obtained from the feasibility studies, there are some other sources gotten from field investigation tests carried out after the end of the feasibility report.Based on all the information collected, a new rock mass classification was carried out, identifying all the geological stretches for both tunnels. This classification was undertaken according to the RMR system (Bieniawski, 1973) and the Q-system (NGI, 1974). The support required for both tunnels was estimated mainly based on empirical rock support methods. Numerical model by means of software Phase 2 as well as ground behavior analysis were carried out to provide a better understanding of actual problems expected during excavation that are not always cover by the empirical methods.Once there was a clear understating of the rock masses involved in both tunnels along with their corresponding rock support, some analysis related to the tunnels were performed to improve the economical benefit of the whole project.The first economic analysis undertaken was the optimum cross section for Drill & Blast excavation method. A detail analysis that systematizes the cost and advance rate involved in the round cycle of the Drill & Blast excavation method and rock support was used. A thorough analysis of energy losses was also carried out as well, making a distinction between unlined, shotcrete lined and reinforced shotcrete ribs tunnel stretches. The existing cross section of 6.9 m horse shoe shape tunnel turned out to be very small. The new optimum cross section for Castillo tunnel was 8.7 m diameter and 9 m diameter for Vallical tunnel. The second economic analysis was a tunnel alignment change in order to improve some blast design parameters in stretches where their tunnel axis orientation was close to predominant joint set. In any of the two tunnel stretches analyzed turned out to be economically convenient to extend the tunnel for this purpose, even though the safety factor for the crew was not included.Also, the convenience of extra adits was carried out. In fact, the layout of the feasibility report included one extra adit for each tunnel in order to have an earlier tunnel completion. The findings suggest that these adits are not economically convenient as long as the project’s electromechanical equipments take 34 months from their manufacturing to their assembly on project cavern.

Super Madi Hydrolectric Project (SMHEP) is located in Kaski District of Nepal. It is a run of river scheme with a installed capacity of 44 MW, net head of 295m and design discharge of 18 m^3⁄s.It has planned to build for the fulfillment to minimize the load-shedding problem of Nepal in the current scenario. This project lies in the lower part of the Higher Himalaya, mainly dominated by high-grade metamorphic rocks like gneiss and schists.Major task involve in this thesis work is to check for proper alignment of existing layout, assessment of stability condition with proper support system. Selection of best alternative alignment of cavern with its best shape and size are also another major work in this thesis. Optimum support estimation for the best alternative has also been done. Conclusion and final recommendations are based on stability condition and degree of rock support requirements.Geological and topographical site condition of headworks restrict for exposed settling basin therefore underground settling basin cavern in the left hill side has been selected. Rock mass in the settling basin area is slightly deformed, foliated micaous and banded gneiss with thin layer of schist. Analysis is based on assumption of ``No significant faults and shear zones across the alignment of settling basin cavern``.Both alternatives with axis orientation of N145E have been selected for the analysis. Shape of the caverns in both alternatives are inverted D. Existing alternative consists of two parallel settling basin caverns with a clear spacing of 9.5 m. Average width and height for both the caverns of existing alternative (Alternative I) are 8.4 m and 15 m whereas for proposed alternative (Alternative II) are 18.3 m and 20 m are respectively.Stress-strength factor plays a vital role for overall stability condition of the cavern. Stress induced problems such as rock bursting and spalling in hard rock whereas squeezing in weak rock is assumed. Some Empirical, Analytical, and Numerical approaches have been used for stability assessment and for designing of proper rock support system.RMR and Q-system of rock mass classification are used to classify the rock masses. Grimstad and Barton (1993) method is used in the analysis of rock bursting problem and squeezing problem. As a Semi-analytical approach ``Hoek and Marionos approach`` has been used for squeezing analysis.Numerical approaches have many benefits over empirical and analytical approaches, specifically in complex geometry like settling basin cavern. Rocscience software for numerical analysis such as Phase^2 and Un-wedge has been used. Generalized Hoek and Brown failure criterion are used to determine the state of stresses, strength factors, and deformations around the periphery of the caverns in Phase^2 . To analyze the wedge failure due to low shear strength of joints, empirical approach suggested by Barton and Bandis is used in the numerical analysis through rocscience software-Unwedge.Comparative study of empirical, analytical, and numerical approaches of analysis have been carried out for assessment of stability conditions. Finally, some recommendations to improve the analysis results have been performed.

The accurate simulation of an ungauged basin is one of the great challenges in hydrology. In case of Nepal, most of the gauge stations are located at low level land and getting reliable hydrological data at intake sites, most of which are located at high mountains, are almost impossible. The regional model calibration attempts to make a relationship between parameters of model and characteristics of the modelling units so that the calibrated parameters can be applied to ungauged basin. The main objective of the study is to apply ENKI model system to the Saptakoshi basin and to test the reliability of the model in this area and extract the runoff at ungauged sites. The processed climatic data from 1999 to 2008 are applied to the ENKI model system, which is equipped with tools for regional model setup, for different calibration cases.In case I, all the 16 catchments are included for calibration and average Nash-Sutcliffe Efficiency R2 of -1.57 is obtained which is comparatively very low. The R2 value of Uwa Gaon basin is -27.76; the reason may be due to missing precipitation data of Tibet. Hence, this catchment is excluded for further analysis.Excluding Uwa Gaon catchment in calibration case II, the improved average R2 of 0.33 is achieved. The hydrographs of simulated runoff seem in realistic shapes and patterns. Then validation is carried out for the period from 2004 to 2008. The average R2 of the validation is equal to 0.14 which is less than calibration result. The individual R2 value of the catchments is nearly equal with calibration results except of Pachuwar Ghat basin.In case III, only 8 independent catchments are selected for calibration and rest catchments are applied for validation. The average R2 of 0.59 is achieved which is the best result among the 3 cases. The R2 is found at the range of 0.54 to 0.78 for most of the catchments. Similarly, the average R2 of validation is achieved 0.15 which is greater than calibration case II. While processing data, some errors and inconsistency in flow data were found. The results show that the R2 of independent and upstream catchments are well fitted with observed data and less with downstream basins where observed data were inconsistent. The good quality of observed data and availability of enough data governs the best simulation of the model and best value of the R2.The 30 parameter values are obtained and among these some are less sensitive to the output results which are kept constant. Finally, the obtained regional parameter sets are applied to extract the runoff data at the intake site of Tamor Hydropower project and compared with scaled data. Further improvement of simulation results can be achieved with good quality of data and thus uncertainties in parameters can be reduced.

The objective with this thesis was to describe the challenges related to PSH, both for this particular study and in more general terms.The method used was to make assumptions that would apply to traditional hydropower and do calculations based on these. The assumptions and the results of the assumptions were both commented and discussed. Challenges encountered that are unique to the project area and challenges with PSH in general were also discussed. The project area lies in the Upper Otra area, north in Aust-Agder County, and includes the two reservoirs Urevatn and Botsvatn.Three alternatives with the same layout scheme were chosen with a capacity of 500, 1000 and 1500 MW, referred to as alternative 1, 2 and 3, respectively. The choice of turbines was Francis reversible pump-turbines, which are installed with 10% extra capacity for frequency balancing. The excavation method is drill-and-blast, based on the flexibility and cost. The total cost were found to be 6900, 12900 and 18500 MNOK for alternative 1-3, where the cable cost was 4300, 8600 and 12900 MNOK.The price of pumping was chosen to be 0,1 kr/kWh, and the necessary price for production that gave zero NPV, was found to be 0,4 kr/kWh.Some environmental conditions would be affected in the area, but most likely this would not include the wild reindeers in the area.The total operation time was decreasing with a larger installation, and the number of days in a row with either pumping or production was stable regardless of the installation. With a larger installation there would be bigger fluctuations in the reservoirs, and more occurring larger fluctuations. It would be meaningless to have two different LRWL for summer and winter. The result would only be loss of production, but still large fluctuations. The biggest change in the water level during summer from one day to the next was 11 meter for Urevatn and 9 meter for Botsvatn.If the existing power plant were taken out of production the fluctuations in Urevatn and Botsvatn would have the same maximum and average, approximately 1,5 and 3 meter/day. The efficiency for Holen III would decrease, if maintaining the current production level.The existing limitations in the operation regime should be ignored if developing PSH in Norway. The PSH-plant should be operated without limitations and have priority over any existing power plant in the same reservoir, to make full use of the PSH-plant and to make sure the investment would be profitable.

AbstractIn June 2012, Germany has been able to supply half of its own electric demand from solar energy. This is one of the promising examples for which renewable energy is taking a larger part in the total demand. But with the increase of solar or wind power on the market, there is more pressure on the stability of the grid and there is a need to balance the surplus of these new sources of energy. One of the most promising technologies for such power balancing is pumped storage hydropower (PSH). There is now a rapidly growing development of pumped storage hydropower in Europe, and a growing interest also in Norway due to the large hydro capacities. The term “Green Battery” has been introduced, where Norwegian hydropower reservoirs can be “charged” by surplus wind power and emptied in order to fill in load during calm periods. The background of this thesis starts by a screening process to identify the possible sites in Nord and Sør-Trøndelag. It is followed by a ranking of the sites based on economic and environmental criteria. 31 Sites have been identified gathering a capacity of 15,000 MW for an average construction cost of 3.1 million NOK per MW installed. The main environmental criterion is the water level variation in the reservoirs, limited to 13 cm/h in this study. This first part of this thesis is followed by a pre-feasibility study for the refurbishment of two existing power plants: Bogna and Slind. They are suitable for the installation of pumped storage hydropower technology. They can supply during 4.5 days, 1,100MW and 430 MW (respectively). These capacities are the result of a cost optimization which was realized to select the optimum size of the two pumped storage hydro power plants.

This study is about 3D Numerical Investigation of Settling basin layout by using numerical modeling program SSIIM. This study is carried out by using SSIIM windows version 1 (SSIIM 1.0). SSIIM is numerical modeling software, developed at NTNU by Professor Nils Reidar B. Olsen. This program has been used for investigation numerical modeling of hydraulic and sediment transport for different layouts geometry of settling basin.In this study a case study has carried out on settling basin layout of Mai Khola Hydropower Project, Nepal. Hydraulics performance of proposed layout and one alternative layout with shorter approach is numerically investigated by water and sediment flow computation. For the Numerical investigation structured grid for settling basin layout has developed with the help of drawing provided and excel spread sheet program. Hydraulics performance is investigated for design discharge with constant flow. The hydraulic performance of closing of one chamber and operation of remaining chamber with design discharge of power plant is also investigated. Based on water flow computation result, sediment computation was carried out for one settling chamber, proposed, alternative and modifications of proposed layouts. Effect of approach geometry on distribution of sediment on four chambers of settling basin and sediment trap performance were studied by sediment flow simulation. Effects of closing of chamber on distribution of sediment concentration were also investigated with the help of sediment simulation. Trapping efficiency is evaluated for one settling chamber, proposed alternative and modification layouts and closing mode models. Trap efficiency of one settling chamber model is compared with trap efficiency by analytical method.Based on hydraulic performance, sediment distribution performance and trap efficiency performance; recommendation of modification on approach geometry has made. Also, studied result shows that SSIIM 1.0 version can be used for investigating performance of hydraulic structures and settling basin.

Skjærkapasiteten mellom betong og fundament i dammer beregnes i dag ofte med det lineære Mohr-Coulomb-kriteriet. Dette er et empirisk kriteriet som er forholdsvis enkelt å benytte mye på grunn av dets enkle oppbygning og få parametere. Et stort antall forsøk har imidlertid vist at det er faktorer Mohr-Coulomb-kriteriet ikke fanger opp. En av disse faktorene er ruheten i grenseflaten mellom betongen og fundamentet, som antas å påvirke skjærkapasiteten betraktelig. Det foreligger derfor et behov for en større vitenskapelig forståelse av ruhetens påvirkning på skjærkapasiteten.Hensikten med denne oppgaven var å undersøke om kalibrerte tredimensjonale beregningsmodeller kan benyttes til å estimere skjærkapasiteten for en vilkårlig ruhet i grenseflaten mellom betong og fundament. For å få en bedre forståelse av ruhetens påvirkning på skjærkapasiteten skulle det gjennomføres skjærforsøk i sammenheng med tredimensjonale simuleringer av samme forsøk. De numeriske simuleringene lot seg imidlertid ikke gjennomføre, men denne oppgavens resultater fra litteraturstudie og skjærforsøk vil kunne være grunnlag for senere numeriske simuleringer innenfor relevant forskning.Oppgavens problemstilling er som følgende:Kan kalibrerte tredimensjonale beregningsmodeller benyttes til å estimere skjærkapasiteten for en vilkårlig ruhet i grenseflaten mellom betong og fundament?•Hvilke faktorer påvirker skjærkapasiteten mellom betong og berg?•Hvordan påvirker ruheten og vinkelen på ujevnhetene skjærkapasiteten mellom betong og berg?•Hvilke faktorer er bestemmende for bruddmekanismene i grenseflaten mellom betong og berg?For å løse denne oppgavens problemstilling er det gjennomført et litteraturstudie og direkte skjærforsøk. Selve litteraturstudie er gjennomført for å:•få et innblikk i generell glidestabilitetsanalyse og metoder for glidestabilitetskontroll av betongdammer•få et innblikk i regelverket for kontroll av glidestabilitet av betongdammer i Norge og i andre land•avdekke faktorene som påvirker skjærkapasiteten mellom betong og berg•skaffe informasjon og inspirasjon angående gjennomførelse av direkte skjærforsøk og hvordan belyse ruhetens påvirkning på skjærkapasiteten på en hensiktsmessig måteSkjærforsøkene ble gjennomført ved Luleå Tekniska Universitet (LTU) i Sverige. Det ble gjennomført totalt 12 forsøk på betong-berg prøvelegemer av lik størrelse (0.24x0.24m2). For å se hvordan ruheten påvirker skjærkapasiteten, ble det valgt å manipulere bergoverflatene med et sagtannet profil. Altså triangulære ujevnheter med lik vinkel og lik lenge over hele flaten. Forsøkene ble gjennomført med fire ulike overflateprofiler med vinkler på henholdsvis: 40°, 20°, 10° og 0°. Ca. 100-110 mm med betong ble støpt over steinblokkene. To av prøvene ble støpt med heft mellom betongen og berget, mens de 10 resterende ble støpt uten heft. Betongen og berget (granitt) hadde en trykkfasthet på henholdsvis ca. 60 MPa og 283 MPa. Forsøkene ble gjennomført med tre ulike normalspenninger: 0.4 MPa, 0.8 MPa og 1.2 MPa.På bakgrunn av litteraturstudie og resultatene fra direkte skjærforsøk, er det sannsynlig at disse faktorene påvirker skjærkapasiteten mellom betong og berg:•Ruhet og ujevnheter, og da spesielt størrelse og vinkelen på disse•Materialenes styrkeegenskaper (skjær-, strekk-, trykkstyrke)•Normalspenning og skjærspenning•Kohesjon•Om det tidligere har oppstått skjærbrudd eller ikkeResultatene fra forsøkene viser at en økning i ruhet, altså større vinkel på overflatens triangulære ujevnheter, øker skjærkapasiteten betraktelig. Forsøkene viser at en prøve med triangulære ujevnheter på 40 grader har en skjærkapasitet (183 kN) som er over tre ganger så stor som skjærkapasiteten for en prøve med en helt plan flate (52 kN), utsatt for samme normalspenning. En prøve med ujevnheter på 20 grader som er utsatt for normalspenning på 0.8MPa, har nesten dobbel skjærkapasitet (162 kN) som en prøve med ujevnheter på 10 grader (85 kN) utsatt for samme normalspenning.På bakgrunn av denne oppgaven er det ikke mulig å konkludere med hvorvidt en kalibrerte tredimensjonale beregningsmodeller kan benyttes til å estimere skjærkapasiteten for en vilkårlig ruhet i grenseflaten mellom betong og fundament, da de numeriske simuleringene ikke lot seg gjennomføre. De konklusjoner som imidlertid kan trekkes er nettopp ruhetens betydelig påvirkning på skjærkapasiteten mellom betong og berg, og det at det ikke er normalspenningen som er hovedgrunnen til hvordan bergets ujevnheter brytes ned, men derimot ujevnhetenes vinkler. Ujevnhetene i betongen viste seg å være mer sensitiv for både normalspenning og vinkel. Sammenligning med det lineære Mohr-Coulomb-kriteriet viser at dette kriteriet ikke tar hensyn til ruhetens bidrag til skjærkapasiteten.Denne oppgaven belyser det faktum at en økning av ruheten øker skjærkapasiteten mellom betong og berg betraktelig. Det må imidlertid trekkes frem at forsøkene i denne oppgaven er gjennomført i liten skala og at det dermed vil være behov for mer forskning på problemstillingen på en større skala for å kunne implementere ruhetens påvirkning i et regelverk for sikker glidestabilitet av betongdammer. Det anbefales derfor at det gjennomføres videre forskning på blant annet:•Gjennomføre numeriske simuleringer på bakgrunn av denne oppgavens resultater.•Direkte skjærforsøk på betong-berg grenseflater under in-situ forhold.•Direkte skjærforsøk på kjerneborete prøver for betongdammer fundamentert på ulik bergart.•Nærmere undersøke kohesjonens påvirkning på skjærkraften. Hvor stor betydning vil ruheten faktisk ha når kohesjon er tilstedeværende?•Se på metoder for å bekrefte at kohesjon er tilstedeværende.

Research to date analyzing socioeconomic, social and environmental implications emanating from hydropower development in China has focused disproportionally on macro-scale projects, specifically large dams. The very size of these projects should not, but largely have, obscured other developments of significance; small hydropower operations. Small dams and diversion stations with an operating capacity of 50 Megawatts or less represent approximately a third of installed hydroelectric capacity in China. Recently, the proliferation of small hydropower has rapidly increased, particularly in Yunnan province. A belief that small hydropower operations are an environmentally sound alternative to burning coal, which contributes to China’s much publicized air quality issues and global climate challenges drives current development. However, despite the significance of small-scale projects, research to date has largely neglected their role. As a result of this ‘tunnel vision’, an integral component of China’s hydropower assemblage has received inadequate attention, remaining little known and less understood. This dissertation is the result of research that investigates small hydropower development in a rural and remote corner of China’s Nu river valley, located in the far northwest of Yunnan province. Objectives of the research were evaluating the effectiveness of small operations to promote socioeconomic development in rural and remote communities while contributing to China’s broader energy security demands. In addition, the research evaluated the ways hydropower development and the supply of electricity shaped the social circumstances in village communities of the upper Nu river valley. Finally, this research analyzed a range of environmental implications resulting from small operations that were both evident on local landscapes and in spaces far removed. / 10000-01-01

No description available.

Hydropower is often termed "green energy" and proffered as an alternative to polluting coal-generated electricity for burgeoning cities and energy-insecure rural areas. India is the third largest coal producer in the world; it is projected to be the largest coal consumer by 2050. In the Himalayan state of Uttarakhand, India, over 450 hydroelectric power schemes are proposed or are under development. Hydropower projects ranging from micro hydro (run-of-the-river systems with generating capacity up to 100 kW) to large reservoirs (storage systems up to 2000 MW) such as the Tehri Dam are in various stages of planning, construction or implementation. Run-of-the-river hydropower projects are being developed in Uttarakhand in order to avoid some of the costs to local communities created by large dams. Stakeholders in this rapid hydropower expansion include multiple actors with often diverging sets of interests. The resulting governance challenges are centered on tradeoffs between local electricity and revenue from the sale of hydropower, on the one hand, and the impacts on small-scale irrigation systems, riparian-corridor ecosystem services, and other natural resource-based livelihoods, on the other. We focus on the Bhilangana river basin, where water dependent livelihoods differentiated by gender include farming, fishing, livestock rearing and fodder collection. We examine the contradictions inherent in hydropower governance based on the interests of local residents and other stakeholders including hydropower developers, urban and other regional electricity users, and state-level policymakers. We use a social justice approach applied to hydropower projects to examine some of the negative impacts, especially by location and gender, of these projects on local communities and then identify strategies that can safeguard or enhance livelihoods of women, youth, and men in areas with hydropower projects, while also maintaining critical ecosystem services. By assessing the Bhilangana basin case, we also offer hydropower-livelihoods-irrigation nexus lessons for headwater regions across the Himalayas and globally.