The range of possible uses of inflatable hydraulic structures is very great provided a suitable design and analysis technique is available. The object of this project was to study both theoretically and experimentally the behaviour and performance of inflatable hydraulic structures under both hydrostatic and hydrodynamic conditions for dams inflated with air, water and a combination of the two. The theoretical analysis was based on a finite element approach to design a dam under different inflation fluids in order to find the dam parameters of tension, profile of the dam, upstream slope, and elongation of the material under both hydrostatic and hydrodynamic conditions. A series of models of different sizes were constructed and tested under both hydrostatic and hydrodynamic conditions. A comparison of different output parameters was carried out between the experimental and theoretical results showing a good relationship between the two. Relationships were derived so that the length of the membrane could be found for the design of a dam to satisfy particular conditions. A new formula was derived for calculating the rate of flow and coefficient of discharge for all three types of inflation allowing the application of inflatable dam as a device for measuring discharge. A range of computer programs was written for the analysis and design of all dams based on the finite element approach. This work was restricted to single anchor dams with the anchor located on the upstream side.

A dissertation submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in fulfilment of requirements for the degree of Master of Science in Engineering Johannesburg, 2017 / South Africa is a water scarce country and dams play a large role in the infrastructure of our country by providing water for many purposes. With the growth of the country, new dams are needed and existing dams require rehabilitation. Often, increasing a spillways capacity forms part of the rehabilitation required at dams. Therefore, one of the main aims of this study is to look at an option for increasing a spillways discharge capacity. The labyrinth and Piano key weirs (PKW) were investigated together with a combination of the two spillway types. Different geometric attributes were combined and varied to develop a new design that would assist in improving discharge capacity while reducing the cost, producing an economically viable option. Thirty five physical models were built and tested in this regard. Comparison was made with the standard PKW design in terms of discharge capacity, hydraulic efficiency, length ratio (L/W) and cost related to concrete volume required. It was concluded that efficiency, discharge capacity and cost can be improved with this new combined design however more geometric variations need to be studied to ascertain these results. / MT 2018

Student Number : 9903228W - MSc dissertation - School of Molecular and Cell Biology - Faculty of Science / Plant populations show an ability to survive and adapt under varying environmental conditions. Adaptation to heavy metal contaminated soils usually results in a decrease in genetic variation. Slimes dams consist of the pulverized rock slurry left after the extraction of gold or uranium. High toxicity levels mean that these wastes often remain uncolonised and are therefore easily eroded through wind or water. Plant populations that will be viable for long-term vegetation of slimes dams will prevent erosion, and stabilise and improve the quality of the soil. Indigenous, locally adapted species are the most likely to be successful candidates for vegetation. Indigenous, slimes-tolerant species Indigofera adenoides and Indigofera zeyheri were therefore studied. The aim was to determine if plant populations show local adaptation to the adverse substrate conditions emanating from slimes dams, by investigating genetic and morphological variation between adjacent populations growing at different distances in relation to slimes dams. The AFLP technique was used to analyse genetic variation as it produces rapid results, is inexpensive, reproducible, and capable of screening the entire genome. Lower genetic diversity was observed in those areas of the dams with higher levels of slimes-associated contamination. This difference was observed in both species, and for all measures of genetic diversity (Shannon’s information index, Nei’s gene diversity, percentage of loci polymorphic). This may be due to a founder effect following colonisation, natural selection, flowering time differences, or a combination of these factors. Reduced morphological variation was observed in those areas of the dams with higher levels of slimes-associated contamination. Significant morphological differences were observed between groups of plants from different areas, some of which appear to have the capability to assist the plants in a slimes-contaminated environment. Some degree of adaptation to slimes-contaminated soil therefore seems to have occurred, with this being more pronounced in Indigofera adenoides, although it cannot be determined whether this is purely phenotypic, or a combination of phenotypic and genetic. These species therefore seem suitable as candidates for vegetation of slimes dams, although further work must be done to fully understand the effect of slimes-associated toxicity.

Thesis (Ph. D.)--University of Washington, 2001. / Vita. Includes bibliographical references (leaves 353-370).

Dams are among the most critical of civil engineering structures and are susceptible to damage due to seepage. Geomembranes have been used to minimize seepage problems in dams since 1959. However, geomembranes are vulnerable to damage, in the form of tears and punctures, during installation and throughout the service life. These defects impact the effectiveness of a geomembrane as an infiltration barrier resulting in leakage through the geomembrane liner and into the body of the dam. The majority of previous studies conducted to investigate leakage through defects in geomembranes considered heads below 0.3 m, which corresponds to flow for conditions experienced by landfill liners. The main objectives of this study were to quantify the leakage rate through defects in geomembrane lining systems for dam and to evaluate the implications of the leakage on the performance of dams. Experimental, analytical and numerical studies were conducted as part of this investigation. The experimental testing program included permeameter cell tests for the following lining systems: i) geomembranes over clay layers, ii) geomembranes over sand layers and iii) geomembranes over geosynthetic clay liners. The permeameter tests were conducted to investigate the effects of soil type, initial water content, dry unit weight and hydraulic head on leakage through a defect in a geomembrane liner. The analytical component was conducted to evaluate the transmissivity at the interface and radius of wetted area for the tests conducted as part of the experimental component. The numerical component of this study was performed using the finite element method to simulate the experimental tests and the performance of actual dams. Ultimately, the laboratory tests and subsequent analyses were used to develop a set of tools (e.g., empirical models, design recommendations) that are expected to assist engineers in the design of geomembrane lining systems for dams. Also, the study was used to identify and address potential concerns (e.g., global stability) that may result in failure of systems in which geomembrane liners are used. This study is expected to contribute to a better understanding of the performance of geomembranes as dam liners. The presence of a geomembrane, even with a defect, was found to reduce the amount of leakage that occurs through a soil layer. New predictive equations were developed to estimate leakage through defects in composite lining systems. The finite element analyses indicated that a dam with a geomembrane with very large defects would not develop pore pressures that were similar to those observed for an unlined dam. The factor of safety for the unlined dam was improved by the placement of a geomembrane on the upstream face. Consequently, a geomembrane may also eliminate the need for a blanket drain at the downstream toe, which could decrease the cost of construction. / text

Στην παρούσα εργασία έγινε προσπάθεια να μελετηθούν οι περιβαλλοντικές επιπτώσεις από την δημιουργία του τεχνητού φράγματος του παραποτάμου Παραπείρου στην μορφογενετική εξέλιξη της περιοχής καθώς και την επίδραση του φράγματος στην φυσική διατήρηση της ακτογραμμής. Ο Σκοπός της παρούσας διπλωματικής εργασίας είναι η μελέτη και χαρτογράφηση των γεώμορων κατά μήκος και γύρω της κοιλάδας του ποταμού Παραπείρου καθώς και τις πιθανές αλλαγές τους , από την δημιουργία του ταμιευτήρα ή των ταμιευτήρων και οι επιπτώσεις του έργου στο μορφογενετικό ισοζύγιο της περιοχής. / In this work, an attempt was made to study the environmental impact of the creation of the artificial dam tributary Parapeiros in morphogenetic development of the region and the impact of the dam on maintaining natural shoreline . The purpose of this thesis is the study and mapping of landforms along and around the river valley Parapeiros and possible changes thereof, of the creation of the reservoir or reservoirs and the impact of the project on morphogenetic balance of the region .

No description available.

This master thesis has been conducted through cooperation between Elforsk, Uppsala University and Tsinghua University in Beijing. Ashele Tailings Dam, located in Haba Town, Xianjing Province, China, is designed and used for high sulphur tailings. Because of a new mineral separation technique, the dam is now also being filled with low sulphur tailings. Since the dam was not originally designed for the new tailings materials, the seepage and stress-strain analyses of the dam need to be re-evaluated and refined. The Ashele Ltd. is also planning on building a new dam to meet its growing need for tailings deposit capacity. This dam will be used for the new low sulphur tailings and a thorough analysis of the dam will have to be performed.The purpose of this thesis is to re-evaluate the analyses of the seepage and stress-strain in the old dam and to perform the same type of analyses on the newdam. Numerical analyses of the seepage, solute transport and strain-stress in the dam are performed, using the physical and mechanical properties of the tailings materials. It is shown, that the construction of the new tailings dam, will have a good effect on the seepage and therefore also solute transport. The results also show that theseepage, solute transport, stress and deformation are depending on the amount ofwater in the tailings pond and that a lower water level has a positive effect on all thestudied variables.

Thesis (M.E.)--University of Canterbury, 2007. / Typescript (photocopy). Includes bibliographical references (leaves 178-189). Also available via the World Wide Web.

Thesis (Ph. D.)--University of Oregon, 2006. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 236-246). Also available for download via the World Wide Web; free to University of Oregon users.