This thesis deals with the study of flow through tailings dams. Examination of the current practices led to the construction of a valid experimental model. A unique system of instrumentation was developed, which was employed successfully to measure pore water pressures accurately and thus provide the necessary information to locate the position of the phreatic surface. Using the developed technique, models of tailings dams were constructed and monitored and it was discovered that a major deviation in the expected position of the phreatic surface occurred in a tailings dam. Further investigation by the construction of various types of dams led to the redefining of the phreatic surface and thus the flow regime. A computer programme based on the use of the finite difference technique was applied to water retention dams and found to locate the position of the phreatic surface accurately.

Thesis (M.S.)--Oregon State University, 2002. / Typescript (photocopy). Includes bibliographical references (leaves 118-123). Also available via the World Wide Web.

Olympic Dam underground mine is located in South Australia approximately 520km north-north-west of Adelaide. The copper-gold-uranium deposit is extracted by open stope mining. The empirical Mathews stability method has been applied to open stope stability forecasting at Olympic Dam for the more than 20 years. This method adjusts the rock tunneling quality index (Q’) to allow for a rock stress factor, the orientation of any discontinuity and the orientation of the geometric surface formed by the excavation. The applicability of the Mathews stability method at Olympic Dam was analysed by assessing the volume of over break outside the stope design profile. It was found that 41% of all stope surface predictions were correct, and that 59% (by difference) of all predictions were therefore incorrect. This was found to be primarily due to the method as applied at Olympic Dam, rather than the inherent errors of the Mathews stability method. However there are a number of weaknesses in the Mathews stability method including the inability to identify structural weaknesses in the rock mass, to allow for different stress concentrations around irregular shaped stopes and to account for stope relaxation. A high resolution non-linear, Hoek Brown, numerical model is capable of providing displacement, velocity and strain rates for points within a rock mass. Velocity is the modelled rate of displacement of the points within the rock mass relative to the stope profile. An existing numerical model of this sort at Olympic Dam was used to investigate the relationship of the velocity of points moving toward a stope, and the probability of them becoming over break. It was found that with increasing rates of velocity the probability of a point becoming over break increased. The identified limitations of the application of the Mathews stability method are not enough to justify removing the method from the stope design process at Olympic Dam. With the implementation of recommended improvements such as, increasing the frequency of window mapping collection, live stress measurements and detailed post-mining assessment of stopes, an increase in the methods reliability can be expected. These improvements should be incorporated in conjunction with the continued trial of velocity as a stope performance indicator at Olympic Dam.

The techniques for computing dam-break flood waves in prismatic channels are reviewed. Numerical models for cases with or without an initially dry downstream bed are developed. The models are based on the characteristic forms of the shallow water equations, both in (X-T) and (R-T) space, using specified time intervals and incorporating the Rankine-Hugoniot shock equations. Three numerical models for rectangular section channels are studied, namely the parallel (X-T), the expanded (R-T) and the contracted (R-T) cases; any two of these are then linked to produce three further models, described as the Contracted-Plain (RT-XT), the Contracted-Expanded (RT-RT) and the Plain-Expanded (XT-RT) models. Four physical models were tested and compared with results from the numerical models and with those from Barr and Das (1980), Marshall and Menendez (1981) and Katopodes and Schamber (1983). The numerical and experimental results are given in the form of comparative plots of front heights, surface profiles, front trajectories and depth hydrographs. Variations from the well-known solutions by Ritter (1892) and Stoker (1957), including those caused by radial flow effects are found to occur and are discussed.

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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.)--Ohio State University, 2005. / Title from first page of PDF file. Document formatted into pages; contains ix, 147 p. Includes bibliographical references (p. 142-147).

Η παρούσα εργασία πραγματεύεται τις τεχνικογεωλογικές συνθήκες που επικρατούν στην περιοχή του Φράγματος και του Ταμιευτήρα Μόρνου, όπως επίσης και τις υδροχημικές αναλύσεις που έγιναν σε δείγματα νερού που ελήφθησαν από τις διαρροές των σηράγγων του φράγματος. Περιλαμβάνονται διαγράμματα και ταξινομήσεις των αποτελεσμάτων των δειγμάτων των νερών. / This thesis includes the geological and technical conditions that describe the area around the Mornos Dam and Reservoir, as well as the hydrochemical analyses that were performed at samples of water wich were taken from the leaks at the tunnels of the Dam. In this thesis, there are also included diagrams, and classifications of the results of the water samples analyses.

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