The rate of transformation from CaO to Ca(OH)2 during the slaking process is influenced by a number of factors. In this investigation the effects of common ions normally encountered in the slaking water were investigated. It was found that chloride and nitrate ions enhanced the slaking rate, while carbonate, sulphate and phosphate ions retarded the hydration of various limes used in the investigation. The increases and decreases in the degree of hydration correlate with the solubilities of the anions forming more soluble compounds than Ca(OH)2, as well as the solubility constants of the anions that formed less soluble compounds than the hydrated lime. The geological origin of the lime also influenced the slaking of the limes.

<p> Since its completion in 1910, the Chicago Sanitary and Ship Canal (CSSC) has become a pathway for invasive species (and potentially Asian carp) to reach the Great Lakes. Currently, an electric barrier is used to prevent Asian carp migration through the canal, but the need for a secondary method is necessary, especially when the electric barrier undergoes maintenance. The underwater Asian carp &ldquo;cannon&rdquo; (water gun) provides such a method. Analysis of the ground movement produced by an 80 in³ water gun in the CSSC was performed in order to establish any potential for damage to the either the canal or structures built along the canal. Ground movement was collected using 3-component geophones on both the land surface and in boreholes. The peak particle velocities (PPVs) were analyzed to determine if damage would be caused to structures located along the canal. Vector sum velocity ground movement along the canal wall was as high as 0.28 in/s (7.11 mm/s), which is much lower than the United States Bureau of Mines (USBM) ground vibration damage threshold of 0.75 in/s (19.1 mm/s), causing no potential for damage to structures along the canal wall. The dominant frequency of ground motion produced by the water gun is primarily above 40 Hz, so the wave energy should attenuate fairly quickly away from the canal wall, with little disturbance to structures further from the wall.</p>

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Since the beginning of geological investigation of the Rocky Mountain Geosyncline (1) in southwest Alberta and in southeast British Columbia, the problem of the origin of the lower cretaceous sediments has repeatedly arisen. [...]

<p> Seepage barriers have been used extensively to mitigate seepage problems in dams and levees. Although the designs of many of these dams and levees have been based on intact seepage barriers, seepage barriers have been shown to be susceptible to deformation and cracking when high differential hydraulic pressures act across the barrier. Cracking and deformation have also been observed due to thermal expansion and contraction during seepage barrier curing. Under certain conditions, a crack can lead to serious seepage problems, which could potentially lead to the development of a low-resistance seepage pathway. Three scenarios have been identified where there is potential for erosion to occur adjacent to a crack in a barrier: 1) erosion at the interface between a fine-grained soil and a course-grained soil, 2) erosion of overlying soil due to flow along a joint in bedrock, and 3) erosion of the barrier material itself. Previous studies have investigated the first mode of erosion and studies are underway to look into the second mode. The objective of this study is to investigate the third mode of erosion and to identify the conditions under which serious seepage problems can develop. The question considered was whether the combination of highly permeable material adjacent to a crack in a seepage barrier and a large differential head across the barrier combine to develop a velocity within the crack that is erosive to the seepage barrier material. Laboratory tests have been performed on a variety of seepage barrier materials to assess the potential for cracks to develop a preferred seepage path leading to a serious seepage problem. The results of this study will be useful in risk assessment studies of dams and levees with existing seepage barriers as well as in the design of new seepage barriers. Having knowledge of the conditions under which problems may occur will aid in the selection of seepage barrier types for new barriers, placement of instrumentation to monitor new and existing barriers, and mitigation of existing barriers where problems have been identified. The data provided will assist engineers in quantitatively assessing the potential for the propagation of critical seepage problems from cracks in seepage barriers. </p>

The steep, mountainous terrain of southwestern Norway is prone to a high frequency of rockslides. It is known that many of these rockslides are triggered by meteorological conditions, yet there have been few studies dedicated to quantifying the link between rockslides and the runoff conditions and freeze/thaw processes that trigger failure. With recent climate research indicating that southwestern Norway will experience warmer temperatures and increased precipitation, it has become apparent that a better understanding of this link is required to help prepare for future events. Rockslides in Norway lead to road closures, property damage and fatalities every year, and one of the biggest challenges for Norwegian authorities is to react to rockslides as they happen and to reopen roads as soon as possible. This is especially true when several rockslides occur on the same day in multiple locations. As a result, authorities wish to implement a hazard mapping system that uses a weather forecast to predict when and where geohazards are likely to occur. To this end, this thesis is aimed at providing a rockslide forecast map that changes every day based on the weather forecast. By comparing a rockslide database to historic weather records, the work carried out for this thesis has indicated that extreme runoff during winter storms is responsible for triggering the majority of rockslides in the region. Using this knowledge as a basis, two potential hazard mapping systems are proposed, one based on trigger threshold exceedance and the other based on weights-of-evidence susceptibility mapping. Both of these methods operate by mapping areas experiencing extreme runoff conditions. Several runoff parameters were tested for possible inclusion, and it was found that 48-hr antecedent runoff, normalized by mean monthly precipitation had the best correlation with rockslide occurrence. Verification of these methods indicates that both approaches are successful in predicting days with extreme conditions, thereby alerting authorities that a high frequency of rockslides is likely. Due to the complex nature of rockslide triggering, it is not fully understood how climate change will affect future rockslide activity; however, this thesis attempts to answer these questions and to provide a basis for future studies. / Thesis (Master, Geological Sciences & Geological Engineering) -- Queen's University, 2010-01-28 08:12:43.316

Fibroferrite [Fe(OH)SO4•5H2O] is a product of the AMD (acid mine drainage) process and forms by chemical weathering and oxidation of iron sulfides in hydrothermal and magmatic ore deposits. The present work consists of two distinct parts. The first part is a crystallographic and optical study of 30 samples of fibroferrite from natural occurences and mine waste. The second part covers the description of all the experimental attempts to synthesize fibroferrite. Powder-diffraction data were collected and the Rietveld refinement procedure was conducted for each of the 30 natural samples in order to refine the values of the lattice constants of each sample. The a and c values of the lattice constants of fibroferrite measured in this study were found to conform to the values reported in the most recent literature. Optical observations were conducted, using a spindle stage, on each of the 30 natural samples. The purpose of the optical analysis was the selection of crystals adequate for a single crystal X-ray diffraction study. Samples were selected for a study on a rotating anode source and further studies at a synchrotron facility. None of the selected crystals was suitable for a single crystal X-ray diffraction study and the unit cell could not be found. Energy dispersive X-ray spectroscopy chemical analyses using a scanning electron microscope were performed on the 10 natural samples supplied by the Royal Ontario Museum and the Canadian Museum of Nature. The energy dispersive X-ray spectroscopy chemical analyses did not allow a real understanding of the level of substitutions of other cations for ferric iron within the atomic structure of fibroferrite. Several experiments were performed in order to synthesize fibroferrite. Commercially available reagents were used. All the experimental attempts conducted failed in synthesizing fibroferrite. A too restricted Eh and pH range of the laboratory conditions at which the experiments were conducted and the formation of metastable phases could be evoked as reasons of this failure. / Thesis (Master, Geological Sciences & Geological Engineering) -- Queen's University, 2010-05-06 15:08:18.092

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