Three dimensional stability charts for slopes based on limit analysis methods

This paper uses finite element upper and lower bound limit analysis to produce chart solutions for three-dimensional (3D) natural slopes for both short- and long-term stability. The presented chart solutions are convenient tools that can be used for preliminary design purposes. The rigorous limit analysis results in this paper were found to bracket the true factor of safety within ±10% or better, which can be used as a benchmark for the solutions from other methods. The depth of the slip surfaces is observed to be generally shallow for most analyzed cases, particularly for the long-term slope stability problem. In addition, it was found that using a two-dimensional (2D) analysis may lead to significant differences in estimating safety factors, which can differ by 2%–60% depending on the slope geometry and soil properties. Therefore, great care and judgement are required when applying 2D analyses to 3D slope problems.

Limit analysis solutions for very gentle undrained slopes

In view of the demand for energy resources, offshore engineering has drawn the attention of many investigators over the past decade. Recent studies have revealed that seabed landslides can have a sig-nificant influence on the performance of offshore infrastructure, such as pipelines. The vulnerability triggered by seabed landslides can even lead to loss of life. In this context, the importance of offshore slope stability evaluation is obvious. Slope stability is generally assessed by the limit equilibrium method (LEM). However, the accuracy of the method is often questioned due to the underlying assumptions that it makes. This study utilises numerical finite element upper and lower bound limit analysis to produce solutions for very gentle undrained slopes. Using these techniques, the stability can be bracketed from above and below. In this paper, a range of slope geometries and the inhomogeneity of the natural soil have been taken into account. The solu-tions presented are useful tools for preliminary design.

Slope stability analysis for filled slopes using finite element limit analysis method

This paper uses the finite element upper and lower bound limit analysis to assess the stability of slopes mostly found in embankment cases where frictional materials are filled on purely cohesive undrained clay. For comparison purposes, the commonly used stability assessment method, limit equilibrium method (LEM) is also employed. The final results for both methods are then presented in the form of comprehensive chart solutions for the convenience of practicing engineers during preliminary slope designs. The failure mechanism will also be discussed in this paper. Ultimately, it should be noted that finite element limit analysis method holds the upper hand as its prior assumptions are not required. Thus, the obtained failure mechanism from the slope stability analysis will be more realistic. Hence, it will provide a better understanding for the slope failure surface. Therefore, engineers should design more carefully when the LEM is applied to the slopes with frictional materials filled on purely cohesive undrained clay. © 2014 American Society of Civil Engineers.

Slope stability analysis for fill slopes using finite element limit analysis

This paper investigates the stability of fill slopes often found in embankment cases where frictional fill materials are placed on purely cohesive undrained clay with increasing strength. By using finite element upper and lower bound limit analysis for this investigation, the limit load can be truly bounded. It is known that two-dimensional analysis yields a more conservative result due to plain strain condition when compared to three-dimensional analysis. Therefore, this paper will focus on three-dimensional (3D) slope stability analysis and for comparison purposes two-dimensional analysis results will be employed. In fact, the final results are presented in the form of comprehensive chart solutions for the convenience of practicing engineers during preliminary slope design. The failure mechanism will also be discussed in order to further illustrate the situation during failure. It should be highlighted that the failure mechanisms are obtained through the numerical method itself and no prior assumptions are required, therefore, are more realistic and able to provide a better understanding for the slope failure surfaces.

Frederick McCoy`s Mount Macedon Property

In the later part of his life Frederick McCoy selected and developed a bush block on the slopes of Mount Macedon. The conditions for purchase required him to plant and foster the growth of various northern hemisphere trees and shrubs. He duly cleared part of the block, planted trees, shrubs and
grass, put up fencing, constructed a small reservoir and laid pipes. In 1876, having fulfilled government requirements, he purchased the property and retained ownership until 1890.

Floodplain wetlands of the Gellibrand estuary: What type of invertebrate community

Introduction. Along the south coast of Australia, wetlands on the floodplains of lowland rivers and estuaries have been severely altered by agriculture and urbanization. Efforts to restore or rehabilitate these wetlands are hampered by insufficient knowledge of the original condition of these wetlands, or their variability in time and space. This research describes the macroinvertebrate community of wetlands on the floodplain of the Gellibrand River and estuary, which has suffered comparatively few human impacts. The aim of the research was to describe the variability of macroinvertebrate communities as a baseline for the future management of these wetlands, and to contribute to the general understanding of estuary-floodplain wetlands, thereby improving the basis for their management.

The Gellibrand River has a catchment area of approximately 1200 km2 draining the western slopes of the Otway Ranges, and entering the Southern Ocean at Princetown. From a mean annual flow of 315 000 mL, 25 000 mL are removed per annum for agricultural and domestic use (O'May & Wallace 2001), and flows are closer to natural regimes than most other Western Victorian rivers. The estuary is a bar-built, salt-wedge estuary that becomes completely blocked by the sand bar in most years, during summer and autumn. Over past decades, the estuary mouth has been opened artificially in most years. to prevent flooding of agricultural land and roads adjacent to the wetlands. At its maximum, the salt-wedge penetrates approximately 10 km upstream from the river mouth, but the estuary may also be completely fresh during high winter discharge
(Mckay 2000).

The wetlands surrounding Princetown cover 119 ha and are listed as nationally important (Environment Australia 2001). This listing regards the wetlands as an important habitat for animals at vulnerable stages of their life cycle and a refuge from adverse conditions, such as drought. They are a good example of coastal brackish and freshwater marshes, with an important ecological and hydrological role as part of a large wetland
complex.

Distribution of disease caused by Phytophthora cinnamomi in Wilsons Promontory National Park and potential for further impact

The extent of disease caused by Phytophthora cinnamomi was determined within vegetation communities of Wilsons Promontory National Park. Aerial survey of visible symptoms by helicopter and systematic survey along all roads and tracks followed by isolation of the pathogen from soil found that in total 551 ha of moist foothill forest, heath and heathy woodland broad vegetation types were affected by the disease. P. cinnamomi was isolated from 93% of sites that, based on the presence of visible symptoms, were expected to yield the pathogen. The species-rich heathy woodland was most affected with 6.5% of the total area of this type showing symptoms of disease. The size of infestation ranged from 229 ha on the slopes of the Vereker Range in the north to less than 1 ha along the Sealers Cove Walking Track in the south. The potential for disease to spread into uninfested vegetation was estimated for all sites from which P. cinnamomi was isolated. Eight of 18 sites where evidence of disease was found were estimated to have a high potential for further disease spread. This study indicates that even though the disease may be waning in some areas of the Park, the pathogen is active and easily isolated from others and provides a continuing threat to susceptible vegetation communities.

Energy density of foods and beverages in the Australian food supply: influence of macronutrients and comparison to dietary intake

Objectives: The energy density (ED) of the diet is considered an important determinant of total energy intake and thus energy balance and weight change. We aimed to compare relationships between ED and macronutrient content in individual food and beverage items as well as population diet in a typical Western country. Design: Nutrient data for 3673 food items and 247 beverage items came from the Australian Food and Nutrient database (AusNut). Food and beverage intake data came from the 1995 Australian National Nutrition Survey (a 24-h dietary recall survey in 13 858 people over the age of 2). Relationships between ED and macronutrient and water content were analysed by linear regression with 95% prediction bands. Results: For both individual food items and population food intake, there was a positive relationship between ED and percent energy as fat and negative relationships between ED and percent energy as carbohydrate and percent water by weight. In all cases, there was close agreement between the slopes of the regression lines between food items and dietary intake. There were no clear relationships between ED and macronutrient content for beverage items. Carbohydrate (mostly sucrose) contributed 91, 47, and 25% of total energy for sugar-based, fat-based, and alcohol-based beverages respectively. Conclusions: The relationship between ED and fat content of foods holds true across both population diets and individual food items available in the food supply in a typical Western country such as Australia. As high-fat diets are associated with a high BMI, population measures with an overall aim of reducing the ED of diets may be effective in mediating the growing problem of overweight and obesity.

Field-emission characteristics of conical boron nitride nanorods

We present the electron field-emission (FE) characteristics of conical boron nitride nanorods grown on a (1 0 0) n-type silicon substrate. The emission current can be up to ~60 µA at an applied voltage of ~3 kV. Two distinct slopes are evident in the Fowler–Nordheim (FN) plot. The FE characteristics can be explained using a site-related tunnelling-controlled mechanism. The occurrence of two FN slopes is attributed to the switchover from tip emission to side emission, which results from the differences in interface barrier, geometry, as well as the total emission area of the two emission interfaces.

Contribution of multi-tenure reserve networks to biodiversity conservation

A consistent and integrated approach to nature conservation across the landscape and regardless of tenure is widely recognised as essential in ensuring the effective conservation of biodiversity. 'Multi-tenure reserve networks', which incorporate public and private lands managed for conservation, are considered a means of achieving landscape scale conservation. Biosphere Reserves (BR) and Conservation Management Networks (CMN) are characteristic models in Australia. This thesis aims to evaluate the role of such networks in protecting biodiversity, specifically by: (1) analysing the spatial configuration (size, shape, connectivity) of networks and their individual components; (2) evaluating the contribution of networks (in real terms and in reporting procedures) to biodiversity conservation objectives; (3) analysing the influence of the attitudes and perceptions of land managers on the functionality of networks; and (4) evaluating the influence of coordinating bodies on network functionality. In order to account for deficiencies in existing classifications of conservation lands, a new classification system was developed for this thesis - the Conservation Lands Classification. This classification incorporates conservation mechanisms on public and private lands and forms the basis for comparing network components in three Australian case studies - the Bookmark BR located in the Murray Mallee of South Australia, the Gippsland Plains CMN on the eastern Gippsland Plains of Victoria and the Grassy Box Woodlands CMN across the inland slopes of New South Wales. The spatial configuration of individual components within networks was measured using spatial analysis techniques within a geographic information system (GIS). GIS was also used to measure the contribution that networks made to a comprehensive, adequate and representative reserve system through the ecosystems they protected. The attitudes and perceptions of landowners and managers within the networks were obtained using questionnaires. Questionnaires were also sent to network coordinators. Statistical and descriptive analysis was conducted on the results. The sizes of individual components varied markedly between the three networks, however within each network public reserves were on average larger than private conservation lands. Although levels of physical connectivity varied between networks, Bookmark BR and Gippsland Plains CMN showed greater similarity to each other than to the Grassy Box Woodlands CMN. The findings raise important questions about the real and perceived differences in the BR and CMN models. All networks, and particularly those components outside the public protected area estate, contributed to enhancing the protection of ecosystems unrepresented or under-represented in the reserve system, although the extent of this contribution varied between networks. Trade-offs between reserve design efficiency and a contribution to a comprehensive, adequate and representative reserve system were evident between networks. Bookmark BR was characterised by high connectivity, strong reserve design integrity but a lower contribution to protecting under-reserved ecosystems, whereas the opposite was evident in the Grassy Box Woodlands CMN. Over 88% of managers considered their involvement in multi-tenure reserve networks to be a positive or very positive experience. A lack of resources and time for management were considered major limitations of these networks. The majority (80%) of private land managers within networks were willing to be included in a national reserve system of conservation lands. This has important implications for the Australian National Reserve System, which currently incorporates mostly public land. The changing nature of the network coordination arrangements suggests an organic fluid evolution of network structures is likely, contrasting with the desire for legalistic and administrative rigidity promoted by government agencies. The thesis concludes that all the networks studied contribute in varying degrees to biodiversity conservation. The key factors influencing the current and potential contribution that such networks make are: (1) the aims, directions and restrictions set by or imposed upon the coordinating body; and (2) the biophysical nature of the surrounding bioregion and resultant historical land use and tenure pattern. Although the successful operation of such 'multi-tenure' networks ultimately relies on the willing participation of private landholders, ongoing institutional support is likely to be required for maintaining networks in the longer term. Considering networks are increasingly formed outside of the influence of government institutions, this presents a significant challenge for effective coordinated conservation.

Availability of sports facilities as moderator of the intention - sports participation relationship among adolescents

This longitudinal study aimed to identify individual and environmental predictors of adolescents’ sports participation and to examine whether availability of sports facilities moderated the intention–behaviour relation. Data were obtained from the ENvironmental Determinants of Obesity in Rotterdam SchoolchildrEn study (2005/2006 to 2007/2008). A total of 247 adolescents (48% boys, mean age at follow-up 15 years) completed the surveys at baseline and follow-up. At baseline, adolescents completed a survey that assessed engagement in sports participation, attitude, subjective norm, perceived behavioural control and intention towards sports participation. Availability of sports facilities (availability) was assessed using a geographic information system. At follow-up, sports participation was again examined. Multiple logistic regression analyses were conducted to test associations between availability of sports facilities, theory of planned behaviour variables and the interaction of intention by availability of sports facilities, with sports participation at follow-up. Simple slopes analysis was conducted to decompose the interaction effect. A significant availability × intention interaction effect [odds ratio: 1.10; 95% confidence interval: 1.00–1.20] was found. Simple slopes analysis showed that intention was more strongly associated with sports participation when sports facilities were more readily available. The results of this study indicate that the intention–sports participation association appears to be stronger when more facilities are available.