An unusual foundation for an arch dam in mauritania

Between the years of 1981 and 1983 a 45 metres high arch dam was constructed for irrigation purposes at the Gorgol-Noir, a tributary of the Senegal River, in the semi-desert zone of southern Mauritania (Sahel). North of the city of M'bout the Gorgol-Noir erodes through a range of Precambrian metamorphic quartz-schists, trending north to south. The paper describes the investigations—engineering geological and the rock mechanics—undertaken in the course of the design and construction of the dam. Of particular importance were cavities located on the valley sides, proved to be related to shale intercalations.     

The extent and effects of mass wasting in Ghana

Mass wasting in most of its forms have been studied throughout Ghana. The studies covered extent, distribution, effect, and possible corrective measures of slope failures. The performance of a number of slopes have been monitored for long periods and results have served as a basis for re-examination of existing design criteria in Ghana. Back, analysis of one major failure has been performed to obtain velocity and reach of a landslide. From, damage to farms, timber and a road from landslide in one instance, a projection is made to obtain the economic significance of landslides in Ghana. From the mode of failure in one specific case a methodology for corrective measures has been proposed.     

Travelling Fires and the St. Lawrence Burns Project

This paper represents a timely communication that critically evaluates an example of previously inaccessible and aged grey literature that can now be found in the National Research Council of Canada’s open access online repository. This grey literature, in the form of a series of reports detailing two large scale compartment fire tests from 1958, is critically evaluated. While potential credence to the contemporary research theme of travelling fires framework and methodology is given herein, this evaluation supports further and continued investigation into large compartment fire behaviour to help progress the development and the improvement of fire methodologies for the design of buildings. A case is made that aged grey literature, particularly when previously inaccessible, merits second consideration as information can be of contemporary use for fire science researchers and practitioners.     

Double quarries—Grade and artificial hard aggregates

The article deals with an interesting quarry in NW Slovenia, Yugoslavia, which exploits two kinds of rock at the same time: quartz keratophyre at the bottom and dolomite at the top, both of them of mid-Triassic age. Both rocks are processed in the same screening plant as aggregates for bitumen and cement concretes. Explorations for quartz keratophyre with tuffs started in 1966 for wearing courses of motorways. As such rocks are relatively few in Slovenia, and also in Yugoslavia, high grade carbonate aggregates were also proposed for less exacting roads and for lower layers of motorways. In the meanwhile, also artificial aggregates made from basic slags from ironworks were investigated. Good quality was ascertained and confirmed by a survey in use on a road.     

Durability assessment of crush rock road base

Crushed rock road base derived from either volcanic breccia or dolerite is used extensively in the Syndey Metropolitan area. At present three methods of pretreatment of part of a sample are specified by the Department of Main Roads to predict material breakdown during construction. In addition the dry/wet strength variation is measured to determine material durability. This testing is based on the 10% Fines Test procedure. This paper describes an investigation carried out to ascertain whether the three methods of pretreatment are, indeed, necessary with volcanic breccia and to determine the relationship between the effects of various methods of pretreatment and the aggregate strength parameters.     

Correlation between Schmidt hardness,uniaxial compressive strength and Young’s modulus for andesites,basalts and tuffs

Volcanic rocks from the Bodrum Peninsula have been studied to establish a relationship between the uniaxial compressive strength (UCS), Youngs modulus (E) and Schmidt hammer rebound number (N). Test results obtained on andesites, basalts and tuffs have been assessed statistically and the parameters obtained correlated. Regression equations were established between N, E and UCS.The study suggests the following empirical relationships: UCS=2.75 N–36.83, E=0.17 UCS+0.28 and E=0.47 N–6.25. The relationships are somewhat different from the correlations suggested by previous studies and should therefore be used only for andesites, basalts and tuffs with degrees of weathering and mineralogical structure similar to those used in the present study. The results obtained using solely the Schmidt hammer test for estimating mechanical properties of rocks are less accurate than when a full suite of laboratory tests is carried out but it is hoped that these empirical equations will help geotechnical engineers making practical decisions at a preliminary site investigation stage.     

A technical basis for regional aggregates policies

The planning system in England and Wales, the scale of the aggregates industry, and problems due to high levels of demand for aggregates are briefly outlined. A planning policy initiative to solve the problems is described. The information base required for preparation of these Guidelines for Aggregates Provision in England and Wales, and the scope of research commissioned by the Department of the Environment in support of work on aggregates policy are reviewed.     

Caractérisation minéralogique et géotechnique des argiles marneuses gonflantes de la région de Médéa,Algérie

This paper presents the approach followed for the geological, mineralogical, and geotechnical characterization of swelling marly clays in the Médéa region. This investigation is conducted in order to estimate the swelling potential of this marly clay layer. The studied sites, located at about 80 km south of Algiers, Algeria, cover an area of approximatively 400 hectares. Five sites are considered. In the first step, the geological, tectonic, climatic, and hydrological contexts of the region are described. According to the geological map of Médéa, most of the formations encountered in the area are composed of Miocene layers represented by marly clays (Fig. 2). This region is characterized by its high and low temperature in summer and winter, respectively, and variable humidity (Fig. 3). In a second step, the results of geotechnical studies, X-ray diffraction tests, chemical analyses, and scanning electron microscope (SEM) observations are presented (Figs. 3, 4, 5, 6, 7, 8, 9). The soils contain quartz (20–26 %), calcium carbonates (11–55 %), kaolinite (8–13 %), illite (6–14 %) and Montmorillonite (18–26 %). The study of their microstructure by means of SEM indicates that these soils are formed by a compact marly clay matrix that is relatively homogeneous and oriented in the dip direction of bedding. A grain size analysis shows that the clay content varies between 17 and 70 %. The water content of all samples varies between 8 and 30 %. The values of the liquidity limit (LL) and plasticity index (PI) vary between 28–76 % and 16–36 % respectively, indicating a highly plastic soil; this is also confirmed by a specific surface varying between 99 and 179 m²/g. The dry density γ _d varies between 15 and 19 kN/m³. The swelling potential of the marly clay samples is evaluated firstly using various indirect methods. In literature, a number of empirical classifications are proposed by different authors (BRE 1980; Chen 1988; Komornik and David 1969; Seed et al. 1962; Snethen 1984; Vijayvergiya et Ghazzaly 1973 et Williams and Donaldson 1980). The swelling potential is related to certain physical properties of soils, such as consistency limits, clay content, methylene blue value, etc. In general, these methods indicate that all the tested soils have a high swelling potential, which confirms the results of mineralogical analysis. Secondly, direct measurements of swelling parameters are performed. Swelling tests are carried out using a standard slaved one-dimensional odometer using two methods: free swell and constant volume, according to standard ASTM D 4546-90 and AFNOR (1995). The swell pressure, the swell percentage and the swell index are given in Fig. 16. It is noted that the soils develop very significant swell pressures which vary between 25 and 900 kPa. This is in agreement with the results obtained by empirical methods. This investigation clearly shows that the marly clays of the Médéa region have a high swelling potential. Therefore, taking into account the phenomenon of soil swelling in structure design is essential.     

Cyclic loading triaxial testing of crushed rubble and lava

This paper describes a laboratory investigation into the suitability of crushed rubble as a substitute for conventional road base materials. The rubble investigated was a mixture of crushed concrete and crushed bricks, whilst lava from the Eifel was chosen as a reference material. Standard highway engineering tests (Proctor, CBR) and durability tests (Los Angeles Abrasion, Slake Durability and the standardized Dutch crushing test) were performed to provide reference date with every-day engineering practice. Cyclic loading triaxial tests were performed on both materials. The resilient moduli were determined at various levels of confining stress and the cyclic deviator stress. The susceptibility to plastic strain development (rutting) of both materials was determined in triaxial tests with up to 10⁶ load applications. The degradation of the materials in the plastic strain tests was determined through sieve analyses prior to and after the tests.     

Characterization of Flaring and Non-Flaring Container Filled Votive Candles

Authors were provided two sets of 24 exemplar candles. Of these, 24 were identified as the same that the provider had observed “flaring”. Fourier Transform Infrared Spectroscopy (FTIR) analysis of the material showed that the candles that did not flare were soy based wax and that those that did flare were petroleum based wax. Burning the candles showed that melted wax in some petroleum based candles was ignited by the wick flame and produced a pool fire inside the candles’ glass container. Based on measured mass loss rate and the heat of combustion of petroleum based wax, the calculated power output of a normal burning candle is ca. 30 W. When the liquid wax pool ignited, the output was ca. 230 W, with significant flame extension above the top edge of candle’s glass container. The FTIR analysis also showed that twelve of the petroleum based wax candles had a simple hydroxyl compound, likely an alcohol, peak that was not present in the second sample of one dozen petroleum based wax candles. Burn testing showed that the candles from the sample with hydroxyl ignite a pool fire after burning for 15 to 30 min; the second sample of petroleum based wax candles, those that did not have the hydroxyl compound, did not ignite a pool fire. This suggests that the hydroxyl compound reduces the flashpoint of the wax to an ignition temperature attained after burning the candle for tens of minutes. Once the hydroxyl compound petroleum based wax melts and reaches a temperature above its flashpoint/flame point, it vaporizes sufficiently to be ignited, with flame extension of 152 mm (6 in) or more above the wax pool. This flame extension or “flaring” represents a significant fire hazard in that it may ignite nearby combustibles or fracture the candle’s glass container and release burning wax.     

Development of materials specifications and emplacement procedures for backfilling nuclear fuel waste vaults

Atomic Energy of Canada Limited and Ontario Hydro are conducting a research program to assess the environmental impact and safety of the concept of disposal of nuclear fuel waste in an underground vault in plutonic rock of the Canadian Shield. The Vault Sealing Program, one of the components of the Nuclear Fuel Waste Management Program, is concerned with the development of materials specifications and emplacement procedures for backfilling the vault. Backfilling materials would surround the nuclear waste containers and fill all vault openings to minimize leaching and movement of radionuclides. This paper presents the procedure followed to select candidate backfill materials, the integration of mathematical modelling studies and physical testing for the definition of materials specifications, and the principal elements of the recommended handling and emplacement systems.     

Phylogenetic diversity of aqueous microorganisms separated after the advanced tertiary of tap water

The species composition of bacterial community of the drinking tap water and water samples taken at different purification stages of the water conditioning plant at an enterprise producing special drinks has been analyzed. This study involves the analysis of 16S rRNA gene sequences and the use of molecular biology methods based on the phylogenetic analysis. The following bacterial species were identified: Bacillus nanhaiensis, Brevibacterium frigoritolerans, and Lysinibacillus fusiformis. All the studied strains belong to phylum Firmicutes, class Bacilli representing Gram-positive microorganisms that are not pathogenic to human. The presence of the bacteria investigated in different habitats such as the drinking chlorinated water, in the presence of stress factors (arid climate, high or low temperatures, depleted soil, and the occurrence of disinfectants) indicates their ability to easily adapt to new living conditions expanding their habitat.     

Legislation and administration of inground waste disposal in new South Wales and Victoria,Australia

Legislation and administration of waste disposal is primarily a State and Local Government responsibility in Australia. The legal and environmental principles that form the base of present and possibly future legislation and administration are described. Some problems are discussed and in particular that of legal retro-responsibility for wastes. New South Wales and Victoria have different legislative and administrative systems. Both are complex with many overlapping Acts. The role of the recently implemented Environment Planning and Assessment Act (1979) on siting waste facilities in N.S.W. in discussed. Control of disposal in Victoria is decentralized whereas in N.S.W. management is focussed in the Metropolitan Waste Disposal Authority.     

Enhancement of fire protection with directional cooling spray nozzles by use of AFFF

This paper will describe the work done and results of the study to characterize various directional cooling spray nozzles when used with Aqueous Film Forming Foam (AFFF) Agents.     

Reading Through a Plan

Problem: Planners may read plans often, but the profession continues to view the interpretation of plan content as something that is either too obvious or too unimportant to require explicit discussion. Plans are seldom adequately interpreted. This is regrettable because plans contain a rich variety of content and meaning.

Purpose: This article calls for planners to “read through” plans, not just to grasp their essential ideas or the means of implementing those ideas, but also to perceive additional levels of meaning relating to a) a plan's place within a larger intellectual sphere, b) a plan's statement on the social and political values of the time, and c) a plan as a part of the history of the planning profession and the life of cities.

Methods: I propose a visual approach to plan reading descended from Panofsky's (1939 Panofsky, E. 1939. Studies in iconology: Humanistic themes in the art of the Renaissance, New York, NY: Harper and Row.  [Google Scholar]) theory of iconology and use this to examine three very different plans that describe different size cities (small, large, very large) during different periods over the past 80 years (the 1930s, 1960s, 2000s). I analyze three levels of meaning in each plan: its factual meaning, or “plain sense” (Mandelbaum, 1990 Mandelbaum, S. J. 1990. Reading plans. Journal of the American Planning Association, 56(3): 350–358. [Taylor &; Francis Online], [Web of Science ®] , [Google Scholar]); its contextual meaning, or relation to political, social, economic, and physical conditions; and its temporal meaning, or setting within the scope of observations made by other plan readers in the perspective of elapsed time.

Results and conclusions: Factual readings show that information may be found in diverse aspects of a plan document, from seemingly superficial aspects like its cover to unarguably central elements such as recommendations. Factual readings depend on understanding the relationships among different elements, and reveal information about the plan and its framers that may not otherwise be readily apparent. Contextual readings show us that plan recommendations are as much a product of contemporary conditions and norms as they are of plan-specific “survey and diagnosis” (Nolen, 1936 Nolen, J. 1936. Comprehensive city plan for Dubuque, Iowa, Dubuque, IA: City Planning and Zoning Commission.  [Google Scholar]). This raises the question of whether plan quality is to be judged only in terms of skillful execution of concerns of the day or whether innovation is also important. Temporal readings reveal that plans and planning have changed dramatically over time, simultaneously confirming and questioning the conventional wisdom of planning history.

Takeaway for practice: Many planners read plans on a regular basis, and plans continue to constitute the major printed currency of the planning profession. Both plans and planning will benefit if planners become more discerning readers of the profession's principal idea vessels. Formal plan interpretation is rare, but each planner can become a better plan interpreter.

Research support: None.     

Dilemmatic experiences of young migrants in Accra,Ghana: The merciless hands of pirate urbanization and landlordism

The general pattern of internal migration in Ghana has been north to south. While a number of studies have focused on the vulnerabilities and urban problems associated with this pattern, the dynamics of internal migration with emphasis on young people in a slum setting have not been explored. To accomplish the goal of understanding the dynamics of internal migration among young people from the north of Ghana to Old Fadama, an Accra slum in the south, two specific objectives have been pursued. First, I explore the housing and environmental stressors encountered by young migrants at the destination and their proposed strategies to deal with these stressors and second, I explain how government policies are lagging behind to deal with these stressors. I use insights from the concepts of pirate urbanization and landlordism to show that substandard structures and the monetization of equity (property) among the relatively more privileged in the slum exacerbate the predicaments of these migrants. Drawing on the concepts of sovereign power and non-sovereign power, I suggest that lessons from the elements of these concepts (such as ethnic net-like organizations and governmental agencies) provide entry points for programmatic and policy directions aimed toward these young migrants in a high-risk environment. I use a mixed-methods approach to examine the objectives of this work. Semi-structured interviews and focus group discussions were conducted with young migrants (aged 10–29) in Old Fadama. I find that the major stressors faced by these young people include poor shelter, lack of sanitation, poor health outcomes, and human right violations, and these are exacerbated by the privatization of squatting.     

Comparison of hydrogeologic parameters evaluated by deep well testing programs to assess nuclear waste repository feasibility

Hydrogeologic parameters evaluated for rocks investigated in deep well testing projects for nuclear waste repository feasibility are transmissivity, hydraulic conductivity and storativity. Such studies have been carried out in rock formations of different geologic types, origins and ages for nuclear waste management agencies in North America and Europe. From transient pressure testing, an assessment of static pressure in selected fracture zones was measured from which a profile with depth was developed using modelling techniques. As well, temperatures of formation fluids and hence thermal gradients have also been provided. Hydrogeologic parameters are commonly used in risk analysis for repositories with respect to the possible escape of contaminants and worst case scenarios. The parameters are related to the rate of possible radionuclide migration into the biosphere. The techniques of the investigation and analysis methods of this work have been fully described in the literature. This paper is the first to date, however, to compare results from testing in differen geologic environments. High transmissivity zones have been observed in the upper few hundred metres of granite formations. Below that depth, the rock is more competent and discrete zones of higher permeability occur less frequently. Our studies show, however, that in these rocks, zones of high hydraulic conductivity do not always correspond to zones of high fracture frequency. Most formation pressure profiles have a vertical gradient of about 10 kPa/m. In discrete zones, deviations from this trend can occur due to vertical inhomogeneity in the rock. Thermal gradients vary considerably from one investigation site to another. For example, in the Canadian Shield, gradients are of the order of 1.0 degree C per 100 m, whereas in similar rock types in Europe, the gradient is up to 4.0 degrees C per 100 m.