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.     

Preliminary analysis of spatial development of karst using a geostatistical simulation approach

Earth science phenomena are primarily spatially dependent with variations occurring on varying scales. Geostatistics is a well-known approach for the assessment of spatial models of regionalized variables, such as porosity. In this study, we used the results of 953 Lugeon tests (402 tests in exploratory wells and 550 tests in grouting wells) to assess effective porosity and karst development at the Tangab Dam site, Iran. Lugeon values were first normalized, following which the variogram method (i.e., range, sill, and nugget effect) was used to identify the spatial variability of Lugeon values. A high correlation range of 200 m was obtained along the grout curtain galleries, while the range was about 40 m in the vertical direction. The simple kriging method with Gaussian variograms was determined to be the best method for estimating the Lugeon values in the study area using cross validation-criteria (e.g., RMSE = 0.835 and ρ = 0.914). Spatial variation of Lugeon values was mapped using a simulated annealing approach. The analysis revealed: (1) a higher potential for karst development on the left abutment of the Tangab Dam site, (2) the average of simulated Lugeon values decreased from values of about 180 close to the ground surface at 1,440 m a.s.l. to lower values of about 50 at 1,260 m a.s.l., and (3) high Lugeon values in the abutments of the dam site approximately followed the 15° bedrock dip, which confirms the potential development of karst features in the Asmari limestone. A schematic model for development of karst at the Tangab Dam site is proposed based on hydrogeological data and results of simulated Lugeon values around the dam site.     

Laboratory testing of pile fabrics — A proposed flammability standard

At the request of the Consumer Product Safety Commission, the National Bureau of Standards developed a proposed standard for the flammability of upholstered furniture. This paper briefly describes the proposed standard and its history, and examines the performance of pile fabrics tested at the University of Washington Textile Laboratories in accordance with the provisions of the proposed standard.     

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.     

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.     

The influence of alteration on the engineering properties of dolerites: The examples from the Pindos and Vourinos ophiolites (northern Greece)

The influence of alteration on the physico-mechanical properties of dolerites from the Pindos and Vourinos ophiolites, northern Greece, is investigated. Quantitative petrographic analysis shows that the samples display various percentages of secondary minerals. Two new micropetrographic indices are calculated from the results of petrographic modal analysis for the engineering assessment of dolerites: the micropetrographic strength index I_ps and the replacement index I_rep. The samples are also tested to determine water absorption, apparent density, total porosity, sand equivalent, uniaxial compressive strength, Los Angeles abrasion value, aggregate impact value, aggregate abrasion value and polished stone value. The influence of alteration on the rock quality and especially the relationships between the proposed micropetrographic indices and the engineering parameters are determined using regression analysis and the derived equations were verified by the t-test and the F-test. The relationships between the I_ps and I_rep indices and the engineering properties show that alteration products generally result in mechanically weaker rocks. However, the results of the physico-mechanical tests indicate that dolerites retain their strength and durability due to the low proportions of soft minerals and microcracks, along with the preservation of their igneous textures. The polishing resistance is the only engineering parameter that is positively affected by alteration processes, as expressed by the I_ps index. Particularly, the replacement of the primary mafic minerals by secondary minerals, expressed by the I_rep index, can enhance the polishing resistance of dolerites when used in the wearing surface of a road. The results also indicate strong positive correlations between the chlorite content and the water absorption and total porosity values.     

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.     

Elastic wave velocities and permeability evolution during compaction of Bleurswiller sandstone

Field observations and laboratory experiments have recently documented the formation of compaction bands in porous sandstones [Mollema and Antonellini, Tectonophysics 1996;267:209–28; Olsson and Holcomb, Geophys Res Lett 2000;27:3537–40; Bésuelle, J Geophys Res 2001;106:13435–42; Klein et al., Phys Chem Earth 2001;26:21–5]. It has been observed experimentally [Wong et al., J Geophys Res 2001;28:2521–4; Baud et al., J Geophys Res 2003, submitted; Fortin et al., 2003, Abstract EGS-AGU Nice] that under axisymmetric compression, compaction bands develop sub-perpendicular to the main compressive stress which is predicted theoretically in the framework of strain localization theory [Bésuelle, J Geophys Res 2001;106:13435–42; Issen and Rudnicki, J Geophys Res 2000;105:21529–36]. Volumetric strain, fluid transport and elastic properties are intimately coupled to one another, for they all depend on a few intrinsic parameters such as the porosity, the crack density, and the matrix and fluid elastic properties. On the one hand, Scott et al. [Rock Mech Min Sci Geomech 1993;30:763–9] showed that elastic wave velocities were clearly affected during the deformation of porous sandstones. On the other hand, Zhu and Wong [J Geophys Res 1997;102:3027–41] showed that the relation between the evolution of permeability and volumetric strain during compaction of sandstones was not straightforward. In this study, we present for the first time the simultaneous evolution of volumetric strain, elastic wave velocities and permeability for a set of deformation experiments of Bleurswiller sandstone. We show that, although very coherent to one another, those three sets are not systematically correlated. Indeed, inelastic compaction, whether it is distributed or localized, is accompanied by a drastic decrease of elastic wave velocities due to grain crushing, a decrease of permeability and porosity due to pore collapse. Using simple statistical physics concepts based on the study of Kachanov [Adv Appl Mech 1993;30:259–445] and Guéguen and Dienes [Math Geol 1989;21:1–13], we try to understand and address the issue of coupling/decoupling between volumetric strain (mainly sensitive to equant porosity variations), elastic properties (mainly sensitive to crack density) and permeability (theoretically sensitive to both) during the formation of compaction bands. Finally, we show that the mineral composition of a sandstone is a key parameter controlling the effective pressure at which the onset of pore collapse P^* takes place.     

Jointing in chalk: The relation to lithology,bedding thickness,drainage pattern,tectonic stress and cavern openings (Eocene,Bet Guvrin Syncline,Central Israel)

In the area of the Bet Guvrin syncline (central Israel), composed mainly of Eocene chalk, series of joint measurements were conducted, and four, almost consistent, sets of joints were traced. Outcrops of sub-horizontal to horizontal layers are divided into: a lower hard well-bedded unit built of chalk, chalky limestone, silicified beds and concretions of flint, and an upper massive soft unit built of homogeneous chalk, marly in places. The difference in joint density between the lower unit to the upper one is remarkable. The higher the limestone content and the increase in bedding planes, the higher the joint density measured. A good agreement was also found between the joint bearings and the drainage pattern. The study of joint systems, their characteristics and control is of prime importance while planning the use of an underground space.     

An investigation into the influence of size on the mechanical properties of aggregates

Tests have been carried out according to British Standard BS 812-1975 on non-standard and standard size aggregates to study the influence of aggregate size on mechanical properties. Dolerite, granite, limestone aggregates of different sizes have been tested. No basic relations have been found between elongation index, I_E, and flakiness index, I_F, and the different aggregate sizes. Aggregate impact value, AIV, aggregate crushing value, ACV, and 10 per cent fines loads, however, are aggregate size dependent. Tests on larger aggregate sizes give higher test values, whereas tests on smaller aggregate sizes give lower values than test results for standard size aggregates. For each rock type there is a different set of sieve sizes, from those recommended in BS 812-1975, which give the same values as the standard sieve sizes. Additionally, relations have been determined for the mechanical test results for the different size aggregates.     

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.     

A simulation approach to recreation planning (A case of changing quality)

Conventional demand based approaches to recreational economics are reviewed and found unsuitable for analyzing the effects of changes of the quality of recreation. An alternative approach using a simulation model is proposed, which allows the use of both quantitative data and subjective input on the qualitative effects. The critical economic variables are found to be fishing recreation visitor days and investment in recreational facilities at the Salton Sea, California. The model results are projected for 20 years and key parameters and assumptions are identified by parametric analysis. These parameters were then subjected to critical interaction by a group of specialists in the area, during a workshop session. Results of the final model are compared to a previous economic study of the region and found to be more pessimistic about the benefits of quality control. Verification of the model is performed by tests of deviation of the predictions of visitor days by the model from the actual visitor days recorded over eight years.     

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.     

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.     

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.     

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.     

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.     

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.