bluuebunny/crossref_metadata_2025_split huggingface dataset:
An investigation of primary permeability in strata from a mine in the Eastern Transvaal Coalfield, South Africa
Authors: Bell F.G. , Jermy C.A. 
Published: November 2007

Excessive development of methane and water pressures were believed to be a contributory cause of roof fall in a coal mine in the Eastern Transvaal Coalfield. Accordingly, a laboratory investigation of the primary permeability of the strata enclosing the coal seam concerned was undertaken. The principal aim of the investigation was to see if there was a relationship between the various facies of the coal bearing strata and changes in permeability. In this way it may be possible to determine likely zones of pressure build-up.
Permeability testing was carried out on drillholesamples using modified versions of the Ohle cell, the Bernaix cell and the Hoek triaxial cell. The use of the Hoek cell allowed testing to be carried out under different stress conditions. Nitrogen, methane and water were used as the permeating fluids. The liquid equivalent permeability of each sample was determined for the two gases. The permeability tended to decrease with increasing pressure when the two gases were used as the permeating fluid but not when water was used. In addition, the permeability was influenced by the grain size of the material tested and by the direction in which it was tested, that is, along or across the bedding. Hydraulic fracturing occurred in some specimens when tested at high water pressures in divergent flow in the Bernaix cell. An increase in hydrostatic pressure, confining pressure or axial pressure gave rise to a reduction in permeability in triaxial testing, the former giving rise to the greatest and the latter the least decrease. Staged loading showed that the greatest reduction in permeability occurred during initial loading. On cyclic loading the liquid equivalent permeability decreased with increasing applied stress and then increased with subsequent reduction in stress.
Reconnaissance tracer tests in the Triassic sandstone aquifer north of Liverpool, UK
Authors: Streetly H.R. , Hamilton A.C.L. , Betts C. , Tellam J.H. , Herbert A.W. 
Published: November 2007

Three tracer tests were carried out by slug injection of fluorescein, amino-G-acid, and bromide at piezometers with 0.4 m long intake zones located 5 m distant from an 80 m deep pumping borehole. The piezometer intake zones were about 2 m (Tests 1 and 2) and 18 m below static water level, and the pumping borehole was sealed using a packer at about 11 m (Tests 1 and 2) and 19 m below static water level. Analytical expressions were used to interpret the data. Test 2 was unsuccessful.
Four pathways were discernible from the Test 1 tracer breakthrough curves. These pathways were interpreted as being due to three dominantly fracture routes and one dominantly intergranular flow route. The earliest (sharp) peak arrived after a few hours, and the last (broad) intergranular flow peak arrived after around 40 hours. Fluorescein was delayed slightly (retardation factor = 1.4) relative to the other tracers. In the deeper Test 3, three pathways were discernible, with concentration peaks at about 9, 25, and 78 hours. Fluorescein was delayed relative to amino-G-acid (retardation factors = 1.25 and 1.5) in the second and third pathways. As with the first test, the last peak was very broad, suggesting a variety of intergranular routes through the rock, and possibly the effect of diffusion.
The tests clearly demonstrate the importance and complexity of fracture flow over short distances in the Triassic sandstones, the complexity of the intergranular flow routes, and that different retardation factors can be associated with different pathways.
The development of a new testing protocol for sulphur compounds in structural backfills
Authors: Czerewko M.A. , Cripps J.C. , Reid J.M. , Duffell C.G. 
Published: November 2007

The presence of sulphur compounds in soils and rocks can lead to chemical attack on construction materials such as steel and concrete when these materials are used as backfill to structures. Sulphate attack on concrete is a well-known phenomenon and BRE guidance to some of the causes and prevention measures has been available for some time. However, recent cases of the corrosion of corrugated steel buried structures and thaumasite attack on concrete bridge foundations have highlighted the role played by sulphides such as pyrite. The sulphides can oxidise, producing high sulphate concentrations and acid conditions, which can then attack construction materials. Present methods of assessing corrosion potential tend to concentrate on sulphate and pH, and do not fully address the problem of sulphides.
This paper describes research carried out by TRL Limited and the University of Sheffield for the Highways Agency that aimed to develop better test methods for sulphur compounds in structural backfills. Advances in chemical test methods such as direct determination of sulphur by ICP-AES and novel methods of extraction have been investigated and compared with traditional methods for a range of materials with widely varying sulphur contents and mineralogy. The research led to recommendations for a revised suite of tests for sulphur compounds in structural backfills, appropriate methods of sampling and storage and limiting values for species such as reduced sulphur which are not covered by existing guidance. The research will be implemented by means of revisions to the relevant sections of the Specification for Highway Works and Design Manual for Roads and Bridges.
The paper also aims to highlight the distribution of naturally occurring sulphur species within the UK geological materials. As a result of inadequate sampling, storage and assessment procedures, these sulphur species may cause problems to buried steel and concrete structures.
The mineralogy and phase equilibrium of Keuper Marl
Authors: Davis Allen George 
Published: November 2007

Summary
Previously, it has been suggested that the existence of a variable clay mineralogy was responsible for the anomalous engineering behaviour of Keuper Marl. Using x-ray diffraction techniques and chemical analyses, it is shown here that 80 per cent of the samples examined fall in the mineral suite illite-corrensite-carbonates-quartz-hematite, and that there is good evidence that this mineral assemblage has attained phase equilibrium.
Calculation of the true clay mineral content of the samples analysed shows that much of the clay content is aggregated into silt size units, which accounts for the large range of measured Activities.
Classification tests on African red clays and Keuper Marl
Authors: Sherwood Philip Thomas 
Published: November 2007

Summary
This paper describes the results of soil classification tests carried out on African red clay soils from Kenya and soils from the Keuper Marl formation in England. It shows that in both groups of soils aggregations of clay particles can occur and give rise to anomalous classifications of the soils when they are tested by standard procedures.
The manner in which the particles are cemented together is different for the two groups of soils. In the case of the red clay soils the aggregations give rise to low plasticity values being obtained whereas in the case of the Keuper Marl soils they give rise to low clay contents being obtained when the particle size distribution is determined by sedimentation techniques.
The reason for the aggregation in the red clay soils is shown to be the presence of free iron oxide cementing the particles together. Silica is shown to be the most likely cementing agent in the Keuper Marl soils.
Apart from the aggregation of the Keuper Marl soils there is evidence that non-aggregated clay particles in excess of 0·002 mm diameter are also present. This is an additional reason for anomalous particle size distribution results being obtained for these soils.
Site investigations in coalfields
Authors: Taylor Roy Kenneth 
Published: November 2007

Summary
The paper primarily considers the diagnosis and evaluation of shallow workings from which coal, ironstone and fireclay have been extracted by underground methods close to outcrop. Instability problems affecting normal structures are mainly attributed to 'room and pillar' workings, and current work on the behaviour of the latter is briefly discussed. The resultant compaction of collapsed strata (goaf) is problematical and evidence is presented which throws doubt on the compaction of 'bell-pit' workings of probable mediaeval age.
Investigation techniques are discussed in detail and attention drawn to the importance of geological structure, particularly faults. Associated 'steps' caused by differential movements are not always fully appreciated. The detailed case histories are taken from the Yorkshire coalfied and consider urban development, re-development and a major road project.
It is concluded that exploration on an areal basis is necessary if all the factors connected with shallow workings and other industrial legacies are to be fully elucidated. In order to rationalize techniques it is advocated that larger investigations should comprise more than one stage. A detailed pre-survey appreciation of the available mining, industrial and geological literature is an integral part of this type of project, and the full co-operation of all the parties involved should stem from this period.
The structure of Keuper Marl
Authors: Davis Allen George 
Published: November 2007

Summary
Calculation of the true clay-mineral content of samples of Keuper Marl analysed has shown that much of the clay content has been aggregated into silt-size units. This aggregated structure accounts for the large range of measured Activities of the Marl.
A system of structural classification used in pedology will conveniently describe the structural features of the more heavily aggregated, overconsolidated clay soils such as Keuper Marl; some preliminary work with the electron micro-probe analyser supports this method of describing soil structure.
It is suggested that variations in the structure of these sediments indicate varying conditions of deposition and diagenesis, and are related to differences in the magnesium content of the samples analysed.
The microstructure of London Clay
Authors: Tchalenko John Stephen 
Published: November 2007

Summary
The microstructure of London Clay from several localities and depths was examined in thin section under the polarizing microscope. Except where severely weathered the clay was found to have a strong preferred particle orientation and frequent microscopic discontinuities. These features are compared with those observed in the study of some other clays. The microstructure of an artificially sedimented and consolidated sample of London Clay helps us to understand the origin of the microstructures observed in the natural specimens.
Ground-water conditions in Greater Tehran
Authors: Knill John Lawrence , Jones Kenneth Stuart 
Published: November 2007

Summary
Tehran is situated on an alluvial plain immediately south of the Alborz Mountains which form an east-west chain stretching across northern Iran. The alluvium is composed of an older, folded group, of probable Pliocene age, which is overlain by flat-lying Quaternary gravels, sands, silts and boulder beds. Recharge from surface streams takes place in the areas underlain by the flat-lying alluvium. The pattern of ground-water flow is related to the sub-surface structure of the alluvium. Chemical data are presented which indicate that extensive surface recharge takes place below the city. The ground-water balance is discussed and it is concluded that, at present, there is a balance between inflow and abstraction.
Classification tests on African red clays and Keuper Marl
Authors: Davis A. G. , Birch N. , Chandler R. J. 
Published: November 2007

From
A. G. DAVIS, N. BIRCH & R. J. CHANDLER:

The author has produced some useful data on the influence of aggregation on the index properties of red clays and Keuper Marl, in particular confirming that the apparently silty nature of Keuper Marl results from the aggregation of clay-mineral particles. We would however like to take up some points made by the author with reference to Keuper Marl.
One point on which we wish to comment is the assumption made by the author that in determining the liquid limit, further mechanical working beyond the 10 minutes specified in B.S. 1377 did not increase the liquid limit. This occurred in spite of an apparent increase in the measured clay-size fraction. The author further assumed that prolonged pre-treatment mixing was sufficient to break down all aggregations, leaving some of the clay-mineral fraction having particle diameters larger than 0–002 mm.
In Fig. 1 we show the variation of liquid limit with mixing time for two similar marl samples. Mixing was carried out in a Hobart paddle mixer which could take a sample of about 1/8 cu ft. It is seen that the liquid limit increased appreciably above that obtained using the B.S. 1377 method. Clearly for this particular marl the liquid limit increases with further working, though we hesitate, in view of the variable nature of Keuper Marl, to state that this will be the case for all marls. We do however question the use of the greaseworker as a substitute for mechanical working
Classification tests on African red clays and Keuper Marl
Authors: Sherwood P. T. 
Published: November 2007

AUTHOR'S REPLY:
Davis, Birch & Chandler raise a number of points which I shall deal with in order of importance:
(1) They state that, “they see no reason to depart from the B.S. procedures for index [plasticity] tests on Keuper Marl”, and elsewhere they quote a sentence of my paper out of context which may leave the reader with the impression that I think that B.S. plasticity test results on Keuper Marl soils give anomalous results.
In fact, I fully agree that there is no reason to depart from B.S. procedure for the plasticity tests on Keuper Marl; I have never suggested otherwise, either in my paper or elsewhere.
My paper shows that the aggregations of particles in Keuper Marl are broken down by the mixing procedure specified in B.S. 1377 (i.e. 10 minutes' working with palette knives on a glass plate) and that consequently the results obtained are the ultimate values. Evidence for the B.S. results being the ultimate values is provided by:
(a) Table 3 of my paper which shows that the liquid limit reaches its ultimate value after ten minutes' mixing;
(b) the fact that the plasticity data obtained by B.S. procedure correlates well with the clay content obtained by mineralogical analysis (Fig. 2 of my paper);

(c) the correlations between liquid limit and other soil properties listed in the fifth paragraph of the comments of Davis
et al.

(2) Figure 1 of the comments by Davis
et al.
shows that for the particular marl studied by
Classification tests on African red clays and Keuper Marl
Authors: Coleman J. D. 
Published: November 2007

From
J. D. COLEMAN:

I write to support and amplify the conclusions (p. 54) of this author concerning the fabric of African red clays and Keuper Marl. It is clear that:
(1) The properties of undisturbed engineering soils may differ from those of a simple mixture having the same composition as the soil.
(2) The differences may arise because the mineral grains in the soil are not in random positions, but have a structure within the soil resulting from the sedimentation, chemical and stress history.
(3) The structure may be physically stable, or preserved in the soil by cementing agents derived from the chemical history. Crystalline cements may be detected optically or by x-rays, but fine amorphous cements may be detected by a chemical/mineralogical mismatch as shown by Sherwood for Keuper Marl.
(4) Sherwood has also shown that where cementing agents are present, the normal soil classification tests may give misleading results, and research based on soil chemistry may be needed.
May I add that research based on soil physics leads to similar structural conclusions for African red clays. Thus, their reflexion spectrum has been used (Coleman 1965) to show that the colouring agent (disordered alpha ferric oxide in one instance) is present mainly as a particle coating, and moisture-sorption studies suggest that the coating is porous, so that the soils may have a moisture content in the field as high as 30 per cent.
J. D. Coleman
Soil Physics Laboratory, Department of Civil Engineering, The City University, London e c
Site investigations in coalfields—the problem of shallow mine workings
Authors: Short A. G. 
Published: November 2007

From
A. G. SHORT:

I congratulate the author on his paper and his outline of the methods of investigating old, shallow workings. This is one of the most difficult parts of any investigation, and it is one where laboratory testing and theory cannot be relied upon. The successful evaluation of a site underlain by workings must be dependent on a knowledge of the geology of the area and methods of working, boreholes, excavations, powers of observation and considerable experience in this work.
The author indicated a maximum depth of bell-pits in the order of 40 ft. In his book on Derbyshire, Farey(1811) gives an interesting description of this type of working and quotes 10 yd as a maximum depth. This is almost certainly an understatement, and Pilkington (1789) stated that it was usual not to descend lower than 18 yd.
Electrical-resistivity methods of survey can give a reasonable degree of success under certain site conditions. I have a slide of the iso-resistivity lines produced from a survey where the existence of an adit was proved. Negative results, however, cannot be interpreted as indicating undisturbed ground or the absence of old workings. Reference was made to the site in Doncaster which was underlain by old galleries in the Bunter Sandstone at shallow depth. Access was obtained to the galleries and a full survey carried out.
A. G. Short 26 Abercrombie Street, Chesterfield, Derbyshire, Farey (1811) gives an interesting description of this type of working and quotes 10 yd as a maximum
Mechanism of the alkali-carbonate rock reaction
Authors: Gillott J. E. , Swenson E. G. 
Published: November 2007

Summary
This paper reviews the main hypotheses proposed for the alkali-carbonate rock reaction, and presents evidence supporting the mechanism advanced by this laboratory. The latter postulates that the alkali-expansivity of certain carbonate rocks containing dolomite is due to a wetting of previously unwetted clay minerals; the wetting is made possible by the de-dolomitization reaction which produces access channels for moisture.
The new evidence consists of (a) no volume change of pure dolomite crystals immersed in 2M NaOH for 4 months; (b) the decreasing expansion of solid plus liquid of rock powders in 2M NaOH with increasing particle size of pure dolomite, using a dilatometer technique; (c) the observation from scanning electron micrographs of alkali-reactive and non-reactive rocks that much of the clay constituent appears to be distributed close to the dolomite rhombs, thus accounting more readily for the idea that dedolomitization opens up channels for moisture to gain access to the clay; and (d) a detailed study of some 50 carbonate rocks from the highly calcitic to the highly dolomitic with special emphasis on petrographic examinations and their correlations with results of laboratory performance.
Influence of boundary effects on the packing and porosity of granular materials
Authors: Lees Geoffrey 
Published: November 2007

Summary
External boundaries, i.e. the walls of containers, and internal boundaries, for example, reinforcement bars, exert an influence on the packing and hence porosity of granular particles. Many attempts, both theoretically and practically based, have been made to establish correction factors for this influence so that the porosity of a material in one container could be predicted from its known porosity in a different container. The limitations of such approaches are discussed and the general conclusion reached that although these methods may be of use for containers and particles of certain shape and for circumstances where the particle size does not approach the size of the container, they are not universally applicable to containers and particles of all shapes or to cases where the aggregate size approaches the size of the container.
The consequent conclusion is made that where it is desired to know the porosity in a given container, for example where such knowledge is a pre-requisite for design of an aggregate grading, there may be no alternative to making the porosity determination in a container of the size and shape in which it is intended the aggregate should ultimately be placed.
The influence of tectonics on the geotechnical properties of Calabrian rocks and the mapping of slope instability using aerial photographs
Authors: Burton Alfred Norman 
Published: November 2007

Summary
The Calabrian peninsula is undergoing rapid degradation at the present time by erosion and landsliding. These phenomena are aggravated by the reduced strength of many of the rock formations forming the peninsula, resulting from Alpine tectonic movements. Maps showing landslides and related features were prepared, with the aid of aerial photographs, in conjunction with the geological re-mapping of the peninsula at a scale of 1 : 25 000.
Studies of inter-particle void characteristics
Authors: Lees Geoffrey 
Published: November 2007

Summary
A method is described for studying certain characteristics of the voids contained within a mass of aggregate particles. Measurements have been made on void cells dissected from single size aggregate systems of a variety of particle shapes in dense and loose packings. The measurements refer to the critical ratio of occupation and the critical ratio of entrance. From these measurements occupation size distribution curves and entrance size distribution curves can be drawn, analogous to particle size distribution curves. The application of the results to the problem of the design of aggregate gradings to minimum or controlled void content, by pre-mixing or filtration techniques, and of the related problem of segregation of mixed aggregates is discussed.
Some
in-situ
permeability tests in sands
Authors: James Peter Michael 
Published: November 2007

1. The site

The construction of a new head barrage for the Muda Irrigation Project, in northwest Malaya, involved knowledge of the
in-situ
permeability of adjacent alluvial sands, in order to determine the extent of sheet pile cut-off needed on one side of the structure.

Figure 1 shows the geological conditions at the site extending from the proposed structure, through the river diversion to the permeability test site.
This profile was determined from a number of earlier boreholes and a seismic traverse made during the initial site investigation of the area. The layer of coarse sands with fine gravel seen on the figure was of particular interest in the test. Figure 2 shows the particlesize distribution of both this layer and the overlying layer of fine sands and clayey silty sands. The clays with sand lenses underlying the coarse granular layer were taken as an impermeable base.
Three 'wells' were used for the permeability tests. These are marked on Fig. 1 as kl, k2, k3. The spacing between kl and k2 was 38 ft and between k2 and k3, 54 ft. The wells were sunk in line and at right angles to the flow of the river.
2. Method of testing
The three permability test wells, each 6 inches in dia., were terminated in the clays below the coarse granular layer. Four-inch internal dia. p.v.c, tubing was inserted inside the cased holes down to the clay stratum and the casing was withdrawn. The bottom 20 ft of the tubes had