bluuebunny/crossref_metadata_2025_split huggingface dataset:
The hydrogeological investigation of fissure flow by borehole logging techniques
Authors: Tate A. K. , Robertson A. S. , Gray D. A. 
Published: November 2007

The variety and sophistication of the equipment which the authors have at their disposal are impressive, as are the data obtained and the conclusions reached.
It is opportune, however, to acquaint readers with an additional tool in the armoury of the hydrogeologist: radio active tracers.
In Rhodesia the majority of boreholes are sited in the crystalline rocks (granites, gneisses and the highly metamorphosed volcanics and sedimentary rocks of the Basement Complex) where the aquifer consists of fissured or decomposed rock.
The delineation of fissures and zones of flow and the estimation of natural through-flow is, at times, of considerable importance.
Radio active tracer in the form of Iodine 131 is emplaced in the borehole, at 3 or 4 points in the water column, by a simple injection device whereby the isotope ampoule is shattered by a messenger sent along the wire holding the tracer ampoule. Either compressed air or the drill bailer is used to mix the tracer uniformly throughout the water column. Subsequent monitoring with a nuclear detector at time intervals reveals the zones of flow. We have used both the pulse/velocity method and the Total Count Technique, (which is uniquely applicable to radio tracers) to quantify the flow into or out of the borehole at the particular zone. Further, a quantitative measure of through-flow in the borehole as an entity can be obtained.
The direction of flow can also be determined by use of a collimated detector which is rotated through 360° at the required horizon. The position
Engineering geology of the Gordon Dam, South West Tasmania
Authors: Andric M. , Roberts G. T. , Tarvydas R. K. 
Published: November 2007

Summary
The Gordon Dam is a double curvature concrete arch structure 140 m high, forming part of a hydro-electric scheme. The dam is sited on folded and faulted Precambrian quartzite. Driving adits was favoured over diamond drilling in siting the dam and for detailed investigations to prove the stability of the foundations.
Considerable excavation on the left abutment was necessary to remove unfavourable rock and a continuous pre-split face of 122 m was produced.
The geological conditions found during excavation were better than anticipated thus raising the computed factor of safety.
Mudrocks of the Devonian
Authors: House M. R. 
Published: November 2007

Introduction
Around the close of the Silurian, but with associated igneous and volcanic events lasting well into the Devonian, occurred the major phase of the Caledonian Orogeny. The main mountain belt resulting from this, stretched from the joined area of Spitsbergen, E Greenland and Norway SE for some 4000 km, the belt being up to 600 km in width. Detritus from the erosion of this belt produced the Old Red Sandstone deposits of Ireland, Wales and Scotland with extensions in the early Devonian into southern England. Later, south of the Bristol Channel to Thames Estuary line, elastics were laid down mostly under marine conditions with a transitional zone in N Devon.
Mudrocks in the Devonian thus occur in several distinct sedimentary regimes: in the north, terrestrial facies (Old Red Sandstone) formed as intermontaine basins and lacustrine areas in Scotland, and as alluvial and pedogenie facies of extensive coastal plains in southern Wales and, whilst usually thought to consist of coarse and red arenites, do, in fact, include in aggregate significant proportions of usually poorly-sorted, fine-grained rocks. The near-shore marine deposits (Rhenish facies) include mixed arenite/pelite/carbonate sequences in which the pelites may be thick. But it is in the offshore and basinal areas (Hercynian facies) that mud-grade sediments reach their finest development, seen especially in Cornwall, where successions of little else total several thousand metres. These are now in the form of indurated and cleaved argillites forming most of the ‘killas’ of southern Devon and Cornwall.
The areas of outcrop of
Laboratory investigation of mudrocks
Authors: Taylor R. K. , Spears D. A. 
Published: November 2007

Summary

The problems associated with mudrocks are largely controlled by their lithology and degree of compaction, their susceptibility to water (volume change), the high frequency of discontinuities and their anisotropic character. It is in ground engineering where difficulties are most frequently encountered and for this reason the laboratory investigation is directed towards these issues. Mudrocks are distinguished for these purposes as argillaceous sediments containing more than 500y weight of clastic grains of less than 60 ώm in size. They can range from
very strong
indurated Palaeozoic mudstones to
stiff
over-consolidated clays of the Jurassic, Cretaceous and Eocene sequences.

Because the spectrum of types is so wide, the laboratory investigation is considered as a testing programme which is itself determined by known mudrock behaviour. In this way the rationale behind the test modules is developed under the following sectional titles: I. index tests and classification; II. bearing capacity and settlement; II. physical effects of water; IV. mineral changes and porewater chemistry; V. stability of slopes; VI. mine and tunnel considerations.
Attention is drawn to specific references (and standards) in which details of advocated laboratory tests and methods may be found.
C. D. W
arren
writes
Authors: Warren C. D. 
Published: November 2007

The author is to be congratulated on a most interesting paper, but with regard to the use of the computerized data bank of borehole records for the Jubilee Line investigation it should be emphasized that the data bank was not programmed to include such detail as the presence of hard limestone bands, flint beds and minor lithological variations along the route. This detail was added from existing borehole information.
Furthermore, since the computer was not programmed to include a break and known throw across faulted areas, faults were represented by steep monoclinal gradients between definitive boreholes. For example, Fig. 1, which is based on approximately 2500 boreholes covering the London area, shows the Raynes Park and Greenwich faults south of the Thames river as monoclinal flexures superimposed on the general geology.
Some of the differences between the real and predicted geologies for the Jubilee Line can be explained by lack of previous borehole data along certain sections of the route and this was taken into account in the siting of the investigation boreholes.
On the engineering properties of salina soil
Authors: Stipho A. S. 
Published: November 2007

Summary
Subsoil in desert regions is a product of temperature changes, wind and rainfall. Soil in a subtropical climate, such as that of Saudi Arabia, would be the best representative example for the study of soil condition in arid and extremely arid regions. A high temperature climate increases evaporation and reduces moisture in the soil, resulting in development of salt-bearing soil. Depending upon some geological, climatic considerations salt content in Saudi Arabia soil is invariably high. Understanding and anticipating the nature of changes in such considerations and the associated geotechnical problems in these regions is very important for practising engineers in the area. This is particularly important during the design and construction stage, in order to evaluate and solve unforeseen problems. The foundation problems which arise due to various concentrations of sodium or calcium chlorides in desert soils are pinpointed and discussed. The influence of the salt on the laboratory-observed properties of desert soil is investigated.
Field techniques using borehole packers in hydrogeological investigations
Authors: Brassington F. C. , Walthall S. 
Published: November 2007

Summary
As part of a hydrogeological investigation in a Permo-Triassic Sandstone aquifer in northwest England, various methods of field permeability testing have been developed and evaluated. These techniques involve the use of borehole packers to isolate specific test sections and permeability measurements made by either injection or pumping tests. Field results have been compared with both laboratory permeability measurements and conventional pumping tests. The test procedures were found to have a significant effect on the results obtained. Packers have also been employed to examine the vertical distribution of piezometric heads within an aquifer, both in pumping and non-pumping conditions, and to obtain groundwater samples from selected horizons. Some of the test results are presented to illustrate the value of packer techniques in hydrogeological investigations.
Discussion on ‘The stabilization of some arid zone soils with cement and lime’ by G. Akpokodje
Authors: Clarke J. D. , McMahon P. H. 
Published: November 2007

Whilst investigating the use of cement stabilized minestone (discard from coal mining operations) as a structural element in a highway pavement, a number of soaking tests were conducted using a similar procedure to that described by the author. The results were broadly similar to those shown in his table 4 with soaked strengths (calculated as percentages of normally cured strengths), shown below in Table 1.
Observations made during these tests have provided an opportunity to re-appraise the philosophy of the experimental procedure.
The mechanism for strength changes described by the author is widely accepted and the comments relating to salt content are particularly useful, but the test procedure is not sufficiently investigative and merely reflects conventional wisdom with respect to water adsorption by clay soils and volume changes imposed by sulphate-cement reactions.
Water absorption by clay minerals is a function of mineral type and of previous stress history. Those clays which have been subject to diagenetic changes imposed by high overburden pressures react quite differently from geologically ‘young’ clays with respect to swelling characteristics as an inspection of e-σ′ curves will show. The strength reduction mechanism for soaked specimens of cement stabilized materials containing clay shale is probably related to the generation of excess pore water pressures caused by a combination of the applied load and the free water held in the voids of the material. Measurements of mass increase after 7 days soaking confirm water uptake but these are not balanced by contributory volume changes.
For the mixing moisture
The cliff face under the Clifton suspension bridge, Avon Gorge, Bristol
Authors: Hawkins A. B. 
Published: November 2007

For many years, blocks of rock have occasionally fallen from the slope of the Avon Gorge on to the A4 road (the Portway), which runs along the eastern side of the Gorge. Indeed, there is no reason to believe this was not a hazard long before Brunei designed the impressive suspension bridge over the river.
The photograph opposite shows the general area at the eastern side of the Gorge the bridge tower being almost directly at the top of a sub-vertical rock cliff face, about 75 m high. The photograph also shows a number of fractures, aligned almost parallel to the rock face. It does not show the partially dissolved fracture, about 300 mm wide, which can be seen from the Portway in the cliff immediately behind the eastern tower.
In the late 1970s, the owners of the cliff face and the highway authority both became increasingly conscious of the danger of falling blocks and instigated a study to determine most effective and economically viable course of action. Although it was considered that bolting and meshing could provide a solution, it was felt that long-term security and environmental requirements would best be served by the construction of a canopy.

Figure 1
shows the fractured nature of the rock when it was inspected after the face had been cleaned of all vegetation. The sub-parallel tectonic-stress induced fractures are clear, as is the broken state of the limestone beds.

Figures 2
and
3
show the detailed state of the rock when inspected.
Laboratory measurement of the thermo-hydro-mechanical properties of rock
Authors: Elliott G. M. , Brown E. T. 
Published: November 2007

The need to exploit further a number of potentially important energy resources has necessitated a better understanding of the behaviour of rock at elevated temperatures. This paper describes a testing facility capable of testing medium sized cylindrical rock specimens under confining pressures to 140 MPa, pore pressures to 105 MPa, axial loads to 2.67 MN and sample temperatures to 400°C. Descriptions are given of the procedures and techniques used in the test facility to carry out triaxial compression tests, permeability and thermal conductivity tests, and measurements of the coefficient of linear thermal expansion. Data for a granite and a sandstone are given and discussed briefly in order to illustrate the wide-ranging capability of the test facility to meet many of the perceived needs for research into the thermo-hydro-mechanical behaviour of rock.
In addition to these basic types of test, an example is given of the use of the test facility to simulate in situ conditions in order to observe the response of the rock to engineering procedures.
Analytical photogrammetry: a method for monitoring slope instability
Authors: Chandler J. H. , Moore R. 
Published: November 2007

Abstract
Developments in analytical photogrammetry provide the engineering geologist and geomorphologist with a quantitative technique capable of monitoring slope instability from ground or oblique aerial photographs. This paper outlines ‘analytical’ photogrammetry and its applications to the study of slope instability. Procedures and developments in data processing are described that enable both a morphogenetic analysis of slope form and the derivation of displacement vectors for monitoring unstable slopes. The methods are illustrated by research work carried out by the authors in Nepal and southern England.
The influence of macropores on debris flow initiation
Authors: McDonnell J. J. 
Published: November 2007

Abstract
Soil structure affects the movement of water in hillslope soils and therefore exerts a strong influence on slope stability. A debris flow is analysed within the confines of an instrumented catchment on the South Island, New Zealand, in order to examine the influence of soil macropores on slope stability. Tensiometric and slope throughflow data for nearby slope areas show that vertical cracks conduct rainfall at rates well in excess of the mineral soil matrix conductivity. The presence of a well connected pipe system at the soil-bedrock interface distributes this water quickly downslope. Under exceptionally high rainfall intensities, however, this crack-pipe system may induce slope instability by increasing the rate of infiltration over lateral pipeflow rates. This results in a build-up of pore pressure at the soilI–rock interface and subsequent slope failure.
Gas migration studies at a disused mine to detect possible rock fracture patterns and the extent of underground workings
Authors: Sibley R. D. 
Published: November 2007

Abstract
Bushdown Mine in southwest England was operational in the late 18th to early 19th Centuries for the extraction of tin. Natural concentrations of five soil gas components were investigated across the probable position of an adit. The gas variations detected are attributed to the presence of the adit and the near-surface enhanced fracturing thought to be associated with it. A tracer gas was released underground near the collapsed end of another adit at shallow depth. A programme of monitoring at a series of locations on the surface indicated the emergence of the gas a few hours after its release. The increase of tracer gas at the surface and the time lapse between gas release and measurement of the maximum increase is attributed to increased permeabilities along preferential gas migration pathways leading from the adit.
Comparison of interpretations of a major landslide at an earthfill dam site in Papua New Guinea
Authors: Fookes P. G. , Dale S. G. 
Published: November 2007

Abstract
An earthfill tailings retention embankment across the Ok Ma valley in a remote tropical rainforest area of western Papua New Guinea was abandoned during construction in early 1984 because of a very large landslide that occurred in the eastern abutment of the dam. Ensuing litigation between the mine owners and their insurers brought together highly qualified and experienced geotechnical experts. The experts developed their own views on the form, nature and mechanism of the landslide which occurred in limestone colluvium and Miocene mudstone bedrock.
After preliminary studies and site investigations, work for the mining company on the tailings dam was carried out as a design-and-construct package by a major consortium. Sub-sequent design investigations used most of the available techniques, including aerial photograph interpretation, seismic traverses, pitting, drilling and in situ and laboratory testing, all carried out by experienced specialist companies. Although concern was expressed on various aspects of temporary and permanent slope stability, the large size of the landslide came as an unforeseen event.
This paper presents the authors' interpretation of six different models proposed for the landslide by various authorities who worked on the case. This has been done to illustrate the difficulties in attempting a precise interpretation of a large landslide and as a commentary on the state of the art on the subject.
Clay linings to landfill sites
Authors: Murray E. J. , Rix D. W. , Humphrey R. D. 
Published: November 2007

Abstract
Seepage of leachate or the migration of noxious gases from landfill sites can pollute the ground and groundwater to a considerable distance from the source of the problem. Current trends and legislation dictate that future practice at waste disposal sites will be to provide a lining capable of eliminating or minimizing the migration of contaminants. Geotechnical considerations in the design and construction of low-permeability clay linings are addressed and laboratory test results for a range of clay types are presented in support of the arguments. The use of the moisture condition value (MCV) test in the selection of acceptable materials and the control of earthworks operations is discussed. A permeability requirement of no greater than 10-9 m/s for the clay lining dictates the upper limit to the acceptable MCV range while the shear strength dictates the lower limit.
Bedding karst and multilayered groundwater flows in karstic block mountains in the northeast of Mount Xishan, Taiyuan, China
Authors: Zhang Dachang 
Published: November 2007

Abstract
The hydrogeology of the northeastern part of Mt Xishan has historically been interpreted in terms of a simple unconfined aquifer model. The groundwater required is characterized by (1) karst terrain, (2) multilayered unconfined groundwater flow developed in block mountains involving rapid hanging discharges and (3) deep confined groundwater with a carbon 14 age of 1000–2800 years and low tritium content. The flows are partly towards the southern part of Mt Xishan, partly east towards the porous aquifers of the Nitun Basin and partly discharging through the Lancun Spring system.
The spatial structure of karst aquifers in block mountains is elucidated by an understanding of stratigraphic, structural, lithological, climatic and karst geomorphological evolution. The actual complex hydrogeological conditions in the Mt Xishan area considered are demonstrated by a comprehensive model proposed by the author. Such a model may also be applied in other karstic block mountains.
Recharge of the Lower Greensand aquifer at Slough, England
Authors: Egerton R. H. L. 
Published: November 2007

Abstract
The Lower Greensand beneath Slough has provided a constant and reliable supply of high quality water to local industry since 1909. The source of this water has always been uncertain and it is thought that it is either derived from storage or recharged from the outcrops. An alternative explanation is presented that assumes downward leakage from the Chalk through the Upper Greensand and Gault, together with recharge occurring under the Chilterns to the north of Slough. The clay minerals in the Gault have removed the calcium ions, thus softening the water. The mineral glauconite in the Lower Greensand and other factors may also affect the hydrochemistry. The structure of the strata beneath Slough is such that there is a corridor of more transmissive Lower Greensand abutting the London Platform. This has enabled flow to occur from north to south since the Pleistocene so that the saline connate groundwater has been largely flushed out and replaced by water of high quality.
Aggregate properties and resources of granitic rocks for use in concrete in Hong Kong
Authors: Irfan T. Y. 
Published: November 2007

Abstract
Granitic rocks are the major source of crushed fine and coarse aggregates for use in concrete in Hang Kong. The existing quarries are situated in a variety of granite types. Although some quarries produce coarse aggregates with better properties, most are considered unsuitable for special purposes.
Laboratory testing of the various granite types present in the Territory indicates that fine-grained granites have superior mechanical and physical properties in comparison with other granite types and hence are potentially suitable for many special concrete purposes.
A revision of the graphical method for assessing the excavatability of rock
Authors: Pettifer G. S. , Fookes P. G. 
Published: November 2007

Abstract
A ‘size-strength’ graph, subdivided for various methods of excavation, was published by Franklin, Broch & Walton in 1971. Although this graph allows excavatability to be assessed rapidly, the subdivisions have become outdated as more powerful, more efficient equipment has become available. A complete revision of the graphical method, based on more than 100 case studies, is proposed. Particular emphasis is placed on rock masses which can be broken up solely by mechanical means such as ripping. Procedures are recommended for obtaining geotechnical data, and the importance of interpreting field observations in their geomorphological context is discussed. Consideration is also given to the effects of block shape and orientation on ripper performance, and adjustments to the input data are suggested. The revised graph is intended for all types of project but especially for road construction, where plant mobility and flexibility are important.
A technique for defining non-linear shear strength envelopes, and their incorporation in a slope stability method of analysis
Authors: Perry J. 
Published: November 2007

Abstract
The peak shear strength envelope of soils, rock fills, highly weathered rock and jointed rock can exhibit significant curvature over a range of stresses. In the past a power curve relation has been used to represent this non-linear envelope. An accurate and rigorous method is given which calculates the ‘best fit’ power curve relation to test data in the form of Mohr circles. The mathematical function for the power curve then represents the shear strength equation. In order to test and study the method, it is applied to shear strength results, from tests on six overconsolidated clays. The failure envelopes for the clays are significantly curved and a power curve relation provides a good estimate of the failure envelopes. Comparisons with linear failure envelopes clearly show that, over the same stress range, the power curve relation is the more realistic approximation of shear strength.
A slope stability method of analysis is given which uses the power curve relation for the shear strength of materials. It can be used for slopes in, or constructed of, soils, rock fills or highly weathered rock where a non-linear failure envelope is representative of shear strength. The method is based on Janbu's Rigorous Method of Slices and is for use in analysing failures with a failure surface of arbitrary shape.