bluuebunny/crossref_metadata_2025_split huggingface dataset:
The engineering of a cementitious barrier
Authors: Claisse P. A. , Unsworth H. P. 
Published: April 2008

Abstract
When cementitious materials are used for the containment of waste they act in two different and sometimes conflicting ways. The first is physical containment in which the waste is physically isolated from the environment. The second is chemical containment in which the water passing through the barrier is buffered to high pH thereby very substantially reducing the solubility of many harmful species and promoting sorption onto the cement matrix. Chemical barriers have been extensively researched for nuclear waste containment and this paper explores the possibility of using them for non-nuclear waste.
Initial results are presented which show that cementitious barriers containing cement replacement materials may be well suited to barrier construction. It is, however, concluded that cementitious barriers would have to be used as part of a composite system in order to comply with current legislation.
An assessment of permeability of clay liners: two case histories
Authors: Langdon N. J. , Al Hussaini M. J. , Walden P. J. , Sangha C. M. 
Published: April 2008

Abstract
Two sites, each utilizing natural clay from the same geological formation but from sources in different depositional basins, are compared together with their method of site control and their test results. From a series of laboratory test results the geotechnical differences in the material are compared and tentative trend lines for various parameters drawn. Conclusions from these two sites and these soils suggest that precise determinations of permeability would not have been easily predicted from relationships in published information. However, there remains a major need for a method of determining permeability appropriate to the site conditions and limitations pertaining to a landfill site. The concept of the falling head test ‘failing safe’ and determining a rough threshold level at 109 m s-1 can be used but an on-site water absorption approach or infiltrometer may be more readily adaptable to determine permeability rapidly in quantities and also cost-effectively.
Research into the mobility of a gas phase within a porous network
Authors: Boltze U. , de Freitas M. H. 
Published: April 2008

Abstract
This paper presents work conducted at Imperial College on the mobility of a gas phase through a partially saturated porous medium. The research is based on the observation of the behaviour of a discrete gas phase in place rather than on gas in solution. The experiments were designed to ensure that chemical reactions and the nucleation of the gas phase were kept to a minimum if not prevented.
Glass micromodels of porous media were used to allow visual analysis of the movement of the gas phase in a partially saturated porous medium under conditions of rapidly changing head. Both conditions of heavy localized rainfall or rapid increase in atmospheric pressure, and rapidly changing water levels are simulated.
Images of gas bubble positions, sizes and frequencies under given potentials are analysed using a Geographical Information System (GIS) to enable the bubble population to be quantified in time and space.

From these studies conclusions concerning the behaviour of the gas phase under these conditions have become apparent. These have significant implications for the monitoring of gas emissions and movement of gas
in situ
.
The protection of groundwaters from the effects of waste disposal
Authors: Hart P. A. , Davey I. 
Published: April 2008

Abstract
Powers available to the NRA are summarized. Definitions of waste and groundwater are given. The scale of the problem is described by reference to the legacies of historical ‘dilute and attenuate’ landfills, mainly occupying disused surface mineral excavations.

An explanation is given of an interpretation of the National Rivers Authority
Policy and Practice for the Protection of Groundwater
in context of waste disposal. Special emphasis is placed on the protection of groundwaters by development control. Reference is made to work regarding best practice for containment and management of leachates generated at landfills.

Scenarios are described which are then used to assess the likely impact of the policy on the future of waste disposal.
It is concluded that the NRA's policy provides a framework which is being used to promote the practical protection of vital natural groundwater resources.
Setting the standard for geophysical surveys in site investigation
Authors: McCann D. M. , Culshaw M. G. , Fenning P. J. 
Published: April 2008

Abstract
This paper reviews the state of geophysics as applied to the engineering and environmental industries in the 1990s. The site investigation process is described emphasizing that inadequate attention is paid to understanding the ground in, or on, which structures are built. The basic principles of geophysical surveying are described, particularly the five major factors that influence the success of a geophysical survey: depth of penetration, vertical and lateral resolution, contrast in physical properties, signal to noise ratio and existing information about the site. The main surface, downhole and crosshole geophysical methods used in engineering and environmental investigations are discussed and illustrated with brief case histories from the literature. The integration of geophysical surveys into the site investigation process is described and a new procedure for the designing, commissioning and carrying out of a successful geophysical survey is presented. The underlying reasons why geophysics is perceived as ‘not working,’ are identified as a lack of understanding of both geological variability and geophysical methods on the part of the engineer and of engineering design and practice on the part of the geophysicist.
Geotechnical applications of the spectral analysis of surface waves
Authors: Cuéllar V. 
Published: April 2008

Abstract

Spectral analysis of surface waves is a simple and efficient method of determining the shear-wave velocity of soils
in situ
and their variation with depth. The non-destructive character of the method, together with the possibility of generating long wavelengths by letting a weight drop from a certain height, makes it a very suitable technique to obtain shear wave velocity profiles without requiring the drilling of boreholes.

In this paper, examples are given of how the method has been used in Spain to identify the deformability of compacted embankments and waste landfills, to assess the liquefaction potential of alluvial sediments, to characterize the geomechanical behavior of foundations and rock-fill dams, to determine the extent of the alteration zone behind the lining of a tunnel excavated in rock and to judge the degree of improvement achieved in some ground treatments.
Some improvements in the processing of borehole acoustic signals for the characterization of geological structures
Authors: Rousseau A. , Jeantet D. 
Published: April 2008

Abstract
We show how a new type of 3D visualization of the raw data of full waveforms can be used as a method of signal processing, allowing the characterization of fractures, dykes, and soft/hard formation contacts. We provide a method of calculating the interface dip in adequate conditions and we propose a new means of calculating the velocities of all types of waves by ‘animation’. Finally we suggest a way to assess the dip azimuths.
Application of the microgravity technique to cavity location in the investigations for major civil engineering works
Authors: Emsley S. J. , Bishop I. 
Published: April 2008

Abstract
The detection of subsurface cavities, including mine workings, mine shafts and solution features, is an essential component of any site investigation for major civil engineering works and often relies on drilling investigations to identify the presence of any cavities. However, there is no standard, cost-effective site investigation technique which can be readily used for the physical investigation of such features.
Whilst a desk study may yield documentary information on the presence of recorded mine workings and shafts, the location of solution features is generally even more problematical. Two complementary approaches have been developed for the location of subsurface cavities. Firstly, closely spaced boreholes are drilled in a specific pattern to locate cavities. This method can prove prohibitively expensive, with no guarantee of intersecting all voids or cavities. Secondly, remote sensing geophysical techniques have been used. Such techniques rely on the existence of contrasts in physical properties between the rock mass and the cavities, which can be detected using suitable geophysical methods.
This paper describes the application of the microgravity technique to the detection of solution cavities and mine workings with reference to three case histories. In the first and second examples the microgravity technique was used as a reconnaissance method for defining targets for subsequent physical investigation; in the third, the technique was used to define the extent of solution features, having been initially and unexpectedly encountered by a drilling programme. These examples demonstrate the applicability of the microgravity method in detecting and delineating both solution cavities and mine workings within differing geological settings.
Cross-hole seismic tomography for engineering site investigation
Authors: Jackson P. D. , McCann D. M. 
Published: April 2008

Abstract

The results of cross-hole seismic tomography at sites where there is good geological control are presented. Comparisons have been made between the tomograms and the geological cross sections in order to assess the technique under
in situ
conditions. It is shown that while the geological sections do not contain velocity information they have provided structural constraints which provided fresh insight when interpreting the seismic tomograms.

Processing artefacts in field-data tomograms, particularly when the angular ray coverage is incomplete, have been identified using ‘synthetic’ tomograms based on the geological section. In addition, velocity anisotropy and critically refracted arrivals were identified as likely causes of differences between ‘synthetic’ and ‘field data’ tomograms, given a knowledge of the geological section.
It is proposed that cross borehole tomographic surveys should not be taken immediately at their face value in the absence of geological control.
Hydraulic tomography in fractured bedrock aquifers using high-resolution borehole flowmeter measurements
Authors: Paillet Frederick L. , Morin Roger H. 
Published: April 2008

Abstract
Geophysical soundings and tomographs can provide two- and sometimes three-dimensional images of the structure of fractured rock masses, but regions of anomalous geophysical properties are only indirectly related to the hydraulic properties of rocks. Hydraulic tomography based on cross-borehole flow tests cannot rigidly constrain all possible fracture flow connections, but such tests provide direct measurements of hydraulic connections between boreholes. The combination of flow tomographs based on high-resolution flowmeter measurements and conventional geophysical tomography can provide information about the hydraulic connections and large-scale flow paths that cannot be obtained by either method alone. The effectiveness of this combination of flowmeter and geophysical measurements is illustrated by results obtained in cross-borehole flow measurements at Mirror Lake, New Hampshire, and a hydraulic fracture experiment near Boulder, Colorado.
Azimuthal resistivity and seismic measurements for the determination of fracture orientations
Authors: Bushy J. P. , Peart R. J. 
Published: April 2008

Abstract
There is an increasing need to map and understand rock fracture networks in order, for instance, to predict the spread of contaminants in the sub-surface, to optimize borehole siting in aquifers whose storage results from fracturing, and for civil engineering applications. The use of azimuthal resistivity and seismic measurements for the determination of concealed sub-vertical fracture orientations has been previously reported but to date the methods have found little general
application.
The results of resistivity and seismic azimuthal measurements on chalk and limestone at several sites in southern and eastern England are reported. A number of distinct preferred azimuths are apparent in the data and the two independent techniques give generally consistent results. The geophysical indications are assessed relative to outcrop measurements of fracture and joint azimuths and conclusions are drawn on the persistence of fracture sets both laterally and vertically.
Geophysical survey planning for the Dounreay and Sellafield geological investigations
Authors: Norton M. G. , Arthur J. C. R. , Dyer K. J. 
Published: April 2008

Abstract
Between 1989 and 1994 two large engineering site investigation projects in the United Kingdom at Dounreay in Caithness and the Sellafield area in West Cumbria were carried out for the study of possible locations for a deep underground facility for low-level and intermediate-level radioactive waste. In the geophysical domain, management of a diverse range of specialist services required initial desk studies, survey design, acquisition and processing supervision, interpretation, reporting and archiving.
Document creation (design intent memoranda, tenders and contracts, Quality Assurance, technical reviews and reports) together with technical control during the data acquisition phase was followed by involvement in the interpretation of the results. A range of geophysical methods were employed including onshore and offshore seismic reflection with associated gravity acquisition, transition zone seismic, airborne geophysics (utilizing spectroscopy, magnetics and VLF) and ground electromagnetic surveys.
At the peak of activity, responsibility for the geophysical operations involved the simultaneous management of five field crews - two land seismic with some gravity, one marine seismic with gravity and two helicopters acquiring airborne data - as well as ongoing VSP in the deep, fully cored, boreholes. Some of the work undertaken for each of these disciplines will be described in relation to both projects.
Thermal conductivities of argillaceous sediments
Authors: Midttømme K. , Roaldset E. , Aagaard P. 
Published: April 2008

Abstract
Thermal conductivities of selected samples of shales, clay- and mudstones from the Norwegian Continental Shelf have been measured with a divided bar apparatus. The samples investigated are from conventional cores and side wall cores. Thermal conductivities for watersaturated samples measured perpendicular to the layering vary from 0.79 to 1.14 W/m K. The conductivities measured parallel to the layering are up to 1.7 times higher than those measured in the perpendicular direction. The investigation also confirms that the temperature has an influence on the conductivity. A model to predict thermal conductivity, based on water content and mineralogy has been proposed and tested.
Assessment and specification of armourstone quality: from CIRIA/CUR (1991) to CEN (2000)
Authors: Latham J.-P. 
Published: April 2008

Abstract

As a typical by-product to normal quarrying, armourstone has many attributes that make its objective specification and testing less straightforward than most producers would wish. Neither, it appears, has the market forces principle and tendering practices in the UK construction industry, leading to minimal forward planning of armourstone testing, helped to enhance quality control of materials. The undoubted advances heralded by the standardizing approach of the CIRIA/CUR
Manual on the Use of Rock in Coastal and Shoreline Engineering
and its model specification have done much to rationalize a previously over-simplistic view of armourstone specification. However, recent practical experience with many coastal contracts which have adopted the CIRIA/CUR specification has exposed a number of problems with the detailed implementation of the rock quality testing part of the model specification. In particular, this experience draws attention to a lack of published correlation studies between the various abrasion tests and between strength tests. Rock suppliers are reporting that designers are continuing to specify using the BS812 suite of aggregate tests. The potential for bias in the taking and preparation of representative test portions has also remained a problem.

The manual specification's rationale, its strengths and weaknesses, are outlined. Correlation analysis of new research data from a suite of rocks is presented. A re-examination of the manual specification's acceptance criteria for resistance to wear and to breakage is presented. A way forward is offered for the continued use of the manual specification until its supersedence by the European CEN specification for armourstone. Improvements in the 16th draft of the CEN standard are briefly discussed, and it is found that certain problems that the manual began to address remain unsolved.
Meeting the demand for rock armour and its grading specification
Authors: Rees-Jones R. G. , Storhaug E. 
Published: April 2008

Abstract
An analysis of tenders for contracts requiring armourstone issued since 1991 has been carried out. The results show the market size, the impact of major projects, the proportion of deliveries by sea and the extent to which the CIRIA/CUR specifications have been adopted. Proposals from the CEN armourstone committee regarding grading and shape are discussed, together with developments in quality control procedures at the loading port.
Lime stabilization of inorganic contaminants in clays
Authors: Glendinning S. , Rogers C. D. F. , Boardman D. I. 
Published: April 2008

Abstract
The legacy of industrial operations over the past 200 years are contaminated natural clays and clay-based sediments. There is an urgent need for economic methods to stabilize these materials since the problem is widespread. Chemical fixation or encapsulation of inorganic contaminants using lime provides one potential solution that has yet to be adequately explored.

This paper aims to review the methods of chemical stabilization of inorganic contaminants using pozzolanas, and in particular discuss the interaction of clays with both metal ions and lime. The parallels between cement, lime-fly ash and lime-clay stabilization reactions are examined to determine the potential for contaminant stabilization using lime and suggest the mechanisms upon which success would rely. The factors affecting the lime stabilization process are discussed. Methods of incorporation of lime in practice are thereafter discussed, covering deep mixing as well as surface mixing
in situ
and mixing
ex situ
. Specific research required to prove the potential of lime is then discussed.

The paper concludes that lime stabilization provides a potentially valuable and economic means of treating both natural clays and (often very wet) clay-rich sediments. This is achieved via both enhanced contaminant adsorption and precipitation of metal ions under conditions of high pH, and binding in of the contaminants with the reaction products of the pozzolanic reaction between lime and clay. However, the fundamental nature of the clay/sediment is altered by the lime-clay reactions, most notably in the context of future potential for ion mobility by an immediate increase followed by a progressive decrease in coefficient of permeability. The degree to which inorganic contaminants become associated with the reaction products and the permanency of this association under conditions of seepage (i.e. resistance to leaching) need to be researched in detail before confidence in the technique can be engendered.
Policy maturity and the development of novel remedial techniques
Authors: Wills J. G. C. , Jones C. J. F. P. 
Published: April 2008

Abstract
The need for a legislative framework to deal with contaminated land and its relationship to the market for novel remedial techniques is described. Problems of bureaucracy, inflexibility and liability are cited as reasons for a move towards more mature policy approaches, including brownfield development, the use of economic incentives, and remedial action based on suitability of land use. The contaminated land policy of the UK is outlined and the question as to whether this policy will prevent the kind of protracted legal battles experienced in the USA under Superfund is posed. Regulatory capture is suggested as a reason for the UK's predominantly deregulatory stance and it is proposed that this has the potential to stifle the development of advanced techniques. Barriers and opportunities to development are outlined: licensing, pilot studies and perception. It is concluded that ‘Suitable for Use’ will protect public health and the environment cost effectively — albeit at the expense of a strong market for advanced remedial techniques in the UK. Poor policy decisions by government are highlighted as a reason for uncertainty in the UK's remedial market. Niche markets and turnkey operations are identified as areas where UK firms have the potential to succeed.
Integration of environmental assessment indicators into site assessment procedures
Authors: Tucker P. , Ferguson C. , Tzilivakis J. 
Published: April 2008

Abstract
The amount of information that can be gathered for contaminated site assessment is often limited by the cost of making measurements. Effective decisions on site management rely heavily on this information. Lower cost measurements or more effective use of the diverse information already available should increase the quality of these decisions, provided that final data quality is not compromised. However, fundamental problems can arise from interpreting the reliability, uncertainty and significance of the raw measurements or other indicators. Such problems are paralleled in Environmental Impact Assessment and Life Cycle Analysis methodologies. Drawing on the work undertaken within these disciplines may help clarify the solution for site assessment. Scoring, ranking and valuation techniques have been used successfully in providing decision support for the design of sampling strategies for contaminated sites through maximizing the use of desk study data and site reconnaissance observations.