bluuebunny/crossref_metadata_2025 huggingface dataset:
Engineering geology of Snebra Ghyll bridge, A595(T) Hensingham Bypass
Authors: Ball M. J. , Sims B. E. F.
Published: April 2008

The construction of Hensingham Bypass, Cumbria was completed in December 1991. Snebra Ghyll is a deep ravine opening into convex, rounded slopes at the top. An eight span arch bridge was adopted for the ghyll crossing, with bank seats supported on the approach embankments. The northern approach embankment has reinforced earth slopes above the ravine. Intermediate piers and arch springings are founded on bedrock, in which open joints were identified. These were grouted before foundation
construction. Steep faces beneath the bridge are protected by soil nailing.
Applications of jet grouting in civil engineering
Authors: Essler R. D.
Published: April 2008

Jet grouting has been carried out for a number of years and is of increasing interest as engineers understand its application and advantages in civil engineering construction. While the process of jet grouting is widely known, the design of a jet grout solution is not. This paper will outline the design of jet grouting, suggest ways the techniques can be utilized and presents a number of case histories.
Pipeline route investigations using geophysical techniques
Authors: Fenning P. J. , Hasan S.
Published: April 2008

Recent increased expenditure on water supply infrastructure has involved the construction of many underground pipelines in a variety of geological situations. Variations in ground conditions not revealed by site investigation boreholes have sometimes led to major cost implications.

It is suggested that geophysical surveys along planned pipeline routes before construction can assist in highlighting potential problem areas and lead to the cost-effective location of site investigation boreholes.

Background

In many instances the route of a new pipeline is constrained by significant factors such as land access, topographic variations along the route and local planning conditions.

The geological conditions along the route are often relegated to a minor consideration to be determined by a few shallow boreholes after the route has been almost decided and land access provisionally agreed. These boreholes or trial pits are often conveniently sited at regular intervals along a pipeline route. Unfortunately, the geological conditions are often variable and carry with them cost implications. Typical examples are when a sandstone which can be easily ripped by a machine changes laterally into a more durable lithology which requires blasting, or when the depth of soil cover overlying the bedrock decreases sharply, requiring a change in the type of excavator used.

In the selection of any pipeline route an initial desk study is carried out by engineers and planners, who collate all the available relevant information.
Estimation of rippability and excavation conditions from seismic velocity measurements
Authors: McCann D. M. , Fenning P.J.
Published: April 2008

Rock excavation conditions at engineering construction sites such as roads and pipeline routes can be assessed from a measurement of the seismic P-wave velocity. From a knowledge of the seismic velocity it is possible to establish where blasting may be required along the route rather than conventional excavation procedures. The popular term `ripping' is applied to excavation without blasting and manufacturers of excavation equipment have produced charts relating the rippability of a rock
mass to its measured in situ seismic velocity. These charts are a basic guide to the assessment of rippability and cover a limited range of rock types; in addition, they do not always include the effects of weathering or the degree of stress relief in the rock mass resulting from removal of the overburden.

The effectiveness of the use of seismic velocity measurements for predicting rippability is examined. It is shown that, provided each lithological type is considered, in conjunction with an assessment of the degree of fracturing and weathering in the rock mass and an appraisal of the effects of stress relief, then seismic velocity is a valuable parameter for predicting rippability. This can lead to a consequent reduction in costs due to the decreased use of blasting.
Pre-design evaluation of disused quarries as landfill sites
Authors: Lyle P. , Gibson P. J. , Woodside A. R. , Woodward W. D. H.
Published: April 2008

This paper outlines how faults and fracture zones may be detected with use of a total field precession magnetometer during the initial and preliminary stages of the assessment of disused quarries as possible landfill sites. The technique has been applied across a range of lithologies and can help in the more accurate assessment of potential pollutant conduits.

The use of standard permeability tests for natural liners and tensile tests for synthetic liners in the pre-design evaluation phase are discussed. The approximate costs of using such tests and geomagnetic profiling in pre-design evaluation are discussed.
Permeability considerations about rock foundation on waste disposal
Authors: Foyo A. , Tomillo C.
Published: April 2008

The use of the traditional permeability test (the water pressure test) to analyse the permeability of rock foundations for waste disposal, is not applicable in all materials because the high pressures used in the test may produce hydraulic fracturing. This paper describes a new permeability test, called the low pressure test or LPT, which is used to obtain the true permeability of a waste disposal foundation on weak and impervious rock. Finally, the results obtained with the use of the LPT to analyse the permeability of a waste disposal foundation are described.
Geomembrane landfill liners in the real world
Authors: Mollard S. J. , Jefford C. E. , Staff M. G. , Browning G. R. J.
Published: April 2008

This paper provides an introduction to high-density polyethylene (HDPE) geomembranes, emphasizing some practical aspects essential for the successful installation of such liners at landfill sites. Installation procedures are discussed, including quality of the sub-grade, methods of laying panels, seaming techniques and destructive and non-destructive methods of testing. The need for construction quality assurance (CQA) is highlighted as a means to minimize leakage and to ensure that geomembrane liners function as specified throughout the life of the landfill facility.
Disposal of radioactive wastes in argillaceous formations
Authors: Horseman S. T. , Volckaert G.
Published: April 2008

One option presently under investigation internationally for the disposal of the hazardous by-products of the nuclear fuel cycle is the construction of underground repositories in low-permeability argillaceous rock formations. The host-rock represents the most important barrier to the migration of radionuclides to the surface environment. The performance of this geological barrier will depend on a wide variety of factors, including the degree of compaction and diagenetic alteration of the rock during burial, affecting plasticity and response to deformation, stress history which determines some important structural attributes (faults, fissures, etc.), mineralogy and chemistry which are primary factors influencing radionuclide sorption and mobility, and the thickness and lithological variability of the low-permeability sequence. Our paper provides a brief overview of these considerations and identifies a number of areas of uncertainty, including our, as yet, incomplete knowledge of the precise mechanisms of groundwater movement in clay-rich media, possible departures from Darcy's Law, the occurrence of long-term transient flow, the role of ‘coupled flow’ phenomena, and the difficult problem of gas migration within the host-formation.
Geotechnical core and rock mass characterization for the UK radioactive waste repository design
Authors: Rawlings C. G. , Barton N. , Løset F. , Vik G. , Bhasin R. K. , Smallwood A , Davies N.
Published: April 2008

The NGI method of characterizing joints (using JRC, JCS and ø
r
) and characterizing rock masses (using the Q-system) have been and are currently being used extensively in geotechnical consultancy projects. One such project recently completed for UK Nirex Ltd included the logging of 8 km of 100-mm-diameter drill core from boreholes up to 2 km in depth. Preliminary rock reinforcement designs were derived from the Q-system statistics, which were logged in parallel with JRC, JCS
and ø
r
. The data from the NGI method of characterizing joints and the Q-system for characterizing rock masses have also been used as the basis for UDEC-BB numerical modelling of the proposed cavern excavations for the disposal of solid, low- and intermediate-level radioactive wastes. The purpose of this numerical modelling was to investigate the stability of rock caverns and in particular the rock reinforcement requirements (giving predicted bolt loads and rock deformations),
the extent of the disturbed zone (joint shearing and hydraulic aperture) with respect to cavern orientation, the effect of various pillar widths, and the effect of the cavern excavation sequence.
Prediction of groundwater flow around an underground waste repository
Authors: Zhao J.
Published: April 2008

Leakage and transport of waste in a waste repository is generally through the circulation of groundwater flow. Waste repository design, therefore, requires the study of the hydraulic performance of the surrounding rock masses in the presence of groundwater. Rock mass permeability, conductivity and flow rate at various depths can be predicted by hydrogeological data of the joint frequency, joint aperture, stress joint closure relationship and water-table, obtained at shallow subsurface exploration. Predictions using an improved hydraulic model show that the permeability of a rock mass decreases with increasing depth; the groundwater flow into and around the repository, however, increases with repository depth until it reaches a maximum rate. The groundwater flow stabilizes or decreases after the peak rate due to joint closure of the rock mass surrounding the repository under high
in situ
stress.
A model for adsorption of organic species by clays and commercial landfill barrier materials
Authors: Davies M. C. R. , Railton L. M. R. , Williams K. P.
Published: April 2008

The adsorptions of four carboxylic acids and phenol onto three substrates have been examined. It has been demonstrated that modifying montmorillonite with the diethyl ammonium ion increases the adsorption of the acids at the higher concentration. The amount of adsorption cannot be explained simply by consideration of adsorbate solubilities in water, but depends on more complex interactions between adsorbate-adsorbent and solvent. A model to predict the adsorptive lifetime of a barrier has
also been developed.
Development of a lined landfill site adjacent to a major potable supply river
Authors: Apted J. P. , Philpott M. , Gibbs S. W.
Published: April 2008

The site at Pen-Y-Bout is based on a deep clay pit in Ruabon Marl and is on a piece of land almost completely surrounded by a loop in the River Dee, a major source of potable water. The proposals for developing a landfill at the site required two stages of investigation with particular regard being given to permeabilities and groundwater flow. A strategy for landfilling was developed that took into account the need to protect the Dee with particular emphasis being given to leachate control. In addition, the requirements for landfill liners in terms of current guidance were also considered.
Engineering geological and legal aspects involving proposals for a large waste disposal facility in The Netherlands
Authors: Maurenbrecher Pieter Michiel
Published: April 2008

In the densely populated area of the Netherlands proposals for a waste disposal tip can involve drawn-out legal proceedings before permission is granted. A case history is given in which the author acted as advisor for one of the objectors to the scheme and hence gives insight into shortcomings in the quite extensive environmental laws concerning, amongst other items, waste disposal facilities. The licensing authorities for such a scheme are the municipal and provincial authorities who, in this instance, are also supporters of the scheme. Such authorities, hence, do not maintain an unbiased role. High-court arbitration procedures are also outlined and the role of an expert witness. To date, the proposers of the scheme have not been successful in being granted a licence, in part, due to the proposer trying to precede new environmental laws before their ratification by Parliament.
Landfill failure survey: a technical note
Authors: Roche David
Published: April 2008

A survey of reported pollution incidents and other modes of failure affecting landfill waste disposal sites has been undertaken, and the key results are summarised here. A questionnaire survey was made of selected representative organizations in the waste management industry in England and Wales, including operators, regulators and specialists, and the results from which constitute a substantial database. The majority of the sites included in the survey have been active during the past 20 years. Currently active sites and recently commenced sites are included.

The Initial Survey comprised around 1000 sites. Of this sample, about one in six sites had suffered a significant pollution incident or failure which has required substantial remedial treatment (see Fig. 1(a)). Landfill gas migration was the most frequent form of problem, identified affecting nearly 1 in 10 sites. Surface water pollution incidents affected more than 1 in 20 of the sites and groundwater pollution more than 1 in 40 sites (see Fig. 2(a)).

For Stage 2, a more detailed questionnaire survey has been undertaken. The survey targeted over 200 selected representative members in the waste management industry. The survey now takes account of around 4000 landfill sites.

The findings of the more detailed survey essentially confirm the results of the initial survey, although with the much larger sample the trends are modified in certain respects.

Of the larger sample, about 1 in 20 sites have suffered a significant pollution incident or failure which has required substantial remedial treatment (see Fig. 1(b)). This indicates a lower
Electrical imaging and its application in engineering investigations
Authors: Barker R. D.
Published: April 2008

Recent developments in electrical tomography field acquisition and data inversion technology have resulted in the production of electrical images which more accurately mirror the subsurface than is possible with conventional resistivity surveys. The technique is particularly suitable for engineering site investigation where understanding complex subsurface structure in detail is important. This is demonstrated with examples of its application in determining depth to bedrock, in resource and contaminants studies and in monitoring subsurface fluid flow.
Novel regularized inversion of VLF(R) data and coincident radar sections over a probable fault affecting Carboniferous sedimentary rocks in the Saar region, Germany
Authors: Beamish D. , Clasen D. , Greenwood P. G. , Peart R. J.
Published: April 2008

Coal mining induced subsidence along the surface trace of faults has caused extensive damage and consequent expense in parts of the Saar, Germany. An ongoing CEC assisted project was established to determine an efficient strategy for the detection of fault traces, prior to undermining, involving geological mapping, lineament analysis and surface and borehole geophysics. We present VLF(R) and GPR (multi-frequency) results from three traverses, 10 m apart, crossing a suspected fault that was subsequently proved by inclined core drilling. The modelled resistivity distribution (VLF) indicates a dipping, blind conductive zone of limited depth extent, while the radar sections reveal a well defined anomalous zone separating contrasting lithologies on either side of the fault. Additional geophysical data (EM conductivity and DC gradient array mapping and sounding) provide supportive evidence of the faulting.
The application of electromagnetic techniques to environmental geophysical surveys
Authors: McNeill J. Duncan
Published: April 2008

Conventional DC resistivity techniques have been applied for many years to a variety of environmental geophysical applications. More recently electromagnetic techniques, with different advantages (and disadvantages) compared with conventional DC, have been used effectively to measure the resistivity (or its reciprocal, the conductivity) of the earth. Electromagnetic techniques can be broadly divided into two groups. In frequency-domain instrumentation (FDEM) the transmitter current varies sinusoidally with time at a fixed frequency. In most time domain (TDEM) instrumentation the transmitter current, while still periodic, is a modified symmetrical square wave.
Multicomponent geophysical surveys over completed landfill sites
Authors: Fenning P. J. , Williams B. S.
Published: April 2008

Engineering geophysics can play a useful role in assisting the engineering geologist in mapping subsurface features and in particular the targeting of boreholes for detailed investigation. Frequently the problem of the geophysicist is the selection of the most cost-effective technique prior to commencing geophysical surveys at site. At landfill sites the usual problems are location of the subsurface margins, shape of subsurface margins and determination of fill thickness. The physical properties of the landfill material are usually not known and are difficult to measure in the laboratory. A comprehensive multi-component geophysical survey has been carried out using a wide range of geophysical survey techniques profiled across a concealed landfill margin in Southern England to assess the effectiveness of geophysical techniques in solving the above problems. Interpretation of the results indicates that electrical techniques such as inductive conductivity and galvanic resistivity, are the most cost-effective for providing the required information. The results of the more expensive gravity surveys also provide a very effective means of determining the features of the landfill but the physical properties of the landfill prevent the ground penetrating radar and seismic refraction techniques from providing diagnostic information.
The detection of cavities using the microgravity technique: case histories from mining and karstic environments
Authors: Bishop I. , Styles P. , Emsley S. J. , Ferguson N. S.
Published: April 2008

The presence of mining-related cavities (workings, shafts and tunnels) or karstic (solution cavities and sinkholes in limestone) within the top 100 m in the rock mass restricts land utilisation, and their migration to the surface may damage property or services or cause loss of life. Confirmation of features marked on existing plans prior to design and construction may be sufficient but it is often necessary to determine the detailed sub-surface structure. The standard method of site
investigation is to drill a pattern of boreholes to locate the spatial extent of any cavities. However, unless the spacing is less than the cavity dimensions it is possible to miss it completely. A cavity may be filled with air, water, or collapse material resulting in a contrast in physical properties which may be detected using appropriate geophysical methods. One powerful technique is microgravity which locates areas of contrasting sub-surface density from surface measurements of the earth’s gravity. Although the method is fundamentally simple, measurement of the minute variations in gravity (1 in 10
8
) requires sensitive instruments, careful data acquisition, and data reduction and digital data analysis. Final interpretation must be performed in conjunction with independent information about the site’s history and geology. This paper presents three examples in both mining and karstic environments demonstrating that microgravity is a very effective technique for detecting
and delineating cavities in the sub-surface.
The potential of on-shore multichannel high-resolution shallow seismic techniques when applied to coastal site investigation
Authors: Brabham P. J. , McDonald R. J.
Published: April 2008

A combined seismic P-wave refraction and shallow high-resolution multichannel common midpoint (CMP) reflection approach to onshore coastal site investigations in the UK is described, using case studies from two sites on the South Wales coast. The land-based surveys are performed within the inter-tidal zone, using a 24-channel seismic acquisition system, targeting to a depth of interest of 50 m.

Reflection events from rockhead and lithological boundaries within the overlying unconsolidated sediments are clearly imaged using CMP stacked data. The reflection data show a dominant frequency around 550 Hz, which combined with seismic velocities averaging 1600 m/s, produces a quarter-wavelength vertical resolution of 0.7 m. Comparisons of hammer, buffalo gun and detonator sources are made, and their relative suitability for high-resolution shallow reflection surveys within the inter-tidal zone is discussed.

For successful interpretation of shallow reflection data, the necessity of additional rockhead depth control from seismic refraction surveying and/or borehole data is emphasized. Additional depth control is of particular importance if the acoustic contrast between deeply weathered rockhead and overlying sediments is low. Combined refraction and reflection surveys are a relatively inexpensive way of providing information on rockhead topography, rock structure and sediment stratigraphy. Such information is invaluable to the coastal engineer in both the design and location of engineering structures.
The use of geophysics at the new airport, Chek Lap Kok, Hong Kong
Authors: Covil C. S. , James J. W. C.
Published: April 2008

The new Hong Kong Airport at Chek Lap Kok is to be constructed on a 1248 hectare offshore reclamation platform. The design and construction of the airport platform are strongly influenced by the marine geology. A model of the marine geology, as well as a comprehensive understanding of the geotechnical properties of the materials, were essential to the design and construction of the platform and airport structures. 1100 km of seismic reflection survey were carried out to investigate the superficial deposits over the airport site. This was complemented by over 230 boreholes and 400 piezocone tests. This information, along with knowledge of the regional geology, formed the basis for the production of an interpreted 3D digital model of the marine geology.

The paper describes the interpretation in developing a consistent model of the marine geology and a framework upon which the engineering decisions can be made. It explains how the seismic interpretation was calibrated using other geotechnical data such as boreholes and penetration tests. The paper makes reference to the engineering decisions that were based partly on the interpretation of the seismics, such as the estimation of settlement and the identification of areas requiring further site investigation. The seismic surveys were also valuable in identifying the more critical areas and horizons in which to install comprehensive suites of instrumentation. It proved a useful and reliable technique in establishing the presence of unconformities linked with palaeosol crusts within the superficial deposits, which had a large effect on the stability of the advancing reclamation tip face.
Electrical resistivity imaging systems for ground investigations, with particular reference to dissolution features in Chalk areas
Authors: Rigby-Jones J. , Matthews M. C. , McDowell P. W.
Published: April 2008

The collection of high-quality resistivity data using conventional systems is time-consuming, particularly where large areas are to be surveyed at small electrode spacings. With the advent of modern computer controlled resistivity meters, used in conjunction with multicore takeout cables and switched electrode arrays, two-dimensional resistivity imaging systems have been developed. These systems lend themselves to the search for small-scale, near-surface, anomalies due to their improved accuracy and resolution over more conventional equipment and their ability to produce true resistivity modelled images. Near surface dissolution features in the Chalk can produce variations in ground resistivity and this paper discusses the field trials of two resistivity imaging systems at the known locations of such features. The results are compared to those obtained using conventional resistivity equipment and related to ground truth data obtained by drilling.
Shallow over-water seismic reflection surveys for determining inland waterways sediment distribution in The Netherlands
Authors: Degen B. T. A. J. , Herbschleb J. , Maurenbrecher P. M.
Published: April 2008

Shallow reflection geophysical surveys were carried out using high-frequency pipeliner equipment to determine sediment distributions in inland waterways. The method gives sufficient resolution for most situations such as rivers, canals, harbours and disposal basins to adequately assess both the quantity and locality of sediment types for both pre- and post-dredging operations. Examples of different case histories in the Netherlands are given including some instances where such techniques are less successful.

Geoscience information systems are used to both store, process, enhance, analyse and interpret the data. Specially developed modules in the geoscience information system allows the determination of the quantity of pollution and presentation in map form the degree and extent of the polluted sediment layers. Maps are produced immediately following the surveys on-board the survey vessels.
The acquisition of geophysical wireline logging data as part of the UK Nirex Ltd investigations of a potential radioactive waste repository at Sellafield, Cumbria
Authors: Gunning A.P. , Pearson R. A. , Emsley S. J.
Published: April 2008

UK Nirex Ltd is currently carrying out an investigation of the Sellafield area of West Cumbria to assess the potential for a radioactive waste repository. The investigation includes the drilling of deep boreholes to acquire data for site characterization and safety assessment. Geophysical wireline logging takes place at intervals within the drilling schedule and includes the use of the latest ‘state-of-the-art’ technology. Acquisition is carried out under a rigorous quality control regime in order to generate quality assured data sets which are then processed to generate additional information. Wireline data is used extensively in the acquisition programme and in the verification of results. The data is also used by interpretation teams to assist in geological and hydrogeological interpretation and rock mass assessment.
Integrated study of fracture systems in southern Zimbabwe
Authors: Shedlock S. L.
Published: April 2008

In areas of shallow crystalline bedrock lineaments have been commonly targeted for the siting of water boreholes, although the nature of these extensive geological features is not fully understood. The study employing borehole geophysical techniques attempted to examine the hydro-geological conditions arounda typicallineament and to help explain the reasons for dry boreholes drilled close to these features.

Both vertical and inclined drilling were undertaken in the vicinity of the lineament and the rock characteristics were investigated by both borehole geophysics and core inspection. The study showed a distinct rock quality variation across the lineament which marked the contact between a more massive, friable granite and a weathered granite.

Crosshole seismic tomography suggested, in this case, that the lineament represented a displacement fracture with a downthrow of around seven metres. This displacement could account for the considerable disparity in water levels observed across a relatively short distance and confirmed that fracturing controlled the yield of the boreholes.
Surface and borehole microseismic monitoring of mining-induced seismicity
Authors: Styles P. , Bishop I. , Toon S.
Published: April 2008

To determine whether 130 felt earth tremors around Edwinstowe, Nottinghamshire, UK, which also experienced severe surface fissuring, were caused by coal extraction, a surface seismometer array was established around Thoresby Colliery. Over the next year, 785 microseismic events were detected. The spatial and temporal variations in seismicity are clearly associated with the commencement, continuing extraction and closure of faces. Of particular note are events which locate at the surface and appear to be related to the active fissuring. Events occur within days of commencement of production and cease when production finishes, with good correlation between face advance and hypocentral position. Naturally occurring microseismic events have also been detected up to 1 km ahead of active longwall faces in the Midlands using triaxial geophone packages grouted into the seam together with a surface seismometer in the top of the borehole. The quality of these data was very high and guided waves can clearly be seen with the dispersive characteristics associated with seam waves. In one experiment, more than 2000 events were detected in only two days of monitoring even in a relatively noisy surface environment. This paper demonstrates how useful locations can be generated using three-component digital data from only one borehole. The event distributions give a dynamic, three-dimensional image of the developing patterns of fracturing above, below and ahead of the longwall face with important implications for roof control, subsidence prediction and gas migration.
The use of shear wave transmission as a non-destructive tool to assess soft soil stiffness in dredging applications
Authors: McDermott I. R.
Published: April 2008

Interest in the behaviour of naturally consolidated soils stems from the relevance of these materials to the dredging industry, and the environmental impact of dredging and the dumping of pollutants at sea above soft cohesive sediment beds. Since these soils are compositionally and behaviourally complex, there is a need to characterize their properties in a non-destructive manner. This paper presents the seismo-acoustic behaviour of a number of these soft soils as studied in the laboratory. It is shown that the changing behaviour of the sediment, as it consolidates, and as the soil structure develops, has a considerable influence on its stiffness characteristics. Shear modulus is determined using shear wave velocity and bulk density measurements which were found to range between zero and 160 kPa during the course of the experiments. Estimation of soil shear stiffness in this manner would be a parameter of interest to the dredging industry in defining navigable depth. In terms of environmental matters, such estimates of marine soil shear stiffness may be of use in quantifying the erodibility of the sea bed; this is of particular significance where sediments are contaminated by pollutants.
Measurement of stiffness of soils using small strain triaxial testing and bender elements
Authors: Gordon M. A. , Clayton C. R. I.
Published: April 2008

With the growing appreciation of the value of measuring very small strain stiffness,
G
max
, by determining shear wave velocities, the authors have installed piezoceramic bender elements into a conventional triaxial cell. Whilst the installation process and high speed data acquisition requirements presented no serious problems, interpretation of bender element data was not as straightforward as was first thought. This paper describes the tests carried out and the
problems encountered. Analytical techniques which remove the subjective nature of shear wave travel time determinations are discussed along with ways to discriminate between near field compressional-wave components and genuine shear waves.
A flexible algorithm for seismic refraction interpretation using program REFRACT
Authors: Leung T. M. , Win M. A , Walker C. S. , Whiteley R. J.
Published: April 2008

REFRACT is an interactive seismic refraction interpretation software package, based on the Reciprocal and Intercept Time methods, developed by the Roads and Traffic Authority of New South Wales (Australia). REFRACT operates in graphic and spreadsheet displays on PCs and preserves much of the flexibility of manual methods. The power of REFRACT lies in its treatment of a seismic line as a single data set, combining overlapping segments and handling lateral velocity changes in all layers, and
in its optimization of manual interpretation operations. After entry of first arrival times the T-X data may be checked and edited for shot depth and reciprocal times. Interpretation includes operations such as parallelism testing and layer labelling (Segmentation) on the T-X graph, Phantoming of overlapping segments, minus times Velocity Analysis, automatic Thickness Calculation and edits to the interpreted section. The interpretation stages employ a number of optimization routines that may be
applied with default settings or may be reset and manipulated for close control of the interpretation process over part or all of the T-X data set. The Distance Range is a fundamental concept in REFRACT that controls the application of the Reciprocal and Intercept Time methods for the calculation of time depths, intercept times and harmonic mean velocities. REFRACT provides a new standard for seismic refraction interpretation.
Evaluation of seismic refraction interpretation using first arrival raytracing
Authors: Leung T. M.
Published: April 2008

A critical factor in the evaluation of a seismic refraction interpretation is the consistency between the model and the data. This can be achieved through assessing differences between the field first arrival data and the synthetic data calculated from the model. A practical tool to calculate accurate first arrival times is essential to fulfil this task.

Raytracing is a straight forward technique for first arrival time calculation but there are problems such as shadow zones in some algorithms. As a tool for evaluation of refraction interpretation it is important to ensure the minimum traveltime paths are computed. This is not provided in many raytracing algorithms.

The first arrival raytracing software presented here introduces a new standard for minimum traveltime path assurance. The program, which has been developed specifically for testing seismic refraction interpretation, is based on a 2-D earth model with uniform velocity polygons. A complex but typical field example is used to demonstrate the usefulness of the program.
Sources of sand and gravel on the Northern European Continental Shelf
Authors: Harrison D. J. , Laban C. , Leth J. O. , Larsen B.
Published: April 2008

The extraction of marine sand and gravel has taken place in a number of countries around the North Sea, the Baltic Sea and English Channel for several centuries, but large-scale dredging for aggregates only began in earnest in the 1960s. Today, marine sands and gravels have an increasing role to play in maintaining European supplies of concreting aggregates as well as material for beach nourishment and constructional fill. The distribution of sand and gravel resources offshore is uneven. They vary in their thickness, their composition and grading, and their proximity to the shore. Many deposits lie in places that are currently inaccessible to the dredging industry.

This paper outlines the production of marine sand and gravel in northern Europe and describes the distribution, composition and Quaternary origins of the most important marine sand and gravel resources in northern Europe. Examples are given for the UK, the Netherlands and Denmark, and in summary form for France, Belgium, Norway, Sweden, Ireland and Germany. Most marine sand and gravel deposits are of fluvial or glacial origin and have been reworked to varying degrees by marine and coastal hydrodynamic processes. They represent a range of former depositional environments, including fluvial channel-fill or terrace deposits, glacial meltwater plain deposits, seabed lag gravels and degraded shingle beach or spit deposits, as well as modern marine tidal sandbanks and sandwave deposits.
Assessment of offshore sand and gravel bodies for dredging
Authors: Selby Ian , Ooms Klaas
Published: April 2008

Reliable assessment of offshore sand and gravel resources permits efficient dredging, the maintenance of cargo quality control and the effective mitigation of environmental impacts. Site investigation should be based on the interpretation and correlation of high resolution seismic profiling and CPT/sampling data. A preliminary interpretation of the seismic data reveals the geological setting of the sand bodies and leads to the selection of appropriate sampling methods and the recognition of key sampling positions. Geologically complex sand bodies demand phased data acquisition to delineate geometry, physical properties and compositional variability. The alternative approach, of grid-based sampling using a predetermined sampling density, is costly at best and probably misleading. A three-dimensional model is created from the integration of acquired data and a resource volume calculated. Dredging constraints and overflow losses are applied to the model resulting in the determination of a reserve volume and critical dredging parameters. It is advisable to carry out a wide-ranging testing programme on the recovered samples to ensure compliance with relevant standards or requirements. The potential penalties for superficial site investigation include delay, unpredictable cargo quality and unforeseen environmental problems.
The UK marine sand and gravel dredging industry: an application of Quaternary geology
Authors: Bellamy Andrew G.
Published: April 2008

Marine sands and gravels currently contribute 24% (over 20 million tonnes/year) of the total sand and gravel aggregate consumption of Great Britain. To maintain or increase this contribution into the future, the identification, assessment and licensing of additional sand and gravel resource areas is of fundamental importance. Research into the Quaternary history of the continental shelf surrounding the UK assists in the prediction of sand and gravel resource locations. Similarly, resource assessment is significantly improved through an understanding of the origin and formation of these Quaternary deposits.

Geological considerations also feature strongly in the management of existing dredging licence areas and in the acquisition of future licences from the Crown Estate. Precise resource assessment, coupled with accurate dredger positioning and track recording systems, minimizes the extent of dredged sea bed, thereby limiting environmental impact and improving the consistency of dredged cargoes. Also important is the need to overcome marine aggregate prejudice which arises from the perception by some customers that marine dredged sands and gravels differ markedly from those obtained onshore. Central to this issue is the argument that some of the most substantial marine deposits originated in subaerial environments at similar times and by the same processes as their present-day terrestrial equivalents, having been deposited in Quaternary cold climate fluvial environments.
The CIRIA research project on beach recharge materials
Authors: Arthurton Russel Scott
Published: April 2008

A CIRIA report presenting a regional review of the marine resources of sand and gravel around the coasts of England and Wales assesses the capacity of these resources to meet the anticipated demands for these materials by the aggregate industry and for beach recharge over the next 20 years. In an analysis of the demand for the materials required specifically for beach recharge — shingle and sand — the report identifies a shortfall for shingle in five of the twelve defined sub-regions, though there appears to be capacity within adjoining sub-regions to meet the demands. The report indicates a huge capacity at the regional level for satisfying the combined demands of beach recharge and the aggregate industry for sand, although at the sub-regional level some shortfalls have been identified off the coasts of northern England.
Canadian experience with the micro-Deval test for aggregates
Authors: Rogers Chris
Published: April 2008

Several aggregate test methods used in evaluating the mechanical strength and predicting the performance of aggregate have been in use since the 1930s. Today there is a need for precise tests that have a demonstrated correlation with field performance. The micro-Deval test has good multi-laboratory precision and is a suitable replacement for the sulphate soundness test for fine aggregate. A micro-Deval test on coarse aggregate is a useful means of predicting performance of aggregate in concrete, bituminous pavement and as granular base.
Assessing the wear characteristics of aggregate exposed at the road surface
Authors: Woodside A. R. , Woodward W. D. H.
Published: April 2008

This paper considers the assessment of highway surfacing aggregate wear using the Aggregate Abrasion Value and micro-Deval test methods. Their historical development is discussed. The influence of test sample preparation and number of chippings assessed is compared. Data for both methods are presented for a range of rock types. Dry, wet and soaked versions of the micro-Deval test are compared. The use of a density correction to modify the micro-Deval test value is proposed. The ability of the Aggregate Abrasion Value and micro-Deval test methods to assess heterogeneous aggregates is assessed.
A statistical study of aggregate testing data with respect to engineering judgement
Authors: Howarth Richard J. , French William J.
Published: April 2008

Aspects of product-testing and measurement uncertainty are addressed with the intention of providing guidelines to enable engineering judgements to be made which are based on valid scientific criteria. Suggestions are made to enable improved estimates of: (1) the critical range when defining measurement uncertainty; (2) the number of tests required to ensure, with a stated probability, that there is a 95% probability that the estimated mean lies within a stated absolute amount of the underlying population mean; (3) confidence intervals for a
single
determination; (4) confidence intervals on observed abundance in point- or grain-counts, including an
exact
upper bound on the proportion of a constituent which could be present (e.g. opal or chert as a contaminant) when no occurrences have been observed; (5) confidence interval on the proportion of sub-standard product present in a source of bulk material, on the basis of routine testing of a continuously delivered product,
J
-charts for the mean and range are also introduced as an aid to quality assurance. These have excellent performance compared to the better-known Shewhart and cusum charts and are well-suited to manual implementation at a ‘shop-floor’ level.
Is cleanup of VOC-contaminated groundwater feasible?
Authors: Mackay D. M.
Published: April 2008

VOCs are the organic contaminants most widely detected in public supply wells. Due to the complexity of VOC behaviour in the subsurface and the disappointing performance of many past attempts at site remediation, it appears that for many VOC-contaminated sites complete remediation of the subsurface may be practically infeasible for the foreseeable future. The contaminants do not reside solely in the easily extractable groundwater, but also in less readily treated non-aqueous phase liquid phases, sorbed phases and dissolved phases within relatively lower permeability media. Thus complete remediation is not directed solely at ‘groundwater’,
per se
, but at all locations of subsurface contaminant mass. New technologies under investigation may improve prospects for complete remediation, but the problems yet to be solved are many. Thus there has been a justified shift of attention to approaches to limit the migration of plumes and thereby control the risks they pose. These migration control approaches return the attention solely to groundwater, but specifically at that passing through a selected cross-section of the subsurface. With these and other technologies under development, there may soon be a range of tools available for remediation which will match the range of remediation goals necessitated by the site-specific complexities of VOC contamination.
Biological treatment of crude oil contaminated soil in Russia
Authors: Christofi N. , Ivshina I. B. , Kuyukina M. S. , Philp J. C.
Published: April 2008

Oil spillage on land accounts for the majority of hydrocarbon contamination of our planet and bioremediation of these habitats is possible because of the existence of hydrocarbon-oxidizing microorganisms
in situ
and in culture collections. A number of physical, chemical and environmental factors affect the degradation of oil in soils including soil pore structure, aeration, toxic oil constituents and nutrient availability. In addition, strongly sorbed hydrophobic constituents, such as polycyclic aromatic hydrocarbons, are difficult to solubilize and make available for degradation. Various remediation techniques were used in field experiments on bioremediation of oil contaminated agricultural soils after an accidental oil-spill which occurred on the territory of the Mezhevskoe oilfield (‘Polaznaoil’ company). Composting systems were utilized to increase oxygen transfer with degradation further enhanced by combination of nutrient additions, bulking with straw and inoculations of
Rhodococcus
-biosurfactant complexes. After a three-month bioremediation the content of chloroform extracts decreased to 2.85–1.60% (from an initial amount of 3.75%). The percentage oil degraded varied from 24.0 to 57.1 depending on the remediation methods used. C0
2
evolution rates (36.1–54.6
µ
g g
-1
day
-1
) indicated the intensity of aerobic oil degradation. It is not clear whether fertilization with NPK, and bulking, increased oil degradation rates in the systems used. Our initial results show that soil remediation progresses more effectively if composting systems are used with increased ventilation, nutrient additions and, particularly, inoculation of
Rhodococcus
-biosurfactant complexes.
A comparison of European state policies on ‘orphan’ sites
Authors: Christie Stella , Teeuw Richard M.
Published: April 2008

Contaminated land is a serious problem in most countries with any industrial history. Contaminated land policy is still being formed, and there is little commonality in approach. Some states have laws, either on statute, or in draft, which deal specifically with contaminated land. Some use other legislation to control this area. Those states with vulnerable water supplies tend to be most concerned, particularly with ‘orphan’ sites. However, responsibility for identification and remediation varies within countries, as well as between states, as does the funding regime. There are few specific remediation standards. The number of sites in need of remediation is also largely unknown. Costs are high, leading to prioritization due to inadequacies in funding. The European Environment Agency could act as a focus for co-ordination and dissemination of knowledge. ‘Orphan’ sites need to be part of national and international policy.