bluuebunny/crossref_metadata_2025 huggingface dataset:
Genomics and equal opportunity ethics
Authors: Cappelen A W , Norheim O F , Tungodden B
Published: April 2008

Genomics provides information on genetic susceptibility to diseases and new possibilities for interventions which can fundamentally alter the design of fair health policies. The aim of this paper is to explore implications of genomics from the perspective of equal opportunity ethics. The ideal of equal opportunity requires that individuals are held responsible for some, but not all, factors that affect their health. Informational problems, however, often make it difficult to implement the ideal of equal opportunity in the context of healthcare. In this paper, examples are considered of how new genetic information may affect the way individual responsibility for choice is assigned. It is also argued that genomics may result in relocation of the responsibility cut by providing both new information and new technology. Finally, how genomics may affect healthcare policies and the market for health insurance is discussed.
Is truth a supreme value?
Authors: Peleg R
Published: April 2008

Is truth a supreme value? At times, we doctors have to contend with a complex dilemma in which we face the value of truth on the one hand and conflict with another value on the other. Is it sometimes permissible and even necessary not to report the truth in favour of another, more important value? This is a description of an experience in which a doctor had to handle such an issue when a pregnant Muslim woman asked for a document that she wasn’t pregnant when in fact she was, in order to avert the possibility of being murdered to preserve the honour of the family. The doctor decided that the value of life was more important than the value of truth.
To what extent should older patients be included in decisions regarding their resuscitation status?
Authors: Wilson J
Published: April 2008

As medical technology continues to advance and we develop the expertise to keep people alive in states undreamt of even 20 years ago, there is increasing interest in the ethics of providing, or declining to provide, life-sustaining treatment. One such issue, highly contentious in clinical practice as well as in the media (and, through them, the public), is the use of do-not-attempt-resuscitation orders. The main group of patients affected by these orders is older people. This article explores some of the arguments regarding who should make the decision to implement such an order, with particular reference to older people and the unique issues they face in relation to resuscitation. The author concludes by arguing that official guidelines, while representing an ideal, are not easily applied in a typical acute setting where decisions regarding resuscitation are most commonly made, and makes suggestions as to how they may be implemented more successfully.
Compressibilité des argiles gonflantes non saturées à partir des essais rhéologiques
Authors: Karalis T. K.
Published: April 2008

The expression for the modulus of compressibility has been established on the basis of rheological experiments in an oedometer that measured the swelling pressure and the vapor pressure of the adsorbed liquid phase of a swelling clay hydrated by water injections under different applied loads. Key words: swelling rheology, soil compressibility, unsaturated swelling clay, oncodynamics, swelling pressure. [Journal translation]
Appareil triaxial pour l'étude du comportement thermique dé sols non saturés
Authors: Saix C. , Jouanna P.
Published: April 2008

The thermal consolidation of unsaturated soils in a thermo-hydro-mechanical framework is studied in a thermal triaxial apparatus described in the paper. The results of the first tests performed, under a given state of stress, on both silty and clayey soils, show some similarities between purely thermal consolidation and mechanical consolidation on saturated soils. Key words: unsaturated soils, temperature, triaxial, consolidation. [Journal translation]
Seasonal variation in communities of ammonia-oxidizing bacteria based on polymerase chain reaction – denaturing gradient gel electrophoresis in a biofilm reactor for drinking water pretreatment
Authors: Zhang Xiao-Wen , Qin Ying-Ying , Ren Hong-Qiang , Li Dao-Tang , Yang Hong
Published: April 2008

The diversity and variation of total and active ammonia-oxidizing bacteria in a full-scale aerated submerged biofilm reactor for drinking water pretreatment were characterized by clone libraries and denaturing gradient gel electrophoresis (DGGE) analysis of 16S rRNA and its gene during a whole year. Sequences obtained from clone libraries affiliated with the Nitrosomonas oligotropha lineage and the Nitrosomonas communis lineage. An uncultured subgroup of Nitrosomonas communis lineage was also detected. Seasonal variations in both total and active ammonia-oxidizing bacteria communities were observed in the DGGE profiles, but an RNA-based analysis reflected more obvious dynamic changes in ammonia-oxidizer community than a DNA-based approach. Statistical study based on canonical correspondence analysis showed that a community shift of active ammonia oxidizers was significantly influenced by temperature and pH, but no significant correlation was found between environmental variables and total ammonia-oxidizer community shift.
Characterization of formulated microbial products by denaturing gradient gel electrophoresis, total cellular fatty acid analysis, and DNA microarray analysis
Authors: Nowak E. , Brousseau R. , Garrett J. , Masson L. , Maynard C. , Trevors J.T. , Edge T.A.
Published: April 2008

Two commercial products, Biotize and Cycle, containing bacteria as an active ingredient were characterized for species identification and batch-to-batch variation by denaturing gradient gel electrophoresis (DGGE), total cellular fatty acid analysis (FAA), and a taxonomic DNA microarray. DGGE was useful at assessing the stability of consortia in different batches, and cluster analysis differentiated each batch even when only slight differences in species composition were observed. DGGE, FAA, and DNA microarray results indicated little batch-to-batch variation in Biotize and some batch variation in Cycle. The 3 methods agreed well with species identification in Biotize but generated conflicting results in the species composition of Cycle. This multi-method approach was useful in determining if the observed bacterial species present in the products matched the expected species composition.
Characterization of the Serratia marcescens SdeCDE multidrug efflux pump studied via gene knockout mutagenesis
Authors: Begic Sanela , Worobec Elizabeth A.
Published: April 2008

Serratia marcescens is an important nosocomial agent having high antibiotic resistance. A major mechanism for S. marcescens antibiotic resistance is active efflux. To ascertain the substrate specificity of the S. marcescens SdeCDE efflux pump, we constructed pump gene deletion mutants. sdeCDE knockout strains showed no change in antibiotic susceptibility in comparison with the parental strains for any of the substrates, with the exception of novobiocin. In addition, novobiocin was the only antibiotic to be accumulated by sdeCDE-deficient strains. Based on the substrates used in our study, we conclude that SdeCDE is a Resistance–Nodulation–Cell Division family pump with limited substrate specificity.
Characterization of plant growth-promoting Bacillus edaphicus NBT and its effect on lead uptake by Indian mustard in a lead-amended soil
Authors: Sheng Xia Fang , Jiang Chun Yu , He Lin Yan
Published: April 2008

The plant growth promotion characteristics of a heavy-metal-resistant strain of Bacillus edaphicus NBT was characterized. The strain was also evaluated for promoting plant growth and lead (Pb) uptake of Brassica juncea L. Czern (Indian mustard) in soil artificially contaminated with 0, 400, and 800 mg Pb·kg–1 soil. Atomic absorption spectrometer analysis demonstrated that strain NBT could release water-soluble Pb from lead carbonate in the solution. Strain NBT had the capacity to produce indole acetic acid, siderophores, and 1-aminocyclopropane-1-carboxylate deaminase. Low and high Pb treatments significantly decreased the growth of Indian mustard. Inoculation with strain NBT was found to increase root dry mass (ranging from 16% to 22%) and above-ground tissue dry mass (ranging from 24% to 30%) of Indian mustard in the Pb-amended soil. Strain NBT was able to mobilize Pb efficiently in plants in Pb-amended soil. In the soil treated with 400 and 800 mg Pb·kg–1 soil, the increase in Pb uptake varied from 18% to 46% in live bacterium-inoculated Indian mustard plants compared with dead bacterium-inoculated control. The strain was also able to colonize and develop in the rhizosphere soil of Indian mustard after root inoculation.
Flavonoid-responsive nodY-lacZ expression in three phylogenetically different Bradyrhizobium groups
Authors: Yokoyama Tadashi
Published: April 2008

Previously, restriction fragment length polymorphism analysis using the nodD1YABC gene probe showed the genetic diversity of common nodD1ABC gene regions of Bradyrhizobium japonicum , Bradyrhizobium elkanii , and the Thai soybean Bradyrhizobium. The nodD1 sequences of representative strains of the 3 groups differed phylogenetically, suggesting that responses of NodD1 proteins of the 3 Bradyrhizobium groups to diverse flavonoids may differ. To confirm this hypothesis, 6 representative strains were chosen from the 3 Bradyrhizobium groups. Six reporter strains were constructed, all carrying the pZB32 plasmid, which contains a nod box and the nodY-lacZ fusion of B. japonicum USDA 110. Differences in nodY-lacZ expression among the strains in response to 37 flavonoid compounds at various concentrations were evaluated. Of those compounds, prunetin (4′,5-dihydroxy-7-methoxyisoflavone) and esculetin (6,7-dihydroxycoumarin) were identified as Bradyrhizobium group-specific nod gene inducers. Esculetin showed nod gene induction activities unique to Thai Bradyrhizobium strains. The levels of nodY-lacZ induction among B. japonicum and Thai Bradyrhizobium strains increased with increasing concentration of prunetin, whereas, those in B. elkanii strains did not.
Heat stability of chaetoglobosins A and C
Authors: Fogle M.R. , Douglas D.R. , Jumper C.A. , Straus D.C.
Published: April 2008

Chaetomium globosum is commonly found in water-damaged buildings and produces the mycotoxins chaetoglobosin A and chaetoglobosin C (Ch-A and Ch-C, respectively). While attempting to purify Ch-A and Ch-C, we observed that these mycotoxins were broken down after heating. The objective of this study was to determine the temperature and the amount of time necessary to break down Ch-A and Ch-C. We demonstrated that the amounts of Ch-A were significantly reduced when exposed to 75 °C for 24 h and 100 °C for 90, 120, or 150 min. Under the same conditions, the levels of Ch-C were also lower (although not significantly). At 175 °C, no Ch-A was detected after 15 min and Ch-C was significantly reduced after 30 min. Our findings will aid other researchers who work with these mycotoxins in the future.
The Application of Ground Conductivity and Offset Wenner Resistivity Soundings to Optimise the Investigation of a 300 ha Site in the West Midlands
Authors: Frost F. B. , Dumble J. P.
Published: April 2008

In order to evaluate quickly and cost effectively the detailed shallow sub-surface geology of a 300 ha area in the West Midlands, geophysical techniques were used in conjunction with shell and auger drilling. Since the area contains one of the largest landfill sites of its type in Europe and is crossed by a river which is abstracted for drinking water within a short distance downstream, it was important to determine the geology and hydrogeology in some detail.

Previous geological surveys of the area, which included the drilling of over 80 boreholes for sand and gravel extraction, indicated the presence of up to 5 m of highly variable sandy overburden overlying Keuper Marl. It was apparent from an initial desk study that despite the large number of boreholes the geology had been completely misinterpreted.

A ground conductivity map was produced using a Geonics EM-31 which rapidly gave a picture of the general structure and identified targets for drilling and Offset Wenner resistivity soundings. The geophysics revealed the presence of a major buried channel cutting deeply into the marl, which was later confirmed in several places by drilling. Surface outcrops of clay or marl could be identified using the ground conductivity values alone.

The use of the geophysical techniques has considerably reduced the cost and time of the investigation and has allowed the major effort to be concentrated in problem areas.
Disturbed Sampling Using Reverse Circulation
Authors: Hurley M. R. , Lavender M. D.
Published: April 2008

The exploration of unconsolidated and semi-consolidated strata is generally undertaken using shell and auger and continuous flight augering techniques. These methods have serious limitations, especially when accurate sampling is required below the water table.

To improve the reliability of samples British Industrial Sand Ltd. have developed a drill bit for use with reverse circulation drilling. When used in combination with a non-return valve this method allows continuous drilling and sampling both above and below the water table.

Comparisons with other drilling techniques show that the duo-pipe method is capable of delivering uncontaminated samples and recovering material of all anticipated size ranges.

The system could be adapted for use in the exploration of other mineral deposits e.g. alluvial tin, beach sands, sand and gravel, or for offshore drilling programmes.
The Point Load Test
Authors: Norbury D. R.
Published: April 2008

In the twelve years since the paint load test was introduced, much experience has been gained in its use. This paper reviews published papers reporting constructive criticism of test procedures and case histories.
Site Investigation for Areas Affected by Limestone Workings
Authors: Solera S. A.
Published: April 2008

This paper describes the techniques used to investigate the conditions, dimensions and stability of underground workings in Silurian limestone in the West Midlands. Drillholes were formed by rotary coring methods through the rock strata overlying the cavities. Rock cores were taken in the drillholes and classified.
In situ
permeability tests, geophysical logging and a closed-circuit television survey were carried out. The shape and dimensions of the workings in the proximity of the holes were established by ultrasonic surveys. The paper describes the use of a variety of techniques, some of which were primarily developed for use in fields other than civil engineering.
Benefits of engineering geology for land use planning in areas of past metalliferous mining
Authors: Holt D. N. , Marker B. R.
Published: April 2008

Metalliferous mining in the United Kingdom has left an inheritance of subsidence and contamination which can affect the viability and suitability of land for present and future use. The science of geology developed and grew against a background of mining in a situation of mutual interdependence. Geologists whose profession is rooted in mining are therefore uniquely able to assess the implications of the present-day inheritance of past mining activity. The planner needs guidance on areas of past mining as a basis for safe strategic planning and to aid rapid, effective decisions on development and reclamation proposals. This can best be founded on a data base compiled by appropriate specialists who should have geological training, and professional interpretation of the information. Thus it is that the engineering geologist is able to provide planners with information and guidance on matters central to the question of assessing problems, not only of stability and contamination of mined ground, but also in making recommendations for the most suitable and cost effective ways of dealing with these. To be fully effective in this role the engineering geologist must, however, be sure to express himself in the clearest and most readily understood terms at all times.
The value of engineering geological desk study appraisals in scheme planning.
Authors: Herbert S. M. , Roche D. P. , Card G. B.
Published: April 2008

Abstract>

Engineering geological factors are too often given insufficient prominence in scheme planning. Whereas desk studies form an important part of ground engineering practice, their relevance to early planning and feasibility studies is not always fully appreciated by planners. It is suggested that they should be regarded as encompassing a range of appraisals varying from comprehensive research of all available information to a preliminary, rapid study of easily accessible data. In this way a desk study can be designed to meet the specific requirements appropriate for any particular stage of a project. This allows engineering geological factors to be incorporated into scheme planning without significant costs being incurred. This approach is illustrated briefly by four case histories. In each, the client was forewarned of anticipated site conditions and hence likely development costs at a sufficiently early stage in the project for scheme planning to be modified as necessary.
Cliff stability evaluation using geomorphological maps based on oblique aerial photographs
Authors: Kalaugher P. G. , Grainger P. , Hodgson R. L. P.
Published: April 2008

Geomorphological mapping is a well established tool in terrain evaluation. A case record is presented in which high-oblique aerial photography from a light aircraft has been used for basic mapping of a 3 km length of coastline with the purpose of assessing relative landslide hazard.

The cliffs at Budleigh Salterton, East Devon, are formed in a succession of Permo-Triassic mudstone, conglomerate and sandstone which dip gently eastwards along the coast. The coastline is divided into five units based on changes in the stratigraphic succession exposed in the cliff face; each unit correlating with distinctive geomorphological features and cliff profiles. Groundwater discharges, wave attack and weathering ensure that there is continuing geomorphological activity. This necessitates frequent updating of local hazard assessment.

Overlapping aerial photographs of the cliff face have been taken at intervals during the past six years. With limited ground inspection these photographs provide adequate data for basic geomorphological mapping of the principal forms represented in the cliff. Successive series of photographs are used to follow the development of individual features and to identify the hazards present in each section of the cliff. Data from early Ordnance Survey maps, old photographs and personal reminiscences extend parts of the history of the coast back into the last century. The positions of landslides are controlled largely by geological and hydrological factors whereas the timing of events is often a function of external environmental triggering mechanisms such as weather, tide or waves.

A classification of the relative hazard of cliff-top instability has been used to map hazard zones for the coastline. Together with the system of photographic data acquisition advocated, this provides a rapid and economic method to assist planning authorities in determining development strategy.
The supply and use of engineering geology information relating to slope instability hazards for planning purposes
Authors: Fulton A. R. G.
Published: April 2008

This paper seeks to examine the use of one type of information which engineering geologists can supply to planners, in particular, that relating to slope instability problems. Mass-movement phenomena can provide major obstacles to planning objectives and may require costly measures if they are to be avoided or stabilized.

The recent publications of Varnes (1984), Brunsden & Prior (1984) and Crozier (1986) all bear witness to the intense interest and importance attached to slope instability phenomena and their planning impacts. This paper examines how information is supplied by engineering geologists to planners and the role that it may play in producing safer, more cost-effective planning solutions to the risks to both life and property posed by mass-movements.

The paper focuses its attention on the methods of supply of hazard information to planners and especially on hazard mapping. A selection of the more widely used slope hazard mapping techniques is examined and critically evaluated in planning terms. In addition, the ways of describing phenomena presently used on the relevant documents is examined for its suitability for, and compatibility with, planning requirements.

The second part of the paper focuses attention on the use of hazard information within planning systems basing its discussion on working systems in North America, Australia, and Continental Europe while also making reference to work being produced in the United Kingdom. The potential contribution of engineering geology to hazard avoidance and planning controls in hazardous areas is discussed drawing upon case-study material.

The final part of the paper discusses possible areas of incompatibility between earth-science information and planning systems drawing upon practical examples. In particular the differences between the planning and geological timescales are discussed.
Studies for the extension of a major urban quarry in Hong Kong
Authors: Choy H. H. , Earle Q. G. , Irfan T. Y. , Burnett A. D.
Published: April 2008

The paper describes the history and setting of a major urban quarry complex in Kowloon, Hong
Kong in relation to current and future town planning, the local aggregate industry and various environmental
pressures. These factors dictate that the quarries now work toward a final configuration which will be both safe
and land efficient. This will involve additional land take and an extension to the current two quarries. The
planning of this major extension will involve several investigations being carried out and in this paper the
preliminary engineering geology studies are described. The influence that these studies are likely to have on both
the future planning of the layout and after-use of the site and the type and quality of aggregate and overburden
to be produced is discussed and contrasted.
The engineering geology of road projects in North Borneo
Authors: Cook J. R. , Younger J. S.
Published: April 2008

The influence of geology and terrain on the planning, undertaking and interpretation of site
investigations, and on the subsequent geotechnical design guidelines, is discussed with particular reference to
three recent road projects in North Borneo. The locations of these projects range from coastal plain to inland
mountainous terrain, and the geological environment from Quaternary alluvial peat deposits to folded Tertiary
geosynclinal sedimentary rocks. The different styles of investigation planned for each project are tabulated and
discussed in the light of the varying problems and requirements posed by the differing terrain units. Particular
engineering geological problems relating to the geotechnical design of the projects are listed and discussed.

The engineering geological influence on construction planning is indicated by the variation in geotechnical
design guidelines as a response to the information recovered from the various geological environments.
Examples are presented of the derived geotechnical outline designs for cut-slopes, embankments, stability
measures, etc, for the various terrains and geological environments. It is proposed that the outline designs will
form the basis of a geotechnical working programme to be used during construction. The usefulness of outline
geotechnical designs, in conjunction with a knowledge of geology and terrain, is indicated with respect to
estimation of construction costs and quantities.
Planning and construction of an industrial site on the Bristol Coalfield
Authors: Hawkins A. B. , Tomlinson D.
Published: April 2008

The paper examines the progress of a large industrial/retail development on the Bristol Coalfield,
from the planning stage through the site investigation to the construction phase. The planning history of the site,
the local geology and the history of mining in the area is reviewed.

Following completion of the major part of the site investigation, a zonal system was evolved to define the
preferred locations for various elements of the development. This is described and the application and
limitations of such a system explored. The paper examines a number of problems encountered during
construction and describes in detail the method and criteria adopted in the ground treatment operations and
foundation construction for a large retail warehouse. The financial and planning/layout constraints operating
on this type of speculative development are considered.
Geophysical mapping during the planning of new roads: an aid to thedetection of mine-workings
Authors: Jackson P. D. , McCann D. M. , Russell D. L.
Published: April 2008

Magnetic field strength and electrical conductivity surveys have been made over an extensively
mined area north of Dalton-in-Furness along parts of a proposed by-pass route. This approach was successful in
detecting shafts and other workings, which were brick-lined and back-filled with debris and ash, since the
magnetic field and electrical conductivity values are normally higher in the vicinity of such areas. The use of non-contacting instruments resulted in the rapid location of the geophysical anomalies associated with the contrast
in the physical properties between the material in-filling the mine shafts and the surrounding rock mass. Shafts
covered with debris or back-filled with the original overburden did not generally give rise to significant magnetic
anomalies but often produced a conductivity anomaly associated with changes in the drainage pattern of the
area resulting from the presence of the shaft.
Route selection for natural gas pipelines in Ireland
Authors: Redding J. H.
Published: April 2008

By the end of 1986, over 400 km of high pressure (70 bar) natural gas pipeline will have been constructed in the Irish Republic, much of it laid in sparsely populated rural areas where topography,
hydrology, near surface geology and ground conditions can significantly influence construction feasibility and cost. Identifying, quantifying and (where possible) avoiding areas of potential difficulty or hazard are aspects of
route selection to which engineering geology can make an important contribution. This contribution is discussed in relation to the Cork-Dublin pipeline completed in 1982, and the Limerick, Waterford and Mallow lines due
for completion this year. In particular, the application and merits of stereo aerial photographic interpretation, superficial geological mapping and field study are outlined, together with the use of more traditional methods of
site investigation. Attention is focussed on indigenous engineering geological problems associated with shallow rock, limestone karst, peat bog and poorly drained alluvial and morainic soils. Data acquisition and presentation are discussed within the overall context of civil engineering contract preparation and administration. The usefulness of this approach, particularly for predicting and minimising construction costs, forestalling claims and generally facilitating on-site supervision, is emphasised.
Geological investigations and proposed development of the Colonia Soto district, Tegucigalpa, Honduras
Authors: Warren C. D. , Blakeway D.
Published: April 2008

The twin cities of Tegucigalpa and Comayaguela, Honduras are located within an intermontaine
basin. The urban area is dissected by several rivers which converge to form the main River Choluteca, flowing
northwards. The river channels follow tortuous courses dictated principally by accidents of geology. As a
consequence of the variable rainfalls and hurricanes that periodically lash the Republic, and the previous lack of
management, the channel profiles have generally attained unacceptable physical dimensions inside the urban
perimeter with some sections showing signs of instability. To add to this, the absence of appropriate stormwater
drainage systems within certain areas of the City has given rise to foundation problems associated with collapse
settlement. This paper summarizes the geological investigations carried out in the Colonia Soto district of the
City with a view to eliminating the present hazardous conditions, as related to the underlying geology, with
recommendations being made for future development of the hillside.
Coastal erosion and slope instability at Downderry, south-east Cornwall: an outline of the problem and its implications for planning
Authors: Coard M. A. , Sims P. C. , Ternan J. L.
Published: April 2008

The Quaternary head deposits which overlay a wave-cut shore platform along a 2 km sector of coast between Seaton and Downderry in south-east Cornwall, have been subjected to significant coastal erosion over many years. As a result, a number of landslips have occurred with considerable damage and even loss of cliff top dwellings. An outline of recent investigations conducted on the cliff and landslip sections with regard to slope stability and the nature of the head deposits is presented. Attention is drawn to the need for adequate drainage of the cliff material, particularly in the siting of gutter soakaways from the cliff top settlements.

Despite the history of landslipping in this coastal sector, planning permissions have been granted and a number of new dwellings have been constructed on the cliffs. Ultimately, these properties will be affected by the receding cliff edge and associated slope failures.

The paper thus reviews the efficacy of both public and private coastal defence schemes, particularly in relation to the overall stability of the head materials, beach sediment budgets and the ‘natural’ protection provided by longshore sediment transport at the foot of the cliffs.
Opportunities and responsibilities
Authors: Payne H. R.
Published: April 2008

Some of the administrative and social responsibilities facing Local Authorities in dealing with hazardous events such as landslides, rockfalls, mining subsidence and coastal erosion are considered. These are illustrated by examples drawn from Wales.
An overview of site investigation and long-term tunnelling-induced settlement in soil
Authors: Attewell P.B.
Published: April 2008

Ground settlement amplitudes and distributions in clay soils depend both on ground losses at the tunnel and on longer-term consolidation effects. In granular soils there is a dependency on an initial density state. The problem of the degree of ground movement transfer into structures, building foundations and buried pipelines, can be examined both analytically (Winkler-style modelling) and numerically (finite element modelling). Finally, it is noted that published damage criteria for buildings are not accurately applicable to tunnelling-induced damage.
Induced subsurface movements associated with the presence of natural and artificial underground openings in areas underlain by Cretaceous Chalk
Authors: Edmonds C. N.
Published: April 2008

Induced subsurface ground movements in areas of pre-existing metastable ground conditions associated with natural solution features and underground mining in the Chalk, commonly produce dolines (sinkholes) and crown holes (subsidence pits) at the surface, respectively. Although the nature of underground movements differs between natural and artificial sources, the range of subsidence triggers is generally the same. Man’s Activities via urban development can increase the incidence of subsidence, and, therefore, subsurface movements too. Considerable damage to buildings, and even loss of life, can result from induced subsurface movements. New hazard mapping techniques are available to predict zones where the subsidence hazard due to these movements is greatest, hence ground investigations, foundations and drainage measures can be purpose-designed to take account of possible ground movements. This approach greatly improves the engineering geological understanding of ground movements at chalkland sites and gives confidence that the most critical zones of ground have been both accurately delineated and correctly assessed.
A study of the effects of mining relatively shallow overlying longwall panels with staggered inter-panel pillars at Sigma Colliery, South Africa
Authors: van der Merwe J. N.
Published: April 2008

When two coal seams in close proximity are to be mined by longwall, a number of alternatives regarding the placing of the panels relevant to one another are possible. The main factors influencing the final choice are gate road stability, face conditions and the extent of surface deformation.

The paper describes the rationale and investigations leading up to the decision to stagger overlying longwall panels at Sigma Colliery. A two dimensional boundary element program was used to predict the stability of gate roads, after having obtained excellent correlation between predicted and actual conditions in a test case. Observations to date also confirm the prediction of stability conditions in the staggered panel’s.

Surface deformations were measured in detail. A computer program was written which permitted the analysis of a huge volume of data in a very short time. The results of the analysis confirm that less damaging surface disturbance is caused by staggering the panels, compared with superimposing them.
Subsidence prediction by the use of influence functions
Authors: Bell F. G. , Coulthard J. M.
Published: April 2008

Surface subsidence occurs as a result of extraction of a mineral resource at some depth below the surface. Most coal is mined in this way in the United Kingdom and such coal workings are responsible for the great majority of subsidence and associated damage that occurs. Hence it has become necessary to develop methods of predicting the amount of subsidence likely to develop due to coal mining.

Many methods have been advanced, dating back to the latter part of the last century. However, they can be separated into three groups, namely, the theoretical, the empirical and the semi-empirical methods. A number of these methods were reviewed with the object of selecting one which lent itself to the development of a relatively simple computer program that could be used on a microcomputer.

The complementary influence function method was chosen and, although by no means a perfect method, a program was developed to predict a complete subsidence profile for a given set of circumstances. The concept of complementary influence functions considers not only the influence of the extracted elements on a surface point but also the influence of the material remaining after extraction. The subsidence of a surface point then is found by integrating the response of every element in the area of influence, whether mined or not. The mined region is divided into a number of mined and unmined elements. Summing the influence of all the elements on a particular point yields a picture of subsidence at that point. If this is done for a number of points across the proposed extraction area, then a complete picture of the subsidence over the area can be obtained.
The geology of Castlefields Mine, Dudley, and its effect on the stability of the mine roof
Authors: Forster A.
Published: April 2008

The mining of the Wenlock Limestone, which has taken place in the West Midlands during the last two hundred years, has resulted in a long and continuing history of subsidence and crownhole formation in a mainly urban area.

In 1983, as part of a major study of the abandoned limestone mines, a programme of micro-seismic emission monitoring of rock falls and of rock paste infilling trials was started at the Castlefields Mine near Dudley.

The mine is in Upper Wenlock Limestone with an overburden of approximately 22 m comprising about 1.5 m Passage Beds overlain by Lower Ludlow Shale. A number of stages of instability were observed, ranging from initial slabbing failure of the Passage Beds to extensive upward void migration through the Lower Ludlow Shale to within a few metres of the surface.

The pattern of joints, and their condition, plays an important role in controlling the instabilities in a mine. Five joint sets, with varying degrees of dilation, movement and infilling, were identified in a survey of structural discontinuities in Castlefields Mine. One master joint set, characterized by uneven dilation and clay infilling, was found to exert a major influence on the position and development of roof instabilities within the mine.

In this paper, the lithology, geological and mining history and structure of Castlefields Mine are described and their influence on mine stability discussed.
A case study on past shortwall mining methods and the risk of ground subsidence in the Lanarkshire Coalfield, Scotland
Authors: Evans J. A. , Lawrence M. S.
Published: April 2008

A site investigation involving archival research and a borehole drilling programme was carried out in order to assess the risk to surface stability from abandoned shallow shortwall mineworkings at a proposed housing development site located on the Lanarkshire Coalfield.

Of the exploitable coal seams present below the site, the Ell coals were confirmed to be at shallow depth and were mined into the mid-1950’s from the adjacent Thankerton Colliery. The Ell coal in this part of the coalfield occurs in three distinct leaves, the uppermost of which crops through the site and was not mined. The investigation confirmed the extent of mining in the Mid and Lower Ell seams which were proved to be no more than 0.5 m apart with a combined unworked thickness of 1.5 to 1.9 m.

The mine records indicate that the Mid and Lower Ell seams were mined by shortwall methods, individual panels having been worked from a network of main roadways or headings with subsidiary side or haulage roadways. Due to the thin partings between the seams, a method of mining each seam from common roadways extending to the full height of combined seams was used in addition to single seam workings of the thicker Mid Ell. From the abandonment information it has been deduced that mining involved the total extraction of the Mid Ell whilst maintaining the integrity of the roadways. Subsequently, the same roadways allowed access to the Lower Ell for extraction below the collapsed Mid Ell workings.

The investigations recorded the shortwall panels to be largely consolidated but also noted that several panels had been undeveloped with respect to the lower seam and that some roadways were confined to the Mid Ell seam. The borehole investigation together with the use of down-the-hole closed circuit television (CCTV) also confirmed the presence of broken ground and open voids of 0.3 to 2.0 m height along former roadway alignments.

A risk to surface stability was identified from these open voids and development constraints zones are discussed in relation to the likely mining methods. Seam depths, void heights, condition of roof strata and thickness of superficial cover are considered in the assessment of void migration mechanisms arising from such a past mining situation.
Consolidation characteristics of clays from self-boring pressuremeter tests
Authors: Clarke B. G.
Published: April 2008

The self-boring pressuremeter can be used to determine in situ consolidation characteristics of clays (Clarke
et al.
1979). The test procedure includes undrained loading from which total horizontal stress, shear modulus and strength can be determined. Excess pore pressures are generated during loading. These decay during the holding portion of the test when the membrane is held at about 10% cavity strain. The rate of decay is used together with a theoretical prediction of consolidation around a cavity to determine the horizontal coefficient of consolidation. The main disadvantage of this is the difficulty with measuring the pore water pressure. As the excess pore pressures dissipate the total applied pressure within the membrane is reduced. The total pressure can be monitored more accurately than the pore pressure and, hence, holding tests based on total pressure decay would be a preferred field technique. This paper discusses work carried out at the SERC Bothkennar soft clay site where undrained SBP and holding tests were carried out down to a depth of 19.6 m. The tests have been interpreted using total pressure observations. The tests have also been interpreted using a finite element package which includes the Cam Clay model and coupled consolidation. This interpretation allows a comparison to be made between the use of pore and total pressure decay in the analysis and recommendations for an alternative test procedure are made.
Self-boring pressuremeter testing in London Clay
Authors: O’Brien A. S. , Newman R. L.
Published: April 2008

With the large amount of literature on London Clay, it is generally assumed that its properties are both well understood and well documented. However, there are few reports of how man-made features, such as tunnels, can alter the in situ horizontal stress field and stiffness of London Clay. This paper describes the self-boring pressuremeter tests carried out at a site in north east London at locations in close proximity and remote from a London Underground Ltd tunnel. Two aspects are considered; firstly, the analysis, assessment and interpretation of data and, secondly, the effect of the tunnel on the profiles of in situ horizontal total stress and coefficient of earth pressure at rest.

The analysis of the test data has indicated that interaction between the instrument and the soil may effect the measured ‘lift off’ pressure. Methods of interpretating the test data are suggested. The variation with depth of the ratio of shear modulus (at a particular cavity strain) to mean effective stress proved to be a useful method of checking the reliability of the test data.

During the pressuremeter tests unload-reload loops were performed to measure shear modulus. Because of the nonlinear stress-strain behaviour of London Clay it is recommended that the magnitude of cavity strain imposed during the unload-reload loop is taken into account during the assessment of shear modulus. Finally, in situ stress and stiffness from the self-boring pressuremeter tests are compared with case history data.
Self-boring pressuremeter in situ lateral stress assessment in London Clay
Authors: Corke D. J.
Published: April 2008

Recently a considerable amount of self-boring pressuremeter testing has been carried out in London Clay. This paper considers the results of tests from four sites and the methods for obtaining the in situ total lateral stress, undrained shear strength, limit pressure and shear modulus are reviewed.

In order to provide some means of checking the consistency of results produced from self boring pressuremeter tests, the normalized parameters
C
u
/
P
I
(shear strength/limit pressure) and
P
0
/
P
1
(in situ total lateral stress/limit pressure) have been assessed and found to be reasonably consistent with depth within the London Clay for a wide range of shear strengths.

On all of the sites considered, the measured lateral pressures were generally higher than would have been assumed from published information. During the course of the erosion of what is generally considered to have been several hundred metres of material, it is possible that passive conditions could have existed and may have had a controlling influence on in situ lateral pressures both in the past and at present. The self-boring pressuremeter tests generally indicate that plastic deformation of the soil commences at pressures only slightly higher than the measured in situ lateral stress. Also, the values of passive pressure calculated using the pressuremeter are similar in value to those stresses. It is concluded that at some locations London Clay may be at, or near to, the passive condition.

It is recommended that long-term monitoring of ground pressures on deep structures is undertaken to provide independent confirmation of the findings of this paper. Also, a field study of the effects that self-boring can have on the ground, particularly in very stiff and hard clays is needed. This would clarify the influence these effects may have on the test results.
Some recent in situ stress testing experience with strong clays and weak rocks in Britain
Authors: Stevenson M. C. , Martin J. H. , Squire P. O.
Published: April 2008

Intensive pressuremeter testing at two sites in lower Lias clays, together with laboratory testing has enabled general conclusions to be drawn about strength-stress compatibility in heavily overconsolidated materials. Three limit states of effective horizontal stress are described which demarcate in situ test results into four distinct ranges relating to the stress history of the material. These may be used to validate pressuremeter measurements. The
in situ
test results for the two sites are related to the regional geomorphology and the results of conventional geological logging.
The interpretation of standard penetration tests in geologically aged sands
Authors: Barton M. E.
Published: April 2008

The standard penetration test represents a traditional and convenient method for the assessment of the engineering properties of cohesionless soils for the purpose of foundation design. This test, however, is not a direct measure of the static load/displacement characteristics of a sand and hence it is an empirical one in which the blow count is correlated firstly with the in situ density and shear strength obtained by other methods and, secondly, with case records of foundation performance. Most, if not all, of the existing correlation charts are based either on measurements of density and shear strength in remoulded sands or on the performance of fills or recent sands. The unique properties of sands which have geologically aged (that is been subjected to a variety of diagenetic processes) are often ignored with the erroneous assumption that the correlation charts will apply equally to all sands.

The paper examines the penetration resistance of uncemented sands in Southern Britain ranging in age back to the Jurassic. It is seen that there is a marked difference between tests carried out well above the groundwater table (dry tests) and those either below or in close proximity to it (wet or saturated tests). Only dry tests give the high resistances expected from the very dense and strong geologically aged sands. These results show an exponential increase in blow count versus depth and vertical effective pressure. Reasons for the reduced resistances measured in water filled boreholes are discussed. Of significant influence is the markedly moisture sensitive strength behaviour of ancient sands. In addition, the conditions of the test are such that other adverse effects, inevitable with conventional boring operations, can be operative and hence weaker foundation characteristics may be assumed than is actually the case in the undisturbed sand.
Applications of continuous dynamic probing in ground investigation
Authors: Card G. B. , Roche D. P. , Herbert S. M.
Published: April 2008

Four case histories are described where the continuous dynamic probing technique has been applied in chalk and non-cohesive deposits. The results are correlated with adjacent conventional boreholes for which standard penetration test (SPT) data have been obtained. The applications of this technique are discussed and reviewed, and consideration is given to the degrees of consistency and inconsistency in the results obtained, particularly the correlation with SPT.