bluuebunny/crossref_metadata_2025 huggingface dataset:
Full-scale mixing, pumping and surface spreading trials of rock paste for filling mines
Authors: Ward W. H.
Published: April 2008

A stage in the development of a new, cheap and environmentally beneficial method of filling potentially dangerous abandoned mines with large voids in the West Midlands to prevent their collapse is outlined. The filling material, known as rock paste, consists of colliery spoil from tips mixed with water, prepared near the mine to be filled, pumped through long surface pipelines and down boreholes into the mine. It then spreads laterally long distances through the mines.

Some details are given on the selection of suitable spoil, its processing into paste and its pumping behaviour through instrumented pipelines, up to 260 mm diameter and 220 m long, at high pressures and rates up to 80 m
3
/h. Some 1000 tonnes of spoil were pumped.

Observations on the spreading performance of large heaps of paste pumped out on to a level surface, and one sloping at about 4°, demonstrate the capacity for paste to spread long distances through mines as a heavy plastic yielding material. The basic plastic spreading theory and its application to the design for a mine filling operation is outlined in the Appendix.

Despite some shortcomings and recommendations for their improvement, the results of the trials were sufficiently encouraging for them to be applied to the trial filling of part of Castlefields Mine at Dudley.
Basal Permian Sand mines and associated surface movements in the Castleford and Pontefract area of West Yorkshire
Authors: Baldwin M. J. , Newton M. A.
Published: April 2008

Surface movements in the Castleford and Pontefract areas of West Yorkshire have come to light in the past few years. Various investigations, the more recent to determine the causes of these movements in relation to specific buildings and other properties, have shown that mineworkings in the Basal Permian Sands are the cause. Research has revealed that a significant proportion of the developed Redhill area is underlain at very shallow depth by sands which between the mid-nineteenth and twentieth centuries have been extensively mined; much of this mining is unrecorded.

Underground inspections of abandoned mines has shown the roof material to be a well jointed limestone of the Lower Magnesian Limestone group. Investigations of failure mechanisms have been based on these underground observations. The type and thickness of the workings in relation to the limited overburden and the joints in the roof material have been found to be responsible for the occurrence of sudden and large surface movements. Remedial measures have been taken to stabilize a property affected by subsidence movements, however problems have arisen due to the unexpectedly great height and extent of the workings.

During the research, it has become evident that workings were not confined to the Redhill area, but also occur at several other localities. Observations indicate that there is an urgent need to investigate the full extent of all the workings in order that properties at risk can be identified and an economic, practical and effective method of stabilization established.
Mining induced seismicity in UK coalfields identified on the BGS National Seismograph Network
Authors: Redmayne D. W.
Published: April 2008

Earthquakes induced by coal mining are seen often on the widely spaced seismograph stations operated by the British Geological Survey. They are characterized by shallow depths of focus, proximity to current workings, repeatable signals, and good correlation with mining activity. The background and history of such mining induced seismicity is discussed, drawing upon specific examples of past and present activity.

Presently active areas include the Midlothian coalfield in Scotland and in particular the village of Rosewell and its immediate surroundings. The series of tremors which has been recorded there during 1985 and 1986 is examined in detail with regard to depth, location, signal character and correlation with mining activity in order to verify its induced nature. These tremors, with magnitudes of up to 2.8 ML, were strongly felt locally and at times caused slight damage. Examples are given of building damage and a crown hole occurrence which may be attributable, at least partially, to these events.
Dynamic surface effects of underground copper ore mining in the Legnica Copper District, Poland
Authors: Ciesielski R.
Published: April 2008

In the region close to Legnica, Poland, copper ore is mined at a depth of about 900 m by the process of explored chambers collapsing as a consequence of controlled explosions. These explosions generate underground shocks which propagate to the surface as seismic waves. This paper discusses the characteristics of these waves, their propagation through the rock mass, the vibrations they cause at the ground surface and their effect on certain structures at the surface. Some data on seismic energy are presented and discussed, including cases of medium and maximum energy, up to 10
10
J. Surface vibrations above the explored ore layers are analysed using the spectral amplitude – frequency approach. The correlation between source energy and measured magnitude is discussed, together with surface effects, in terms of existing MCS and MSK scales. A method for evaluating the degree of potential damage to structures caused by the vibrations is presented; this involves computational analysis in accordance with physical load models determined from measurements and simplified scales of vibration (SWD). Structural engineering designs for withstanding these paraseismic influences in these areas are also mentioned.
A determination of the shear strength parameters of a fine-grained cemented alluvium in the US Desert Southwest
Authors: Muller Eugene , Nowatski Edward A. , DeNatale Jay S.
Published: April 2008

Laboratory determination of shear strength parameters for alluvial soils in the US Desert Southwest is imprecise at best. These soils contain varying amounts of carbonate cementation and it is extremely difficult to acquire undisturbed samples using conventional soil sampling techniques. Furthermore, even when samples can be retrieved, they are usually not representative of the in situ soil which can demonstrate a wide range of cementation. Therefore, the results of laboratory strength testing may not be representative of the actual in situ behaviour. For these reasons, a simple field test is developed which may be used in conjunction with conventional laboratory testing and analytical procedures to estimate the in situ strength properties of such alluvial deposits. The in situ testing involves a series of plate load tests performed at the crest of freshly cut slopes. A steel plate of known dimensions is loaded by an 89 kN (10 tons) hydraulic jack until the slope fails. The counter weight of a power shovel is used as a reaction support. The failure load and slip surface geometry are measured and recorded. A two-dimensional slope stability procedure (Bishop’s Modified Method) is used to back calculate the value of cohesion associated with failure of the field slopes. The analytical procedure developed by Hovland is used to account for the three-dimensional ‘end effects’ present in the field load tests and to correct the value of cohesion obtained from the Bishop solution. The values of
c
and φ obtained in this way are used to evaluate the stability of the trench slopes at the State of Arizona’s site for the US Department of Energy’s proposed Superconducting Super Collider (SSC) Project. The determination of a realistic factor of safety during construction is critical to the economical use of open-cut construction techniques for approximately 50 per cent of the 83.7 km (52 miles) circumference of the proposed SSC ring.
The scale effect with regard to the deformability of calcarenite
Authors: Nienhuis H. , Price D. G.
Published: April 2008

In order to investigate the effect of scale on the deformability of homogeneous rocks, plate bearing tests have been performed on Maastrichtian calcarenite in an abandoned room and pillar mine in the southern part of The Netherlands. The rock mass tested was weak, free of mechanical discontinuities and apparently homogeneous. The tests were conducted horizontally, parallel to the bedding, using rigid plates of seven different diameters. Cyclic loading was undertaken. Plate pressure and displacement were computer monitored. The results of these tests, together with the results of past in situ tests and past and present laboratory tests, are reviewed.
Measurements of effective strength parameters of stiff fissured clays using large in situ shear boxes
Authors: Marsland A.
Published: April 2008

Large in situ shear box tests have been made to measure effective-stress strength parameters of three highly fissured clays. The tests on all these clays gave effective stress strength envelopes which differed significantly from those obtained from standard laboratory tests.
Measurement of relative density of saturated sand using a piezovane
Authors: Atkinson J. H. , Jessett C. A.
Published: April 2008

During undrained shearing of saturated soils loose samples show increasing pore pressure while dense samples show decreasing pore pressure. The magnitude and sign of the pore pressure change for a given soil is determined principally by its relative density. This suggests the possibility of measuring relative density in situ by observing pore pressures generated during shearing imposed by an instrument. The most suitable instrument for this purpose is a vane fitted with a piezometer (piezovane) as a vane imposes shearing with only small changes of normal stress. A series of experiments was carried out on piezovanes in beds of fine sand prepared in the laboratory at different relative densities. The tests showed clear relationships between relative density and pore pressures measured by the piezovane. The piezovane may also be of use as an in situ test for the potential for liquefaction of loose saturated fine sand deposits.
The determination of the dynamic elastic moduli of rock masses by geophysical methods
Authors: McDowell P. W.
Published: April 2008

Dynamic moduli values for rock masses are calculated from corresponding compressional and shear wave velocities and in situ bulk densities using standard equations based on elastic theory. These moduli values can be used for the design of foundations for vibrating machines to avoid resonance during operation. Static moduli values can be assessed from the dynamic moduli values if the rock mass quality has been determined either directly or from the ratio of ν
field
to ν
lab
. Where possible, the results of these procedures should be correlated with the results of in situ static tests, such as large scale plate bearing tests.

Geophysical surveys need to be carefully designed to ensure that the correct seismic event is being recorded and wave velocities are being measured accurately. There are several field techniques in common usage, which include seismic refraction surveying, cross-hole shooting and a variety of along-hole methods. In each case, careful consideration should be given to timing errors resulting from inadequate coupling of energy sources and receivers. Enhancement of shear-wave events is usually required to avoid ambiguity and misinterpretation, particularly in layered ground. For fractured rock masses the wavelength of the seismic events may also be significant for both compressional and shear wave events.

The results of ground investigations at the proposed sites of generators for the Akjoujt Power Station in Mauritania, West Africa, are presented to illustrate the advantages and limitations of geophysical techniques for assessing rock mass deformation moduli. Compressional and shear wave velocities were determined by cross-hole, along-hole and surface seismic refraction surveying techniques for the very weathered metamorphic rocks. Dynamic values of Young’s modulus were obtained for 1 m intervals to a depth of 15 m.

The results of this investigation are reviewed in the light of recent developments in equipment, field procedures and data processing techniques.
Focussed packer testing: a structured approach to save time and improve results
Authors: Black J. H.
Published: April 2008

The idea of ‘focussed’ packer testing is to focus the cost and effort of packer testing on the regions of greatest concern. The effect is to reduce the amount of unnecessary testing and hence cut the cost of testing. It is based primarily on identifying the use of the collected data. In work concerned with the disposal of radioactive waste the prime use of the derived data is in numerical modelling. For most modelling purposes data from highly transmissive rock are of more importance than those from low permeability regions. It is proposed that the testing should be structured so that there is a smooth increase of value and locational accuracy from the lower measurement limit up to the maximum.

Two basic methods of test and data structuring are proposed. These are based on a specific test management procedure termed ‘log-linear structuring’ and the ‘active packer string’. These two techniques have different effects on costs and derived data quality.

In procedural management, the technique described as ‘log-linear structuring’ has a straightforward effect on the ‘value-accuracy’ of the data set. It reduces the accuracy and reliability of the derived data progressively as its value decreases. It does not change the overall form of the data set. Its effect on programme costs is only in the order of a 20 to 30% reduction.

The use of the ‘active packer string’ to structure ‘locational accuracy’ changes the form of the overall data set. There are subtle controls on the form of the data set produced by the ability to set not only sample size but also thresholds for improved quality of data. If an ‘active packer string’ is used to reduce costs then cost savings of 50% or more are possible whilst maintaining data quality.

In order to carry out ‘focussed’ packer testing it is necessary to:

(i)

have foreknowledge of the use of the data and the rock to be tested;

(ii)

be able to simulate the effect of ‘focussed’ testing in a particular rock and borehole environment;

(iii)

be able to analyse the results instantly in the field;

(iv)

have access to an ‘active packer string’ for most effective test design and control.

A set of results from a field test in Sweden shows the form of data which is obtained using an ‘active packer string’, the form of the overlapping and a time saving of about 50%.
An introduction to the geology of central Scotland
Authors: Browne M. A. E.
Published: April 2008

The first public event of the Silver Jubilee meeting was a lecture introducing the geological background to the seven technical excursions. The text of the talk, which was recorded, is presented with the minimum of amendment but with selected references also included.
The application of stochastic modelling to the evaluation of ground conditions in Late Quaternary Sediments in Göteborg, Sweden
Authors: Rosenbaum M. S. , Stevens R. L.
Published: April 2008

Statistical analysis based on the spatial analysis of variance has been applied to the characterisation of Late Quaternary sediments within the valley of Kvilledalen in Göteborg, illustrated in this paper by the bed thickness of the marine clay. The analysis of the thickness demonstrates a low random disturbance which was attributable to small scale environmental variability rather than to errors of measurement, and a maximum range of influence of 300 metres from the location of each observation point. Beyond this distance there was no spatial dependency and reliable prediction of values was not possible using the existing data. Stochastic modelling solved using kriging has been used to estimate the distribution of each bed thereby giving a quantifiable degree of certainty and improving the basis for predicting ground conditions based upon the assessment of existing information.
Field and laboratory investigations of the clay tills at the test bed site at the Building Research Establishment, Garston, Hertfordshire
Authors: Marsland A. , Powell J. J. M.
Published: April 2008

Detailed investigations have been made of the clay tills on a site located at the Building Research Station about 30km NW of central London. Inspection of the soil macrofabric suggests that two advances of the ice occurred in this area.

Results from insitu tests using cone penetrometers, pressuremeters, 100mm diameter screw plate tests, 292 and 865 mm diameter deep insitu loading tests, and laboratory tests are given. The results obtained from different types of tests are compared against the background of the modes of deposition, post depositional conditions and the variations in the soil fabric down the soil profile.
Suitability and acceptability for earthworking with reference to glacial tills in Scotland
Authors: Matheson G. D. , Oliphant J.
Published: April 2008

The paper describes the criteria currently in use for determining the suitability and acceptability of soil for earthworking, and discusses the specification, control and monitoring of both earthmoving and compaction on highway contracts in the UK. In particular the paper describes the application of the Moisture Condition Apparatus (MCA) to the testing of Quaternary soils and its successful use on Scottish Trunk Road Projects.
Theme lecture: Periglacial and slope processes
Authors: Hutchinson J. N.
Published: April 2008

Following a palaeoclimatic outline of the Late Quaternary, the paper reviews the periglacial and slope processes which have most effect on engineering works, particulary with regard to relic forms of such features in Britain. The first topics covered are; frost heave and thaw consolidation, thermokarst and periglacial mass movements, with particular attention to periglacial solifluction and slope development. Ground water discharge features, comprising pingos, anomalous depressions in the London Basin and perforated clay feather edges, are then discussed, as are superficial valley disturbances in various geological settings. The paper concludes by exploring theoretical and geological approaches to the determination of the former depths of permafrost in Britain.
Report on Session 2a
Authors: Privett K. D.
Published: April 2008

Introduction

The papers in this session of the conference concentrate on some of the processes described by the Theme Lecturer, Professor Hutchinson, and the engineering properties of the materials. Engineering implications are referred to in the papers but are included in this session because the process/properties element is stressed. This report is intended to provide a brief introduction to the session papers and all references are to papers in this conference.

The term “periglacial” is sometimes restricted to geomorphological processes where freeze-thaw is the dominant action but the definition generally is widened to include all those processes, and their landforms, taking place in cold climated outside the margins of an ice sheet and so encompasses everything that is not directly glacial. This conference has used this wider definition and thus deposits such as laminated glacial lake sediments (Bell and Coultard) are included in this session. Table 1 illustrated the range of features that could be considered, many of which are discussed to varying degress in the papers.

TABLE 1: List of periglacial features/processes.

LARGE-SCALE LANDSLIPS

SOLIFLUCTION, MUDFLOWS, SHEARS

ASYMMETRIC VALLEYS

FROST CREEP

CAMBERS, VALLEY BULGES

ICE WEDGES

POLYGONS

FROST HEAVE, INVOLUTIONS

FROST MOUNDS, PINGOS

FROST SHATTERING

LOESS DEPOSITION

LAMINATED LAKE DEPOSITS

CHEMICAL OF CaCO
3

SLOPE PROCESSES

The various processes involved in the formation and modification of slopes, either in their natural condition, or if modified by some engineering works. Is is not
surprising then, that the majority of
papers submitted to this session concern
periglacial slope processes.
The identification of features due to former permafrost in the North Sea
Authors: Long D.
Published: April 2008

Analysis of offshore data at scales varing from macroscopic to kilometric suggest the former presence of permafrost in the North Sea. However due to the nature of marine data, the techniques used in recognizing features due to former permafrost differ from that used on land. The evidence can also occur in forms unique to the marine field. Awareness of the former existence of permafrost in the North Sea will aid geological assessment of offshore site investigations.
Solifluction shears at Carsington, Derbyshire
Authors: Skempton A. W. , Norbury D. , Petley D. J. , Spink T. W.
Published: April 2008

A clayey solifluction deposit of Devensian age on the lower slopes of a broad valley in Namurian mudstone is about 1.2 m thick and near its base are shear surfaces, gently undulating and occupying on average 40% of the length (56 m) examined in trial pits. Within a shear zone up to 2 mm in thickness the clay mineral aggregates are aligned sub-parallel to the shear surface; otherwise the aggregates are in random orientation. Tests show that strength on the shear surface falls to the residual value (c′ = 0, φ
r
′ = 12°) after small displacements. The resultant peak strength parameters of the deposit, allowing for the undulating and discontinuous nature of the shears, are c′ = 6 kPa and φ′ = 18°; as compared to c′ = 10 kPa and φ′ = 20° for the intact clay. Average index properties are w = 40, LL = 75, PL = 32 and clay fraction = 62%.
The application of geophysical methods to the geological mapping of Quaternary sediments
Authors: Cornwell J. D. , McCann D. M.
Published: April 2008

The geological mapping of Quaternary sedimentary deposits is usually hindered by the lack of exposure and by the rapid lateral and vertical variations in the lithologies. With the continuing development of new techniques, geophysical methods offer practical means of complementing conventional mapping in these conditions. The methods available are suitable for application to problems ranging from regional mapping to detailed site investigation. The application of the appropriate method can produce solutions to these problems and reduce expenditure on drilling and trenching, the main alternative means of sub-surface investigation. In this paper, the use of geophysical methods in the geological mapping of Quaternary sediments is reviewed and illustrated by a number of case histories from eastern England.
Engineering geology and mapping of the Quaternary deposits of the city of Xanthi, N. Greece
Authors: Marinos P. G. , Xidakis G. S.
Published: April 2008

The city of Xanthi is situated on the border between the crystalline massif of Rodope and the extended coastal plain of Thrace. The broader urban area is covered mainly by Quaternary formations of screes and talus deposits from the mountain slopes, various generations of alluvial deposits in the form of torrential fans, recent fluvio-torrential deposits and eluvial sheets on marly slopes. From data collected from natural ground cuts, boreholes, excavations for foundations and some laboratory testing, the area has been divided into four main geotechnical zones and a number of subzones. The soils in the main zones have similar or analogous geotechnical behaviour. A folio of engineering geology and hydrogeology maps was produced.

This study shows how a reliable geotechnical evaluation and zoning in Quaternary formations can be approached by detailed engineering geological mapping, mainly for the types of terrain found in the Xanthi area, where coarse materials are predominant.
Computer aided compilation of settlement maps for the provinces of Friesland and Gelderland, The Netherlands
Authors: Schokking F. , Hoogendoorn B.
Published: April 2008

Engineering geological thematic maps for the prediction of settlement in Quaternary near surface sediments, resulting from hydrological changes, were compiled to be used in the regional groundwater planning for the Provinces of Gelderland and Friesland in the Netherlands.

An existing computer program “ZETTING” used for settlement calculations for civil engineering purposes, was adapted for the processing of large data sets. The compilation of the settlement maps using Geographical Information Systems in the Geological Survey of The Netherlands and in the Departments of Water and Environment of the two provinces is described.

For the map for the Province of Gelderland digitized type-profile map information and geotechnical properties of sub-regions were combined with hydrological data to calculate settlement and hydrodynamic period.

A translation was made of borehole data into geotechnical properties, and hydrological data joined to the resulting data set for the calculation of the settlement map for the Province of Friesland.

For both provinces a set of grid maps were compiled. Aspects of the computer aided compilation of the maps, such as data handling, choice of grid and grid transfers, computer calculations and map accuracy are discussed.
Report on Session 3b
Authors: Nash D. F. T.
Published: April 2008

Introduction

The theme of this session covers a very wide spectrum of deposits and processes. The thirteen papers submitted from all over the world, together with several from other sessions which also relate to this theme, describe numerous deposits and processes - mostly the former. Some of the processes which influence the geotechnical properties and behaviour of soils are listed in Table 1. This is a reminder of the importance of fully appreciating the geological history of a site when planning and undertaking construction projects.

The papers can be conveniently divided into four groups under the general headings Tectonics and Uplift, Problems relating to Reservoirs, Regional Studies of Soils, Studies of Soft Clays.

Quaternary Tectonics and Uplift

As part of the study of the background to the present seismicity of the
UK, Ringrose, Hancock and Davenport
have observed the distribution of recorded seismicity and noted the coincidence of areas which are currently the most seismicly active with the areas of highest topography and the areas of maximum present day uplift. They have examined several Quaternary faults in Scotland and related the patterns of movement to the inferred state of stress in the earths crust, and concluded that ice-loading must have been sufficient to trigger fault movements. On other faults the displacements are consistent with a zone of uplift coinciding with the maximum zone of present day uplift in the highlands of west central Scotland. The authors report some very substantial fault movements during the Quaternary. The studies, of which these form
Tigris river terrace mapping in northern Iraq and the geotechnical properties of the youngest stage near Dao Al-Qamar Village
Authors: Al-Dabbagh T. H. , Al-Naqib S. Q.
Published: April 2008

During the course of an investigation to evaluate the area for mapping distribution of deposits , different proposed hydraulic structures and construct ion materials.Terraces within the Valley of the River Tigris were mapped at three locations in northern Iraq. Four stages, ranging in age from pleistocene to Recent have been recognized.

The paper reveiws previous work concern ing these terrace deposits and describes the mapping work. The geomorphology of terraces is discussed with reference. to the evaluation of the river System. Finally some preliminary geotechnical data concerning the sediments are presented and discussed .
Records of settlement of the M5 motorway over the Somerset Levels
Authors: Cook D. , Pereira G.
Published: April 2008

An account is given of the secondary consolidation characteristics of recent alluvial deposits under the line of the M5 motor-way where it crosses the Somerset levels. It uses a group of 161 long term settlement records between East Clevedon and St George which were maintained after contract completion in 1973 as the instrumentation installed during construction had .predicted continued settlement. The records were combined with a data file of soils information from the same area compiled by the first author in 1984. The key features of secondary consolidation are reviewed as a guide to the analysis of the records, which are examined for statistical relationships between the measured rates of secondary compression and the operative field variables namely, the embankment loading, the depth of consolidating material and its light preconsolidation. Because of the complex deposition sequence it was only found possible to follow trends. These showed that secondary consolidation was most sensitive to the loading relative to the preconsolidation, or thresh-hold pressure. They also gave some indication of decreasing overall rates of secondary strain with increasing thickness of deposit. Laboratory tests significantly underestimated the field rates of secondary consolidation in all cases. It was reckoned that persistent low level vibrations from heavy traffie contribute to the variations, affecting the shallower layers by a greater amount.
The effect of Quaternary uplift on the stability of slopes in the central part the Skorusinske Vrchy mountains in the west Carpathians
Authors: Kovacik M. , Ondrasic R.
Published: April 2008

The Skorušinské vrchy mountains are part of the West Carpathians in northwest Slovakia near the Polish border. They consist of four Palaeogene sedimentary complexes and comprise a 1500 to 2000 m thick sequence of conglomerates, claystones, flyschoid rocks and sandstones. The older complexes erop out on the margins of the mountains and are covered by relatively thin clayey soils. The central part, the most highly uplifted block, consists of Eocene calcareous sandstone which are disturbed by joints and deep-seated faults. The difference in elevation between the mountain summits and the valley floors is more than 400 m.

A detailed investigation of mass movement has been carried out using aerial photographs,air borne radar and satellite imagery foliowed by a field survey.

Three main types of slope deformation were identified - rock block slides along bedding surfaces, rock siumps across bedding surfaces and landslides in slope debris. The occurrence of the largest and most deep-seated slides are controlled by faults. The presence of these mass deformations indicate the existence of tilted fault blocks which are the result of neotectonic arch uplift. About 15–17% of the area covered by sandstones is affected by mass movements. This paper describes the methodology of the investigation, the mechanism and genesis of slope deformations, the occurrence and parameters of slides and the role of the Quaternary uplift in the slope instability component of regional geomorphological evolution.
Quaternary tectonic activity in Scotland
Authors: Ringrose P. S. , Hancock P. , Fenton C. , Davenport C. A.
Published: April 2008

The main features of seven faults inferred to have been active during the Quaternary in Scotland are summarized and their significance in terms of possible tectonic explanations is discussed. One fault in Glen Roy (Central Highlands) is described in detail and evidence is presented for changing stress fields inferred from modes of strain release. Quaternary tectonic activity is interpreted as being dominated by regional effects involving left-lateral simple shear in a NNW direction and some uplift. Stresses associated with ice-load flexure are thought to have played an important role in triggering fault rupture.
Examples of ground response to various types of structural foundation construction
Authors: Rowe P. W.
Published: April 2008

As a prelude to the new case histories reported in this book, 17 cases of construction activities are cited that identify the ground responses to various types and methods of construction in the light of the geological age and relevant geological structure. In most cases, unexpected events occurred in spite of prior geological and geotechnical investigations. Whether new treatment is seen in old examples or old treatment of new examples, the ultimate objective is to underline the value of
case histories and the real need in site investigation reports to isolate and interpret those particular aspects of the geology relevant to the proposed engineering works, in the light of precedence, so that all concerned may be aware of the likely consequences of the construction operational types and steps up to completion.
The Bargate Centre, Southampton: engineering geological and geohydrological aspects of the excavation for basement construction
Authors: Barton M. E.
Published: April 2008

The Bargate Centre is a large, four-storey shopping arcade constructed during 1986–1990 within the medieval town walls of Southampton. It incorporates a basement requiring construction to between 6–7 m below ground level through fill, brickearth, and water-bearing river terrace gravels overlying mainly laminated clays of the Bracklesham Group. The case record is of particular interest in that the excavation cut-off wall acted as a barrier to the original (that is,
pre-excavation) groundwater seepage in the terrace gravels. Observations of the piezometric levels before and after construction confirm ponding on the upstream side of the basement. However, it appears that the pre-construction seepage pattern on the downstream side was modified by the medieval double moats which are known, at least in part, to have been excavated into the terrace gravels.
Regional distribution of sulphate in rocks and soils of Britain
Authors: Forster A. , Culshaw M. G. , Bell F. G.
Published: April 2008

The damaging effect of sulphate salts on concrete is well known and is usually a problem encountered by concrete structures buried below the water-table in sulphate-bearing soils. Although some individual sulphate-bearing soils, such as London Clay, are well known, little attempt has been made to consider sulphate-bearing soils on a regional basis. The environmental geology and other mapping projects carried out by the British Geological Survey have enabled geotechnical databases to be
compiled which can be used as a basis for an examination of the regional distribution of the sulphate-bearing rocks and soils of Britain. The occurrence of sulphate in geological formations is examined and a five part division of geological formations with regard to sulphate attack potential is suggested, which can be used as a guide when specifying the sulphate test requirement for a site investigation.
Construction problems and building control
Authors: Sutherland J. A. , Allen J. C. M.
Published: April 2008

With statutory duties for health and safety, United Kingdom building control departments are in a unique position to encourage and demand good engineering practice. This is particularly so in Scotland where the legislation requires plans to be agreed before construction can commence. Published Codes of Practice leave little leeway regarding basic structural design. However, geotechnical engineering does not lend itself to such rigid rules and requires an experienced engineer or geologist to produce a workable and economic design. It is important, therefore, that large building control departments have the expertise to examine critically submissions for approval. The Building Control Department within the City of Glasgow District Council includes a small Ground Engineering Unit with such a capability. The primary function of this unit relates to the geotechnical aspects of warrant submissions, but it can be called in during construction where health and safety problems arise of a geotechnical nature.

The part played by a geotechnical section of a building control department before and during construction is considered. Other areas in which the information held by such a section can be used to benefit the community as a whole are highlighted. Problems with geotechnical submissions are outlined and a framework for minimum, acceptable presentation discussed.
Engineering geology of soils in highway construction: a general overview
Authors: Perry J.
Published: April 2008

By its linear nature, a major highway is likely to encounter a large variety of geological materials with different engineering properties. Therefore, highway designers and contractors are faced with materials having different properties and
in situ
characteristics, requiring different methods of investigation, types of design and ways of handling. They are also required to maximize the use of these materials. Technical methods are available for achieving this objective,
particularly for applications in general fills, capping and slope stability. The input from engineering geology in the construction process is an important element in achieving the best use of materials.
Geogrid reinforced piled road over peat
Authors: Barry A. J. , Trigunarsyah Bambang , Symes T. , Younger J. S.
Published: April 2008

The construction of roads over up to 11 m of peat in East Sumatra has required extensive engineering investigations. Environmental constraints in a sensitive undeveloped forest area required the use of a combination of locally available materials combined with geogrids to produce a satisfactory solution.

Previous difficulties with road construction in this terrain are discussed, together with the design of the geogrid reinforced raft and the field trials which resulted in substantial changes to the design and construction procedures to provide a practical and economic solution.
Application of evaporative dewatering methods to allow the use of wet fills in the construction of earthworks
Authors: Thomas B. R.
Published: April 2008

Delays to earthworks construction and difficulties in winning material potentially suitable for fill commonly occur in the UK due to adverse climatic conditions, especially where wet fills comprise a major proportion of the earthworks. The moisture content of wet fills is such that the materials cannot be compacted to the required dry density or maximum voids content. If the moisture content could be reduced, then the materials may become acceptable and be incorporated into current earthworks specifications.

Depending on the soil type, wet fills may variously be treated by consolidation with or without drainage, by mixing with lime addition, or by evaporative drying. Research was undertaken in developing methods to accelerate the evaporative dewatering of fine-grained soils. Dewatering was examined using appropriately scaled test plots and full-scale trials. This led to the development of a mathematical model of the evaporative dewatering process which uses readily determined soil dewatering parameters. The model was validated against the test data and used to describe the dewatering process under laboratory and field conditions. The application of the dewatering model for estimating the optimum dewatering conditions for earthworks fill is described. The method may reduce the amount of ‘unsuitable’ soil sent to a tip, with the potential for substantial cost savings on large earthworks contracts.
Petrographical examination of road construction materials
Authors: West G.
Published: April 2008

Petrographical examination of road construction materials has been employed at the Transport Research Laboratory (TRL) in a wide range of research applications. These include the search for polish-resistant roadstones for surfacings, research into ‘clean, hard and durable’ aggregates for use in bitumen macadam roadbase, and in the investigation of alkali-silica reaction in concrete road pavements. After briefly reviewing earlier work, the paper describes these applications and
concludes that petrographical examination of road construction materials is most effective when it is made with a specific objective in mind, rather than in an attempt to provide generalized information, Some remarks are made about the need to standardize rock nomenclature in petrographical description.
Potential of grouting methods to prevent and compensate for tunnelling-induced settlement of London Clay
Authors: Kimmance J. P. , Linney L. F. , Stapleton M. J.
Published: April 2008

Tunnelling beneath a congested urban area leads inevitably to the settlement of structures located in the ground above. In the past settlement has been allowed to take place and remedial work has been undertaken to make good any damage which has occurred. Grouting techniques have sometimes been used as a remedial measure to restore structures to their original elevation. Advances in grouting techniques, together with advances in monitoring, have led to the use of grouting in a compensation mode, whereby grout injection is carefully balanced against ground loss, such that settlement is not allowed to reach the surface. This method has been used in the USA and continental Europe, but so far has not been used in the UK. The development of grouting techniques used to remediate or compensate for ground settlement are reviewed and the results presented of a trial undertaken in London to investigate the viability of this technique.
Influence of geological structures in slope stability analyses for opencast mining and quarry excavations
Authors: Cojean R.
Published: April 2008

The influence of structural features on slope stability in rock masses is analysed, with particular reference to opencast mining and quarrying. Various failure mechanisms are illustrated at different scales. The primary importance of the method of modelling rock masses is highlighted, with discussion about the need to emphasize either the continuous or discontinuous properties of the rock masses. The choice of mechanical parameters for the joints, as well as the rock material, is significant and a slight variation may alter the mode of failure of the slope. There is therefore a need for further investigation into the geological description and mechanical analysis of rock masses. In many instances, sound judgement by an experienced engineering geologist is required to identify the relevant features of the rock mass and to assess the mechanical behaviour that may operate.
The role of the engineering geologist in construction
Authors: Eddleston M. , Murfin R. E. , Walthall S.
Published: April 2008

A current trend is the requirement for complex civil engineering projects to be carried out to very short time-scales. These projects often involve difficult and protracted planning consultations. This leads to increased pressure on all the professionals involved to work at a very fast, though erratic, pace that is dictated by others. This is particularly the case with the collection and utilization of information about the ground that is required for the design and construction phases of projects. Large changes in scope and detail often occur due to a wide range of environmental, technical, financial and other external factors.

The engineering geologist plays a crucial part in the management of projects that are to be completed successfully to time and within budget. This paper discusses key areas in which engineering geologists can significantly affect the outcome of a project and also factors that may influence the professional development of engineering geologists in future years.
Investigation, hazard assessment and remediation of existing landfills
Authors: Marsh A. H. , Garnham A.
Published: April 2008

Disposing of waste to land is an activity as old as the human race itself. Any ancient deposits still in existence are now principally of archaeological interest. However, with the advent of the industrial revolution the volume of man's waste started to rapidly increase and with it the problems.

In Britain and other similar developed countries the nature and composition of waste has evolved over the decades, reflecting contemporary industrial and domestic practices. Perhaps the most significant such trend concerns the gradual change from the relatively high-density, low putrescible content of Victorian and early to mid-twentieth century waste, when it was the practice to burn domestic waste and dispose of the ashes, to modern unburnt, low-density, highly putrescible domestic waste. The 1950s and 1960s witnessed the most rapid period of change in this respect.

The manner in which waste has been disposed of to land has similarly undergone a process of gradual evolution, but with three key events taking place in the UK in modern times. Historically, waste has been disposed of either heaped on the ground, with the natural strata beneath remaining essentially undisturbed, or in convenient holes previously excavated for other purposes, generally quarries of one sort or another. In the latter case the waste abuts natural strata in the side walls and, often different, strata or the groundwater table beneath.

Any attempts to engineer the containment of waste and control the spread of pollution from it were the exception not the rule until the Control of Pollution
Landfills and associated leachate in the greater Durban area: two case histories
Authors: Bell F. G. , Sillito A. J. , Jermy C. A.
Published: April 2008

Two waste disposal sites in the greater Durban area used for codisposal of solid and liquid wastes are considered. One site is still operational and the other has been closed for a number of years.

An investigation of Site 1 revealed that much of the area is covered by Berea Red Sand. However, the clay content of much of this formation means that it generally has a low permeability. The sandstones and tillite which occur beneath the sand also are of low permeability or are virtually impermeable. This is necessary when the character of the leachate produced is considered. The very high values, for example, of chemical oxygen demand are attributable to a large extent to the disposal of
hop waste. Accordingly the leachate is conveyed from a sump at the toe of the landfill to a sewerage works.

At site 2 very little has been done since its closure to ensure that leakage from the landfill does not pollute the surrounding ground or surface waters. It was suspected that this was occurring. Small non-perennial and perennial streams occur in the area of the site. The site itself is underlain by sandstones and tillite. These rocks have been weathered to form a mantle of residual soil of variable thickness which is overlain by colluvium on the valley slopes and alluvium in the valley
floor. An investigation was undertaken to determine the extent of the pollution and revealed that a plume extended some 300 m downstream of the leachate pond. Two main remedial measures were proposed. First, a subsoil drain should be constructed immediately downstream of the landfill site. This should be located in bedrock, its purpose being to intercept seepage from the landfill. The drain should lead into a pump chamber that would remove polluted water which would then be conveyed to the
sewer system. Secondly, to make doubly sure that the pollution was contained, a cement-bentonite cut-off trench, founded in bedrock, should be constructed 3 m downstream of the subsoil drain.
Remidial containment measures for a peat bog landfill site
Authors: McShane K. , Gregory B. J.
Published: April 2008

Many landfill sites in Northern Ireland have been formed by infilling waste in low-lying bog areas, without any containment or control measures being incorporated. Typical of this is a working landfill site at Drumlough Moss in County Down, which has an area! extent of approximately 20 ha. It has been in operation for over 30 years and is situated on a peat bog, known locally as a ‘moss’, in an interdrumlin hollow.

Pollution of the nearby River Lagan, which is the major river flowing through the city of Belfast, was traced to the site. Consequently remedial measures had to be designed and constructed to provide effective containment so as to minimize future risks associated with the site. An understanding of the engineering geology and hydrogeological aspects of the site were critical and this paper describes those aspects and their influence on the design and construction of the works, not least of which was the selection of appropriate construction techniques.