bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydrogeological conditions in the Middle East
Authors: Burdon D. J.
Published: November 2007

The geology of Middle East is summarized under the subheadings: Precambrian basement, epicontinental sediments, geosynclinal and shelf deposits, Tertiary volcanics and Quaternary cover. The main tectonic episodes including epeirogenic movements, rifting and the Tertiary orogeny, are reviewed.

The imposition of hydrometeorolocal and climatic conditions upon the regional geology provides the setting for the hydrogeological discussion. Five factors which influence infiltration to aquifers under conditions of low precipitation and high potential evaportranspiration are discussed.

The predominance of fossil groundwater is the most striking hydrogeological phenomenon occurring on a regional scale in the Middle East. Its mode of formation during the pluvials is outlined and the isotopic evidence is reviewed. The main physical and chemical characteristics of fossil ground-waters are described.

It is conservatively estimated that some 65 000 km
3
of good- to medium-quality groundwater are stored in the great artesian basins of the Near East. These fossil ground-waters are a non-renewable natural resource. Current annual abstraction is, as yet, a small percentage of the total reserves but economic factors rather than the volume of reserves will determine the ultimate extent of their exploitation.

The renewable groundwater resources of the Middle East tend, by comparison, to be of local rather than regional significance. Some originate outside the Middle East, coming in as surface flows in the Nile and Tigris-Euphrates and infiltrating into the sediments in and adjacent to the flood plains.

Other renewable resources accumulate within the region where high precipitation and mountainous relief are associated. Such areas include the Djebel Akhdar of Cyrenacia, the Tertiary fold mountains from the Taurus through the Zagros to the Oman ranges, and the volcanic and basement highlands of Yemen, Asir and Ethiopa. Locally, in areas of lower precipitation, lenses of recent fresh groundwater float on regional more saline groundwater. In some areas subsurface flows towards and through wadi systems are also of importance.
Hydrogeology of the Great Nubian Sandstone basin, Egypt
Authors: Shata A. A.
Published: November 2007

In Egypt, the strata of major hydrogeological interest are composed of a sandstone complex ranging from Cambrian to Upper Cretaceous in age. This sandstone complex, commonly known as the Nubian Sandstone, has a thickness varying from less than 500 m to more than 3000 m and rests directly on Precambrian basement.

This simple picture is complicated by a number of major structural fault and fold axes which traverse the region in a north-easterly direction. The sandstones reach their max-imum development in the Ain Dalla basin, a downthrown structural block SW of Bahariya oasis. Basement features exercise a dominant control on the structural and sedimentological form of the sandstone complex.

In spite of the structural complications, the Nubian sand-stone, underlying an extensive area of Egypt, probably con-stitutes a single hydrogeological system to the W of the Gulf of Suez. To the E, on the Sinai peninsula, a second system may exist with some connection to the main western system in the N.

The main western system, which extends into Libya and Sudan, comprises a multi-layered artesian basin where huge groundwater storage reserves were accumulated, principally during the pluvials of the Quaternary.

The carbonate rocks overlying the Nubian Sandstone complex display karst features locally and are recharged by upwards leakage from the underlying major aquifer.

Large-scale development of the Nubian Sandstone aquifer in Egypt has been under consideration since 1960. Latest proposals for the New Valley development project involve exploitation at the annual rate of 156.2 × l0
6
m
3
at El-Kharga, 509.2 at
Texture changes in crushed basalt road base
Authors: Wylde L. J.
Published: November 2007

The internal texture of undisturbed samples of granular road base has been studied by microscope examination of pet-rological thin sections prepared from samples impregnated with epoxy resin. The study of compacted crushed basalt road base materials subjected to repeated loading from traffic and in laboratory tests, showed that the -75 μm particles become rearranged to give local accumulations of finer particles. A ‘Texture Factor’ (TF), assessed by a point counting method, was developed to quantitatively describe and follow such changes in the internal texture. The TF increases progressively with repeated loading and the increase is more rapid at higher moisture contents. The TF in road pavements is highest near the surface and a possible relationship between TF and existing pavement condition is described. Possible applications of TF measurements on existing roads to problems of material durability and pavement performance are discussed.
Discussion on ‘The development and geotechnical problems of sabkha, with preliminary experiments on the static penetration resistance of cemented sands’ by W. Akili & J. K. Torrance
Authors: Martin P. L.
Published: November 2007

Drs Akili & Torrance are to be congratulated on a timely and interesting paper.

Over the past decade there has been a considerable involvement of British consulting engineers and contractors in the Middle East generally and in the Gulf area in particular, and as a result a fairly large volume of experience has been gained on Middle East engineering construction, much of which is concerned with sabkhas. However, the vast majority of this experience is not yet published and, indeed, may never be so, as it is often buried quite deeply in the files of clients and clients' contractors or engineers.

Nevertheless, there has been a reasonable amount of engineering geology, geotechnical information published in the British and, to a certain extent, the Continental technical press and the authors may be interested to have their attention drawn to the following list of references which, although by no means exhaustive, gives an indication of the range and scope of recent publications on this side of the Atlantic.
Results of preliminary experiments on the influence of fabrics on the migration of groundwater and water-soluble minerals in the capillary fringe
Authors: French W. J. , Poole A. B. , Ravenscroft P. , Khiabani M.
Published: November 2007

Laboratory experiments are described in which soil and groundwater regimes approximating those of hot arid areas have been modelled. The motions of saline groundwater and the solution and precipitation of phases such as halite, gypsum and calcite in the capillary fringe have been studied. The non-woven permeable fabrics ‘Terram’ and ‘Filtram’ have been placed in the soil beds and it is shown that fabrics such as ‘Filtram’ are capable of preventing both the capillary rise of moisture and the downward penetration of water infiltrating from above. The lower surface of the fabric may act as a locus for mineral precipitation but crystalline phases have not been found growing into the pores of the fabric. The work is relevant to both horticultural and engineering applications of the fabrics and the first experiments have been followed by larger scale experiments, which are not yet complete, in which further details of the behaviour of permeable membranes in unsaturated soils are being studied, including their ability to protect building materials.
The performance of impermeable and permeable reinforcement in clay subject to undrained loading
Authors: Ingold T. S. , Miller K. S.
Published: November 2007

During the rapid loading of clay soils there is often no opportunity for the dissipation of any porewater pressure that may be generated. It is largely for this reason that heavy clay fill is not currently specified for use in reinforced soil construction where this short-term, or undrained, condition might be associated with instability. The response of reinforced clay to undrained loading will be a function of the nature of the reinforcement, and to investigate possible responses a pilot study was undertaken using two different reinforcing materials. These were installed in cylindrical clay samples which were subject to either rapid shear or shear at constant volume, both of these regimes being consistent with the notion of undrained loading. It was found that impermeable ‘reinforcement’ in the form of aluminium foil caused a consistent and substantial decrease in strength compared to that of an unreinforced sample. For clay reinforced with porous plastic reinforcement the strength of the soil improved as reinforcement spacing decreased and ultimately exceeded that of the unreinforced clay. This response reflects the fact that rapid loading is not necessarily associated with undrained loading if the reinforcement, which also acts as a drain, is installed at a sufficiently small spacing. In truly undrained tests, where constant volume conditions are imposed, a strength decrease was anticipated. That this was not the case, is thought to be due to the low porewater pressure response of the reinforcement which has the effect of depressing the otherwise high deleterious porewater pressure generated in the clay.
Some scale model tests to investigate the use of reinforcement to improve the performance of fill on soft soil
Authors: Milligan G. W. E.
Published: November 2007

Introduction

The use of a fabric as a separating layer between a soft subgrade and granular fill, for access roads, working platforms, vehicle standing areas, etc., was one of the first uses of geotextiles in ground engineering and is probably still commercially the most important. Al-though there have been many studies of such a form of construction (e.g. see
Ruddock 1977
and several papers to the International Conference on Soil Reinforcement, Paris, 1979) design methods are still largely empirical and it is often difficult to calculate the balance of costs and benefits of using fabrics in this way. A research programme has been started at Oxford University to investigate the problem by means of model tests and computer analyses. The study is mainly concerned with the reinforcing effect of the material, rather than its performance as a filter, particularly in view of the recent introduction of high-strength, high-modulus mesh or grid structures for soil reinforcement.

As a preliminary stage a series of simple two-dimensional tests have been performed at approximately 1/l0th scale. Granular fill, with or without reinforcement, was spread over a soft subgrade, represented by foam rubber, and deflections due to a surface strip loading determined. Several different reinforcing materials were used, including smooth sheet material as well as various mesh or grid structures, and the effects of varying fill particle size, fill thickness, reinforcement stiffness and subgrade stiffness investigated. It is appreciated that foam rubber is not an accurate substitute for soft clay, and the tests deliberately
A fabric reinforced trial embankment
Authors: DuBois D. D. , Bell A. L. , Snaith M. S.
Published: November 2007

A sand fill embankment, 4 m high by 100 m long has been constructed to investigate the ability of medium strength woven polypropylene sheets to act as reinforcing agents. Fabrics with nominal tensile strengths of under 20 kN/m and under 50 kN/m both performed satisfactorily to give side slopes to the construction of better than 70°. Attempts were made to measure both fabric and fill strains as construction proceeded. Data from these measurements indicate that the major fabric extensions occurring at the time of construction are caused by the influence of compaction and are largely independent of embankment height. Since construction, almost three years ago, the embankment has continued to stand with no evidence of decline in the structural function of the fabric reinforcement.
The design of a two-layer permeable membrane/webbing filter system for a marine causeway wave defence system in the Gulf of Arabia
Authors: Rankilor P. R.
Published: November 2007

The unusual problems connected with the re-furbishment of a distressed marine causeway in the Middle East are described together with the design solution, comprising a double-layer permeable membrane/webbing filter system. A comparison is made between this design and the design requirement for a new causeway to be built in the same locality.
The potential use of a degradable erosion control membrane in the United Kingdom
Authors: Henderson Michael S.
Published: November 2007

In simple terms, erosion is the removal and loss of soil by the action of water, ice, gravity or wind. In the UK and elsewhere, on construction sites of all kinds, erosion by water is the major problem. There are three steps involved in water erosion: detachment, movement and deposition. Of these three phases, detachment is the most critical, since this is where erosion starts.

In this first phase soil particles are detached from the soil mass by raindrop impact or by water running over the soil. Initially some moisture may be absorbed, depending upon soil condition, but eventually water impact causes splashing and brings the soil particles into suspension by breaking down soil aggregates. This process has two consequences. The first is the obvious: direct erosion. Since the soil particles are detached from the soil mass they are much more susceptible to being transported by surface run-off. The second, the splashing soil particles, creates a turbid fine suspension which, when it enters the soil, clogs the soil pores. Continued raindrop impact compacts and seals the soil surface and reduces the possibility of penetration by water. This then allows greater run-off and more erosion. This secondary factor can be important and it has been demonstrated that rain falling on to an exposed soil for less than 4 min can decrease water penetration to the point where 98% of water falling thereafter runs off.

The problems associated with erosion are both environmental and economic. Detachment and movement of soil means a
Physical controls of water movement in the unsaturated zone
Authors: Wellings S. R. , Bell J. P.
Published: November 2007

Traditional hydrogeological concepts of the unsaturated zone imply that the water is essentially static, and do not take account of the dynamic nature of the annual water cycle in the field. The basic concepts of water content, water potential and unsaturated hydraulic conductivity are defined as they are developed in soil physics and applied to the flow of water in the unsaturated zone. The emphasis is on a practical and non-numerical description of what happens in the field. An appreciation of the controls of water flow in the unsaturated zone is essential to an understanding of many hydrogeological problems.
The genesis of a numerical model for the study of the hydrogeology of a steep hillside in Hong Kong
Authors: Leach B. , Herbert R.
Published: November 2007

A finite-difference numerical model has been developed to assist in understanding the hydrogeology of a steep hillside in Hong Kong. The development testing and proving of this multi-layer model are described and discussed. Calibration of the model against observed piezometric responses during the 1980 wet season has demonstrated the importance of indirect recharge from bedrock in sustaining the system, and of evapotranspiration in assessing direct recharge from rainfall to the system. The use of this model in the estimation of extreme water levels as input for slope stability analysis problems is described. An analysis of model discretization errors is presented.
Discussion on ‘Stratigraphy and geotechnical properties of weathered lodgement till in Northumberland’ by N. Eyles and J. A. Sladen
Authors: Smith D. B.
Published: November 2007

In their otherwise excellent paper on the ‘Stratigraphy and geotechnical properties of weathered lodgement till in Northumberland, England’ Eyles & Sladen (
Q. J, eng. Geol.
14
p. 135) claim that the till sequence of east Durham needs to be re-examined in the light of the discovery that till sequences in Northumberland and North Yorkshire are simpler than once thought; the implication is that such re-examination would reveal that the east Durham sequence is also simpler than previously thought, and that the red-brown Upper Boulder Clay there is the weathered upper part of the Lower Boulder Clay.

All geological sections can benefit from periodic re-examination in the light of new discoveries and new interpretations, and extra details and perhaps new interpretations would emerge from another look at the east Durham drifts. But, having carefully examined all the cliff and valley sections of the Durham coast and traced the sequence between exposures by traditional field mapping, I cannot accept Eyles and Sladen's implication that the Middle Sands there might be a series of unconnected localized beds of sand and gravel at various levels within a single thick till sheet. Instead I re-iterate the view made clear in Geological Survey Six-Inch maps NZ 44 NW, 44 SW, 44 SE and 43 NE that for at least 9 km in cliffs stretching from near Hawthorn (NZ 44 46) to near Crimdon (NZ 48 37) there are two distinct tills separated by mappably continuous level-bedded sands and subordinate gravels that are only locally less than
Discussion on ‘Chloride ion concentrations as an aid to estimating recharge to the Woburn Sands’ by W. M. Irving
Authors: Puri S.
Published: November 2007

S. Puri writes: In his studies
Irving (1982)
has used chemical analyses obtained from pumped wells over a period 1883 to mid 1970's to suggest that the chloride ion concentration is an aid to estimating recharge derived from rainfall or via leakage through rivers. He has applied this method to the aquifers of the whole of Lower Greensand formation in the Anglian region: Woburn Sands is a local name for the ‘silver sands’, found in only a limited area in the Anglian Region, and is a member within the Lower Greensand formation.

A more detailed study of the hydrochemistry of this acquifer
(Binnie & Partners 1982)
reveals a rather complicated system which casts doubt on this technique. On the author's own admission there are many unexplained observations of anomalous chloride concentrations, e.g. Clophill and Histon. (Southill, according to the grid reference given, falls well off the unconfined outcrop.) Fig. 1 shows the Piper plot for the chemistry of Bir-chmoor pumping station, which is situated on the unconfined aquifer. There are eight abstraction holes to differing depths within an area of less than 1 km
2
. The Cl
–
concentration range is between 20% and 60% of the total cations. We consider these chemical variations to reflect the layered hydrochemical nature of the water in the acquifer. Thus, if a pumped well were abstracting from a greater saturated thickness, its chloride ion content would be different from that abstracting a smaller thickness. Application of the author's method would give
A review of the geotechnical aspects of the construction of the first phase of the Mass Transit Railway, Hong Kong
Authors: Linney L. F.
Published: November 2007

Work on the first phase of the Hong Kong Mass Transit Railway (known as the Modified Initial System) started in November 1975 and the line was opened to the public in February 1980. It is 15.6 km in length and runs from the Central District of Hong Kong Island to Kwun Tong in mainland Kowloon. The system includes 12 underground stations, three overhead stations and a maintenance and repair depot covering an area of 16.5 hectares. At the depot site a medium density high rise residential development is being constructed above podium level, providing housing and facilities for 25,000 people. The railway runs predominantly in bored tunnel, but includes short cut and cover and overhead sections, whilst the 1.4 km long harbour crossing is an immersed tube. The underground stations are box structures constructed by cut and cover methods. This paper describes the geotechnical aspects of the project, including the geology of the route, preliminary investigations, construction methods (some of which were novel to this part of the Far East), geotechnical instrumentation and the effects of the work on the surrounding high density urban environment.
The engineering behaviour of jointed rock mass models composed of weak and strong strata
Authors: Knox W. R. A. , Zacas M.
Published: November 2007

The influence of the occurrence of weaker strata in a layered, jointed, model rock mass was examined. The model materials used were lightweight concrete and gypsum mortars. The models were constructed from blocks of these materials in a plane frame testing rig. The load/settlement characteristics, bearing capacity, pattern of deformation and modes of failure under a steel plate were observed, and the experimental results were then compared with those predicted by finite element analyses. No obvious correlation of results between the mathematical models and the laboratory models was discovered.
Groundwater chemistry of the Birmingham Triassic Sandstone aquifer and its relation to structure
Authors: Jackson D. , Lloyd J. W.
Published: November 2007

Hydrochemical aspects of the Triassic Sandstone aquifer of the Birmingham area are discussed to show the effect of aquifer structure upon the quality and nature of ground-waters. The presence of faulting and its effects upon ground-water flow and quality are demonstrated by reference to major ion chemistry. Carbon isotope data show that old groundwater exists in an unconfined outcrop area, its distribution being controlled by a structural low in the base of the Triassic. Radiocarbon ages of 20 samples show that low levels of chloride (<20 mg/l) are indicative of old ground-waters.
The relation between fracture patterns and hydraulic anisotropy in the Norfolk Chalk, England
Authors: Toynton R.
Published: November 2007

Structurally the Chalk in Norfolk forms a relatively uniform aquifer and it is therefore possible to distinguish between aquifer inhomogeneity and anisotropy in this area. This has been achieved by comparing directional transmissivity values with the fracture pattern in the Chalk. A map of fracture directions has been constructed for the whole of the Norfolk Chalk.

Aquifer properties have been calculated as areal values, point values, and directional point values. The ability to represent aquifer anisotropy by transmissivity ellipsoids has been extended to allow prediction of properties, and, through the use of the mean radius of the ellipsoid, comparisons between point values over an area.

A family of ellipsoid curves has been developed which summarize and aid analysis of transmissive anisotropy over an area.

A comparison of fracture orientations with point and areal transmissivity ellipsoids shows not only that the anisotropic nature of the aquifer is a direct result of the fracturing but also that this behaviour can be predicted by studying the fracture pattern and vice versa.
Late Pleistocene periglacial degradation of lowland Britain: implications for civil engineering
Authors: Jones P. F. , Derbyshire E.
Published: November 2007

The geotechnical implications of the inherent complexity of glacial sedimentary sequences have been recently emphasized and it has been suggested that more extensive use be made of engineering geological and geomorphological mapping, especially in the preliminary stages of site investigations. The incidence of certain geomorphic processes beyond the ice margins, notably periglacial solifluction, obscures the relationship between glacial depositional landforms and glacial deposits, especially when periglacial activity has prevailed throughout a glacial period. In such a case, the level of discrimination and sophistication required of these techniques is higher than that demanded using a‘land system’ approach in ice-moulded terrain such as that of the last (Devensian) glaciation.

This paper describes examples from the east Midlands of England, where recent engineering operations have encountered serious difficulties due to complex glacial assemblages or unstable bedrock being found beneath apparently simple morphostratigraphic surfaces. Surfaces mapped, for example, as late Tertiary‘erosional platforms’ and late Pleistocene river terraces can be shown to be the product of periglacial processes.

Examples are described from recent engineering projects and suggestions are presented as to how similar problems may be avoided in the future.
Deposition and engineering properties of sediments in the Lagos area and their influence on recent development
Authors: Ajayi L. A. , Epps R. J. , Farrington P. , Robinshaw A. D.
Published: November 2007

Sedimentary environments within a lagoonal régime and the occurrence of sediment types, with specific reference to the Lagos area, are described. The engineering properties of the sediments may be related to their environment of deposition and the effect of their variation on the development of the area is considered.
Discussion on ‘An analysis of secondary toppling rock failures—the stress distribution method’ by R. S. Evans
Authors: Dunbavan M.
Published: November 2007

M. D
unbavan
writes: Evans used the assumption of two discrete basal support columns of different moduli in developing his stress distribution equations. An alternative assumption is that the Young's modulus varies continuously across the base of the column and the following equations were derived for a linear variation.

The general form of the linear relationship for Young's modulus,
E
, is:

where
x
is the distance from the inside edge of the column towards the free face along the base (see inset of Fig. 1) and
E
0
is the value at the inside edge of the column. In comparing the variation of modulus with the two discrete values used by Evans, two interpretations for the value of
m
arise as shown in Fig. 1. One case assumes that the moduli for the two columns are the values at each end of the base, giving:

The second case assumes that the moduli for the two columns are average values for the half base width, giving:

The stress distribution across the base for linear variation in settlement then becomes:

with the notation being the same as that used by Evans. Using integration methods with the independent variable
x
, vertical force and moment equations when solved yield:

and

For

For

Evans' data was used for calculations so that a comparison of results could be made:

and the values are given in Table 1

The first interpretation for the linear variation of Young's modulus is more practical, indicating that any other functional would best be
J. V. Hamel & H. F. Ferguson write
Authors: Hamel J. V. , Ferguson H. F.
Published: November 2007

Rock slope failures involving secondary toppling and/or slumping of joint-bounded columns due to weathering of underlying materials appear similar to slab-type rock falls which are common in many parts of the world. The writers' experience with such rock falls has been primarily in the Appalachian Plateau of the Eastern United States (Hamel & Adams 1974; Gray
et al.
1979). This experience prompts the following comments:

Lateral stress relief accompanying valley erosion (or escarpment development) in flat-lying interbedded strong and weak sedimentary strata produces vertical to sub-vertical tension joints in strong brittle beds (e.g., massive sandstones), diagonal to curved shear joints and fissures in weak deformable beds (e.g., claystones), and mylonites or shear zones at contacts between beds of different strength and stiffness (Ferguson & Hamel 1981). These features define the geometry of rock fall masses and also increase weathering and erosion potential of underlying beds. Ground water flow through tension joints in brittle strata is commonly perched on underlying argillaceous strata of lower permeability. This ground water flow contributes to softening and alteration of argillaceous strata and of mylonite seams, if any, at the tops of these strata. Creep, tilting, and differential settlement of overlying rock blocks is thus enhanced (fig. 4(c) of Ferguson & Hamel 1981).

Within this framework of geology and geometry, rock fall mechanisms typically involve differential weathering and erosion which undercut weak argillaceous beds beneath joint-bounded rock blocks. Whether a rock block topples (with forward rotation) or slumps (with backward rotation) depends on its geometry, the
Engineering geophysics
Authors: Hooper J. W.
Published: November 2007

Review of the meeting of the Engineering Group held at Burlington House on 9 November 1982.

Dr Hawkins, Chairman of the Engineering Group, welcomed everyone to the meeting, which began with a review of the value of geophysical surveys in ground engineering. The presentation entitled ‘Engineering geophysics—an overview’ by Dr B. W. Darracott of Wimpey Laboratories took the form of a narrated slide show of various case histories undertaken by the speaker. The usefulness of seismic refraction surveys was discussed, particularly for rock head determination, foundation design and the selection of quarry face advance direction. The analysis of shear waves was shown to aid in the better determination of the rock type and its properties. Cross-hole shooting between boreholes also enables shear waves to be measured accurately and leads to the determination of the Shear modulus and Young's modulus of the rock mass between the boreholes. This latter method may also be useful where ground surface shooting methods would not be possible due to unfavourable conditions. Over-water seismic surveys were also covered by the speaker, showing how continuous profile reflection work could be carried out on river estuaries and off-shore.

Electrical resistivity surveys were shown to be particularly useful for resolving rock layering problems and for helping with many aspects of field work involving water supply. Dr Darracott illustrated a case history where a semi-confined aquifer at depth had given rise to a slip plane in the upper near surface layers.

Magnetic methods were shown to be potentially useful in
Book Review CraigR. G.CraftJ. L.Applied Geomorphology1982George Allen & Unwin2530-04-551050-4£18.00
Authors: Jones D. K. C.
Published: November 2007

As geomorphology is the study of the surface of the Earth, its form, evolution and the processes that sculpture it, so applied geomorphology can be defined as the application of this knowledge in the resolution of engineering, planning and environmental/resource management problems. It is a rapidly expanding and diverse field of enquiry and one that would be extremely difficult to adequately describe within the confines of a slim volume. It is not surprising, therefore, that the editors, in their preface, state that the purpose of the book “is not to codify a distinct set of methods and data that represent a branch of knowledge called ‘applied geomorphology’. Rather it is designed to show geomorphology as it is (and can be) applied to current problems facing the people of the world”. This they attempt to achieve by means of 16 contributions written by 33 authors, all but two from the USA, which represent the proceedings of the 11th Binghampton Geomorphology Symposium held in October 1980 at Kent State University, Ohio.

Published anthologies of conference papers are notoriously variable in terms of quality and coverage, and this is no exception. The book has no real structure, although the early papers do tend to focus on mapping and cataloguing, while the later papers deal with aspects of change. A general introductory chapter focuses on the need for more information on the rates of operation of geomorphological processes for environmental management purposes, and is followed by a descriptive paper which discusses the role of
Engineering implications of earth surface processes—engineering geomorphology
Authors: Bromhead E. N.
Published: November 2007

The Engineering Group held its Annual Regional Meeting for 1982 at Birmingham University from 13 to 17 September, hosted by the Department of Transportation and Environmental Planning. Dr Lees, the Head of this Department, well known to Fellows of the Society as a former Editor of the
Quarterly Journal of Engineering Geology
, acted as local secretary, with the notable assistance of Major D. A. Parsons and Mrs J. Freelands of his administrative staff. Many thanks are due to Dr Lees and his staff for the success of the meeting and to Mr T. Spink, Mr R. A. Fox and Dr R. McDermott who played important roles in the organizing committee, and to the leaders of the field trips.

In planning this meeting and selecting its theme, it was intended to complement the meeting of the British Geomorphological Research Group which had the same venue and took place the following weekend. A high point of the whole meeting was the shared day when four speakers of international repute addressed a joint meeting of both groups. Former Editors of
Q.J.E.G.
were much in evidence on that day with Dr R. J. Chandler giving the Frost Lecture to the
BGRG
in the evening.

The theme of the conference was broad and reflected in some degree the nature of the Engineering Group which draws its members from a wide range of disciplines allied to, but different from, geology. This was amply demonstrated at the meeting where the theme, style and content of papers varied
Engineering geomorphological investigations of a possible landslide, Killiecrankie Pass, Scotland
Authors: Chaplow Robert
Published: November 2007

Preliminary site investigations indicated the possible presence of a partially degraded landslide along the proposed route of the A9 Perth-Inverness Trunk Road Improvement through Killiecrankie Pass in Scotland. The steep natural topography and the congested nature of the site, with an existing trunk road and railway line, necessitated the design of relatively deep cuttings through the landslide area.

To investigate the ground conditions in the area and to enable designs for the cuttings to be prepared, a programme of site investigations was implemented, consisting primarily of engineering geomorphological mapping, seismic refraction surveys and the excavation of trial trenches and pits.

The investigation revealed the presence of a sequence of glacial tills, outwash deposits and ancient mudflow deposits overlying a steeply sloping and undulating rock-head. Spring sapping was identified as the only major mechanism controlling natural slope instability. Preliminary designs for the cutting slopes were proposed incorporating the need for extensive drainage of the slopes cut in the glacial deposits.

This paper describes the scope of the investigations carried out, the interpretation of the ground conditions and an outline of the approach adopted towards design of the cut slopes.
A preliminary geomorphological assessment of part of the Karakoram Highway
Authors: Jones D. K. C. , Brunsden D. , Goudie A. S.
Published: November 2007

The Karakoram Highway has been constructed through extremely difficult high arid mountainous terrain characterized by long, steep slopes, highly fractured and heavily weathered rocks, extensive areas of debris accumulation and locally high rates of geomorphological activity. The problems for road construction imposed by difficulties of access and remoteness have been compounded by rockslope instability, debris flows, river and meltwater surges, and fluctuating glacier snouts. As a consequence, the employment of sophisticated engineering techniques was abandoned in favour of widespread blasting and an extended period of labour-intensive maintenance. This paper is concerned with an 147 km stretch of the Highway and essentially subdivides into two parts. The first part describes the terrain conditions and main hazards posed to road construction, and includes a geomorphological assessment of the chosen alignment. The second section presents the results of a detailed survey of 128.8 km of the Highway in terms of the patterns of disruption experienced during the first three years of its life, and the distribution of a variety of hazards which will continue to endanger the road. This survey clearly reveals the importance of a good appreciation of geomorphological processes to highway engineering in arid mountains, as well as indicating the potential for geomorphological inputs to highway design.
Postscript to ‘The collapse of the Dale Dyke dam in retrospect’
Authors: Binnie G. M.
Published: November 2007

In his capacity as Reporter for Question 55 at the International High Dams Conference in Rio de Janeiro last year, Dr A. D. M. Penman discussed the hydraulic fracture of the cores of earth dams and wrote ‘It was considered to be a cause of the failure of Teton dam in 1976 and has been suggested as the cause of failure of Dale Dyke dam in Britain in 1864 by Binnie (1978) in his reconsideration of that classical failure.’ This refers to the above paper which appeared in Volume 11, pp. 305-324 of the Quarterly Journal. Subsequent to the publication of this paper, the accompanying longitudinal section of the Dale Dyke embankment was discovered in the archives of Messrs. Watson-Hawksley and is reproduced with their permission.

The dangerous planes in a core are vertical ones passing from upstream to downstream through it but with sufficiently low strength, as would be the case with puddle clay, it should normally be possible to maintain sufficiently high stresses on these planes. Dr Penman states that ‘this fact may account for the successful behaviour of the very many puddle clay core dams’.

The longitudinal section helps to explain why theDale Dyke dam appears to have been an exception. It can be seen that below and near the centre of the part of the embankment that was washed away, there was a 35 feet high step in the cut off trench. This step, which was not disclosed at the inquest nor during the subsequent Parliamentary
Introduction: Waste disposal—where are we now?
Authors: Bonney G.
Published: November 2007

‘Science uses concepts which are in theory precise, but in practice more or less vague’. Few hydrogeologist working in waste disposal could disagree with Russel, but considerable effort is being expended to lessen the vagueness. Mounting pressure from environmental legislation has produced commendable attempts to codify the assessment of waste disposal sites. It has been found however, that although the measurement of environmental impact may be more or less precise, accounts of the mechanisms in operation around the sites are only now becoming less vague.

In January 1983, the Society held a Hydrogeology Group meeting entitled ‘Waste disposal—where are we now?’ to review recent developments in the hydrogeology of waste disposal, and the following six papers were presented, to a capacity audience: C. J. Swinnerton: Protection of groundwater in relation to waste disposal in Wessex Water Authority; R. Holmes: Infiltration of rain through waste materials and its significance in the planning of leachate management schemes; C. Barber & P. J. Maris: Recirculation of leachate as a landfill management option: benefits and operational problems; H. D. Robinson: On-site treatment of leachate using aerobic biological techniques; G. M. Williams: Migration of contamination from the waste disposal lagoon at Villa Farm; R. C. Harris & D. R. Lowe: The organic component of domestic refuse leachate with reference to two landfill sites in Nottinghamshire. The meeting attracted members from six other societies and the central topic was the leachate production caused by landfill disposal of mainly domestic waste.

Such a meeting was considered to
Protection of groundwater in relation to waste disposal in Wessex Water Authority
Authors: Swinnerton C. J.
Published: November 2007

Although the Wessex Water Authority is one of the smallest water authorities the hydrogeology of the region is varied with major aquifers ranging from the Chalk in the south-east to Carboniferous Limestone in the north-west. Approximately half of the public water supplies for Wessex are obtained from groundwater so it is imperative that the aquifers are protected from pollution from landfill.

Within Wessex no aquifer protection policy as such has been developed and, although tipping on aquifers is discouraged, each proposed site is looked at on its merits and, subject to adequate safeguards based on reliable data, sites on aquifers may be permitted. This approach, coupled with inherited sites, has resulted in a wide range of types of waste disposal site.

Four examples of different types of site on aquifers are presented together with a non-aquifer site which is a contain and treat site and which might be considered by many to be the optimum type of site.
Recirculation of leachate as a landfill management option: benefits and operational problems
Authors: Barber C. , Maris P. J.
Published: November 2007

Recirculation of leachate through landfilled solid wastes offers potential advantages in reducing the volume of liquid by surface evaporation, and reducing the strength of leachate by crude anaerobic treatment within the landfill. Increasing the moisture content of the fill is also reported to give rise to a more rapid stabilization of solid wastes, and to enhance gas (methane) production.

Results of research using 7 m
3
lysimeters essentially confirmed these benefits and produced a predicted volume of low strength leachate within 18 months. A full-scale study at a lined landfill at Seamer Carr, North Yorkshire, has shown that on a large scale these benefits are more difficult to obtain, although this three-year study has proved successful in considerably reducing the volume and organic strength of leachate.

It is concluded that recirculation by itself cannot provide a lasting solution for leachate management, although significant reductions in the volume and strength of leachate can be obtained. Careful control is required and, in particular, it is necessary to consider the hydrology of a landfill and how this is affected by use of (final and intermediate) cover material.
On-site treatment of leachate using aerobic biological techniques
Authors: Robinson H.
Published: November 2007

Although major advances have taken place in recent years in the engineering and control of landfill operations, the generation of highly polluting leachates as water percolates through wastes remains a major consideration. Despite the fact that many leachates contain high proportions of readily degradable organic materials and are frequently treated successfully at sewage treatment works for discharge to surface waters, in the United Kingdom very few facilities have been constructed on landfill sites for the treatment of leachate.

In the Federal Republic of Germany research, which has been stimulated by changes in legislation, has resulted in the construction of several relatively sophisticated leachate treatment plants since the later 1970s. These have been designed to very high standards, but only at very high costs (of up to £4 for every m
3
treated).

It is considered that on-site aerobic biological treatment systems will become more common in the UK, as individual landfill sites continue to increase in size and also as research results allow process designs to be optimized further. It is therefore appropriate that geological assessments of the suitability of landfill sites are made in the light of research and experience, in particular as advances are made in the technology of leachate treatment.
Changes in the organic fraction of leachate from two domestic refuse sites on the Sherwood Sandstone, Nottinghamshire
Authors: Harris R. C. , Lowe D. R.
Published: November 2007

Two domestic refuse landfill sites, situated on the outcrop of the Sherwood Sandstone in Nottinghamshire, have been investigated with a view to elucidating possible mechanisms of attenuation in operation within the unsaturated zone. Two cored boreholes have been drilled at each site, separated by a two-year interval, and the pore water analysed for a wide range of parameters. Although acetogenic degradation has been identified within both landfills, and it is postulated that methanogenesis is occurring in the Gorsethorpe site, there is little evidence for attenuation of the organic fraction of the leachate within the 6 m of unsaturated zone penetrated.
The use of resistivity and gamma logging in lithostratigraphical studies of the Chalk in Lincolnshire and South Humberside
Authors: Barker R. D. , Lloyd J. W. , Peach D. W.
Published: November 2007

Electrical resistivity and natural gamma logs obtained from 70 boreholes in Lincolnshire and South Humberside can be interpreted in terms of lithology and show excellent agreement with the detailed lithostratigraphical divisions of the Chalk, obtained by
Wood & Smith (1978)
from the study of surface exposures. As, to the best of our knowledge, this sequence is complete, for the first time a direct correlation between continuous borehole logs and a detailed lithostratigraphical succession is possible. Important marl bands and some erosion surfaces and flint bands can be identified on the resistivity and gamma logs and traced over most of the study area. Stratigraphical positions of the logged boreholes can be determined and formation thicknesses measured. This information has enabled the construction of an accurate contour map of the elevation of the base of the Chalk and the eastward extension of the Caistor Monocline has been identified.
The reliability of packer tests for estimating the hydraulic conductivity of aquifers
Authors: Bliss Jane C. , Rushton K. R.
Published: November 2007

This paper investigates the suitability of the double packer testing technique when it is used to estimate how the hydraulic conductivity of an aquifer varies with depth. A mathematical model of the radial and vertical flow from a borehole in a typical aquifer is devised and used to investigate the nature of flow in the aquifer due to the injection of water between two packers. It is shown that the existing formulae usually provide adequate estimates for zones of both high and low hydraulic conductivity. Other features that are considered include the effect of the length of fissures, the presence of boundaries, the possibility of water flowing around the packers, the length and spacing of the packers and the influence of the free water surface.
The location of the Stour buried tunnel-valley using geophysical techniques
Authors: Barker R. D. , Harker D.
Published: November 2007

A detailed gravity survey has been conducted over the Stour buried tunnel-valley between Sturmer and Long Melford in Essex. The resulting Bouguer anomaly map indicates that the density of the boulder clay filling the valley is higher than that of the underlying chalk. The interpretation of the Bouguer anomaly clearly indicates the subsurface position of the Stour buried tunnel-valley and calculations of the depth to the base of the valley fill have been attempted. Detailed resistivity sounding surveys at proposed borehole sites confirmed the gravity interpretation and provided more detailed information on drift lithology and thickness.
Land surface evaluation for engineering practice: applications of the Australian PUCE system for terrain analysis
Authors: Finlayson Alan A.
Published: November 2007

Terrain is classified on the basis of characteristics such as the engineering properties of the underlying soil and rock, the slope of the land and its vegetation. It can then be mapped, described, evaluated, and assessed for different purposes at increasing levels of detail in terms of areas known as provinces, terrain patterns, terrain units, and terrain components. The main method of terrain analysis specifically related to civil engineering purposes currently being implemented in Australia, the PUCE System, is explained briefly and examples cited to illustrate its development and scope. A complete bibliography is also included.