bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spring mudflows at Wrightwood, Southern California
Authors: Morton D. M. , Campbell R. H. 
Published: November 2007

Summary
The Wrightwood area in the San Gabriel Mountains of southern California is known as a site of recurring mudflow activity. The community of Wrightwood is built on the coalesced fans of Sheep, Acorn and Heath Creeks, and the fan deposits are probably chiefly of mudflow origin. Historically, mudflows there have been observed in association with three climatic conditions: (1) short period of high-intensity rainfall during the summer dry season (thunderstorms); (2) periods of heavy rainfall during the October-March winter season, when most of the year's rain and snow fall; and (3) thaw of the winter snow pack. The mudflow activity associated with heavy rainfall has generally been of only a few hours or at most a few days duration. Mudflow activity associated with spring thaw has been of longer duration, as much as several weeks. At various times in the past, mudflows generated by all three conditions have inundated homes and highways in the Wrightwood area, which is now defended by a flood control levee system.
During May and June, 1969 the rapid melting of a heavy snow pack resulted in a 40-day period of mudflow activity in Heath Creek. All flows originated in the steep upper reaches of Heath Creek, where steep ravines are incised in the toe of a large active landslide. Direct observation by the authors showed that flows formed when small masses of debris fell or slid from the surface of the landslide mass into the steep channel. Some of the masses were fluid enough to continue downstream without interruption; others stopped in the channel until remobilized by added melt water or the passage of a mudflow from a higher altitude. Both processes resulted in discrete ‘slugs’ which continued down the steep ravine, through an allu-viated canyon, to a fan where most of the debris was deposited.
The activity may be described as a spring mudflow cycle, within which three stages were observed in a gradational sequence. A waxing stage began with sporadic short-duration mudflows, during which the lower alluviated canyon floor of Heath Creek was aggraded. A climactic stage of larger mudflows at more frequent intervals and of longer duration was characterized by the incision of a single, narrow, U-shaped channel in the alluviated canyon floor, and transportation of debris as much as 2 miles (3.2 km) from the source. A waning stage followed as meltwater supply decreased; short-duration flows backfilled the U-shaped channel and spilled over the banks, again aggrading the alluviated canyon floor.
The application of geophysical methods in the exploration and development of Sandstone aquifers
Authors: Worthington Paul F. , Griffiths Donald H. 
Published: November 2007

Summary
Procedures are suggested for the optimum use of electrical resistivity and seismic techniques in determining hydraulic conductivity and transmissivity within sandstone aquifers. The object is to improve the siting of abstraction boreholes. The primary emphasis is placed upon electrical methods for studying consolidated formations from which there has been good core recovery, and within which intergranular flow is important. The recommendations are based upon experience gained during hydrogeological and geophysical investigations of the Bunter Sandstone in the Fylde area of northwest Lancashire, England.
Investigation of a coastal landslip at Charmouth, Dorset
Authors: Denness Bruce , Conway Bernard Walford , McCann David Michael , Grainger Peter 
Published: November 2007

Summary
The Dorset coast is an area with a long history of landslide activity and coastal erosion. Geologically the area is composed of the clays, mudstones and limestones of several divisions of the Lower Jurassic (Lower Lias) which are overlain unconformably by Cretaceous clays and sands (Gault and Upper Greensand.) Areas of serious instability appear to occur in close association with naturally occurring reservoirs of ground water, of which Black Ven at Char-mouth is a good example.
Problems connected with a small coastal landslip near a private housing estate at Char-mouth were studied and shown to be related to a Pleistocene mudflow. The main purpose of the investigation was to suggest remedial works but the subsidiary aim, forming the theme of this paper, was to assess the usefulness of shallow depth geophysical and geotechnical methods not normally used in instability studies.
Factors affecting the detection of slope instability with air photographs in an area near Sevenoaks, Kent
Authors: Norman John Wakelin , Leibowitz Theodor Herzl , Fookes Peter George 
Published: November 2007

Summary
Twenty-six sets of air photographs were used to test the best photographic conditions for detecting landslips, mainly old periglacial solifluction movement, along a ten mile stretch of sloping ground. A total of 141 old landslip features were detected and many varied in clarity on the different photographs, some being hard or impossible to detect on foot without the aid of air photographs. The repeated images of the same landslips on different sets of photographs produced a total of 2 715 photo-features for statistical studies.
Analysis of the results showed that the best technical photographic conditions for detecting such features are the use of infra red colour film, stereoscopic photography with a short focal length lens, a nominal photographic scale of about 1:5 000, and a sun angle that casts local but not very extensive shadows. It is considered that automatic dodging can both enhance and suppress vital information on images, and that the best seasons for photography are likely to be spring and late summer to early autumn.
Some unusual structures in the river gravels of the Thames Basin
Authors: Wakeling T. R. M. , Jennings R. A. J. 
Published: November 2007

Summary
Four sites in the London area are described where sandy gravel overlies London Clay. On two of these sites the unexpected occurrence of deep steep-sided natural depressions in the surface of the London Clay gave rise to delays during the construction of civil engineering works. On the other two the depressions were discovered during the initial site investigations and appropriate measures for dealing with them were taken in good time.
The application of air-flush rotary percussion drilling techniques in site investigation
Authors: Honer P. C. , Sherrell F. W. 
Published: November 2007

Summary
The technique of drilling boreholes using air-flush rotary-percussive drilling rigs is widely used in the quarrying and civil engineering industries, but its application in site investigation does not appear to have been appreciated. It involves the drilling of boreholes under controlled conditions, using a rotary-percussive drill, and measuring the rate of penetration. Systematic sampling of the drilling flushings and observation of the drilling characteristics enable an indentification of the rock type to be made, as well as an interpretation of some important aspects of its geotechnical behaviour. Although the technique does not provide a continuous visual record of the intact material drilled, it has been extensively and economically applied in South-west England, particularly in the search for cavities in rocks and the depths to, and quality of, bedrock and variations in the properties of some types of soils. The interpretation of the results is further improved if the results of some core-drilled or shell-and-auger drilled boreholes are available for direct comparison, correlation and “calibration”. The technique can also be applied in cases where the boreholes are drilled for other purposes, such as grouting, rock anchoring and blast-hole drilling, in order to supplement knowledge of the ground conditions.
Interborehole acoustic measurements in site investigation
Authors: Grainger Peter , McCann David M. 
Published: November 2007

Summary
Interborehole acoustic measurements are made by transmitting a pulse of sound energy from one borehole to another. Analysis of the recorded signals can provide useful information on ground conditions between and beneath the boreholes. This includes the location of boundaries between different rock and soil types, and an assessment of geotechnical properties in certain cases. A sparker source of energy has been developed for use in boreholes, giving a repetitive pulse shape. The received signal may contain direct, refracted and reflected arrivals, which can be timed. These times are converted to apparent velocities and a vertical scan of two boreholes presented as an apparent velocity versus depth curve.
Two case histories from the Dinorwic hydro-electric scheme in North Wales and from Whatley Quarry near Frome in Somerset, illustrate the nature of the interpretation process, and the quality and distribution of the additional geological data that can be achieved. Interborehole scanning has certain advantages over conventional surface seismic refraction; for example, in the detection of low velocity layers at depth. It does of course have its limitations, in the theoretical, interpretational and the practical senses. With these limitations minimized, interborehole acoustic measurements can be a very useful addition to site investigation.
Discussion by J. N. Hutchinson
Authors: Hutchinson J. N. 
Published: November 2007

In 1958–59, 25 loading tests were made at Khorramshahr on concrete friction piles driven in connection with extensions to the port, where the ground consists of deep deposits of soft to medium estuarine silty clays. Thirteen of the piles tested had been coated with a thin layer of bitumen as a protection against attack by soil acids: the remaining twelve piles were uncoated.
The loading tests showed that the shaft bearing capacities of the coated piles were between 30 and 80 percent lower than those of equivalent uncoated piles. A further, most interesting, finding was that the bearing capacity of the coated piles fluctuated seasonally (Fig. 1). This fluctuation was shown to be consistent in phase and magnitude with that which could be predicted from the seasonal fluctuation in ground temperatures and the temperature-viscosity characteristics of the bitumen used. Full details of the work are given in Hutchinson & Jensen (1968).
Engineering geological case study of the site investigation and design of a major trunk road cutting in Carboniferous rocks
Authors: Buist D. S , Burnett A. D. , Sanders M. K. 
Published: November 2007

Summary
The 7.1 km dual two-lane Unstone-Dronfield By-Pass, Derbyshire, first opened to traffic in 1975, incorporates a 30 m deep rock cut at Monk Wood, excavated in strata of Lower Coal Measures age. Cuttings in similar geological settings elsewhere had resulted in mass slide failures and the measures adopted at Monk Wood to avoid a similar problem are described. The site was complicated by the presence of extensive old workings for coal and ironstone; their treatment is discussed.
Discussion on ‘A numerical model for the perdiction of long term well yield in an unconfined chalk aquifer’ by B. J. Connorton & R. N. Reed
Authors: Puri S. 
Published: November 2007

Connorton & Reed's paper on the use of a radial flow model is an interesting addition to the knowledge of chalk aquifers and their hydraulic response. There are, however, a number of points that arise and need comment.
The first of these is concerned with the use of a radial flow concept in aquifers that are recognised to have a marked anisotropy. The authors have dismissed this by stating that within a short distance of the well (up to 100 m) radial symmetry can be assumed. During studies of a number of pumping tests in the Middle Chalk in east Kent, which had the good fortune of having observation wells located at right angles to the pumped well, I noticed that radial symmetry of aquifer parameters almost never occurs, even at distances sis near as 50 m.
The second comment relates to the use of ‘saturated thickness’ and the associated corrections for its decrease. Assigning a value related to the frequency of fissuring implies complete absence of pore water, which plays an important role in the aquifer's hydraulic response. Owen & Robinson (1978) in the same study area suggest that these thicknesses range from 45 to 60 m, while the authors have implied it to be 100 m as shown by their use of adjusted T values for their modelling.
The complexities involved indicate that the best way to understand the interactions between various parameters is to use a simple model, such as the radial model. One of the greatest
Porewater composition in the unsaturated zone of the Chalk, with particular reference to nitrates
Authors: Spears D. A. 
Published: November 2007

Summary
Thirty-seven samples of Upper Chalk from a borehole in the unsaturated zone near Manston in Kent were analysed for major elements and the mineralogy was determined. Porewaters were extracted and analysed for major cations and anions. Changes due to infiltrating water were not detected in the whole-rock analyses, but the porewater analyses generally show a decrease in concentration with increasing depth. The cause of the variations and the origin of the elements are discussed.
Morphological mapping in the Axmouth-Lyme Regis Undercliffs, Devon
Authors: Pitts J. 
Published: November 2007

Summary
Morphological mapping has proved extremely useful in a renowned area of coastal landslipping.
The undercliffs form a coastal strip nearly six miles long, and up to 500 m in width. The antiquity (possibly late Pleistocene in part), and the large scale of much of the landslipping have assisted in the development of a mature, luxuriant vegetation cover, which masks much of the ground detail. However, the main back and side scars have often remained clear from the air, enabling photogrammetry to be used to produce base maps at a scale of 1:2500. Ground details where added to the base maps from fieldwork clearly reveal the patterns of mass movement. Examples of the final geomorphological maps are presented.
Some 19th century interpretations of the mechanisms of landslipping indicate the advantages of observing the features in a fresh, lightly vegetated state. The present programme of morphological mapping has, hopefully, revealed a sufficient quantity of the detail to enable a reassessment of the area in the light of modern theory. Detailed morphological mapping is also presented as a site investigation technique of considerable merit in areas of difficult access and terrain, or in protected areas.
Problems of engineering-geomorphological mapping on impermeable surface materials and in karst regions
Authors: Lang S. 
Published: November 2007

Summary
The author outlines the type of information which should be presented on engineering-geomorphological maps, and stresses the need to show the relationship between this data and the possibility of natural catastrophes. For example, it is proposed that a system of maps covering areas where there is a high probability of landslipping should be devised, with priority to be given to populated tropical and equatorial regions. The mapping of other ‘problem’ areas (e.g. arid, polar, and karst regions) is also discussed. However, it is concluded that, in all areas, an overall evaluation of climatic, morphological, and lithological factors is essential for engineering-geomorphological mapping.
Engineering geomorphological mapping as a technique to elucidate areas of superficial structures; with examples from the Bath area of the south Cotswolds
Authors: Hawkins A. B. , Privett K. D. 
Published: November 2007

Summary
From the literature and the geological maps it is known that superficial structures occur extensively associated with the Jurassic strata in the south Cotswolds. There is some discrepancy in the representation of superficial structures on the small-scale geological maps (1:63,360 and 1:50,000 scales).
Examples from the Bath area have been selected and engineering geomorphological maps of some superficial structures are presented. It is concluded that valley bulges and cambers are difficult to delimit using this technique but landslips, especially the more recent, large-scale ones, and mudflows can often be clearly depicted. An important consideration is the subsequent ‘smoothing’ of natural features by hillwash or intensive agriculture and associated ploughing. It is concluded that this form of mapping is no substitute either for geological mapping or for a proper site investigation; it can, however, add valuable data.
The representation of the morphology of slopes on engineering geomorphological maps with special reference to slope morphometry
Authors: Kertész A. 
Published: November 2007

Summary
Engineering geomorphological maps are expected to represent the characteristics of surface morphology in relation to economic and technical planning in a concise and easily understandable form. The most satisfactory means of attaining this objective is to use morphometric methods for the characterization of relief. Morphometric methods include quantitative description of the relief.

Hungarian engineering geomorphological maps indicate the stability of slopes, the nature, intensity, and direction of slope processes, as well as the delineation of slope categories. Among these factors only the latter gives quantitative morphometric information, the others being qualitative classifications. This paper presents methods of representing the above properties and reviews morphometric methods of representing slopes, such as:

the values of average and extreme slope angles, which are equally important for engineering applications. Among slope maps those representing
slope categories
are particularly successful.

slope morphology maps show the slope direction, the average slope angle and the slope form (convex, concave, rectilinear, and compound) within the pattern of the drainage network

isotangent maps give information on the surface gradients

relative relief maps represent the maximum relative level differences relating to territorial units.

These techniques complement engineering geomorphological maps; some of the information can be transferred to general engineering geomorphological maps. But, most importantly they are used in the precise and quantitative definition of certain types of relief.
Beach and dune interactions during storm conditions
Authors: Leatherman S. P. 
Published: November 2007

Summary
Recently, coastal investigators have questioned the function of barrier dunes during storm conditions. Dunes were believed to interfere with swash processes by constricting the beach profile over which the energy must be dissipated. Also, some researchers believed that dunes act as seawalls and reflect a significant portion of the incident wave energy. Either of these two possible effects would result in accelerated beach erosion. Considering the worldwide importance of coastal dunes as a protective barrier system, it was paramount to gather information by which to further examine these hypotheses. In this paper, the author reports field data collected to date during storm conditions and summarizes the pertinent laboratory investigations. Finally, a new model is conceptualized regarding the functioning of barrier dunes during storms versus flow dissipation by overwash.
The Portavadie dry dock, west Scotland: a case history of the geotechnical aspects of its construction
Authors: Clark A. R. , Hawkins A. B. , Gush W. J. 
Published: November 2007

Summary

The paper discusses the construction of a dry dock in western Scotland designed for the fabrication of offshore concrete oil production platforms. The project involved the excavation of some 830 000 m
3
of soft material and rock from a tidal inlet to a base level between 11 and 13 m below Chart Datum. The construction period was limited through the necessity to meet a climatic window for float out. The progress achieved and the organizational relationships of the project are described.

The site investigations prior to commencement of the site work were limited. These and the subsequent investigations carried out during the course of the works are described. The authors also discuss methods of construction, and show how certain aspects of these and the original designs were modified as the work proceeded.
P-wave velocity measurements in a machine-bored, chalk tunnel
Authors: Hudson J. A. , Jones E. J. W. , New B. M. 
Published: November 2007

Summary
During tunnelling trials in the Lower Chalk at Chin-nor, Oxfordshire, two techniques for assessing rock quality based on measurement of P-wave velocity were evaluated. Ultrasonic pulse velocity measurements at 54 kHz were made over 0.2 m path lengths at the tunnel face and the conventional hammer seismograph method was used over 10 m path lengths along the tunnel side wall.

The ultrasonic measurements were obtained by placing transducers on the flat surfaces of circular grooves cut by the tunnel boring machine picks and provided an excellent method for
in-situ
evaluation of local variations in the mechanical characteristics of the chalk. In order to obtain the relation between acoustic velocity and geotechnical properties of the chalk in this region of complex fissuring, it was necessary to compare average values of velocity and chalk properties for successive readings over a distance of 1.6 m which is equivalent to ten times the mean distance between fissures. Linear relations were found for acoustic velocity versus both chalk strength and discontinuity spacing for the range of chalk variability that was encountered.

P-wave velocities from the hammer seismograph observations over 10 m path lengths showed considerably less scatter than the ultrasonic velocities because such a large number of discontinuities was included in each path length but a significant change in values from the range 1.08-1.27 km/s to the range 1.45-1.64 km/s occurred some 35-40 m from the tunnel portal. This increase is directly associated with the change in ground surface level and consequent increase in overburden stress. Moreover, the velocity ceased to increase significantly at an overburden stress of 0.4 MN/m
2
, a level that corresponds well with the stress at which a discontinuity became acoustically closed in laboratory tests. The measurements emphasize the fact that, when the P-wave velocity is used as an indicator of rock quality near the ground surface, it is important to take the effect of overburden stress into account.
Applied petrology—the stability of concrete aggregates
Authors: French W. J. 
Published: November 2007

The papers in this issue were presented at an Ordinary General Meeting of the Society in February 1979. They illustrate some of the aggregate problems that can arise in modern concrete and the value of petrological and geochemical techniques in the study of potentially deleterious systems. It is common to regard concrete aggregates as inert filler. Perhaps in Britain this is fair, although in recent years several examples of damage due to aggregate instability have been described. Internationally, the difficulties of finding good aggregate are more profound; British flint may make good concrete but Danish and German flint is often reactive and extremely deleterious. The problems are particularly acute in extreme climatic zones and where hard rock and good gravel is scarce or must be transported for great distances.
The Chairman of the first session, Mr A. D. Robertson of Sir William Halcrow and Partners, referred to the very great interest created by the problem of the behaviour of concrete in the Middle East and recalled that one of the first occasions on which this had been aired was in the Society's meeting room, as recently as 1975. Since the first signs of trouble had manifested themselves in Bahrain the scale of construction in the Middle East had increased dramatically and the earlier problems had been exacerbated by the need to find sources of aggregate in quantities far in excess of earlier demands for use in more elaborate forms of construction capable of sustaining higher stresses. Early considerations of concrete