Environmental geology study: parts of west Wiltshire and south-east Avon

The objective of this study has been to collect and interpret the available environmental geology data and to use it to compile a set of thematic maps and this report. The maps and report are intended for use by those not trained in geology as well as specialists, and to help assess the land-use planning implications of surface and subsurface development

SHRINKiT: Automated measurement of shrinkage limit for clay soils

This report describes the development at the British Geological Survey (BGS) of a new automated apparatus, titled ‘SHRINKiT’, for measuring the shrinkage limit of a clay soil. This has been developed at the BGS’s geotechnical laboratories, in part with NERC Innovations funding. The new method is intended to replace two British Standards (BS1377) methods which have fallen into disuse at BGS, in common with many other laboratories in the UK, and to some extent worldwide, partly as the result of safety concerns in their required use of large quantities of mercury. During the test the cylindrical specimen is allowed to air-dry and shrink. The apparatus carries out repeat measurements of diameter, height and weight; the dimension-measuring component being in effect a simple laser scanner. Each test takes a few days to complete; the duration depending on specimen size, soil type, initial water content and environmental conditions. The output of the test is a plot of water content vs. volume from which the shrinkage limit of the soil can be calculated using the graphical construction method described in BS1377. The shrinkage limit is defined as the water content below which there is little or no further structural shrinkage of the soil. Additional information may also be obtained from the results. The test may be carried out on a wide variety of soil types in an undisturbed, remoulded or compacted state

Slope dynamics project report : Holderness Coast - Aldbrough, drilling & instrumentation, 2012-2015

This report is a published product of an ongoing study by the British Geological Survey (BGS) of the coastal change at Aldbrough on the Holderness coast, East Riding of Yorkshire, UK. The test site at Aldbrough has been selected as one of the BGS Landslide Observatories because it is representative of the high rates of coastal recession along this stretch of the east coast. The Aldbrough Landslide Observatory is operated under the BGS ‘Slope Dynamics’ task within the BGS’s ‘Landslide’ project of the ‘Shallow Geohazards and Risk’ team. As well as providing new insights with respect to the volumetric rates of recession and the near surface processes, it is a focus for the trialling of new surface and subsurface monitoring technologies. The establishment of the Aldbrough observatory and the initial research findings are reported in a series of reports in addition to this report. These are: Hobbs, P. R. N., Jones, L. D., Kirkham, M. P., Pennington, C. V. L., Jenkins, G. O., Dashwood, C., Haslam, E. P., Freeborough, K. A. and Lawley, R. S. (2013) Slope Dynamics Project Report: Holderness Coast – Aldbrough: Survey & Monitoring, 2001 - 2013 British Geological Survey, Open Report No. OR/11/063. Hobbs, P.R.N., Kirkham, M.P. & Morgan, D.J.R. (2016) Geotechnical laboratory testing of glacial deposits from Aldbrough, Phase 2 boreholes. British Geological Survey, Open Report No. OR/15/056. Whilst this report is focused on the drilling and instrumentation programme, it should be read in conjunction with the reports listed above, which provide further details on survey and monitoring, and the geotechnical properties of the underlying geology. A series of reports will follow presenting the updated drilling and instrumentation reports, and their publication will be announced through the BGS project web page. Readers of these reports will probably also be interested in the context for this research, which can be found in: Hobbs, P.R.N., Pennington, C.V.L., Pearson, S.G., Jones, L.D., Foster, C., Lee, J.R., Gibson, A. (2008) Slope Dynamics Project Report: the Norfolk Coast (2000-2006). British Geological Survey, Open Report No. OR/08/018

Falling head permeability tests on Till deposits from the Vale of Eden, England - supplementary report including new data

This report describes permeability tests carried out on twenty three samples of glacial till obtained from boreholes drilled in the Vale of Eden area in Cumbria, England. The results of 134 initial tests are also documented in Internal Report IR/13/034 (ibid.). Further samples were obtained in September 2013 and results of an additional 76 tests on seven additional samples are reported here. The report outlines the testing procedure and presents the results of the permeability tests. The laboratory permeability values of till soils from the Moreland and Pow Focus Catchments ranged from 10-5 to 10-10 m/s, suggesting permeability is variable, with Medium Low to Impermeable soils

The relationships between effective porosity, uniaxial compressive strength and sonic velocity of intact Borrowdale Volcanic Group Core samples from Sellafield

The effective porosity, saturated sonic velocity and saturated uniaxial compressive strength were determined on a large number of Borrowdale Volcanic Group volcaniclastic core samples from three boreholes at Sellafield, Cumbria. The work formed part of the UK Nirex Limited site investigation into whether the Sellafield area could be suitable as a repository for intermediate and low level radioactive waste. Most of the intact samples were of low to very low effective porosity, had a high sonic velocity and were very strong to extremely strong. However, a proportion of values deviated significantly from this. Bivariate analysis showed a negative relationship exists between sonic velocity and effective porosity. The cross plots of these two parameters with uniaxial compressive strength showed a wide range of strength values for samples of low effective porosity and high sonic velocity. Six failure types were identified during the uniaxial compressive strength tests. The strongest samples tended to fail through the matrix and the weakest rock samples tended to fail through haematized material or along haematized veins. Effective porosity and sonic velocity measurements could not distinguish between those samples that failed through the matrix and those that failed along discrete narrow veins. The presence of narrow haematized veins has a major effect on the intact rock strength

Falling head permeability tests on Till deposits from the Vale of Eden, England

This report describes permeability tests carried out on sixteen samples of glacial till obtained from boreholes drilled in the Vale of Eden area in Cumbria, England. The report outlines the testing procedure and presents the results of the permeability tests. Measured permeability values were variable and ranged from 10-5 to 10-10 m/s, Medium Low to Impermeable

Engineering geology of British rocks and soils : Lias Group

The report begins with an introduction and a detailed modern assessment of the geology of the Lias Group in terms of both stratigraphy and lithology. The modern lithostratigraphy is placed in the context of the old, and sometimes more familiar, usage. The next two chapters deal with the mineralogy of a suite of samples collected for the project, and an assessment of the nature and influence of weathering based on a detailed analysis of the Lias dataset held in the BGS National Geotechnical Properties Database. The following chapters cover geohazards associated with the Lias Group, and a brief overview of the wide variety of industrial applications for which the Lias is well known. The geotechnical database forms the basis of the penultimate chapter, geotechnical properties. The contents of the database are analysed, interpreted, presented in graphical form, and discussed in terms of statistical variation and in the light of likely engineering behaviour. The engineering geology of the Lias Group is discussed in the final chapter, borrowing from the preceding chapters. A comprehensive cited reference list and a bibliography are provided. In addition to the large number of technical data provided to BGS, a small data set has been generated by BGS laboratories, particularly in areas where the main database was deficient, and also in connection with associated BGS studies of the swelling and shrinkage properties of the Lias Group. The individual items of data making up the database are not attributed. However, the contribution of a wide range of consultancies, contractors, authorities, and individuals is acknowledged. It is hoped that this report will provide a source of useful information to a wide range of engineers, planners, scientists, and other interested parties concerned with Lias Group materials. It should be noted that whilst quantitative technical data are included in this report, these should not be used as a substitute for proper site investigation

A new apparatus for determining the shrinkage limit of clay soils

A new apparatus for the determination of shrinkage limit is described. Two versions have been produced: a manually operated prototype ‘version1' followed by an automated version named SHRINKiT. Test results using the former for British and overseas clay soils are described and comparisons made with the British Standards preferred method. A further set of test results is described for SHRINKiT. However, it was not possible to compare these with the BS 1377 method owing to the introduction of a ban on the use of mercury in the British Geological Survey's geotechnical laboratories. The new method is set in the context of the huge cost of shrink/swell-related subsidence damage in Britain and the relative disuse of both BS 1377 methods for shrinkage limit, for reasons of safety. The shrinkage behaviour of different soils types and sample states is discussed, in addition to the advantages and disadvantages of the new method

Local scale investigation and advanced modelling of the geo-hazards affecting the Derwent Valley Mills World Heritage Case Study Site : version 1.0

PROTHEGO (PROTection of European Cultural HEritage from GeO-hazards) is a collaborative research project funded in the framework of the Joint Programming Initiative on Cultural Heritage and Global Change (JPICH) – Heritage Plus in 2015–2018. The aim of the PROTHEGO project is to develop and validate an innovative multi-scale methodology for the detection and monitoring of European Cultural Heritages exposed to natural hazards. Work Package 5 (WP5) focussed on the local-scale assessing, monitoring and modelling of geohazards affecting the Derwent Valley, one of the World Heritage List (WHL) site selected during WP4 (D04.02) The analysis conducted used in-situ observation, Interferometric Synthetic Aperture Radar (InSAR) results and flooding simulations based on different climate change scenarios in order to validate the impact of the natural hazards in the Derwent Valley catchment area. The results show that two landslides, in Starkholmes and Ambergate, and flooding, mainly over the west river bank, are the main geohazards affecting the site with the possibility to experience increased geohazards in the coming decades due to changes in climate

Shrinkage limit test results and interpretation for clay soils

The shrinkage limit is one of the Atterberg limits and is a fundamental geotechnical parameter used to assess the settlement of engineering soils containing clays, yet is rarely tested for as part of ground investigation. This paper describes shrinkage limit test results on a variety of soils from Britain and overseas obtained using an improved laboratory testing procedure developed at the British Geological Survey (BGS). The co-relationships with the other Atterberg limits and with density are explored. In particular, the coincidence of the shrinkage limit with the water content at the peak bulk density achieved in the test is examined. The shrinkage behaviour for undisturbed and remoulded states and a 3-way relationship between water content, density and suction are demonstrated. Some tropical residual and highly smectitic soils show a very wide range of shrinkage behaviour, albeit for a small dataset, when compared with the larger dataset of temperate soils tested. Consideration is given to limitations of the new and existing test methods