Establishment of a baseline DEM on the Soufriere Hills Volcano, Montserrat, using terrestrial LiDAR

This report provides the results of a study by the British Geological Survey (BGS). It refers to work carried out on behalf of the Montserrat Volcano Observatory (MVO), under the International Business Development (IBD) and the Physical Hazards Programmes of the BGS. This report details the first phase of work carried out to investigate the nature and instability of the Soufriere Hills Volcano, Montserrat, West Indies. The purpose of the monitoring programme is to provide the best possible information to the MVO to assist in decisions about the long-term management of the current volcanic crisis. This primary aim of the survey was to provide a ‘baseline’ survey, incorporating a terrestrial LiDAR (Light Distance And Ranging) survey of the volcanic crater to allow a future assessment to be made, based on subsequent periodic ‘monitoring’ surveys of any changes in the conditions, in particular, the continued growth of a new lava dome or the potential weakening of the crater walls

Strategy, location and sampling of the Lias Group (2) ground movements : shrink/swell project

The authors published a report in 2002 describing the sampling of argillaceous formations of the Lias Group at twenty-eight sites in South Wales, Eastern and Southern England. This report forms an addendum to the original report and describes the sampling of further Liassic formations in the counties of Nottinghamshire and Lincolnshire. Weathered and unweathered material was collected as undisturbed block samples and disturbed bulk samples from exposed faces. The samples were taken to give representative geotechnical properties of the lithostratigraphic formations of the Lias Group present at the sampling sites in a weathered and unweathered condition, if possible. The location of each site is described briefly and is indicated on a 1:50K OS map base. The stratigraphic units present at the site are listed and the site indicated on a 1:50K geological map base. Photographs of sections and sampling sites are also present. The types of samples taken from each site are specified and difficulties regarding the sampling are indicated where appropriate

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

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

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

Coulomb Effect: A Possible Probe for the Evolution of Hadronic Matter

Electromagnetic field produced in high-energy heavy-ion collisions contains much useful information, because the field can be directly related to the motion of the matter in the whole stage of the reaction. One can divide the total electromagnetic field into three parts, i.e., the contributions from the incident nuclei, non-participating nucleons and charged fluid, the latter consisting of strongly interacting hadrons or quarks. Parametrizing the space-time evolution of the charged fluid based on hydrodynamic model, we study the development of the electromagnetic field which accompanies the high-energy heavy-ion collisions. We found that the incident nuclei bring a rather strong electromagnetic field to the interaction region of hadrons or quarks over a few fm after the collision. On the other hand, the observed charged hadrons' spectra are mostly affected (Coulomb effect) by the field of the charged fluid. We compare the result of our model with experimental data and found that the model reproduces them well. The pion yield ratio pi^-/pi+ at a RHIC energy, Au+Au 100+100 GeV/nucleon, is also predicted.Comment: 23 pages, RevTex, 19 eps figures, revised versio

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

H I ABSORPTION TOWARD H II REGIONS AT SMALL GALACTIC LONGITUDES

We make a comprehensive study of H I absorption toward H II regions located within |l| < 10°. Structures in the extreme inner Galaxy are traced using the longitude-velocity space distribution of this absorption. We find significant H I absorption associated with the Near and Far 3 kpc Arms, the Connecting Arm, Bania's Clump 1, and the H I Tilted Disk. We also constrain the line-of-sight distances to H II regions, by using H I absorption spectra together with the H II region velocities measured by radio recombination lines

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

Modelling of Weibull distributions in brittle solids using 2-dimensional peridynamics

Peridynamics is a continuum mechanics modelling method, which offers advantages over traditional continuum methods when modelling brittle fracture. Brittle fracture typically follows a Weibull fracture distribution, but this behaviour is not well represented in bond-based peridynamics using a single valued bond failure stretch. In order to recreate specific Weibull-type behaviour in bond-based peridynamics, consideration must be given to scaling the distribution to account for the size of peridynamics bonds. Care must also be taken to avoid (wherever possible) non-physical crack arrest, caused by the variations in fracture toughness in the model, distorting the distributions. In this work a method for recreating a variety of Weibull distributions is outlined, based on applying Weibull-type bond behaviour only to surface bonds, including a transition zone across one horizon. The method is shown to be insensitive to variations in mesh refinement