119 results on '"Cuss, R.J."'
Search Results
2. The JAC airborne EM system: AEM-05
- Author
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Leväniemi, H., Beamish, D., Hautaniemi, H., Kurimo, M., Suppala, I., Vironmäki, J., Cuss, R.J., Lahti, M., and Tartaras, E.
- Published
- 2009
- Full Text
- View/download PDF
Catalog
3. The application of critical state soil mechanics to the mechanical behaviour of porous sandstones
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Cuss, R.J., Rutter, E.H., and Holloway, R.F.
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- 2003
- Full Text
- View/download PDF
4. Experimental observations of the mechanics of borehole failure in porous sandstone
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Cuss, R.J., Rutter, E.H., and Holloway, R.F.
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- 2003
- Full Text
- View/download PDF
5. Gas network development in compact bentonite: key controls on the stability of flow pathways
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Harrington, J.F., Graham, C.C., Cuss, R.J., Norris, S., Harrington, J.F., Graham, C.C., Cuss, R.J., and Norris, S.
- Abstract
Compacted bentonite is proposed as an engineered barrier material within facilities for the geological disposal of radioactive waste. Barrier performance and its interaction with a free gas phase must be considered as part of sound repository design. This study involved the long-term experimental examination of gas flow in precompacted bentonite, with particular consideration of gas network stability. Results demonstrate that the stress field experienced by the clay is strongly coupled with gas flow. For the first time, three controls on this behaviour are considered: (i) injection flow rate, (ii) constant vs. variable gas pressure, and (iii) stimulation of the microfracture network. A detailed stress analysis is used to examine changes in the gas flow network. The results indicate a degree of metastability despite these changes, except in the case of stimulation of the microfracture network by removal of the primary drainage route. In this case, a rapid redevelopment of the gas flow network was observed. As such, availability of drainage pathways will represent a key control on the generation of peak gas pressures and distribution of gas within the engineered barrier. The cessation of gas flow is shown to result in crack closure and self-sealing. Observations from this study highlight that characterisation of the gas network distribution is of fundamental importance in predicting gas dissipation rates and understanding the long-term fate of gas in radioactive waste repositories. more...
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- 2019
6. CONTAIN D11 : integrated final results and conclusions
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Harrington, J.F., Graham, C.C., Dobbs, M., Cuss, R.J., Daniels, K.A., Wiseall, A.C., Parkes, D., Paluszny, A., Zimmerman, R.W., Salimzadeh, S., Tsaparli, V., Tempone, P., Thomas, R.N., Xenias, D., Whitmarsh, L., Harrington, J.F., Graham, C.C., Dobbs, M., Cuss, R.J., Daniels, K.A., Wiseall, A.C., Parkes, D., Paluszny, A., Zimmerman, R.W., Salimzadeh, S., Tsaparli, V., Tempone, P., Thomas, R.N., Xenias, D., and Whitmarsh, L. more...
- Abstract
Carbon capture and storage is a technology capable of reducing CO2 outputs on a large scale; the concept usually requires CO2 to be removed from post-combustion flue gases and sequestered in geological formations. Depleted gas fields constitute “the most important storage type for the UK” and will provide a large and important potential future offshore storage capacity (DECC, 2012). Over the last 4 years, the CONTAIN research project has focussed on the geomechanical behaviour of depleted hydrocarbon fields in response to injection with CO2, combining a modelling and experimental approach with the public perceptions of CCS into three work packages. The project has provided a better understanding of the hydromechanical impacts of depletion on caprocks and the effect of subsequent CO2 injection, in order to assist with the implementation of CCS in this type of reservoir. Work package 1 outlined a phenomenological approach to assessing possible deformation during operation. Focus was placed on rock mechanics and transport experiments on material from the geologies of target formations in the North Sea, providing information that could be incorporated into numerical simulations. Work package 2 expanded this understanding by considering fractured caprock. Numerical modelling was used to study the deformation of an initially intact caprock caused by the depletion of an underlying reservoir during oil extraction. Deformation and flow were geomechanically modelled in three dimensions using a fully coupled poroelastic model, incorporating discrete fractures and faults into the caprock. Work package 3 offered new and valuable insight on future public awareness campaigns aimed at gaining acceptance of CCS. Qualitative expert interviews have been used, a CCS expert survey and a public survey across four countries to gain an understanding of perceptions of CCS risks and benefits, and has allowed for comparison of views on CCS between experts and public. In addition, the work pac more...
- Published
- 2018
7. The response of compact bentonite during a 1-D gas flow test
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Cuss, R.J., Daniels, K.A., Harrington, J.F., Cuss, R.J., Daniels, K.A., and Harrington, J.F.
- Abstract
This report describes the results of a 1-D gas injection test on compact Mx80 bentonite. The test comprises the first dataset for Stage 1A of Task A of the DECOVALEX-2019 programme, which has been designed to improve our understanding of the migration of repository gases through clay-based materials. Over the duration of the testing period, pressurised helium gas was applied to the face of the injection end of the clay sample, and the gas pressure was increased until the entry pressure was exceeded and gas entered the sample. The gas then migrated through the clay and changes in porewater pressure, swelling pressure and flowrate were observed by the instrumentation around the sample. Gas breakthrough occurred as outflow was recorded by the backpressure pump that corresponded with the changes in pressure. The data presented in this study shows that dynamic processes operate within the clay causing differing responses to be recorded on the monitoring instruments. The recorded response of the clay highlights the spatial and temporal development of permeability within the clay sample over the duration of the test. more...
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- 2017
8. Scoping study examining the behaviour of Boom Clay at disposal depths investigated in OPERA
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Harrington, J.F., Cuss, R.J., Wiseall, A.C., Daniels, K.A., Graham, C.C., Tamayo-Mas, E., Harrington, J.F., Cuss, R.J., Wiseall, A.C., Daniels, K.A., Graham, C.C., and Tamayo-Mas, E.
- Abstract
The Onderzoeks Programma Eindberging Radioactief Afval (OPERA) is the third national research programme for the geological disposal of radioactive waste in the Netherlands, operating during the period 2011 to 2017. The rock types to host a geological disposal facility that are currently being considered in the Netherlands are salt and clay. Earlier Dutch work focussed mostly on salt, but the present programme OPERA is focused on a specific clay formation the Boom Clay. Previous studies have primarily focused on examining behaviour at the Belgium reference depth (~220m). The work presented in this study extends this knowledge-base to repository depths of potential interest in the Netherlands (~500m). In this report, results from a scoping study examining the hydromechanical properties of Boom Clay are presented, including investigations on consolidation, swelling, hydraulic, gas and deformation behaviour. These were performed on preserved core material retrieved from the HADES underground research laboratory, Belgium. Sections of core were then consolidated to a depth representative of the Netherlands. Permeability was sensitive to stress state and thermal load, though incremental changes in NaCl concentration had minimal impact. Hysteresis was observed in thermally induced changes in permeability. Gas entry was closely linked to the minimum principal stress component, with mass and volume changes of samples observed as a result of gas migration. Stress, porewater pressure and gas flow were integrally linked with pathways evolving temporally and spatially. A transition from brittle to ductile deformation was noted with increasing stress in both compression and shear. Boom Clay is both complex and anisotropic in its behaviour. more...
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- 2017
9. Onshore carboniferous basins : third review report
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Hough, E., Bateman, K., Cuss, R.J., Harrington, J.F., Haslam, R.B., Hennissen, J.A., Hobbs, P.R.N., Kilpatrick, A.D., Moss-Hayes, V., Purser, G., Selby, L., Vane, C.H., Waters, C.H., Hough, E., Bateman, K., Cuss, R.J., Harrington, J.F., Haslam, R.B., Hennissen, J.A., Hobbs, P.R.N., Kilpatrick, A.D., Moss-Hayes, V., Purser, G., Selby, L., Vane, C.H., and Waters, C.H. more...
- Abstract
focussed on achieving a better understanding of the Bowland Shale in northern England. The broad aim is to understand the geological variability of the formation from a basin- through to microscale, and assess the impact of variability on hydrocarbon generation, storage and production (for example, the co-incidence or otherwise of factors including organic content and kerogen type; mineralogy; and engineering behaviour). This report is the third summary report describing activities of the consortium, covering the period October 2015 – June 2016. A series of 3 inter-related work packages are designed to improve understanding of the Bowland Shale of northern England. The original numbering of these is retained to allow continuity between previous progress reports. Specifically, these work packages address: 1. Work Package 1,2: Basin analysis of the Pennine Basin; Characterization of shale facies; 2. Work Package 3: Development of chemical stratigraphies through prospective parts of the stratigraphic column; 3. Work Package 4: Hydromechanical behaviour of shales. Two work packages outside the consortium are also considered, namely 4. Retrieval of new materials to test 5. Reprocessing of 3D seismic data to assess rock properties Descriptions of previous activities have been released, covering the period July 2014 to March 2015 (Hough et al., 2015a), and the period April 2015 to September 2015 (Hough et al., 2015b). The consortium currently has 4 sponsors who each contribute £25 000 per year; BGS contributes around £200 000 annually, which results in an annual budget of approximately £300 000. The consortium is planned to last 3 years initially, and started in July 2014 with a scheduled end date of June 2017. more...
- Published
- 2016
10. Cyclic loading of an idealized clay-filled fault: comparing hydraulic flow in two clay gouges
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Cuss, R.J., Graham, C.C., Wiseall, A.C., Harrington, J.F., Cuss, R.J., Graham, C.C., Wiseall, A.C., and Harrington, J.F.
- Abstract
The flow of water along discontinuities, such as fractures or faults, is of paramount importance in understanding the hydrogeology of many geological settings. An experimental study was undertaken comprising two experiments on a 30° slip-plane filled with kaolinite or Ball Clay gouge using a bespoke Angled Shear Rig (ASR). The gouge was initially loaded in equal step changes in vertical stress, followed by unloading of the sample in similar equal steps. This was followed by reloading to a new maximum stress, followed by unloading; the test history was therefore load-unload-reload-unload (LURU). The transmissivity of the kaolinite and Ball Clay gouge showed a power-law relationship with vertical stress. The LURU history showed considerable hysteresis, with flow effectively unchanged during unloading, even when vertical stress was close to zero. Reloading resulted in flow similar to that seen during unloading suggesting that the unloading-reloading path is similar to the rebound-reconsolidation line in classic soil mechanics. These observations show the importance of stress history on fracture flow; consideration of just the current stress acting upon a fracture may result in inaccuracies of predicted hydraulic flow. Once a new stress maximum was achieved the transmissivity of the fracture continued to reduce. No significant variation was seen in the flow response of kaolinite and Ball Clay gouge suggesting that the inclusion of illite and quartz did not have a significant influence on the form of the relationship between stress and flow, i.e. both described by a power-law. more...
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- 2016
11. Information contained within the large scale gas injection test (Lasgit) dataset exposed using a bespoke data analysis toolkit
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Bennett, D.P., Cuss, R.J., Vardon, P.J., Harrington, J.F., and Thomas, H.R.
- Published
- 2012
12. Gas migration experiments in bentonite: implications for numerical modelling
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Graham, C.C., Harrington, J.F., Cuss, R.J., Sellin, P., and Evans, Nicholas
- Abstract
In the Swedish KBS-3 repository concept, there is potential for gas to be generated from corrosion of ferrous materials under anoxic conditions, combined with the radioactive decay of the waste and radiolysis of water. A full understanding of the probable behaviour of this gas phase within the engineered barrier system (EBS) is therefore required for performance assessment. We demonstrate key features from gas transport experiments on pre-compacted Mx80 bentonite, under laboratory and field conditions, and discuss their implications in terms of a conceptual model for gas migration behaviour. On both scales, major gas entry is seen to occur close to the sum of the porewater and swelling pressures of the bentonite. In addition, gas pressure at breakthrough is profoundly sensitive to the number and location of available sinks for gas escape. Observations of breakthrough can be explained by the creation of dilatational pathways, resulting in localized changes in the monitored porewater pressures and total stresses. These pathways are highly unstable, evolving spatially and temporally, and must consequently influence the gas permeability as their distribution/geometry develops. more...
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- 2012
13. The role of stress history on the flow of fluids through fractures
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Sathar, S., Reeves, H., Cuss, R.J., Harrington, J.F., and Evans, Nicholas
- Abstract
Understanding flow along fractures and faults is of importance to the performance assessment (PA) of a geological disposal facility (GDF) for radioactive waste. Flow can occur along pre-existing fractures in the host-rock or along fractures created during the construction of the GDF within the excavation damage zone (EDZ). The complex fracture network will have a range of orientations and will exist within a complex stress regime. Critical stress theory suggests that fractures close to localized shear failure are critically stressed and therefore most conductive to fluid flow. Analysis of fault geometry and stress conditions at Sellafield has revealed that no features were found to be, or even close to being, classified as critically stressed, despite some being conductive. In order to understand the underlying reasons why non-critically stressed fractures were conductive a series of laboratory experiments were performed. A bespoke angled shear rig (ASR) was built in order to study the relationship between fluid flow (water and gas) through a fracture surface as a function of normal load. Fluid flow reduced with an increase in normal load, as expected. During unloading considerable hysteresis was seen in flow and shear stress. Fracture flow was only partially recovered for water injection, whereas gas flow increased remarkably during unloading. The ratio of shear stress to normal stress seems to control the fluid flow properties during the unloading stage of the experiment demonstrating its significance in fracture flow. The exhumation of the Sellafield area during the Palaeogene–Neogene resulted in considerable stress relaxation and in fractures becoming non-critically stressed. The hysteresis in shear stress during uplift has resulted in faults remaining, or becoming, conductive. The field and laboratory observations illustrate that understanding the stress-history of a fractured rock mass is essential, and a mere understanding of the current stress regime is insufficient to estimate the flow characteristics of present-day fractures. more...
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- 2012
14. Observations of heterogeneous pore pressure distributions in clay-rich materials
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Cuss, R.J., Harrington, J.F., Graham, C.C., Sathar, S., and Milodowski, A.E.
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The concept of effective stress is one of the basic tenets of rock mechanics where the stress acting on a rock can be viewed as the total stress minus the pore water pressure. In many materials, including clay-rich rocks, this relationship has been seen to be imperfect and a coefficient (χ) is added to account for the mechanical properties of the clay matrix. Recent experimental results during the flow testing (both gas and water) of several rocks (Callovo-Oxfordian claystone, Opalinus Clay, Boom Clay) and geomaterials (bentonite, kaolinite) has given evidence for stable high pressure differentials. The design of the experiments allows multiple measurements of pore pressure, which commonly shows a complex distribution for several different experimental geometries. The observed stable high pressure differentials and heterogeneous pore pressure distribution makes the describing of stress states in terms of effective stress complex. Highly localized pore pressures can be sustained by argillaceous materials and concepts of evenly distributed pore pressures throughout the sample (i.e. conventional effective stress) do not fit many clay-rich rocks if the complexities observed on the micro-scale are not incorporated, especially when considering the case of gas flow. more...
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- 2012
15. Data analysis toolkit for long-term, large-scale experiments
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Bennett, D.P., Cuss, R.J., Vardon, P.J., Harrington, J.F., Philp, R.N., and Thomas, H.R.
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A new data analysis toolkit which is suitable for the analysis of large-scale, long-term datasets and the phenomenon/anomalies they represent is described. The toolkit aims to expose and quantify scientific information in a number of forms contained within a time-series based dataset in a quantitative and rigorous manner, reducing the subjectivity of observations made, thereby supporting the scientific observer. The features contained within the toolkit include the ability to handle non-uniform datasets, time-series component determination, frequency component determination, feature/event detection and characterization/parameterization of local behaviours. An application is presented of a case study dataset arising from the ‘Lasgit’ experiment. more...
- Published
- 2012
16. Hydraulic fracturing: a review of theory and field experience
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Cuss, R.J., Wiseall, A.C., Hennissen, J.A.I., Waters, C.N., Kemp, S.J., Ougier-Simonin, A., Holyoake, S., Haslam, R.B., Cuss, R.J., Wiseall, A.C., Hennissen, J.A.I., Waters, C.N., Kemp, S.J., Ougier-Simonin, A., Holyoake, S., and Haslam, R.B. more...
- Abstract
This report summarises the current state-of-the-art knowledge of the hydraulic fracturing process used by the shale gas/oil industry using open peer-reviewed literature and from government commissioned research reports. This report has been written to make statements on our knowledge of the following questions: • How do hydrofractures form? • How far do hydrofractures extend during stimulation? • What dictates where hydrofractures propagate? • How do hydrofractures interact with the existing fracture network? • Can the size and distribution of hydrofractures be controlled? Gaps in our knowledge have been highlighted, with the largest of these resulting from differences between North American and European shale rocks. more...
- Published
- 2015
17. Exploratory data analysis of the Large Scale Gas Injection Test (Lasgit) dataset, focusing on 'second-order' events around macro-scale gas flows
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Shaw, R.P., Bennett, D.P., Cuss, R.J., Vardon, P.J., Harrington, J.F., Sedighi, M., Thomas, H.R., Shaw, R.P., Bennett, D.P., Cuss, R.J., Vardon, P.J., Harrington, J.F., Sedighi, M., and Thomas, H.R.
- Abstract
The Large Scale Gas Injection Test (Lasgit) is a field-scale experiment designed to study the impact of gas build-up and subsequent migration through an engineered barrier system (EBS). Lasgit has a substantial experimental dataset containing in excess of 26 million datum points. The dataset is anticipated to contain a wealth of information, ranging from long-term trends and system behaviours to small-scale or ‘second-order’ features. In order to interrogate the Lasgit dataset, a bespoke computational toolkit, designed to expose and quantify difficult to observe phenomena in large, non-uniform datasets, has been developed and applied. Presented results focus on the investigation and interpretation of second-order events occurring in close proximity (temporally and spatially) to a known macro-scale gas flow event that occurred during the second gas injection test. The similarity of the investigated event to dilatant flow observed in laboratory experiments is noted, as is the evidence for localized flow pathways in the bentonite EBS. The sensitivity of the toolkit's ability to highlight second-order events is also evaluated. more...
- Published
- 2015
18. The visualization of flow paths in experimental studies of clay-rich materials
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Wiseall, A.C., Cuss, R.J., Graham, C.C., Harrington, J.F., Wiseall, A.C., Cuss, R.J., Graham, C.C., and Harrington, J.F.
- Abstract
One of the most challenging aspects of understanding the flow of gas and water during testing in clay-rich low-permeability materials is the difficulty in visualizing localized flow. Whilst understanding has been increased using X-ray Computed-tomography (CT) scanning, synchrotron X-ray imaging and Nuclear Magnetic Resonance (NMR) imaging, real-time testing is problematic under realistic in situ conditions confining pressures, which require steel pressure vessels. These methods tend not to have the nano-metre scale resolution necessary for clay mineral visualization, and are generally not compatible with the long duration necessary to investigate flow in such materials. Therefore other methods are necessary to visualize flow paths during post-mortem analysis of test samples. Several methodologies have been established at the British Geological Survey (BGS), in order to visualize flow paths both directly and indirectly. These include: (1) the injection of fluorescein-stained water or deuterium oxide; (2) the introduction of nano-particles that are transported by carrier gas; (3) the use of radiologically tagged gas; and (4) the development of apparatus for the direct visualization of clay. These methodologies have greatly increased our understanding of the transport of water and gas through intact and fractured clay-rich materials. The body of evidence for gas transport through the formation of dilatant pathways is now considerable. This study presents observations using a new apparatus to directly visualize the flow of gas in a kaolinite paste. The results presented provide an insight into the flow of gas in clay-rich rocks. The flow of gas through dilatant pathways has been shown in a number of argillaceous materials (Angeli et al., 2009; Autio et al., 2006; Cuss et al., 2014; Harrington et al., 2012). These pathways are pressure induced and an increase in gas pressure leads to the dilation of pathways. Once the gas breakthrough occurs, pressure decreases and pathw more...
- Published
- 2015
19. Experimental Observations of the Flow of Water and Gas along Fractures in Shales and Clay Gouge
- Author
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Cuss, R.J., primary, Harrington, J.F., additional, Graham, C.C., additional, and Graham, A.C., additional
- Published
- 2015
- Full Text
- View/download PDF
20. Phenomena exposure from the large scale gas injection test (Lasgit) dataset using a bespoke data analysis toolkit
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Norris, S., Bennett, D.P., Cuss, R.J., Vardon, P.J., Harrington, J.F., Thomas, H.R., Norris, S., Bennett, D.P., Cuss, R.J., Vardon, P.J., Harrington, J.F., and Thomas, H.R.
- Abstract
The Large Scale Gas Injection Test (Lasgit) is a field-scale experiment designed to study the impact of gas buildup and subsequent migration through an engineered barrier system. Lasgit has a substantial experimental dataset containing in excess of 21 million datum points. The dataset is anticipated to contain a wealth of information, ranging from long-term trends and system behaviours to small-scale or ‘second-order’ features. In order to interrogate the Lasgit dataset, a bespoke computational toolkit, designed to expose difficult to observe phenomena, has been developed and applied to the dataset. The preliminary application of the toolkit, presented here, has resulted in a large number of phenomena being indicated/quantified, including highlighting of second-order events (small gas flows, perturbations in stress/pore-water sensors, etc.) and quantification of temperature record frequency content. Localized system behaviour has been shown to occur along with systematic aberrant behaviours that remain unexplained. more...
- Published
- 2014
21. Pore-pressure cycling experiments on Mx80 bentonite
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Norris, S., Graham, C.C., Harrington, J.F., Cuss, R.J., Sellin, P., Norris, S., Graham, C.C., Harrington, J.F., Cuss, R.J., and Sellin, P.
- Abstract
The Swedish concept for geological disposal of radioactive waste involves the use of bentonite as part of an engineered barrier system. A primary function of the bentonite is its ability to swell when hydrated by its surroundings. One particular uncertainty is the impact on this function, resulting from deviations in pore-water pressure, pw, from expected in situ hydrostatic conditions. We present results from a series of laboratory experiments designed to investigate the form of the relationship between swelling pressure and pw, for compacted Mx80 bentonite, from low to elevated applied water pressure conditions. The experiments were conducted using constant volume cells, designed to allow the total stresses acting on the surrounding vessel to be monitored (at five locations) during clay swelling. The results demonstrate that swelling pressure reduces nonlinearly with increasing pw, becoming less sensitive to changes at elevated pressures. After cyclic loading a marked hysteresis was also observed, with swelling pressure remaining elevated after a subsequent reduction in applied water pressure. Such behaviour may impact the mechanical and transport properties of the bentonite and its resulting performance. However, such hysteric behaviour was not always observed. Further testing is required to better understand the causes of this phenomenon and the controls on such behaviour. more...
- Published
- 2014
22. Evidence of localised gas propagation pathways in a field-scale bentonite engineered barrier system: results from three gas injection tests in the large scale gas injection test (Lasgit)
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Cuss, R.J., Harrington, J.F., Noy, D.J., Graham, C.C., Sellin, P., Cuss, R.J., Harrington, J.F., Noy, D.J., Graham, C.C., and Sellin, P.
- Abstract
Three gas injection tests have been conducted during a large scale gas injection test (Lasgit) performed at the Äspö Hard Rock Laboratory, Sweden. Lasgit is a full-scale experiment based on the Swedish KBS-3 repository concept, examining the processes controlling gas and water flow in highly water-saturated compact buffer bentonite. Three preliminary gas injection tests have been performed. The first two tests were conducted in the lower array of injection filters (FL903). Both of these tests showed similar behaviour that corresponded with laboratory observations. The third gas test was conducted in an upper array filter (FU910), which gave a subtly dissimilar response at major gas entry with an initial pressure drop followed by a secondary gas peak pressure. Lasgit has confirmed the coupling between gas, stress and pore-water pressure for flow before and after major gas entry at the field scale. All observations suggest mechanisms of pathway propagation and dilatancy predominate. In all three gas tests the propagation was through localised features that tended to exploit the interface between the copper canister and the bentonite buffer. Considerable evidence exists for the development of a highly-dynamic, tortuous network of pressure induced pathways which evolves both temporally and geospatially within the clay, opening and closing probably due to local changes in gas pressure and or effective stress. more...
- Published
- 2014
23. Eye in the sky : locating and mapping potential environmental hazards in the UK with high resolution airborne geophysics
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Peart, R.J., Cuss, R.J., Beamish, D., and Jones, D.G.
- Subjects
Earth Sciences - Abstract
During the past fifteen years environmental scientists have applied airborne geophysical techniques increasingly to the mapping and monitoring of potential environmental hazards such as leakages from landfill sites, the spread of polluted groundwaters and the distribution of possibly harmful natural and artificial radionuclides. Explorationists first applied these techniques more than 60 years ago, initially for metallic mineral exploration in Shield areas with subsequent developments in non-geological applications such as the detection of enemy submarines. In later years the techniques have been improved and also applied to hydrocarbon exploration and geological and structural mapping. The rapid emergence of airborne techniques in environmental studies is a response to high profile nuclear accidents, increasingly stringent environmental legislation, the desire of many large corporations for a green image and the numerous benefits delivered by airborne techniques. These latter include relative ease of access to ‘difficult’ sites, comprehensive data coverage and remote, rapid and non-invasive acquisition of data which in turn informs highly focussed confirmatory ground follow up activities. All of these advantages are especially important in potentially hazardous sites. The success of the airborne techniques results from the use of highly sensitive equipment combined with close flight line spacing, generally low ground clearance and accurate navigation and post survey data location based on differential GPS. In this paper we use data from two recent high resolution airborne geophysical surveys in the UK to show how a broad range of environmental management issues can be addressed. In future volumes further contributions will describe the applications of these airborne data sets to resource exploration and geological and structural mapping. more...
- Published
- 2003
24. Final Report of FORGE WP4.1.2: verification of critical stress theory applied to repository concepts
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Cuss, R.J., Sathar, S., Harrington, J.F., Cuss, R.J., Sathar, S., and Harrington, J.F.
- Abstract
This report describes an experimental study of 48 separate experiments examining the validity of critical stress theory. Two main types of experiment were conducted: 1). Loading-unloading tests, where fracture flow was monitored at constant injection pressure as normal load was increased in steps to a given level and then reduced back to the starting stress state; 2). Gas breakthrough experiments, where gas injection pressure was increased in a pressure ramp at constant vertical load. These were conducted with and without active shear. It was found that critical stress theory is valid in predicting the preferential flow of gas in relation to the orientation of the fracture plane with respect to the maximum horizontal stress direction. However, loading unloading experiments showed that understanding the stress history of the rocks is of paramount importance and a mere knowledge of the current stress state is insufficient in accurately predicting the nature of fluid flow. A total of 17 loading-unloading experiments were conducted, all on a 30° slip-plane. The main conclusions of this part of the study were; a). During a loading (vertical stress) and unloading cycle considerable hysteresis in flow was observed signifying the importance of stress history on fracture flow; b). For the case of gas injection the change in flow is chaotic at low normal loads, whereas for water injection the flow reduces smoothly with increased normal load; c). Hysteresis in horizontal stress observed during unloading demonstrates the importance of the ratio between horizontal stress and vertical stress and its control on flow; d). Differences have been observed between injection fluids (water and helium), especially the hysteresis observed in flow. For water injection flow is only partially recovered during unloading, whereas for gas enhanced flow is seen at low normal loads. A total of 26 gas breakthrough experiments were conducted on 0°, 15°, 30°, and 45° discontinuities; both with and wi more...
- Published
- 2013
25. Information contained within the large scale gas injection test (Lasgit) dataset exposed using a bespoke data analysis toolkit
- Author
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Bennett, D.P. (author), Cuss, R.J. (author), Vardon, P.J. (author), Harrington, J.F. (author), Thomas, H.R. (author), Bennett, D.P. (author), Cuss, R.J. (author), Vardon, P.J. (author), Harrington, J.F. (author), and Thomas, H.R. (author) more...
- Abstract
Geoscience & Engineering, Civil Engineering and Geosciences
- Published
- 2012
26. Final report of FORGE WP3.1.1: the large scale gas injection test (Lasgit) performed at the Äspö Hard Rock Laboratory
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Cuss, R.J., Harrington, J.F., Noy, D.J., Graham, C.C., Cuss, R.J., Harrington, J.F., Noy, D.J., and Graham, C.C.
- Abstract
This report summarises the set-up, operation and observations from the first 2890 days (7.9 years) of the large scale gas injection test (Lasgit) experiment conducted at the Äspö Hard Rock Laboratory. During this time the bentonite buffer has been artificially hydrated and has given new insight into the evolution of the buffer. Three gas injection tests have been conducted during the duration of Lasgit. The first two tests were conducted in the lower array of injection filters at FL903. Both of these tests showed similar behaviour with a well-defined pressure peak; spontaneous negative transient; evidence of dynamic behaviour and unstable gas pathways; asymptote close to stress. The results were remarkably qualitatively similar to the laboratory test results. However, the high gas entry pressures seen in the laboratory were not seen in Lasgit as stress state is much lower due to non-complete hydration of the buffer and the expansion of the buffer to fill construction voids. The third gas test was conducted in an upper array filter (FU910). The response at the time of gas peak pressure was subtly dissimilar to that seen at FL903 with two peak pressures. Lasgit has confirmed the coupling between gas, stress and pore-water pressure for flow before and after major gas entry at the field scale. All observations suggest mechanisms of pathway propagation and dilatancy predominate. In all three gas tests the propagation was through localised features and the general movement direction was towards the bottom of the deposition hole in the direction of the prevailing stress gradient. The injection tests have shown that the interface between barriers is a key part of the system. Gas appears to have exited the deposition hole in Gas test 2, but failed to find a way out during Gas test 3; where gas continued to migrate along the canister/buffer interface. Throughout the history of Lasgit parts of the system have been artificially and naturally hydrated. Hydraulic results, from co more...
- Published
- 2012
27. Summary Report of FORGE WP4.1.2: verification of critical stress theory applied to repository concepts
- Author
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Cuss, R.J., Harrington, J.F., Sathar, S., Reeves, H.J., Cuss, R.J., Harrington, J.F., Sathar, S., and Reeves, H.J.
- Abstract
This report outlines the major conclusions from an experimental study of 48 separate experiments with the primary aim to verify critical stress theory. Two main types of experiment were conducted: 1). Loading-unloading tests, where fracture flow was monitored at constant injection pressure as normal load was increased in steps to a given level and then reduced back to the starting stress state; 2). Gas breakthrough experiments, where gas injection pressure was increased in a pressure ramp at constant vertical load. These were conducted with and without active shear. It was found that critical stress theory is valid in predicting the preferential flow of gas in relation to the orientation of the fracture plane with respect to the maximum horizontal stress direction. However, loading unloading experiments showed that understanding the stress history of the rocks is of paramount importance and a mere knowledge of the current stress state is insufficient in accurately predicting the nature of fluid flow. more...
- Published
- 2012
28. Final report of FORGE WP4.1.1: the stress-path permeameter experiment conducted on Callovo-Oxfordian Claystone
- Author
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Cuss, R.J., Harrington, J.F., Noy, D.J., Cuss, R.J., Harrington, J.F., and Noy, D.J.
- Abstract
This report describes in detail the stress-path permeameter (SPP) apparatus and the test programme conducted on Callovo-Oxfordian (COx) Claystone from the Bure underground research laboratory (URL) in France. Funding for this study has been provided by the French radioactive waste management operator, Andra, the European Union (FORGE Project, Project number 230357) and the British Geological Survey through its well-founded laboratory programme and the Geosphere Containment project (part of the BGS core strategic programme). The results from the first test conducted using the SPP showed that COx has a very pronounced time-dependent component of deformation. This had implications for the following test conducted on COx and also has implications when comparing tests that have been deformed at a much faster rate. Test SPP_COx-1 was conducted with water as a test permeant at constant pore-pressure along a pre-defined stress-path. Volumetric deformation was observed during 16 steps along the stress-path, with considerable time-dependent deformation and anisotropy seen in radial strain. The 16th stage saw the sample fail through the formation of a fracture after the sample had experienced constant stress conditions for 5.5 days; this emphasises the observed time dependent deformation. The results from test SPP_COx-2 clearly showed that the sample dilated at the onset of gas propagation; dilatancy was observed in three radial and one axial direction. A component of this volumetric deformation was associated with changes in pore-pressure. However, pore-pressure variation cannot account for the full amount of strain recorded and a proportion of the strain observed was the result of gas migration by dilatant pathway formation. Prior to the sample attaining steady-state flow, outflow from the sample slowly reduced and the conductive features experienced self-sealing. Gas injection pressure was raised and back-pressure was carefully lowered; neither course of action re-initiated more...
- Published
- 2012
29. Gas flow in Callovo-Oxfordian claystone (COx): results from laboratory and field-scale measurements
- Author
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Harrington, J.F., de la Vaissiere, R., Noy, D.J., Cuss, R.J., Talandier, J., Harrington, J.F., de la Vaissiere, R., Noy, D.J., Cuss, R.J., and Talandier, J.
- Abstract
To understand the fate and impact of gas produced within a repository for radioactive waste, a series of laboratory and field scale experiments have been performed on the Callovo-Oxfordian claystone (COx), the proposed host rock for the French repository. Results show the movement of gas is through a localized network of pathways, whose properties vary temporarily and spatially within the claystone. Significant evidence exists from detailed laboratory studies for the movement of gas along highly unstable pathways, whose aperture and geometry vary as a function of local stress, gas and porewater pressures. The coupling of these parameters results in the development of significant time-dependent effects, impacting on all aspects of COx behaviour, from gas breakthrough time, to the control of deformation processes. Variations in gas entry, breakthrough and steady-state pressures are indicative of microstructural heterogeneity which exerts an important control on the movement of gas. The localization of gas flow is also evident in preliminary results from the large scale gas injection test (PGZ) where gas flow is initially focussed within the excavation damaged zone (EDZ), which acts as a preferential pathway for gas. Numerical models based on conventional two-phase flow theory are unable to adequately describe the detailed observations from laboratory tests. more...
- Published
- 2012
30. Evidence for gas-induced pathways in clay using a nanoparticle injection technique
- Author
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Harrington, J.F., Milodowski, A.E., Graham, C.C., Rushton, J.C., Cuss, R.J., Harrington, J.F., Milodowski, A.E., Graham, C.C., Rushton, J.C., and Cuss, R.J.
- Abstract
Corrosion, water radiolysis and microbial degradation will result in the generation of gas within repositories designed for the geological disposal of high-level radioactive waste. It is therefore crucial in the design of such facilities that the relevant mechanisms allowing gas migration through repository materials, both engineered barriers and clay-based candidate host rocks, are correctly identified. In Belgium, the Boom Clay represents a candidate host material for which the advective gas breakthrough characteristics and transport properties have been extensively tested and are well defined by numerous studies. The Boom Clay displays a significant capacity for self-sealing and both laboratory and field tests indicate that advective gas transport occurs not by visco-capillary flow, but instead through the formation of pressure-induced dilatant pathways. In this study, we present results from a gas injection test designed to demonstrate the presence of these features by injecting nanoparticulate tracers with helium gas into a sample of Boom Clay. The results provide conclusive evidence for the formation of transient, dilatant gas pathways within a candidate clay-based host rock. This technique provides a novel diagnostic tool for the identification of processes governing multi-phase flow, supporting robust long-term assessments of repository performance. more...
- Published
- 2012
31. Update on dilatancy associated with onset of gas flow in Callovo-Oxfordian claystone. Progress report on test SPP_COx-2
- Author
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Cuss, R.J., Harrington, J.F., Cuss, R.J., and Harrington, J.F.
- Abstract
This report describes in detail the stress-path permeameter (SPP) apparatus and the on-going second test conducted on Callovo-Oxfordian (COx) claystone from the Bure underground research laboratory (URL) in France. Funding for this study has been provided by the French radioactive waste management operator, Andra, the European Union (FORGE Project, Project number 230357) and the British Geological Survey through its well-founded laboratory programme and the Geosphere Containment project (part of the BGS core strategic programme). The results from test SPP_COx-2 clearly show that at the onset of gas propagation through the test sample dilatancy is observed in three radial and one axial direction. A component of this dilatancy is associated with changes in pore pressure. However, pore-pressure variation cannot account for the full amount of strain recorded and a proportion of the strain observed is the result of gas migration by dilatant pathway formation. The test is on-going and more insight will be achieved once the test is complete. more...
- Published
- 2011
32. Desk based study and literature review of diapirism in plastic clays and an analysis of the critical state of boom clay
- Author
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Shaw, R., Hobbs, P.R.N., Dobbs, M.R., Cuss, R.J., Shaw, R., Hobbs, P.R.N., Dobbs, M.R., and Cuss, R.J.
- Abstract
NIRAS/ONDRAF is preparing an initial Safety & Feasibility Case (SFC 1) for high-level and long-lived radioactive waste (to be completed by 2013) to demonstrate that geological disposal in poorly indurated (plastic) clays (using the Boom Clay as reference case and the Ypresian clays as an alternative) is a practical and safe disposal option to allow them to progress towards siting a repository. A significant part of the SFC 1 will be a geosynthesis report (edited by SCK-CEN and NIRAS/ONDRAF) to investigate the long-term stability of the Boom Clay. Beneath the Scheldt River, up-doming of the top of the Boom Clay (only at a few 10's of metres of depth) is observed in geophysical records and has been referred to as a ‘diapiric’ structure. NIRAS/ONDRAF has asked the British Geological Survey (BGS) to undertake an initial desk based study to review the literature on diapirism like processes in plastic clays, including the Scheldt River structure, and to discuss the relevance (or lack thereof) of this process in the context of a clay-based geological disposal system for radioactive waste. more...
- Published
- 2011
33. Effect of stress field and mechanical deformation on permeability and fracture self-sealing. Progress report on the Stress Path Permeameter experiment conducted on Callovo-Oxfordian Claystone
- Author
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Cuss, R.J., Harrington, J.F., Cuss, R.J., and Harrington, J.F.
- Abstract
This report describes in detail the stress-path permeameter (SPP) apparatus and the first test conducted on Callovo-Oxfordian (CoX) claystone from the Bure underground research laboratory (URL) in France. Funding for this study has been provided by the French radioactive waste management operator, Andra, the European Union (FORGE Project) and the British Geological Survey through its well-founded laboratory programme and the Geosphere Containment project (part of the BGS core strategic programme). The results from the first test conducted using the SPP show that the CoX has a very pronounced time-dependent component of deformation. This has implications for the following tests conducted on CoX as part of the FORGE project, but also has implications when comparing tests on CoX that have been deformed at a much faster rate. Test SPP_CoX-1 was conducted with water as a test permeant at constant pore pressure along a pre-defined stress-path. Volumetric deformation was observed during 16 steps along the stress path, with considerable time-dependent deformation and anisotropy seen in radial strain. The sixteenth stage saw the sample fail through the formation of a fracture after the sample had experienced constant stress conditions for 5.5 days; this emphasises the observed time dependent deformation. Test SPP-CoX-1 will be used to determine the stress-path steps of test SPP-CoX-2. This much more detailed test will follow 5 or 6 steps up to ultimate failure and will include a full hydraulic test, a gas injection test to determine the gas entry pressure, and constant pore-pressure flow tests to examine the changes in permeability along the stress-path. At all times throughout the test radial and axial deformation will be monitored. more...
- Published
- 2010
34. Large scale gas injection test (Lasgit) performed at the Aspo Hard Rock Laboratory : summary report 2008
- Author
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Cuss, R.J., Harrington, J.F., Noy, D.J., Cuss, R.J., Harrington, J.F., and Noy, D.J.
- Published
- 2010
35. The HiRES airborne geophysical survey of the Isle of Wight : processing report
- Author
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White, J.C., Beamish, D., Cuss, R.J., White, J.C., Beamish, D., and Cuss, R.J.
- Abstract
This report describes the final processing of data acquired during the HiRES airborne geophysical survey of the Isle of Wight and part of the Lymington area. The report is a companion to the logistics report of Beamish and Cuss (2009). The survey was carried out by the Joint Airborne-Geoscience Capability (JAC) established between the Geological Survey of Finland (GTK) and British Geological Survey (BGS). The project is a HiRES survey carried out by the Geophysical Baselines Team under the Environmental Geoscience Baselines Programme. more...
- Published
- 2010
36. The HiRES airborne geophysical survey of the Isle of Wight: Logistics Report
- Author
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Beamish, D., Cuss, R.J., Beamish, D., and Cuss, R.J.
- Abstract
This report provides a summary of the logistics of the HiRES airborne geophysical survey conducted in September and October 2008 across the Isle of Wight and part of the Lymington area. The survey was carried out by the Joint Airborne-Geoscience Capability (JAC) established between the Geological Survey of Finland (GTK) and British Geological Survey (BGS). The project is a HiRES survey carried out by the Geophysical Baselines Team under the Environmental Geoscience Baselines Programme. The survey was conducted at high resolution (a flight line spacing of 200 m) and at low altitude (56m) rising to >200 m in the vicinity of conurbations. The three main data sets acquired are magnetic, radiometric (gamma ray spectrometry) and active frequency domain electromagnetic (AEM). The aim of the present report is to provide descriptions of the logistical and in-field processing elements of the survey operations. more...
- Published
- 2009
37. Hydraulic and Gas Transport Testing of Brauner Dogger and Opalinus Clay
- Author
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Graham, C.C., primary, Harrington, J.F., additional, and Cuss, R.J., additional
- Published
- 2014
- Full Text
- View/download PDF
38. Experimental Observations of the Flow of Water and Gas along Fractures in Opalinus Clay
- Author
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Cuss, R.J., primary and Harrington, J.F., additional
- Published
- 2014
- Full Text
- View/download PDF
39. Large scale gas injection test (Lasgit) performed at the Äspö Hard Rock Laboratory. Summary report 2008
- Author
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Cuss, R.J., Harrington, J.F., Noy, D.J., Cuss, R.J., Harrington, J.F., and Noy, D.J.
- Abstract
This report describes the set-up, operation and observations from the first 1385 days (3.8 years) of the large scale gas injection test (Lasgit) experiment conducted at the Äspö Hard Rock Laboratory. During this time the bentonite buffer has been artificially hydrated and has given new insight into the evolution of the buffer. After 2 years (849 days) of artificial hydration a canister filter was identified to perform a series of hydraulic and gas tests, a period that lasted 268 days. The results from the gas test showed that the full-scale bentonite buffer behaved in a similar way to previous laboratory experiments. This confirms the up-scaling of laboratory observations with the addition of considerable information on the stress responses throughout the deposition hole. During the gas testing stage, the buffer was continued to artificially hydrate. Hydraulic results, from controlled and uncontrolled events, show that the buffer continues to mature and has yet to reach full maturation. Lasgit has yielded high quality data relating to the hydration of the bentonite and the evolution in hydrogeological properties adjacent to the deposition hole. The initial hydraulic and gas injection tests confirm the correct working of all control and data acquisition systems. Lasgit has been in successful operation for in excess of 1385 days. more...
- Published
- 2008
40. Large scale gas injection test (Lasgit) performed at the Äspö Hard Rock Laboratory: summary report 2007
- Author
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Harrington, J.F., Birchall, D.J., Noy, D.J., Cuss, R.J., Harrington, J.F., Birchall, D.J., Noy, D.J., and Cuss, R.J.
- Abstract
The deposition hole was closed on the 1st February 2005 signifying the start of the hydration phase. Groundwater inflow through a number of conductive discrete fractures resulted in elevated porewater pressures leading to the formation of conductive channels (piping), the extrusion of bentonite from the hole and the discharge of groundwater to the gallery floor. This problem was addressed by drilling two pressure-relief holes in the surrounding rock mass. Artificial hydration began on the 18th May 2005 after 106 days of testing. Initial attempts to raise porewater pressure in the artificial hydration arrays often resulted in the formation of preferential pathways. These pressure dependent features were not focused in one location but occurred at multiple sites at different times in the test history. These pathways appear to be relatively short lived, closing when water pressure is reduced. It was determined that both pressure relief holes should remain open until the bentonite had generated sufficient swelling pressure to withstand the high water pressure in the system when these holes are closed. Packers were installed into the pressure relief holes on 23rd March 2006 and sections in them closed off over the period to 5th July 2006. There was no repeat of the formation of piping through discrete channels so, on 20th November 2006, pressures to the artificial hydration filters on the canister were increased to 2350 kPa. more...
- Published
- 2008
41. The Tellus Airborne Geophysical Survey of Northern Ireland. Final results
- Author
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Beamish, D., Cuss, R.J., Kurimo, M., Lahti, M., Leväniemi, H., Tartaras, E., Beamish, D., Cuss, R.J., Kurimo, M., Lahti, M., Leväniemi, H., and Tartaras, E.
- Abstract
The Tellus airborne geophysical survey of Northern Ireland was conducted over a two year period. Measurements from a fixed-wing aircraft operating at 56 m include magnetic (gradiometer), radiometric and frequency-domain electromagnetic. The survey comprises over 80,000 line-km of coverage and was completed in two phases (2005 and 2006). The large geographical scale and two year duration have combined to raise interesting questions regarding data processing and seasonal adjustments. The radiometric and electromagnetic data sets are completely new for N.Ireland, whereas the magnetic data set is significantly better than the existing one. The preliminary results have excited the interest of the planning, mineral and environmental communities. more...
- Published
- 2007
42. Deculturing of the Northern Ireland Tellus magnetic data
- Author
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Lahti, M., Beamish, D., Cuss, R.J., Williams, J., Lahti, M., Beamish, D., Cuss, R.J., and Williams, J.
- Published
- 2007
43. The Tellus airborne geophysical survey of Northern Ireland : final processing report
- Author
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Beamish, D., Cuss, R.J., Lahti, M., Scheib, C., Tartaras, E., Beamish, D., Cuss, R.J., Lahti, M., Scheib, C., and Tartaras, E.
- Published
- 2006
44. The Tellus Airborne Geophysical Survey of Northern Ireland. Phase 1, logistics report
- Author
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Beamish, D., Cuss, R.J., Lahti, M., Beamish, D., Cuss, R.J., and Lahti, M.
- Published
- 2006
45. Gas transport processes in crystalline rocks and engineered barriers within the EDZ : BGS contribution to NF-PRO WP4.4.1
- Author
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Reeves, H.J., Cuss, R.J., Noy, D.J., Reeves, H.J., Cuss, R.J., and Noy, D.J.
- Abstract
This report outlines the contribution made by BGS to the NF-PRO (Key processes in the Near Field) project; part of the EC Euratom Research and training Programme on Nuclear Energy. BGS was asked to contribute to Work Package 4.4.1 examining EDZ Characterisation and Evolution. This work package included a state-of-the-art report on the gas flow properties within the Engineered Damaged/Disturbed Zone (EDZ); BGS was requested to contribute to the chapters on clay (Cuss et al., 2006) and crystalline rock (this report). This work was co-funded by United Kingdom Nirex Limited (Nirex). more...
- Published
- 2006
46. Gas transport processes in argillaceous rocks within the EDZ : BGS contribution to NF-PRO WP4.4.1
- Author
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Cuss, R.J., Reeves, H.J., Noy, D.J., Harrington, J.F., Cuss, R.J., Reeves, H.J., Noy, D.J., and Harrington, J.F.
- Abstract
This report outlines the contribution made by BGS to the NF-PRO (Key processes in the Near Field) project; part of the EC Euratom Research and training Programme on Nuclear Energy. BGS was asked to contribute to Work Package 4.4.1 examining EDZ Characterisation and Evolution. This work package included a state-of-the-art report on the gas flow properties within the Engineered Damaged/Disturbed Zone (EDZ), BGS was requested to contribute to the chapters on clay (this report) and crystalline rock (Reeves et al., 2006). This work was co-funded by United Kingdom Nirex Limited (Nirex). more...
- Published
- 2006
47. Consolidation and rebound properties of Opalinus Clay : a long-term, fully drained test
- Author
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Horseman, S.T., Harrington, J.F., Birchall, D.J., Noy, D.J., Cuss, R.J., Horseman, S.T., Harrington, J.F., Birchall, D.J., Noy, D.J., and Cuss, R.J.
- Abstract
A specimen of Opalinus clay from Mont Terri has been subjected to stress testing over a period of 532 days. Testing was undertaken by changing either (or both) of the axial and confining stresses in sharp steps followed by periods of between 4 and 82 days during which time the specimen was allowed to adjust to the new stress state. In this way, the drained consolidation, creep and rebound behaviour of an Opalinus clay specimen was examined. The test material was subjected to a maximum average effective stress of 38.3 MPa. Volumetric strain data for both volume change and porewater displacement measurements indicate a small inflection in the standard geotechnical plot of void ratio against the logarithm of average effective stress at a value between 20 and 22 MPa. The negative slope of the consolidation curve (α) based on volume change measurements exhibits a general trend of increasing magnitude as effective stress rises. Even though the data do not exhibit the sharp increase in α indicative of classic virgin consolidation behaviour, it would appear that plastic yielding is occurring at an average effective stress below 20 MPa. Analysis of net porewater flow measurements suggest original interstitial fluid was not expelled from the specimen until average effective stress exceeded 20 MPa. Given the data available, an estimate for the preconsolidation stress in the region of 20 to 25 MPa seems reasonable. As effective stress rises the duration of the strain transients lengthen. As the induration state of the mudrock increases, strain traces are characterised by less well-defined transients, indicative of time-dependent plastic yielding at high effective stresses. The volumetric strain data for both volume change and porewater displacement shows similar transient behaviour. These results give an average principal strain ratio of 0.252, suggesting the material is either mechanically anisotropic or behaving as a non-ideal elastic medium. Specific storage values derived f more...
- Published
- 2005
48. Airborne geophysical surveys applied to urban/brownfield investigations
- Author
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Beamish, D., Cuss, R.J., Tartaras, E., Beamish, D., Cuss, R.J., and Tartaras, E.
- Abstract
A number of airborne geophysical surveys have now been conducted in the UK using a fixed- wing system operated jointly by the British and Finnish Geological Surveys. The system provides magnetic, radiometric and frequency domain electromagnetic survey measurements. Regulatory survey permissions force a variety of flight elevations typically between 54 to 244 m. On the fringes of major conurbations, we encounter urban greenspace and brownfield areas. These areas may contain mixtures of infrastructure and built structures together with derelict and green areas. In order to provide valid interpretations of the airborne data, detailed studies of the behaviour of the data to a variety of influences found in the urban fringe of a town have been made. Non-geophysical spatial data sets are increasingly being applied to aid both the processing and interpretation of the survey data. This is particularly true in non-rural areas. Examples from a high-resolution survey acquired across a 5 x 5 km coastal area to the west of Irvine, Scotland are considered. more...
- Published
- 2005
49. Application of ground penetrating radar to geological investigations
- Author
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Busby, J.P., Cuss, R.J., Raines, M.G., Beamish, D., Busby, J.P., Cuss, R.J., Raines, M.G., and Beamish, D.
- Abstract
Ground penetrating radar data have been collected from a number of sites in order to investigate the shallow sub-surface. The purpose was to investigate, through active participation, the benefit that GPR can have to elements of the BGS Core Programme and to explore ways that GPR can be used more widely in the future. Field data were collected mainly with a 250 MHz Noggin GPR system manufactured by Sensors and Software Limited, but some additional data were also collected using frequencies of 50 and 100 MHz. Good results were achieved for mapping fractures, characterising an aggregate deposit and for locating infrastructure including, tunnels, voids, steel reinforcing bars and capping for a mineshaft. The use of new equipment that collects data rapidly was found to be especially useful for creating three-dimensional blocks of data. Three-dimensional displays enable artefacts in the data to be identified and for the true dip of structures to be measured. Surveys were less successful when characterising chalk and estimating the thickness of buried channels where the depth of the channels was found to be too deep for high frequency GPR. GPR is a powerful tool for investigating the shallow sub-surface when used in the appropriate environment. It is therefore important that BGS Programme Managers and project leaders should be aware of the potential of GPR and be prepared to utilise it when devising new projects. This is most likely to be achieved through active consultation with geophysicists during the planning phase of a project. more...
- Published
- 2004
50. The High Resolution Airborne Resource and Environmental Survey- (Phase 1) (HiRES-1): background, data processing and dissemination and future prospects
- Author
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Peart, R.J., Cuss, R.J., Beamish, D., Jones, D.G., Peart, R.J., Cuss, R.J., Beamish, D., and Jones, D.G.
- Abstract
This report provides an overview of the HiRES-1 airborne geophysical survey of Central England. The BGS and World Geoscience (UK) Ltd. carried out the survey jointly in 1998. The three main survey data sets acquired were magnetic, radiometric (gamma ray spectrometry) and Very Low Frequency (VLF) electromagnetic. The main aim of the report is to provide information on the acquisition, processing and storage of the final data and map products produced by the HiRES-1 project. Additional descriptions of ground truthing activities, data licensing and dissemination are also provided. A significant aspect of the project was the assessment of the potential of, and issues raised by, modern, multi-parameter, regional-scale airborne geophysical surveys in the UK context. Some of the main issues outlined in the report are: • The practical difficulties of conducting extensive low level, fixed-wing geophysical surveying in the UK. Issues discussed include CAA regulatory permissions, flight height adjustments above conurbations and surveying near areas with dense air traffic. • The processing challenges introduced by cultural (nongeological) influences on high resolution airborne magnetic data sets in the UK. • The significant amounts of detailed geological and environmental information contained within the radiometric data. • The weak application potential provided by passive (i.e. VLF) measurements, in contrast to active airborne electromagnetic techniques. The future prospects for regional-scale, airborne geophysical surveys in the UK are considered. Such prospects are also influenced by a further set of trial airborne data, obtained in 1999, but not described here. Further detail of the HiRES-1 survey, productivity, technical specifications and data pre-processing are contained in the survey logistics report prepared by WGL: ‘British Geological Survey “Hi-Res Phase One” Airborne Geophysical Survey (Survey Details, Technical Specifications & Processing Summary)’ (WGL 2000). more...
- Published
- 2003
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