Results
- Showing results for:
- Reset all filters
Search results
-
Journal articleElliott GM, Wilson P, Jackson CAL, et al., 2012,
The linkage between fault throw and footwall scarp erosion patterns: an example from the Bremstein Fault Complex, offshore Mid-Norway
, Basin Research, Vol: 24, Pages: 180-197Studies of normal fault systems in modern extensional regimes (e.g. Basin and Range), and in exhumed, ancient rift basins (e.g. Gulf of Suez Rift) have shown a link between the evolution of fault-related footwall topography and associated erosional drainage systems. In this study, we use 3D seismic reflection data to image the footwall crest of a gravity-driven fault system developed during late Middle Jurassic–to-Early Cretaceous rifting on the Halten Terrace, offshore Mid-Norway. This 22 km long fault system lacks significant footwall uplift, with hangingwall subsidence accommodating throw accumulation on the fault system. Significant erosion has occurred along the length of the footwall crest and is defined by 96 catchments characterised by erosional channels. These erosional channels consist of small, linear systems up to 750 m long located along the front of the fault footwall. Larger, dendritic channel systems extend further back (up to 3 km normal to fault strike) into the footwall. These channels are up to 7 km long, up to 50 m deep and up to 1 km wide. Fault throw varies along-strike, with greatest throw in the centre of the fault decreasing towards the fault tips, localised throw minima are interpreted to represent segment linkage points which were breached as the fault grew. Comparison of the catchment location to the throw distribution shows that the largest catchments are in the centre of the fault and decrease in size to the fault tips. There is no link between the location of the breached segment linkage points and the location and size of the footwall catchments suggesting that the first-order control on footwall erosion patterns is the overall fault throw distribution.
-
Journal articleLiu JG, Mason PJ, Yu E, et al., 2012,
GIS modelling of earthquake damage zones using satellite remote sensing and DEM data
, GEOMORPHOLOGY, Vol: 139, Pages: 518-535, ISSN: 0169-555X- Author Web Link
- Cite
- Citations: 20
-
Journal articleBurland JB, Jardine RJ, 2012,
Training of Ground Engineering professionals – how can the UK provide skills required to maintain infrastructure?
, Journal of the Parliamentary Scientific Committee, Vol: 69, Pages: 41-42 -
Journal articleCollins GS, Melosh HJ, Osinski GR, 2012,
The Impact-Cratering Process
, ELEMENTS, Vol: 8, Pages: 25-30, ISSN: 1811-5209- Author Web Link
- Cite
- Citations: 54
-
Journal articleJackson MD, Vinogradov J, 2012,
Impact of wettability on laboratory measurements of streaming potential in carbonates
, COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS, Vol: 393, Pages: 86-95, ISSN: 0927-7757- Author Web Link
- Cite
- Citations: 64
-
Conference paperPelecanos L, Kontoe S, Zdravković L, 2012,
Numerical analysis of the seismic response of La Villita dam in Mexico
, Pages: 120-130This paper presents two-dimensional plane-strain static and dynamic finite element analyses of La Villita earth dam in Mexico, which has experienced a number of large earthquakes. Static analyses are employed to simulate the layered construction of the embankment, water impounding and consolidation, whereas dynamic analyses simulate the earthquake events. The static behaviour of the dam is well captured, as evidenced by the predicted and recorded crest settlement. The dynamic behaviour is satisfactorily captured by comparing the accelerations recorded at both the crest and downstream berm of the dam.
-
Journal articleKontoe S, Zdravkovic L, Menkiti CO, et al., 2012,
Seismic response and interaction of complex soil retaining systems
, Computers and Geotechnics, Vol: 39, Pages: 17-26This paper examines the seismic response of a large and complex system comprising a Lock chamber and three neighbouring water saving basins (WSBs). The developed two-dimensional plane strain finite element model included the entire system in order to explore the interaction of the various structures. The first set of analyses was undertaken under static conditions to simulate the construction sequence and to establish the stress regime prior to the examined seismic event. Subsequently, dynamic time domain analyses were performed to examine the response of the system to seismic loading. The ground motion was applied into the finite element mesh employing a sub-structuring technique which enables economic modelling of large computation domains and accurate representation of the semi-infinite half-space. The paper explores some aspects of the numerical modelling of such complex systems, such as the impact on the predicted seismic response of the adopted constitutive model and the modelling of hydrodynamic effects. The discussion of the dynamic analyses results focuses on the main Lock structure, looking at the prevailing modes of deformation, the potential lift-off of the base of the Lock walls and the interaction of the main wall with the other retaining structures.
-
Journal articleMonroy R, Zdravkovic L, Ridley A, 2012,
Random Uncertainty in the Measurement of Matric Potential Using the Miniature Tensiometer
, GEOTECHNICAL TESTING JOURNAL, Vol: 35, Pages: 41-49, ISSN: 0149-6115 -
Journal articleDmitrieva E, Jackson CAL, Huuse M, et al., 2012,
Palaeocene deep-water depositional systems in the northern North Sea: a 3D seismic and well data case study, North Viking Graben, Block 35/11
, Petroleum Geoscience, Vol: 18, Pages: 97-114Interpretation of 3D seismic reflection data supported by well data provides insights into the geometry of early Palaeogene depositional systems along the eastern margin of the North Viking Graben. The deposits, which consist mainly of sandstones interbedded with claystones and siltstones, are interpreted to document deposition at the edge of a large base-of-slope to proximal basin floor fan system which was sourced from the eastern basin margin. Individual sandstone bodies are up to 80 m thick and occur within four sandstone-prone packages (DU1-4), and well-to-seismic ties indicate that the thicker sandstones (>10 m) are often represented by channellised or sheet-like, high-amplitude anomalies. Both well and seismic data suggest that the sandstones are of limited lateral extent (<1-5 km), implying they were deposited in a series of channels. Channellisation and compensational stacking of sandstones may have been at least partly controlled by differential compaction across previously-deposited sandbodies. The study reveals that deep-water depositional patterns are more complex than is apparent from previous, lithostratigraphically-driven correlations and from regional isochron mapping. In particular, this study has implications for the controls on the distribution and reservoir architecture of deep-water sandstones.
-
Journal articlePapaspiliou M, Kontoe S, Bommer JJ, 2012,
An Exploration of Incorporating Site Response into PSHA Part II: Sensitivity of Hazard Estimates to Site Response Approaches
, Soil Dynamics and Earthquake Engineering, Vol: 42, Pages: 316-330This paper examines the sensitivity of seismic hazard analyses to various site response analysis procedures. Site effects are incorporated in the hazard calculations using a probabilistic approach and specifically the methodology of Bazzurro and Cornell [1] for the transformation of a generic ground-motion prediction equation to a site-specific one. The paper explores the sensitivity of the median amplification function, its standard deviation and the resulting surface hazard curve, to different methods of site response analysis and model input parameters. The computed site-specific surface hazard curves are also compared with those obtained from a generic soil ground-motion prediction equation. For the two sites investigated, it is shown that the choice of equivalent linear or nonlinear analysis with different constitutive model parameters has a significant impact on the hazard results. The sandy site was seen to be more sensitive to the site response analysis approach employed than the clayey site.
-
Conference paperMiljkovic K, Collins GS, Chapman DJ, et al., 2012,
HIGH-VELOCITY IMPACTS IN POROUS SOLAR SYSTEM MATERIALS
, 7th Biennial Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter, Publisher: AMER INST PHYSICS, ISSN: 0094-243X- Author Web Link
- Cite
- Citations: 7
-
Conference paperBell RE, Jackson CA-L, Whipp PS, et al., 2012,
Fault interaction between Permo-Triassic and Mid-Late Jurassic rift episodes in the northern North Sea
, Onshore-Offshore relationships on the North Atlantic Margin -
Journal articleBommer JJ, Stafford PJ, 2012,
Estimating ground motion levels in earthquake damage investigations: a framework for forensic engineering seismology
, International Journal of Forensic Engineering, Vol: 1, Pages: 3-20 -
Journal articlePapaspiliou M, Kontoe S, Bommer JJ, 2012,
An exploration of incorporating site response into PSHA, Part I: Issues related to site response analysis methods
, Soil Dynamics and Earthquake Engineering, Vol: 42, Pages: 302-315This paper presents a series of analyses for the evaluation of the ground response of two NEHRP class D sites, subjected to shaking by a large number of strong ground-motion records. The two investigated sites have very distinct profiles, but they are characterised by almost identical Vs30 values. The site response analyses are performed using various methods of analysis and input parameters in order to explore the sensitivity of the ground response estimates and to identify the dominating parameters. Equivalent linear analysis is performed using different sets of dynamic soil properties curves, while nonlinear analysis is performed using different target dynamic soil curves, viscous damping formulations and fitting procedures for the constitutive model parameters. Particular focus is given to the sensitivity of the response when soil sites are subjected to high-intensity shaking, a subject of particular interest when the prediction of surface ground motions with low annual probabilities of exceedance is the target of probabilistic seismic hazard analyses (PSHA). The site response analysis results of this paper are incorporated into the probabilistic framework of Bazzurro and Cornell [1] in our companion paper in order to assess their impact on the final soil surface hazard calculation.
-
Conference paperBell RE, Jackson CA-L, Elliott GM, et al., 2012,
Insights into lithospheric extension mechanisms and Late Jurassic reservoir distribution from restoring palaeobathymetry in the Halten Terrace
, Deep-Water Continental Margins: The Final Exploration Frontier?, Geological Society conference -
Conference paperBell RE, Jackson CA-L, Whipp PS, et al., 2012,
Fault evolution during polyphase extension: Horda Platform, North Sea
, American Association of Petroleum Geologists Annual Conference and Exhibition -
Journal articleJackson MD, Leinov E, 2012,
On the Validity of the “Thin” and “Thick”Double-Layer Assumptions When CalculatingStreaming Currents in Porous Media
, International Journal of Geophysics, Vol: 2012, ISSN: 1687-8868We find that the thin double layer assumption, in which the thickness of the electrical diffuse layer is assumed small comparedto the radius of curvature of a pore or throat, is valid in a capillary tubes model so long as the capillary radius is >200 times thedouble layer thickness, while the thick double layer assumption, in which the diffuse layer is assumed to extend across the entirepore or throat, is valid so long as the capillary radius is >6 times smaller than the double layer thickness. At low surface chargedensity (<10 mC · m−2) or high electrolyte concentration (>0.5 M) the validity criteria are less stringent. Our results suggest thatthe thin double layer assumption is valid in sandstones at low specific surface charge (<10 mC · m−2), but may not be valid insandstones of moderate- to small pore-throat size at higher surface charge if the brine concentration is low (<0.001 M). The thickdouble layer assumption is likely to be valid in mudstones at low brine concentration (<0.1 M) and surface charge (<10 mC·m−2),but at higher surface charge, it is likely to be valid only at low brine concentration (<0.003 M). Consequently, neither assumptionmay be valid in mudstones saturated with natural brines.
-
Conference paperPelecanos L, Kontoe S, Zdravkovic L, 2012,
Static and dynamic analysis of La Vilita dam in Mexico
, 2nd International Conference on Performance-Based Design in Earthquake Geotechnical Engineering, Pages: 1045-1056 -
Journal articleTaborda DMG, Zdravkovic L, 2012,
Application of a Hill-Climbing Technique to the Formulation of a New Cyclic Nonlinear Elastic Constitutive Model
, Computers and Geotechnics, Vol: 43, Pages: 80-91In the field of constitutive modelling of soil behaviour, optimisation techniques have been mostly employed as a calibration tool, particularly when several model parameters lack clear physical meaning. In this paper, however, a procedure based on a Hill-Climbing optimisation algorithm is presented as a form of improving the performance of constitutive models. Specifically, a simple cyclic nonlinear elastic model, which is shown to be unable to simulate adequately the damping ratio measured under small and large strain amplitudes, is modified by applying the Hill-Climbing technique to the determination of a new relationship describing the unloading/reloading behaviour of soil under cyclic loading. The performance of the proposed model is assessed by evaluating its parameters based on three distinct sets of empirical damping ratio curves and computing the corresponding error in their simulation. It is shown that the introduction of the new unloading/reloading expression formulated based on the outcome of the optimisation procedure increases substantially the precision of the constitutive model.
-
Journal articleDuller RA, Whittaker AC, Swinehart JB, et al., 2012,
Abrupt landscape change post–6 Ma on the central Great Plains, USA
, GEOLOGY, Vol: 40, Pages: 871-874
This data is extracted from the Web of Science and reproduced under a licence from Thomson Reuters. You may not copy or re-distribute this data in whole or in part without the written consent of the Science business of Thomson Reuters.