A5056936638- Landslides and related hazards
- Granular flow and fluidized beds
- Hydrology and Sediment Transport Processes
- Geotechnical Engineering and Underground Structures
- Geotechnical Engineering and Soil Mechanics
- Soil and Unsaturated Flow
- Rock Mechanics and Modeling
- Geotechnical Engineering and Analysis
- Geotechnical Engineering and Soil Stabilization
- Cryospheric studies and observations
- Dam Engineering and Safety
- Geotechnical and Geomechanical Engineering
- Particle Dynamics in Fluid Flows
- Soil erosion and sediment transport
- earthquake and tectonic studies
- Groundwater flow and contamination studies
- Water Systems and Optimization
- Geotechnical and construction materials studies
- Tree Root and Stability Studies
- Tunneling and Rock Mechanics
- Seismic Waves and Analysis
- Mechanical stress and fatigue analysis
- Grouting, Rheology, and Soil Mechanics
- Soil Geostatistics and Mapping
- Fatigue and fracture mechanics
University of Sheffield
2015-2024
Royal Brompton Hospital
2024
Guy's and St Thomas' NHS Foundation Trust
2024
Queen's University
2022
University of Canterbury
2009-2013
ETH Zurich
2010
University of Arkansas at Fayetteville
2010
University of Cambridge
2001-2003
A novel technique for the objective assessment of particle shape is presented. The uses Fourier descriptors and image analysis scanning electron microscope photographs sand grains to provide an accurate quantification morphology texture. Three lower order descriptors, denoted ‘signature descriptors’, measures elongation, triangularity squareness, while additional descriptor, ‘asymmetry’, provides a measure irregularity. Together, these four quantify overall soil particles (defined as...
On 4 September 2010, a magnitude Mw 7.1 earthquake struck the Canterbury region on South Island of New Zealand. The epicentre was located in Darfield area about 40 km west city Christchurch. Extensive damage inflicted to lifelines and residential houses due widespread liquefaction lateral spreading areas close major streams, rivers wetlands throughout Christchurch Kaiapoi. Unreinforced masonry buildings also suffered extensive region. Despite severe infrastructure houses, fortunately, no...
The dynamic fragmentation of rock during avalanche motion has been postulated as a mechanism explaining the long runout large avalanches or Sturzströme. This paper investigates whether test conditions that produce can lead to greater spreading physical model avalanches. Model experiments were carried out under enhanced acceleration generate breakage in coal, fragmentable, brittle solid. Coal blocks released from stationary position on slope run plane. ensuing fragmenting debris was captured...
A rigid-walled ‘transparent soil’ permeameter has been developed to study visually the mechanisms occurring during seepage-induced internal erosion in susceptible granular media under upward flow. The experiments use borosilicate glass particles place of soil, and an optically matched oil mixed with fluorescent dye water. technique known as plane laser-induced fluorescence (PLIF) enables a two-dimensional fluid be viewed inside permeameter, away from walls. Results tests have provided close...
Physical modelling of debris flows has been carried out in the geotechnical drum centrifuge at ETH Zürich. A new apparatus to model is described. The permits final reach a typical flow be modelled within centrifuge, with unconsolidated material flowing down slope deposit as fan around drum. Experiments are described for both fixed base conditions and erodible bases. Tests examine verification (modelling) models show that behaviour governed mainly by friction consolidation processes, although...
A series of 30 tests on dry granular flows were performed using a large-scale flume under varying source volumes and basal friction conditions to capture grain-scale interactions their impact overall runout behaviour. These grain ultimately the flow regimes developed found be function material volume boundary roughness. The dimensionless inertial number was computed for each flow, but limited utility except perhaps define general state (e.g., liquid regime) due high slip velocity encountered...
Debris flows are high speed saturated mass movements, which controlled by gravity and shear processes. The flow matrix consists of water granular material, ranging in size from clays to boulders. Particle diameters below 63 µm, the “fines”, able remain suspension for duration owing their small settling velocities. Therefore, fines often considered as a single, fluid, phase literature. This assumption means fluid properties governed concentration microstructure,...
Physical modelling of debris flow in a small-scale flume has been carried out to investigate the internal stress-transfer mechanisms within unsteady, saturated, and segregating granular free-surface flows. Measurements velocity fields model flows were obtained via planar laser–induced fluorescence particle image velocimetry. Normalized profiles taken at section over duration found essentially collapse onto single curve, shape which was dependent on particle-size distribution. While all...
In this paper, quantitative observations of dry granular flows subject to varying magnitude and direction Coriolis acceleration are presented in order assess the robustness Savage–Hutter shallow water approximation flow for modelling landslides. Nine tests carried out at 70° 45° slope inclinations described cases where no was applied (i.e. performed 1g), acted into or (centrifuge tests). Given that term is velocity dependent, each point within a model landslide on centrifuge experienced...
The motion of debris flows, gravity-driven fast moving mixtures rock, soil and water can be interpreted using the theories developed to describe shearing highly concentrated granular fluid flows. Frictional, collisional viscous stress transfer between particles characterizes mechanics To quantify influence transfer, kinetic models have been proposed. Collisions among result in random fluctuations their velocity that represented by temperature, T. In this paper particle image velocimetry,...
Field observations of debris flows often show that a deep dry granular front is followed by progressively thinner and increasingly watery tail. These features have been captured in recent laboratory flume experiments (Taylor-Noonan et al. , J. Geophys. Res.: Earth Surf. vol. 127, 2022, e2022JF006622). In these different initial release volumes were used to investigate the dynamics an undersaturated monodisperse grain–water mixture as it flowed downslope onto horizontal run-out pad....
A series of triaxial creep tests is described, with the aim shedding light on mechanisms behind displacement pile setup in granular soils. The stress path leading to stages has been designed mimic, as far possible, installation a adjacent an element soil. complex strain response found dense sands at high ratio, rotation vector over time. new hypothesis, involving kinematically restrained dilation soil close shaft and ageing, proposed explain setup. Influences behaviour, hence degree setup,...
Fatigue cracking is thought to be a critical failure mode for Grey Cast Iron (GCI) water pipes; however, this mechanism poorly understood. Using novel approach sourcing GCI pipe material testing, the variation in fatigue strength between pipes from same batch was experimentally quantified. These results were used assess impact of on hypothetical but realistic years-to-failure scenario. Full-pipe sections during testing and observed gave physical meaning years-to-fatigue-failure predictions...