Correlative neutron and X-ray tomography imaging of pile installation in chalk

DOI: 10.1680/jgeot.21.00318

Authors: Fernando Alvarez-Borges (University of Southampton) , Genoveva Burca (ISIS Pulsed Neutron and Muon Source) , Robert Atwood (University of Southampton) , Andrew James (University of Southampton) , Mark Wolstenholme (Labman Automation Ltd) , Sharif Ahmed (University of Southampton)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Géotechnique

State: Published (Approved)
Published: July 2022
Diamond Proposal Number(s): 26232

Abstract: Neutron and X-ray tomography (NCT and XCT, respectively) are imaging techniques increasingly being applied in geomechanics research. They are used to non-destructively reveal different microstructural aspects of geomaterials: XCT is often used to observe/quantify differences in density or porosity, while NCT reveals the presence and distribution of hydrogenous materials such as water. The correlated use of NCT and XCT for geomechanics and geotechnics research is in its infancy. To this date, very few experiments have been carried out that combine both techniques, and none have been used to investigate geomaterial-structure interaction. This paper presents the first correlative NCT-XCT imaging study of pile installation. A scaled model pile was installed in an unsaturated intact chalk cylinder and in-situ NCT and ex-situ XCT synchrotron-based imaging was applied consecutively. Chalk was used because the behaviour of displacement piles installed in this material is still subject to considerable uncertainty. Results reveal for the first time the interaction between installation-induced changes in chalk density and water distribution variations, with evidence of water displacement into the densified material in the vicinity of the installed pile. A straightforward method for correlative bulk density-moisture content determination from NCT-XCT images of geomaterials are presented and their limitations discussed.

Journal Keywords: Chalk; micro-CT tomography; soil/structure interaction; piles & piling

Subject Areas: Earth Science


Instruments: I12-JEEP: Joint Engineering, Environmental and Processing

Other Facilities: IMAT at ISIS

Added On: 01/08/2022 08:49

Discipline Tags:

Earth Sciences & Environment Geology Geophysics

Technical Tags:

Imaging Tomography