Micromechanics of shear failure in a porous rock: a combined dataset of high-resolution time-resolved 3D x-ray micro-tomography volumes and local 3D strain fields with contemporaneous acoustic emissions and ultrasonic velocity survey waveforms

This dataset shows both the micro-scale mechanisms and acoustic response involved in shear failure of a deforming porous rock. To our knowledge, this is the first such dataset to combine simultaneous acoustic measurements and x-ray tomography imaging. It comprises a time-series of 3D in-situ synchrotron x-ray microtomography (µCT) volumes showing a Clashach sandstone sample (CL10) undergoing triaxial deformation to failure under a constant acoustic emissions (AE) event rate. Use of a constant AE event rate slowed down the failure process after peak stress, enabling shear failure to be captured in unprecedented spatio-temporal detail by the µCT volumes. These volumes are accompanied by the local incremental 3D strain fields and simultaneously acquired waveforms from acoustic emissions and ultrasonic velocity surveys, as well as mechanical bulk stress and strain. These data are fully explained in Cartwright-Taylor et al. Seismic events miss important grain-scale mechanisms governed by kinematics during shear failure of porous rock, in review at Nature Communications. We also include an equivalent time-series of the same data types showing a second Clashach sandstone sample (CL04) undergoing triaxial deformation to failure, this time under a constant strain rate where failure happened abruptly, shortly after peak stress. Both collections were acquired in-situ on the beamline I12-JEEP at the Diamond Light Source, Didcot, UK, in September 2019. Each 3D µCT volume of the sample is contained in a .zip file labelled with the sequential scan number. Each volume comprises reconstructed 16-bit grey-scale data in a sequence of 2D image files (.tif), each numbered according to the depth at which it lies within the sample volume. The file dimensions are pixels, with an edge length of 7.91 µm. Two further .zip files contain the incremental 3D volumetric and deviatoric strain fields, obtained from digital volume correlation between neighbouring µCT volumes. Each strain field consists of a 32-bit 3D image file (.tif) in pixels with an edge length of 316.4 µm, labelled with its scan increment. Also included are (i) .csv files, containing the mechanical stress and strain time-series, the time and mechanical data at which each µCT volume was scanned, and the acoustic emissions event rate data, and (ii) .zip files containing times and waveforms for the acoustic emissions and ultrasonic velocity surveys as .ascii files. The .zip and .xlsx files are labelled with the sample name, the data type (grey-scale, strain-volumetric, strain-deviatoric, seismic, mechanical, mechCT, eventrateAE) and the sequential scan number (grey-scale only) according to the following convention: sample_datatype_scan#. We acknowledge Diamond Light Source for time on beamline I12-JEEP under proposal MG22517. This work is supported by the UK's Natural Environment Research Council (NERC) through the CATFAIL project NE/R001693/1 Catastrophic failure: what controls precursory localisation in rocks?

Date (Creation): 2022-04-22

Citation identifier: http://data.bgs.ac.uk/id/dataHolding/13607932

Point of contact

Organisation name	Individual name	Electronic mail address	Role
University of Edinburgh	Professor Ian Main	not available	Originator
University of Edinburgh	Professor Ian Main	not available	Principal investigator
University of Edinburgh	Alexis Cartwright-Taylor	alexis.cartwright-taylor@ed.ac.uk	Originator
University of Edinburgh	Ian B. Butler	not available	Originator
University of Edinburgh	Florian Fusseis	not available	Originator
Edinburgh Hacklab	Martin Ling	not available	Originator
École Polytechnique Fédérale de Lausanne	Edward Andò	not available	Originator
University of Edinburgh	Maria-Daphne Mangriotis	not available	Originator
University of Edinburgh	Roberto E. Rizzo	not available	Originator
University of Edinburgh	Sina Marti	not available	Originator
University of Edinburgh	Derek D. Leung	not available	Originator
Diamond Light Source	Oxana V. Magdysyuk	not available	Originator
British Geological Survey	Enquiries	not available	Distributor
British Geological Survey	Enquiries	not available	Point of contact

Maintenance and update frequency: notApplicable

GEMET - INSPIRE themes, version 1.0

Geology

BGS Thesaurus of Geosciences

NGDC Deposited Data
Sandstone
Faulting
Rock deformation
Compression tests
Acoustic emission

dataCentre

NGDC Deposited Data

Keywords

NERC_DDC

Access constraints: Other restrictions

Other constraints: licenceOGL

Other constraints: Available under the Open Government Licence subject to the following acknowledgement accompanying the reproduced NERC materials "Contains NERC materials ©NERC [year]"

Use constraints: Other restrictions

Other constraints: The copyright of materials derived from the British Geological Survey's work is vested in the Natural Environment Research Council [NERC]. No part of this work may be reproduced or transmitted in any form or by any means, or stored in a retrieval system of any nature, without the prior permission of the copyright holder, via the BGS Intellectual Property Rights Manager. Use by customers of information provided by the BGS, is at the customer's own risk. In view of the disparate sources of information at BGS's disposal, including such material donated to BGS, that BGS accepts in good faith as being accurate, the Natural Environment Research Council (NERC) gives no warranty, expressed or implied, as to the quality or accuracy of the information supplied, or to the information's suitability for any use. NERC/BGS accepts no liability whatever in respect of loss, damage, injury or other occurence however caused.

Other constraints: Available under the Open Government Licence subject to the following acknowledgement accompanying the reproduced NERC materials "Contains NERC materials ©NERC [year]"

Language: English

Topic category

Geoscientific information

Begin date: 2019-09-11

End date: 2019-09-16

Reference System Information

No information provided.

Distribution format

Name	Version
image (TIF)
text files (CSV)
text files (ASCII)

Distributor contact

Organisation name	Individual name	Electronic mail address	Role
British Geological Survey	Enquiries	not available	Distributor

OnLine resource

Protocol	Linkage	Name
	https://webapps.bgs.ac.uk/services/ngdc/accessions/index.html#item173296	Data

OnLine resource

Protocol	Linkage	Name
	https://doi.org/10.5285/56c7802c-93db-4f0f-8b89-e18e10215633	Digital Object Identifier (DOI)

OnLine resource

Protocol	Linkage	Name
	https://doi.org/10.1038/s41467-022-33855-z	Published Paper

Hierarchy level: Non geographic dataset

Other: non geographic dataset

Conformance result

Title: INSPIRE Implementing rules laying down technical arrangements for the interoperability and harmonisation of Geology

Date (Publication): 2011

Explanation: See the referenced specification

Pass: No

Conformance result

Title: Commission Regulation (EU) No 1089/2010 of 23 November 2010 implementing Directive 2007/2/EC of the European Parliament and of the Council as regards interoperability of spatial data sets and services

Date (Publication): 2010-12-08

Explanation: See http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2010:323:0011:0102:EN:PDF

Pass: No

Statement: The samples underwent triaxial deformation at 25 MPa confining pressure and 5 MPa pore pressure in Stór Mjölnir, our x-ray transparent rock deformation rig with integrated acoustic monitoring (Cartwright-Taylor et al., in prep.). The samples were both loaded initially at a constant strain rate of 10⁻⁵ s⁻¹. CL04 continued to be loaded at a constant strain rate of 10⁻⁵ s⁻¹ until it experienced abrupt shear failure. CL10 was loaded in this way until detection of sufficient acoustic emissions to maintain a constant AE event rate of 1 AE s⁻¹, whereupon the sample experienced yield and slow shear failure. In each case, tomographic volumes of the whole sample, comprising overlapping scans of the top and bottom, were acquired every 85 s. At each end of the sample 0.3 mm was not captured due to limits on the x-ray field of view .