Use of X-ray computed tomography to investigate the meso-mechanisms of localized deformation in soil-rock mixture under uniaxial compression

Abstract

This article aims at investigating the meso-scale mechanisms that result in failure by strain localization in soil and rock mixtures (SRM). While the macroscopic failure of SRM has been widely studied, the physical meso-scale mechanisms governing the SRM deformation have not been well understood. A uniaxial compressive test on the SRM sample was performed under tomographic monitoring using a 450 kV industrial X-ray computed tomography (CT). A series of 2D CT images were obtained by carrying out CT scanning at key points throughout the test and from different positions in the sample. The damage evolution of the meso-element and the rock block ID tracking during deformation have been studied using the reconstructed CT images. This work suggests that formation and propagation of localized bands in SRM are mainly controlled by the existing rock blocks, which were the results of interaction between rock blocks and the soil matrix.

Keywords:

• Soil and rock mixture (SRM)
• X-ray CT
• strain localization
• meso-mechanism

Acknowledgments

The authors are very grateful to Dr. Jiemin Que from the Institute of High Energy Physics for his invaluable contribution to the experimental operation.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the State Key Laboratory for GeoMechanics and Deep Underground Engineering, China University of Mining & Technology (SKLGDUEK1824), the National key technologies Research & Development program (2017YFC0804609), the Fundamental Research Funds for the Central Universities (2302017FRF-TP-17-027A1), and the National Natural Science Foundation of China (41502294).