Spalling and brittleness in surface instability failure of rock

作者：Tarokh A^*; Kao C S; Fakhimi A; Labuz J F

来源：Geotechnique, 2016, 66(2): 161-166.

DOI：10.1680/geot.15.P.024

• failure
• laboratory tests
• rocks/rock mechanics
• strain localisation

Failure of rock close to a free surface is reproduced in laboratory tests on two types of sandstone. Digital image correlation is used to study the in-plane displacement fields prior to and during the successive formation of surface-parallel fractures. The axial and lateral displacements suggest that the displacement gradient is uniform in both directions at early loading stages; as the axial load increases, the free-face effect starts to influence the displacement contours, especially the lateral displacement field. Localised damage forms a spall before reaching peak stress. Using a simple model, a rock brittleness index is proposed as the ratio of uniaxial compressive strength and surface instability peak stress.

• 出版日期2016-2