A laboratory characterisation of the response of intact chalk to cyclic loading

This paper reports the cyclic behaviour of chalk, which has yet to be studied comprehensively. Multiple undrained high-resolution triaxial experiments on low- medium-density intact along with index and monotonic reference tests, define conditions under either thousands cycles could applied without any deleterious effect, or failure provoked specified numbers cycles. Intact chalk's response is shown differ from that most saturated soils tested comparable conditions. While chalk can reduced putty by severe two-way displacement-controlled cycling, its proved stable nearly linear visco-elastic over much one-way, stress-controlled loading space examined, stiffness improving cycles, loss shear strength. However, in cases where occurred, specimens showed little sign damage before cracking movements discontinuities led sharp pore pressure reductions, non-uniform displacements onset brittle collapse. Chalk's resembles fatigue metals, concretes rocks, micro-shearing initiates imperfections generate stress concentrations; identify key features must captured representative model.