Effects of cyclic loading on the rheological properties of sandstones

Abstract

This paper presents some results of the laboratory tests on the time-dependent behaviour of three types of sandstone. Research into the rheological properties of rocks is mostly done under static (quasistatic) loading. In nature, however, rocks are also often subjected to cyclic (vibration) loading as a result of vibrations from traffic or the propagation of seismic waves due to, for example, earthquakes, rock bursts, blasting operations and such like. On this account, the research presented is focused on the study of rheological rock properties during vibration (cyclic) loading.The tests of the rheological properties of a cyclic load were conducted both in creep regime and in relaxation regime, at various levels of average load or strain and for various parameters of vibration (frequency, amplitude).The measured values of different parameter settings were compared and evaluated so that it was possible to set the dependence of cyclical rock loading in the rheological regime. For the purpose of the comparison of rock behavior during vibration and static loading, other tests were also carried out.The results of the research show that, in the course of cyclical loading, the rock rheological properties depend, to a significant extent, on the parameters of this loading, especially the amplitude and frequency.

Strengthening effect of cyclic load on siltstone and its macro–micro fracture mechanism

“…Additionally, the fatigue characteristic of rock is influenced by the frequency of cyclic load, although the effect depends on the stress level. 12 Generally, the fatigue damage and failure of rocks occur in the yield stress stage . 13,14 Nevertheless, the strengthening or weakening effects of various rocks under cyclic loading are different.…”

“…It is generally accepted that the higher the amplitude of cyclic loading, the shorter the fatigue life will be. Additionally, the fatigue characteristic of rock is influenced by the frequency of cyclic load, although the effect depends on the stress level 12 . Generally, the fatigue damage and failure of rocks occur in the yield stress stage .…”

Physical model test and numerical simulation study of cumulative damage to deep tunnel surrounding rock under cyclic blasting load

“…Particularly, when subjecting to multiple blasting loads, the damages add up, causing a significant expansion to the damaged range of the surrounding rock (Cao et al., 2020). Generally, the surrounding rock of the tunnel presents significant non-linear deformation and damage characteristics (Šancer et al., 2011; Wang et al., 2020). The size and state of in-situ rock stress have a great influence on blast-induced damage evolution and crack initiation and development (Jayasinghe et al., 2019; Yang et al., 2018; Yi et al., 2017), which subsequently affects rock crushing (Aydan, 2013; Hu et al., 2018; Yi et al., 2018).…”

Rheological Properties of Argillaceous Intercalation under the Combination of Static and Intermittent Dynamic Shear Loads

“…On the other hand, because the rheology of weak discontinuities has a great influence on the long-term stability of geotechnical engineering, some scholars had systematically studied the rheological characteristics of weak discontinuities under static loads [22][23][24], but there are few studies on its rheology under dynamic disturbance. For example,Šancer et al [25] presented some results of the laboratory tests on the time-dependent behavior of three types of sandstone and focused on the rheological rock properties during vibration (cyclic) loading. Hu et al [26,27] studied the dynamic rheological parameters of sludge soft soil through dynamic shear tests, and the rheological mechanism characteristics and rheological parameters of sludge soft soil under dynamic loading were deduced.…”