Evolution of residual strain and strain energy in rocks under various types of uniaxial cyclic loading-unloading

In the process of roadway excavation, rock mass around is often subjected to cyclic loads, and mechanical properties strain energy evolution under loads are obviously different from those compression, so it urgent carry out research on loads. This study aims investigate residual in rocks uniaxial loading-unloading experiments (UCLUE). Four types rocks, namely coal, white sandstone, red granite, were compression (UCE) various (UEACLUE). The findings as follows: analysis UEACLUE revealed a gradual decrease with an increasing number cycles, leading its eventual disappearance. However, if (CLU) was continued beyond this point, displayed reappearance strain. cycles required eliminate found be inversely proportional peak strength while directly upper limit value UCLUE. Among stages loading unloading test, plastic stage sandstone exhibited largest disparity dissipated energy, followed by coal displaying smallest difference. Analysis four tests differences 0.00348 mJ▪mm −3 , 0.03488 0.02763 0.01619 for respective types. Furthermore, examination input density (ISED) (DSED) during CLU showed linear relationship between these variables. Additionally, investigation ISED DSED other UCLUE demonstrated adherence cyclic-linear dissipation law (CLDL). positive significance development fatigue damage mechanics.