Instability mode and creep characteristics of cementation of rock with splitting damage

The creep test of incremental loading is carried out on thirteen damaged rock samples in two groups through RLW-2000 triaxial rheology test system. Instantaneous strain properties and creep ones of cement samples of damaged rock are studied in different creep stress. The effects of different cement state and thickness on the breaking strength of creep are analyzed. The relationships between cement thickness and instantaneous strain and creep one are determined. The creep failure modes of cemented sample are discussed and its basic mode is determined. The results have shown that, with creep stress increasing, instantaneous strain of all the samples in two groups decreases. Creep strain of the marble samples increases and that of coarse sandstone decreases. Creep failure strength of narrow-slit cement samples are more than that of no-cement samples, but creep failure strength decreases with cement thickness increasing. Creep strain of cement samples increases slowly with cement thickness increasing in same creep stress, while the increasing range of creep strain is less than that of instantaneous one. Main failure surface of narrow-slit cement samples is simple and approximately right angle, with larger broken block. In contrast, main failure surface of thickness cement sample is complicated, and slip and dislocation is obvious between the upper and the lower of the sample. Creep failure of cementation samples includes three modes: split failure, fracture splitting, fracture slipping. © 2019, Editorial Board of Journal of Mining & Safety Engineering. All right reserved.