Study on Anchored Red Sandstone's Creep Characteristic Test and its Constitutive Model

摘要

In order to reveal deformation laws of anchored rock under long-term loads, in this paper, creep mechanical characteristics of anchored rock are analyzed, and anchorage constitutive model considering time effect is initially studied based on laboratory tests. Red sandstone of good homogeneity is used as anchored matrix, bamboo as the anchor, mixture of barite powder and rosin alcohol as the binder, then anchored red sandstone is made according to the similar criteria. Non-anchored and anchored specimens' indoor long-time (above 100h) creep test is conducted by RLJW-2000 rheology tester, The results show that, creep stress threshold of anchored rock is increased by about 30%σ_c, creep deformation at different stress level stage is significantly controlled, and anchored specimen's long-term intensity is increased by 5%～10%σ_c, which still has some capacity after destroyed. In addition, starting from the overall mechanical effect of anchor's reinforcement to rock, according to equivalent co-deformation principle, one-dimensional creep constitutive equation of anchored rock is established, the answer of anchored generalized Kelvin (B-K) model is derived and control mechanism on creep deformation of rock by bolt is analyzed.