Experimental Study on Creep Characteristics of Unloaded Rock Masses for Excavation of Rock Slopes in Cold Areas

Seasonal freeze–thaw environments are one of the key factors that aggravate mechanical strength decay excavated and unloaded rock masses on reservoir banks in cold areas. To study time-dependent properties an mass a bank slope under action, triaxial unloading tests were carried out sandstone, simulating freezing conducted, creep implemented with graded incremental loading specimens subjected to action. The test results showed total deformation is significantly increased compared conventional specimens, lateral direction more likely produce behaviour than axial direction. level confining pressure determines affects variation law rate. aggravated by action and, longer period, larger strain share, rate increases significantly. damage pattern mainly manifested as shear damage, process intensifies derivation tension-type cracks specimens. higher specimen, obvious plastic characteristics weaker brittle during failure. reduces long-term which approximately 50~55% instantaneous strength. decays increasing research can provide theoretical reference for evaluation stability