Rheological Tests of Slate and Model Identification of Rock

Abstract:

Circular increment step load and unload test, shear rheological test and two-axes compression test were carried out to study the rheological properties based on Ⅱ-Ⅴ grade surrounding rock of Wuji highway tunnels in Jiangxi Province. The tests results showed that Ⅱ-Ⅳ grade surrounding rock contained two creep sections, namely transitionary creep and stability creep, and the failure behavior of the rock is brittle fracture.Ⅴ grade surrounding rock contained three creep sections, namely transitionary creep, stability creep and accelerating creep, and the failure behavior of the rock is plastic yield. Ⅱ-Ⅳ grade surrounding rock could be reasonably simulated with generalized Kelvin modal through the modal identification, while Ⅴ grade surrounding rock was well agreed with the nonlinear modal. Rheological parameters related to stress level were also obtained by modal identification. The method of modal identification could be applied to other rock beyond slate.