关键词: 田下凝灰岩, 广义应力松弛, 三轴试验, 围压效应

Abstract: In practice, rock mass is neither subjected to pure creep of pure relaxation but to a stress-strain synchronously varies with the lapse of time. Using the visual triaxial compression servo-control test system, the generalized stress relaxation tests are carried out under different confining pressures in different regions including creep and relaxation. The experimental results show that there is different conditions of strain and stress in rock mass, which include strain and stress increase at the same time, strain increase but stress decrease, strain and stress decrease at the same time; creep and relaxation are special cases of generalized stress relaxation of rock. Confining pressure effects of rock mass depend on the condition of generalized stress relaxation; confining pressure curbs the deformation in the condition of axial deformation increasing; and confining pressure promotes the deformation in the condition of axial deformation decreasing. In this paper, the study of generalized relaxation test under triaxial stress is carried out using the generalized stress relaxation test. And the generalized stress relaxation characteristics of the rock under confining pressure are compared and analyzed, so as to provide some guiding and reference significance for the further study of triaxial generalized stress relaxation test.

Key words: tage tuff, generalized stress relaxation, triaxial test, confining pressure effect