关键词: 等效流变损伤模型, 节理岩体, 卸载边坡, 数值分析, 动态稳定性

Abstract: Major engineering projects put forward higher requirements for rock stability in the process of construction, and a dynamic mode of engineering design is usually applied to deal with various kinds of emergencies and diseases. Rheological damage model can simulate both the time-dependent deformation of rock mass and the time-dependent degradation of mechanical properties, which can reflect the dynamic stability of engineering projects. In order to reflect the instantaneous plastic deformation in the unloading-rebound stage of slope as well as the viscoplastic deformation in the time-evolution stage of slope, loading-plastic and viscoplastic components are applied to the rheology model; thus a composite visco-elastoplastic model (elastic-viscous-viscoelastic- viscoplastic-plastic) is established. Results of compression(unloading) creep test proves the rationality of this model; and rheological parameters are recognized. On this basis, damage tensor describes the characteristics of joint geometry, and damage evolution equation based on the viscoplastic partial strain is established; eventually, a new type of equivalent rheological damage model of jointed rock is established. Applying this model to a soft-hard interbedded slope under the cutting(unloading) condition, the results show that instantaneous plastic damage in unloading-rebound stage and viscoplastic damage in time-evolution stage, of the damageable parts (soft rock section, buried section of soft rock, hard rock section of soft-hard handover), gradually accumulate; the unloading damage areas gradually appear; creep rates of every part gradually increase in varying degrees of growth with the damage accumulating. The reasonable analysis results can reflect the dynamic stability in the process of slope cutting, and guide the intervention time of supporting measures.

Key words: equivalent rheological damage model, jointed rock, unloading slope, numerical analysis, dynamic stablility