Elasto-brittle damage analysis of circular roadway based on continuous damage theory

摘要

Considering the brittle damage properties of rock, the relationship of rock damage variable and brittle parameters was established by introducing the nonlinear brittle damage constitutive model of rock and inferring the damage evolution equation from one-dimensional to three-dimensional.The circular roadway surrounding rock was divided into damage residual zone, damage progressive zone and elastic zone, using elasto-brittle continuous damage theory, the analytic solutions of damage range and surrounding rock stress were deduced.When only damage progressive zone appears in roadway surrounding rock, the limit in-situ stress and damage radius of different damage degree were deduced;when damage progressive zone appears in roadway surrounding rock, considering the characteristics of damaged rock still has residual bearing capacity, the damage radius and stress distribution of roadway surrounding rock were deduced.Then, examples were analyzed to show the effect of rock damage degree and brittleness on damage radius and stress distribution of roadway surrounding rock.The results show that the effect of rock brittleness on damage radius is associated with the damage degree of rock, when the rock brittleness is stronger, the peak of tangential stress of surrounding rock will bigger;when damage degree of rock is bigger,damage radius will bigger, then, the peak of tangential stress will farther from the roadway wall.