岩石拉伸流变失稳模型及其应用

Tensile rheological destabilization model of rock and its application

本文从岩石拉伸流变失稳的基本概念出发,建立了描述岩石拉伸流变失稳的模型,推导了有限元公式,并给出了算例分析,模拟了在开挖过程岩梁初次来压拉伸流变失稳的过程。

Proceeding from the basic concept oftensile rheological destabilization of rock,the paper established the model describingthe rock destabilization due to tensilerheological deformation, by adopting themodified Saihara's model, wherein its yieldstrength, σ_f ,was replaced by the long termtensile strength of rock, σ_∞. In fact, whenthe tensile stress surpasses σ_∞, the thirdstage of creep will happen. The modifiedSaihara's model satisfies the condition:when σ>σ_∞, E<0, then t→∞ ε→∞. Thepaper conducted the finite element analysisby using rigidity-variable method, therebyinferred the formulae. and showed an ana-lysing example, simulating the process oftensile rheological destabilization duringthe first weighting of the roof rock beamdue to excavation.