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固体围压岩石三轴实验和理论分析表明,震源环境刚度(包括轴压系统和围压系统刚度)是影响应力降的重要因素。在三轴实验条件下,轴向应力降和围压系统刚度呈双曲线关系,前者随后者的增大而减小。实验应力降显著偏大的基本原因之一在于环境刚度效应。地壳内震源应力降△τ=2λ[(S_s—S_k)+(μ_s—μ_kσ_(n.0)],λ为震源的力学环境因数,主要取决于环境刚度和应力场方向。如果滑移过程中正压力大小和主应力方向无明显变化,则λ大致为0—0.9。
Triaxial tests and theoretical analysis of solid confined rock show that the stiffness of the source environment (including the stiffness of the axial compression system and confining pressure system) is an important factor affecting the stress drop. Under triaxial experimental conditions, the axial stress drop and the confining pressure system stiffness are hyperbolic, the former decreases with the increase of the latter. One of the basic reasons why the experimental stress drop is significantly large is the effect of environmental stiffness. In the crust, the source stress drop △ τ = 2λ [(S_s-S_k) + (μ_s-μ_kσ_ (n.0)], λ is the mechanical environmental factor of the source, which depends on the environmental stiffness and stress field direction. The magnitude of the pressure and the direction of the principal stress have no significant change, then λ is approximately 0-0.9.