张性结构面的力学性质与主应力关系解析

Analysis on the Mechanical Properties of a Tensile Structure Plane and Its Relationship to Principal Stresses

依据弹性理论分析了张性结构面的应力、应变与两向主应力的对应关系。笔者认为在挤压应力条件下,甚至双向挤压应力作用下,完全有可能在最大主压应力方向两侧一定角域内产生张性或张扭性结构面。张性构造区角域的大小受控于主应力比值和岩石材料的泊松比。在两向压缩应力作用下,只有当σ_2/σ_1≥0.5时,才不会有张性构造区域出现。

The stress and strain on a tensile structure plane and its relationship to principal stresses are studied based on the elastic theory. A conclusion is arrived at that in the case of a pressure stress, even a two-direction pressure, it is totally possible that a tensile structure plane is formed in some angular region along the directions of the two sides of the maximum principal stress. The size of the tensile angular regions is controlled by two factors, the principal stress ratio and the rock Poisson' s ratio. However, in the case of a two-direction pressure stress, if the principal stress ratio (σ2/σ1) is greater than 0. 5,it is impossible to form the tensile structural region.