intermediate principal stress meaning in English

第二主应力
中间主应力
中主力

When the effect of intermediate principal stress was considered in different degrees , the dimensions and shapes of surrounding rock mass is rather different , and this phenomenon will be more obvious with the increase of the difference of horizontal stress and vertical stress
当不同程度地考虑中间主应力的影响时，围岩塑性区形状和大小有较大不同，且随水平应力与垂直应力差异性的增大，这种影响趋于明显。