节理起伏角对非贯通节理岩体力学特性的影响

对非贯通节理岩体进行直剪试验,在相同法向应力作用下研究具有不同节理起伏角的非贯通节理岩体的强度特性、变形特征。并采用颗粒流数值模拟软件(PFC 2D)进一步研究非贯通节理岩体的细观扩展机理。两种试验研究表明:(1)非贯通节理岩体的破坏形态受节理起伏角的影响显著,随着节理起伏角增大,岩体的破坏程度逐渐加重,岩体破坏时的张拉裂纹越大,裂纹数目也越多,张拉节理与两节理面之间的夹角将越大,表面破损也越明显;(2)非贯通节理岩体的变形特征受节理起伏角的影响显著,当节理起伏角不同时,非贯通节理岩体的法向变形将不同,随着节理起伏角增大,非贯通节理岩体的峰值切向位移逐渐减小;(3)非贯通节理岩体的强度特性受节理起伏角的影响显著,随节理起伏角的增大,非贯通节理岩体的峰值剪切强度增大,岩体抗剪强度增大。

Influence of Joint Undulation Angle on Mechanical Properties of Non-penetrated Joint Rock Mass

The direct shear test of the non-penetrating jointed rock mass is carried out.Under the same normal stress,the strength and deformation characteristics of non-penetrating jointed rock mass with different joint fluctuation angle are studied.In addition,the particle flow numerical simulation software Particle Flow Code (PFC 2D) was used to further study the microscopic extension mechanism of the non-penetrating jointed rock mass.Two experimental studies have shown that:(1) The failure form of the non-penetrating jointed rock mass is significantly affected by the joint fluctuation angle.With the increase of the joint undulating angle,the damage degree of the non-penetrating joint rock mass is more serious.With the greater the angle of the joint,the greater the tensile crack in the rock mass,the more the number of cracks,the greater the angle between the tensile joints and the two joints,and the more obvious the damage surface is damaged;(2) The deformation characteristics of non-penetrating jointed rock mass are significantly affected by the joint fluctuation Angle.When the joint fluctuation angle is different,the normal deformation of non-penetrating jointed rock mass will be different.With the increase of joint fluctuation angle,the peak shear displacement of non-penetrating jointed rock mass gradually decreases;(3) The strength characteristics of jointed rock mass are significantly affected by the joint fluctuation angle.With the increase of the joint fluctuation angle,the peak shear strength of non-penetrating jointed rock mass increases,and the shear strength of rock mass increases.