尺寸效应对锯齿状结构面抗剪强度影响

Influence of size effect on shearing strength of zig-zag structure plane

为研究尺寸效应对锯齿状结构面抗剪强度的影响,对不同尺寸的具有锯齿状结构面的试样进行直剪试验,得到不同尺寸结构面的抗剪强度,同时运用3DEC数值分析软件对试验过程进行模拟.试验结果表明:随着完整试样尺寸的增大,试样的单轴抗压强度和黏聚力减小,且减小的幅度减弱,最后趋于稳定;材料的内摩擦角随尺寸的增大,变化很小;当结构面尺寸一定,结构面受到剪切作用时,随着法向应力的增大,锯齿状结构面抗剪强度增大;当法向压力一定,随着锯齿状结构面尺寸的增大,锯齿状结构面抗剪强度减小,且减小的幅度减弱.

In order to study the effect of size effect on the shearing strength of the zig-zag structure plane, the experiment was conducted by taking direct shear tests on the rock samples of different sizes with zig-zag structure plane to obtain the relationship between the shearing strength of structure plane and its size. Meanwhile, a numerical analysis software called 3DEC was used to simulate direct shear tests on rock samples with different sizes. Results indicated that uniaxial compression strength and cohesion of rock samples decreased with its increase in size and began to stabilize when reaching a certain size. Internal friction angle changes very little with the increase of size. The shearing strength of the zig-zag structure plane with the same size increased with increase in normal stress. Under the same normal stress, with increase in size of structure plane, the shearing strength of the zig-zag structure plane decreased with a gradually reduced rate.