TAN Xun, JI Feng, PEI Xiang-jun, et al. Impact factors and influence law of joint overriding and cutting
off coupling effect[J]. 2015, 36(S2): 245-251.
DOI:
TAN Xun, JI Feng, PEI Xiang-jun, et al. Impact factors and influence law of joint overriding and cutting
off coupling effect[J]. 2015, 36(S2): 245-251.DOI: 10.16285/j.rsm.2015.S2.032.
Impact factors and influence law of joint overriding and cutting
off coupling effect
In order to study overriding and cutting off coupling effect in process of joint shear
the joint three-dimensional models which have asperities of different combinations of height (h) and angle (?) are made for
conducting model shear tests. The test results confirm this coupling effect. The joint shear movement characteristics are analyzed; and a ratio of cutting off area Sj to shear area S
i.e. K
is proposed to present quantitative characteristics for the degree of coupling effect. In different dominant effect
the K changes between 0-1. Meanwhile
a shear strength formula which is involved in the coupling effect of overriding and cutting off is established to help valuating effect rule of joint shear strength. The results show not only that shear strength is largely determined by overriding friction when the K is low for hard rock with large compressive strength and for slightly undulated joint surface
but also that it is largely determined by strength of the rock material when the K is high for soft rock with small compressive strength and for roughly undulated joint surface.