Strength and failure modes of pre-existing jointed rock mass with different joint dip angles

joint discontinuity degrees

joint sets

load strain ratios

slenderness ratios

joint filling’s depths and its sort under uniaxial compression are studied by means of similar material model tests. The results show that failure modes and peak strength of jointed rock mass are much related to joint configuration. Shear failure along or tensile failure across the joint face will occur in the continuous jointed rock mass

in which the peak strength is less corresponding to the first failure mode. To discontinuous jointed rock mass

its peak strength lies between that of intact rock and continuous jointed rock mass. With increase of parallel joint sets’ number

strength of rock mass gradually decreases. With increase of loading strain ratio

peak strength of rock mass gradually increases; and its failure mode becomes complicated. The slenderness ratio does not change the failure mode of the rock mass; and the intact specimens mainly show tensile failure; while the jointed ones mainly show shear failure. With increase of the slenderness ratio

the peak strength gradually increases; while to joint filling’s depth

it is reverse. The effect of different joint’s fillings on the specimen’s strength exists.