Meso numerical study on the failure mechanism of rock slope with bedding intermittent joints

Abstract

Taking the Muliashi north open-pit mine in Zambia

as a case study, the failure mechanism of rock slope

with intermittent bedding joints was investigated

from a meso mechanical viewpoint using particle

flow theory and PFC2D software. In the rock slope

model, the rock block and joint were represented

by bonded-particle model and smooth-joint model,

respectively. The main research results are as

follows: (1) Due to orientation and discontinuities

of joint, the sliding shape at the bottom of the

sliding mass is relatively straight, while the tailing

edge shape of sliding mass is flexural and is

presenting step-path failure. (2) The fragmented

particle assemblies of sliding mass are primarily

generated in the middle and bottom part of slope.

And they are subsequently generated in the top part

of slope. The bulk of fragmented particle

assemblies in the middle and bottom part are

relatively larger than those in the top part. (3) At

the end of sliding process, the contact force of

particle is relatively larger along with the direction

of rock bridge, and the effect of stress arch is

generated around the primary joints. (4) During

the sliding process of rock slope, the relationship

between the magnitude and count of microseismic

events obeys the normal distribution function

approximately.