Relationship betweenexcavation depth and damaged rock zone for low strength rocks

Abstract EN

The induced stresses around the excavation boundary cause azone where the rock is physically damaged (mechanical properties are permanently affected), this zone is generally known as the Damage Rock Zone.

Damaged rock zone (DRZ) has a significant effect on the stability of the excavation.

Any problems associated with the DRZ create unsafe working environments and increase construction and supporting costs.

In this paper, a simulation study for the Damaged Rock Zone (DRZ) around mine excavations at different depths (100m, 200m and 400m) with disturbance factor (D = 0, 0.5 and 0.8) based on the experimental work with applying two software's (Roclab and Examine 2D).

To accomplish this study, cylindrical core specimens of low strength rock (sandstone) was prepared.

The core specimens tested using tri-axial compression machine at different confining stress levels from 1 to 12 MPa in order to investigate their mechanical properties.

The results introduced to the Roclab software to determine DRZ strength parameters, based on Hoek-Brown failure criterion.

Finally applying Examine2D software to determine DRZ thickness.

The results proved that, the extent of DRZ affected by depth of the excavation, with increasing the excavation depth, the DRZ extent increase.