ROCK MASS DAMAGED ZONE CAUSED BY BLASTING DURING TUNNEL EXCAVATION

Abstract

Izrada podzemnih rudničkih prostorija, tunela i odlagališta radioaktivnog otpada, podrazumijevaju primjenu jednakih odnosno sličnih tehnologija. Uslijed iskopa tunela miniranjem dolazi do određenog stupnja oštećenja stijenske mase oko konture presjeka iskopa. Oštećenja stijenske mase koja nastaju u neposrednoj okolini konture presjeka tunela izražene su proširenjem postojećih i stvaranjem novih pukotina, odnosno promjenom fizičko-mehaničkih svojstava stijenske mase. Prilikom izrade dubokih geoloških odlagališta radioaktivnog otpada zahtjevi po pitanju što manjeg oštećivanja stijene su jednaki ili veći u odnosu na tunele. Opisana istraživanja usmjerena su određivanju dubine zone oštećenja nastale miniranjem. Dubina zone oštećenja određivana je mjerenjem promjena fizičko-mehaničkih svojstava stijenske mase oko konture iskopa tunela. Istraživanjem su parametri bušenja i miniranja uspoređeni s dubinom i veličinom prostiranja oštećenja.Design of underground spaces, including tunnels, and repositories for radioactive waste include the application of the same or similar technologies. Tunnel excavation by blasting inevitably results in the damage in the rock mass around the excavation profile. The damage in the rock mass immediately next to the tunnel profile emerges as the expanding of the existing cracks and the appearance of new cracks, i.e. as the change of the physical and-mechanical properties of the rock mass. Concerning the design of deep geological repositories, requirements in terms of damaged rock are the same or more rigorous than for the design of tunnel. The aforementioned research is directed towards determining the depth of damage zone caused by blasting. The depth of the damage zone is determined by measuring the changes of physical and-mechanical properties of the rock mass around the tunnel excavation profile. By this research the drilling and blasting parameters were correlated with the depth and size of the damage zone