ABSTRACT
The Excavation Damaged Zone (EDZ) is one of the striking issues of deep geological repository, with mechanical excavating technology standing out as a key approach for mitigating EDZ. However, the challenge lies in the severe wear on cutters and the subsequent reduction in excavation rates when dealing with high-strength rock. This not only results in economic losses but also causes project delays. To address this issue, the blasting technique for rock weakening was developed. This study presents the findings of a field experiment conducted in a gneiss quarry in Korea, aiming to investigate the validity of weakening rock and the influence on EDZ. Comprehensive site investigations and laboratory tests were carried out to assess rock and blast properties. Results indicate that Pre-fracturing successfully weakens the rock face and controls the extent of EDZ.
