This report summarizes experience from geoscientific studies of the Excavation Damaged and Disturbed Zones in sedimentary rocks. The bulk of these studies have been performed as part of research programs for radioactive waste disposal in argillaceous rocks. In particular, the report draws on in situ experimental studies performed in Underground Research Laboratories (URLs). 

The creation of any underground opening creates a zone of disturbed rock around it. Within this disturbed zone there may exist a zone of damaged rock. In the past various definitions of the disturbed and damaged zones have been used. This report uses the definitions of the Damaged and Disturbed Zone proposed by Tsang et al. (2005).