Pset_SpatialGeoObsMappedZoneCommon Common properties for mapped zone observations. IfcSpatialZone/MAPPEDZONE IfcSpatialZone/MAPPEDZONE GSI The Geological Strength Index (GSI): A characterization tool for assessing engineering properties for rock masses. RMR The rock mass rating (RMR) is a geomechanical classification system for rocks, developed by Z. T. Bieniawski. Q-value A description of the rock mass stability of an underground opening in jointed rock masses based on Q-system which was originaly developed at NGI.2015 - Handbook on the Q-System - NGI.