R.Q.D

  Rock Quality Designation  RQD RQD was introduced by Deere [5] as a way of correlating natural fracturing intensity with engineering performance of a rock mass. RQD measurements are based on the core run.Run Lengthlength of coresticks 100mmlongRQDΣ≥=%However, the ISRM [3] suggest “that RQD values are determined for variable rather than fixed lengths of core run. Values of individual beds, structural domains, weakness zones etc. should therefore be logged separately, so as to indicate any inhe