ABSTRACT
However, this formula could only be used when RQD is greater than 57%. For the other cases, Gardner suggested to take:
E Em E r (2)
Because of previously mentioned limitation, additional data were collected by Zhang and Einstein (2004), from the literature. Kayabasi et al. (2003), present the following formula which involves the RQD (0 < RQD < 100%) and weathering degree WD.
