Abstract
Method of estimating the pore volume in rock mass has been described. The pore volume is obtained by using the data of the “vacuum-permeability test” which is a method of detecting the loosened zone in rock mass from the air permeability distribution characteristics. To get the pore volume, the airflow rate and the pressure reduction in test section are analyzed during the field measurements and the calibration test executed within the highly sealed steel pipe. The reliability of this method has been confirmed by laboratory test, and some examples of field measurement have been shown.
