Accession Number:

AD0737622

Title:

Scaling Problems of Wave Propagation in Rocks

Descriptive Note:

Final rept. 1 May 1969-15 Oct 1971

Corporate Author:

STANFORD RESEARCH INST MENLO PARK CA

Report Date:

1971-10-01

Pagination or Media Count:

44.0

Abstract:

Propagation of large-amplitude plane waves was studied in rock specimens from 12 to 12 inches thick using in-material piezoresistive stress gages. Sioux quartzite, charcoal black granite, and Coconino sandstone were examined. Good records were obtained in the granite experiments, allowing separation of the precursor from the main wave to be observed at five successive locations in a single experiment. It is concluded that time-dependent effects on wave propagation in quartzite and granite are not significant over these distances. Seven experiments in granite, with dry and water-filled open cracks, displayed the effect of the crack in erasing the precursor. The results show that the presence of a crack volume of a percent or so greatly changes the structure of the precursor. Only a few records were obtained in the sandstone experiments, and these are only partially understood.

Subject Categories:

  • Seismology
  • Explosions

Distribution Statement:

APPROVED FOR PUBLIC RELEASE