SHOCK UNLOADING CHARACTERISTICS OF POROUS GEOLOGICAL MATERIALS.
Technical rept. 15 Dec 64-15 Jul 66,
IIT RESEARCH INST CHICAGO IL
Pagination or Media Count:
The shock unloading characteristics of porous geologic materials have been determined for a number of pertinent variables. Experiments have been conducted on dry volcanic tuff for three different values of initial density. These experiments indicate that the unloading characteristics are essentially independent of the initial density and that a rather universal set of unloading curves exist. A series of experiments was conducted on wet samples of volcanic tuff. These experiments indicate that the moisture content is an important parameter and that the energy recovery can vary from approximately 20 percent of the internal energy for dry samples to 100 percent for completely saturated samples. A 50 percent saturated sample yielded a recovery factor of approximately 80 percent. Experiments were conducted on dry sandstone samples and established the existence of a phase transition in the Hugoniot at approximately 220 kilobars. Unloading data were also obtained on dry sandstone at three different stress levels. These unloading curves were similar to those for dry volcanic tuff. Author
- Geology, Geochemistry and Mineralogy