Accession Number:

AD0759050

Title:

An Investigation of Combined Thermal Weakening and Mechanical Disintegration of Hard Rock

Descriptive Note:

Semi-annual rept.

Corporate Author:

MISSOURI UNIV-ROLLA ROCK MECHANICS AND EXPLOSIVES RESEARCH CENTER

Personal Author(s):

• Clark, G. B.
• Lehnhoff, T. F.
• Allen, V.
• Patel, M.

Report Date:

1973-01-01

Pagination or Media Count:

49.0

Abstract:

The research is devoted to experimental thermal-mechanical fragmentation of Missouri red granite in place, and to supporting theoretical analyses. Theoretical analyses of temperature and thermal stress distribution are progressing well and procedures are being refined for use of more accurate boundary conditions, temperature-dependent rock properties, and other input parameters. Laboratory experiments are being conducted to determine stress and temperature distribution for a cylindrical geometry for basalt. Calculations of projected rates of advance and excavation costs indicate that for a slot type round the process is technically and economically feasible.

Descriptors:

• *GRANITE
• *ROCK
• DRILLING
• DRILLING MACHINES
• FRACTURE(MECHANICS)
• MINING ENGINEERING
• THERMAL STRESSES

Subject Categories:

• Mining Engineering
• Civil Engineering

Distribution Statement:

APPROVED FOR PUBLIC RELEASE