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Heat Induced Fracturing of Rock in an Existing Uniaxial Stress Field

Published online by Cambridge University Press:  28 February 2011

J. I. Mathis ,
O. Stehpansson ,
B. Bjarnason ,
H. Hakami ,
A. Herdocia ,
U. Mattila  and
U. Singh
J. I. Mathis
Affiliation:
Dept. of Rock Mechanics, University of Luleå, S-951 87 Luleå, Sweden
O. Stehpansson
Affiliation:
Dept. of Rock Mechanics, University of Luleå, S-951 87 Luleå, Sweden
B. Bjarnason
Affiliation:
Dept. of Rock Mechanics, University of Luleå, S-951 87 Luleå, Sweden
H. Hakami
Affiliation:
Dept. of Rock Mechanics, University of Luleå, S-951 87 Luleå, Sweden
A. Herdocia
Affiliation:
Dept. of Rock Mechanics, University of Luleå, S-951 87 Luleå, Sweden
U. Mattila
Affiliation:
Dept. of Rock Mechanics, University of Luleå, S-951 87 Luleå, Sweden
U. Singh
Affiliation:
Dept. of Rock Mechanics, University of Luleå, S-951 87 Luleå, Sweden
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Abstract

The thermal fracturing of rock has been the object of several research projects, notably for initial rock breakage in mining [4] as well as crushing [6] In addition, the process has been studied carefully in regards to the storage of radioactive waste underground where rock fracturing could lead to a loss of radioactivity confinement. The Stripa Project, a project concerning large scale testing of procedures for underground storage of nuclear waste, probably has dealt most thoroughly with this subject by theoretical studies and in-situ heater testing in an attempt to describe the thermal failure process in rock [13]

This project was designed to test the agreement between theoretical and actual rock fracture times of a rock block, loaded with a physical as well as a thermal load. Laboratory testing consisted of physically loading center-drilled cubes of rock, 0.3 m on a side, uniaxially from 0 to 25 MPa. These were then thermally loaded with a nominal 3.7 kW (factory rating) cylindrical heater until failure occurred. This time to failure was recorded for comparison with a direct mathematical and a finite element solution. For both cases, calculations were performed at specific time-steps and an estimated failure time calculated from the compiled results.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 50: Symposium STOCKHOLM – Scientific Basis for Nuclear Waste Management IX , 1985 , 799
Copyright
Copyright © Materials Research Society 1985

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References

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