ISSN:
1570-1468
Source:
Springer Online Journal Archives 1860-2000
Topics:
Energy, Environment Protection, Nuclear Power Engineering
Notes:
Conclusions 1. The experiment that we conducted confirmed the earlier existing hypothesis concerning the development of a prestressed state in the rock surrounding a tunnel lining as a result of pressure grouting. 2. The prestressed state of the rock was found to be 15–20% lower than the injection pressure during all stages of and immediately following the injection. 3. Immediately after grouting, and for the next 2 days, the compressive stresses in the lining were, on the average, 25–30% higher than those in the rock mass. Later on, this difference was reduced to 5%, and stabilized. 4. The basic relaxation of prestress in the rock and lining occurs during the first 10 days after grouting. 5. Three months after grouting, the prestress state of the rock and lining is virtually stable, having been reduced by a factor of 1.5–2 at this time. Our experiment is peculiar in nature for the case of an isotropic rock mass of average toughness with group (simultaneous) injection of an entire tunnel section and demonstrates only the practical feasibility of developing prestress in the rock mass around a tunnel. Comprehensive field studies for different engineering-geologic situations are absolutely necessary to the broad utilization of this effect in tunnel construction.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02308017
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