Large scale static and dynamic friction experiments
A series of nineteen shear tests were performed on fractures 1 m/sup 2/ in area, generated in blocks of sandstone, granite, tuff, hydrostone and concrete. The tests were conducted under quasi-static and dynamic loading conditions. A vertical stress assisted fracturing technique was developed to create the fractures through the large test blocks. Prior to testing, the fractured surface of each block was characterized using the Barton JRC-JCS concept. the results of characterization were used to generate the peak strength envelope for each fractured surface. Attempts were made to model the stress path based on the classical transformation equations which assumes a theoretical plane, elastic isotropic properties, and therefore no slip. However, this approach gave rise to a stress path passing above the strength envelope which is clearly unacceptable. The results of the experimental investigations indicated that actual stress path is affected by the dilatancy due to fracture roughness, as well as by the side friction imposed by the boundary conditions. By introducing the corrections due to the dilation and boundary conditions into the stress transformation equation, the fully corrected stress paths for predicting the strength of fractured blocks were obtained.
- Research Organization:
- Terra Tek Engineering, Salt Lake City, UT
- OSTI ID:
- 60626
- Resource Relation:
- Other Information: PBD: 1984; Related Information: Is Part Of Rock mechanics in productivity and protection; Dowding, C.H.; Singh, M.M.; PB: 457-466 p.
- Country of Publication:
- United States
- Language:
- English
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