Abstract
We authors investigated the effects of mechanical properties of gravel and gravel content to the mechanical properties of gravelly rock, using boring-cores from breccia-type andesite and tuff breccia, Neogene Volcanic gravelly rocks in Hokuriku district, which have relatively lower contrast in mechanical properties between gravel and matrix. The result are follow:
(1) No relationship was recognized between gravel content measured around core sample and mechanical properties of rock as qu, E50 and modulus of dynamic elasiticity.
(2) As for the mode of rock failure, in a little case the stress concentration effect was recognized at the boundary between gravel and matrix. But, in most of cases, we were not able to recognize the stress concentration effect between them.
