Shigen-to-sozai, Vol.118, No.12, pp.729-736.

A Consideration on Particle Size Distribution of Fragments and Energy Required in Uniaxial Compression Tests

Seisuke OKUBO^a, Wenli CHEN^a and Katsunori FUKUI^a

Five rocks were compressed and crashed up to 20% of the initial height and the fragments were collected and sieved. The main results are summarized as follows: (1) Particle size distribution of fragments follows the mixed Weibull distribution depending on the grain sizes of rock. R is the weight percentage retained on the sieve of aperture dp, and de is the absolute size constant (de1 < de2< de3). (2) In case of Akiyoshi marble, weighing function W, is nearly zero. Except Akiyoshi marble, all other four rocks show the similar particle distribution trend in which W, is considerably larger than W1. (3) End-surface condition, moisture-and size effect of rock specimen has only small influences on the particle size distribution. (4) Energy required during testing has close relationship with the size distribution of fragments.

KEY WORDS: Rock, Uniaxial Compression, Fragment, Weibull Distribution, Grain Size, Excavation, Specific Energy