ISSN:
1573-1529
Keywords:
Pillar mining
;
pillar strength
;
failure criterion
;
rock mechanics
;
coal mining
Source:
Springer Online Journal Archives 1860-2000
Topics:
Geosciences
Notes:
Summary Based on triaxial compression studies on eight coals, the well known empirical relation $$\sigma _1 = \sigma _{\text{c}} + a\sigma _3^b$$ has been suggested as the best fit. The parametersa, b and internal friction μ are shown to be interrelated. Values for μ given in Bieniawski's classification tables are used to obtaina andb for a given Rock Mass Rating (RMR), according to these interrelations. This procedure thus gives a simple failure criterion for rock masses. This non-linear failure criterion has been used in developing two independent pillar strength approaches, the first based on a Wilson type method (1972) and the second by estimating the total confining stress at the pillar centre. The performance of these new equations has been compared with some of the more popular strength formulae as tested against 16 failed and 27 stable pillar case studies. A nomogram is presented for pillar design based on the second approach developed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01552957
Permalink
