tributary area concept

tributary area concept

[′trib·yə‚ter·ē ¦er·ē·ə ‚kän‚sept]
(mining engineering)
A theory that the weight to be supported by a square coal pillar should equal the weight of the rock strata above it plus the weight of rock equal in area to one-half the size of the opening adjacent to all four sides of the pillar.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.