O'Donahue's theory

O'Donahue's theory

[ō′dän·ə‚hyüz ‚thē·ə·rē]
(mining engineering)
A mine subsidence theory, with subsidence regarded as taking place in two stages: first, a breaking of the rocks in which the lines of fracture tend to run at right angles to the stratification; then, an inward movement from the sides, resulting in a pull or draw beyond the edges of the workings.