where [[epsilon].sub.L] is the bulk strain constant when the pore pressure is infinite and [p.sub.L] is the pore pressure when the bulk strain is 0.5[[epsilon].sub.L] (Pa).
The definition of porosity is [phi] = [V.sub.p]/V, and the bulk strain [[epsilon].sub.v] of coal-rock mass can be obtained by (11) [16, 17]:
When the pore pressure of coal-rock mass is [p.sub.0], the initial porosity is [[phi].sub.0], and the initial bulk strain is 0; then, the porosity can be expressed as
Rotation of this segment of the fold train is the logical alternative, such that [F.sub.2] fold axial planes move close to the orientation of earlier bedding-parallel or sub-parallel structures as bulk strain increases.
A model relating [F.sub.2] (and [F.sub.1]) folds to the initial Fredericton Fault, a low-angle detachment with dip-slip motion, explains the increase in bulk strain toward the present fault.
Bulk strain in this transect suggests a direct relationship between fold-style and the Fredericton Fault.
