Variation in Anisotropy with Dehydration in Layered Sandstone

Anisotropy in rock could significantly affect the stability and safety of engineering by differing physical mechanical properties different directions. Another major factor for is moisture state, however, whether anisotropy can be altered it remains unclear. This study investigated variation (by conduct-ing ultrasonic tests) with state (measured nuclear magnetic resonance) layered sandstones, interpreted phenomenon from perspective linking dehydration pore structure rock. The results show that (1) sandstone more obvious bedding bears stronger anisotropy, P-wave velocity perpendicular direction much lower than parallel direction. (2) index fluctuates around 1 without bedding, while was enhanced dehydration. (3) During bulk water escaped firstly then capillary bound water. (4) Dehydration controlled structure. rates directions inevitably lead to heterogeneity change rock, which reflected non-synchronous changes velocities