Abstract
Mechanical experiments of sandstone were carried out to investigate an influence of sedimentary structure. Especially, the elastic wave velocity and uniaxial compression strength were carefully measured for cylindrical specimens that were prepared in different direction (every 30 degree from North; size: φ 50 mm, h 100 mm). First of all, a plate shaped block (500 mm × 500 mm × 100 mm) which is parallel to the bedding plane was prepared. Then, totally 12 core specimens were taken from the block. P wave velocity test and uniaxial compression test were performed for the naturally dried specimens, respectively. From the uniaxial compression test results, an alteration of Young's modulus was also calculated such as; E10, E30, E50, E70 and E90 (numbers indicate the percentage of each uniaxial compression strength). Moreover, another plate shaped block which is vertical to the bedding plane and the same direction to the maximum uniaxial strength of parallel block specimens was prepared. The anisotropy of P wave velocity was insignificant for both block specimens. However, anisotropy of uniaxial compression strength was noticeably high on the parallel block specimens. In addition, an information of paleocurrent direction which is parallel to the direction of maximum uniaxial compression strength on parallel block specimens supports that a sedimentation process might can make an anisotropy of mechanical properties even though it is parallel to the bedding plane.
