For the purpose of investigating the mechanics of folding process that is formed in relatively shallow underground, we have conducted buckling tests on single layer and threelayered rock beams of KIMACHI sandstone and TOHOKU marble under moderate confining pressures, namely 0, 100, 300 and 500 kg/cm2. From this study, it became clear that folding deformation of rock beam under moderate confining pressure initiates at the near point of buckling fracture stress, and failure strength of those conform to the buckling experimental formula suggested by Shanley. Also, by means of conducting buckling test using intact rock, we confirmed that folding degree of multilayered rock beam depends on thickness of unit beam rather than total thickness of beam, and that of multilayered beam constituted with various rocks depends on competent layer.
Thick deposits of Upper Pleistocene clays are often found over wide areas of the north west of Osaka Bay, and the geotechnical properties of the clays become more important as a number of large reclamation works are in progress in this area. In this paper, we examine the environment in which the Uppermost Pleistocene clay (Ma-12) was deposited, and the micro-fossil analyses and the X-ray analysis were carried out on samples taken at the RokkoIsland in Kobe. We further examine the relationship between the geotechnical properties and the geological conditions of the clay. The results of analyses of pollen-, nanno- and diatom-fossils indicate a distinct variation of the sedimentary environment in Ma-12. However, it is found that there is no major variation in components of the clay minerals with depth, despite of the environmental changes in the clay. On the other hand the geotechnical studies of Ma-12 shows that the sedimentary environment has a strong effect on the geotechnical properties of Ma-12 especially on the value of the liquid limit and the compressibility.