Theoretical study on crystalline rock for evaluating of long-term behavior (Contract research)

Ichikawa, Yasuaki*; Seno, Yasuhiro; Nakama, Shigeo ; Sato, Toshinori  

In this research we aim to clarify a long term behavior of crystalline rocks, and performed the following subjects: (1) Uniaxial and stress relaxation tests under observation of a confocal laser scanning microscope (CLSM) by using granite specimens of Mizunami underground lab. (2) Pressure dissolution experiment using specimens of quartz single crystal and glass beads. (3) Theory establishment of pressure dissolution of quartz and a homogenization analysis for quartz dissolution. In Chapter 2 CLSM was used to acquire clearly focused three-dimensional images of granite specimens of Mizunami underground lab for uniaxial and stress relaxation tests, and observed the change of microscale structure including the mineral configuration under applying compression stress. The local strain distributions were calculated by using quadrilateral meshes of finite elements arranged on the surface of each specimen. In Chapter 3 we performed pressure dissolution experiments using specimens of quartz single crystal and glass beads, since the dissolution reaction is engaged with a deformation and failure process of polycrystalline rock. After applying stress the surface of contacted area of quartz was observed by CLSM and found traces of dissolution and reprecipitation. In Chapter 4 a reaction theory of pressure dissolution of quartz was proposed and by using a homogenization analysis the dissolution of quartz in bentonite was simulated.