Rock stress states and stabilities of Kitakami Mountains as a candidate-site of the ILC project

The International Linear Collider (ILC) is an underground structure that has a 31-50 km long straight tunnel and a collision experiment hall at the central area. The required conditions of geology and rock physics for constructing ILC facilities will be that the hard and sound rock bodies is located around the candidate-site. On the other hand, the establishment possibility of this facility is dependent on the long-term stability of the in-situ stress states, we have also examined the effects of crustal deformation in the 3.11 earthquake. As a result, it has been understood that the crustal strains and the magnitude of rock stress are smaller than other sites in Japan from the results of stress measurement and GPS analysis. (author)