Shigen-to-sozai, Vol.116, No.7, pp.572-576.
Estimation of Global Stress State in Mt. Torigata Region
Katsuhiko KANEKO1, Naoaki NAKAMURA2, Yuzo OBARA3, Kousuke ITO1, Tetsuro YONEDA1 and Masaji KATO1
| 1. Graduate Student, Hokkaido University, 2. Division of Structural and Geotechnical Engineering, Graduate School of Engineering, Hokkaido University, Kita-ku, Sapporo 060-8628 |
| A scheme to estimate the global stress state
from the local stress state evaluated by
the field stress measurement is proposed.
In the scheme it is assumed that the global
stress is expressed by the superposition
of the stress induced by the gravity and
that by the horizontal movement of the upper
crust. The local stress state in the rock mass under the pit of Torigata-yama open cut mine, located in Shikoku Island, Japan, was measured by the Conical-Ended Borehole Technique. The local stress distribution in Mt. Torigata region was evaluated by the 3-dim. FE-analysis and the global strain and stress states were estimated by the proposed scheme. From the comparison between the local stress states measured and calculated, it is made clear that, in Mt. Torigata region, the stress state induced by the horizontal movement of the upper crust is nearly uniaxial compression and the direction of the maximum compression is ranging from N24E to N27E Furthermore, it is pointed out that the distribution of horizontal stresses are strongly affected by the Poisson's ratio of rock mass and that the high horizontal stress is acting at the floor of excavation of the mine. |
| KEY WORDS: Global Stress, Stress Measurement, 3-dim. Analysis, Open Cut Mine, Limestone |