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Proceedings Paper

Stiffness of the ground improved to support the pier of JNLT atop Mauna Kea
Author(s): Fumio Tatsuoka; Yukihiro Kohata; Hiroshi Karoji; Akihiko Miyashita
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Paper Abstract

A 2.5 m-thick cinder layer immediately below the pier of Subaru (Japan National Large Telescope, JNLT) now under construction on the summit of Mauna Kea in Island of Hawaii was improved by recompacting volcanic cinders obtained by excavation at the site mixed with cement. The purpose was to increase the Young's modulus at very small strains of the supporting ground to 500 MPa so as to make the lowest natural frequency of the pier-ground system in its rocking motion to be more than 4.3 Hz. This requirement is essential for the telescope control system to correct as quickly as possible for external and internal disturbance of the telescope tracking. The results of the field and laboratory geotechnical tests including the measurements of elastic wave velocities and cyclic triaxial tests, which were performed for the design of the ground improvement work and the prediction and evaluation of the Young's modulus of the constructed layer, are described.

Paper Details

Date Published: 1 June 1994
PDF: 10 pages
Proc. SPIE 2199, Advanced Technology Optical Telescopes V, (1 June 1994); doi: 10.1117/12.176207
Show Author Affiliations
Fumio Tatsuoka, Univ. of Tokyo (Japan)
Yukihiro Kohata, Univ. of Tokyo (Japan)
Hiroshi Karoji, National Astronomical Observatory (Japan)
Akihiko Miyashita, National Astronomical Observatory (Japan)


Published in SPIE Proceedings Vol. 2199:
Advanced Technology Optical Telescopes V
Larry M. Stepp, Editor(s)

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