Modification of the Colony Tower for Project RIO BLANCO

Technical Report · Fri Feb 01 04:00:00 EDT 1974

DOI:https://doi.org/10.2172/4353310· OSTI ID:4353310

Blume, J A; Freeman, S A; Honda, K K; Lee, L A

The Colony Tower, a 180-H tall steel-frame experimental oil shale processing retort structure with heavy process equipment on various levels, is situated approximately 29 kilometers southeast of the RIO BLANCO emplacement well. The RULISON detonation of September 1969 was about the same distance southeast of the tower. During Project RULISON, recordings of ground and structure response motions were obtained. Recorded motions showed greater responses in the higher frequency ranges than anticipated. Based on this experience and the predicted RIO BLANCO ground motion, it was determined that additional study to evaluate the expected tower performance during Project RIO BLANCO was necessary. Utilizing response spectrum predictions for RIO BLANCO, subsequent analyses showed that several bracing members would be subjected to forces exceeding their yield strength and some would reach a level at which failure could occur. Further analyses were made with assumed bracing members installed and a final scheme for modified vertical bracing was established. Modification, which consisted of fabricating and placing approximately 21 tons of structural steel and 750 pounds of welding electrode, was accomplished during the period from April 30 to May 14, 1973. To obtain measurements and indications of ground and structure response motions, 25 channels of L-7 velocity meters were installed, 19 of which were placed on the structure. No evidence of any damage was seen during the immediate post-detonation inspection of the tower. The modification of the Colony Tower and the procedures used to determine these modifications exemplity the utility of current ground motion and structural response prediction technology for forecasting dynamic behavior of important structures subjected to ground motion from underground nuclear explosions. (auth)

• Research Organization: Blume (John A.) and Associates Research Div., San Francisco, Calif. (USA)
• NSA Number: NSA-29-020827
• OSTI ID: 4353310
• Report Number(s): JAB--99-97
• Country of Publication: United States
• Language: English

Related Subjects

*MECHANICAL STRUCTURES-- MECHANICAL VIBRATIONS
*RIO BLANCO EVENT-- GROUND MOTION
*RULISON EVENT-- GROUND MOTION
DESIGN
HAZARDS
MECHANICAL EFFECTS
MOTION
N42500* --Engineering--Nuclear Explosions
OIL SHALES
STEELS
STRESS ANALYSIS
YIELD STRENGTH MECHANICAL EFFECTS