Location

Arlington, Virginia

Session Start Date

8-11-2008

Session End Date

8-16-2008

Abstract

Synchrotron light source facilities have high demands on admissible deformations and vibrations of the foundation structure during operation. These research facilities are very complex, consisting of pumps, air conditioning equipments, emergency power generators and electrical transformers of several sizes and types. Such equipments are located on the experimental platform itself or in the vicinity of the platform. On the experimental platform, which is usually a ring with a diameter of 100 to 200 m, typical admissible values for the absolute deformations due to static loads (of 500 kg) and dynamic loads (of 100 kg) are in the range of 1 micrometer, while the admissible vibration amplitudes are in the range of 0.4 to 4 micrometers in the frequency bandwidth of 0.05 Hz to 100 Hz. These values are 500 times smaller than the value perceptible by humans. Moreover, the maximum acceptable values for differential displacements along the experimental platform are typically of 0.25 mm / 10 m / year. All these conditions are decisive for the required accuracy of the needed investigations. This paper presents case studies of the design of the experimental platforms for two synchrotron facilities, one located in Switzerland and the other in Spain, with extremely different foundation and environmental conditions: While one facility is founded on sound terrace gravel, the other is founded on mudstones with potential shrinking and swelling characteristics. The facilities and the soil conditions at the two sites are briefly discussed, and potential solutions are presented. Different alternatives for the foundation of the experimental platform are presented and compared to each other, also considering economical aspects. The main problem is that the best solutions to meet the vibration criteria are not compatible with the best ones suitable to meet the settlement criteria. The principal features in the feasibility phase and in the later design and execution phase are presented and discussed. The final solutions and their degree of fulfillment will be presented together with lessons learned for future projects.

Department(s)

Civil, Architectural and Environmental Engineering

Appears In

International Conference on Case Histories in Geotechnical Engineering

Meeting Name

Sixth Conference

Publisher

Missouri University of Science and Technology

Publication Date

8-11-2008

Document Version

Final Version

Rights

© 2008 Missouri University of Science and Technology, All rights reserved.

Document Type

Article - Conference proceedings

File Type

text

Language

English

Share

 
COinS
 
Aug 11th, 12:00 AM Aug 16th, 12:00 AM

Synchrotron Facilities: Meeting Stringent Deformation and Vibration Criteria

Arlington, Virginia

Synchrotron light source facilities have high demands on admissible deformations and vibrations of the foundation structure during operation. These research facilities are very complex, consisting of pumps, air conditioning equipments, emergency power generators and electrical transformers of several sizes and types. Such equipments are located on the experimental platform itself or in the vicinity of the platform. On the experimental platform, which is usually a ring with a diameter of 100 to 200 m, typical admissible values for the absolute deformations due to static loads (of 500 kg) and dynamic loads (of 100 kg) are in the range of 1 micrometer, while the admissible vibration amplitudes are in the range of 0.4 to 4 micrometers in the frequency bandwidth of 0.05 Hz to 100 Hz. These values are 500 times smaller than the value perceptible by humans. Moreover, the maximum acceptable values for differential displacements along the experimental platform are typically of 0.25 mm / 10 m / year. All these conditions are decisive for the required accuracy of the needed investigations. This paper presents case studies of the design of the experimental platforms for two synchrotron facilities, one located in Switzerland and the other in Spain, with extremely different foundation and environmental conditions: While one facility is founded on sound terrace gravel, the other is founded on mudstones with potential shrinking and swelling characteristics. The facilities and the soil conditions at the two sites are briefly discussed, and potential solutions are presented. Different alternatives for the foundation of the experimental platform are presented and compared to each other, also considering economical aspects. The main problem is that the best solutions to meet the vibration criteria are not compatible with the best ones suitable to meet the settlement criteria. The principal features in the feasibility phase and in the later design and execution phase are presented and discussed. The final solutions and their degree of fulfillment will be presented together with lessons learned for future projects.