NEHRP Clearinghouse
- Title
- Damping Capacity of Boston Blue Clay. Optimum Seismic Protection for New Building Construction in Eastern Metropolitan Areas.
- File
- PB294050.pdf
- Author(s)
- Trudeau, P. J.
- Source
- National Science Foundation, Washington, DC. Applied Science and Research Applications., January 1973, 11 p.
- Identifying Number(s)
- INTERNAL STUDY-27
- Abstract
- This report presents the results of the determination of the damping capacity of undisturbed samples of Boston Blue Clay obtained using Massachusetts Institute of Technology's Hardin Oscillator. Two methods of determining damping were used and are illustrated. In the Log Decrement method a photograph of the decaying vibration is used to determine the log decrement of the apparatus and of the system with specimen at the resonant frequency. Equations are then used to compute the damping ratios. In the Frequency and Amplitude of Vibration method, the frequencies and amplitudes of vibration at resonance and at a higher frequency are used to determine the damping capacity. The values of damping of Boston Blue Clay as determined by this testing program are between 1 percent and 3 percent.
- Keywords
- Seismic design; Earthquake resistant structures; Boston blue clay; Damping; Buildings; Earthquake engineering; Secondary waves; Clays; Soil properties; Soil dynamics; Eastern Region (United States)