Microseism Measurements at the Waterfront - An Aid to Navy Base Microzonation.
Abstract
The US Navy has a number of bases in seismically active areas. Mission requirements dictate that these bases be located at the waterfront, often on marginal soils. Since the seismic exposure is high, the Navy has had an active research program to mitigate the risk to waterfront structures. The dynamic response of saturated cohesionless soils results in a loss of strength; liquefaction and the potential for associated damage is a major problem. The 1989 Loma Prieta earthquake caused over $125 million in damages primarily from liquefaction. In 1993 the Guam earthquake caused an additional $120 million loss. The Navy has developed automated procedures for conducting site seismicity studies which utilize an epicenter data base and available geologic data to predict the recurrence of seismic events and compute the probability distribution of site acceleration ground motion. A set of response spectra matched to the site conditions can be assembled from a data base of records. To further define local site response, research was conducted on using microseisms as a means of predicting local site amplification. Procedures were developed to measure microseisms on rock and soil sites and computer amplification spectra.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1995
- Accession Number
- ADA293029
Entities
People
- John Ferritto
Organizations
- Naval Facilities Engineering Service Center