Accession Number : ADA293029

Title :   Microseism Measurements at the Waterfront - An Aid to Navy Base Microzonation.

Descriptive Note : Rept. for Jul-Oct 94,

Corporate Author : NAVAL FACILITIES ENGINEERING SERVICE CENTER PORT HUENEME CA

Personal Author(s) : Ferritto, John

PDF Url : ADA293029

Report Date : FEB 1995

Pagination or Media Count : 179

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.

Descriptors :   *NAVAL SHORE FACILITIES, *EARTHQUAKE ENGINEERING, *MICROSEISMS, *EARTHQUAKE RESISTANT STRUCTURES, *WATERFRONT STRUCTURES, DATA BASES, RISK, EXPOSURE(GENERAL), PROBABILITY DISTRIBUTION FUNCTIONS, DYNAMIC RESPONSE, SOIL MECHANICS, GROUND MOTION, GEOLOGY, SPECTRA, STRENGTH(GENERAL), SEISMIC WAVES, COMPUTER APPLICATIONS, RECORDS, EARTHQUAKES, EPICENTERS, LIQUEFACTION, SEISMOLOGY, ACCELERATION TOLERANCE, SAN FRANCISCO BAY, GUAM.

Subject Categories : Seismology
      Structural Engineering and Building Technology

Distribution Statement : APPROVED FOR PUBLIC RELEASE