@ ŒfÚŽGŽi˜ajF “ú–{’nkHŠwƒVƒ“ƒ|ƒWƒEƒ€˜_•¶W VolF 8-1Šª ”NF 1990”N •ÅF 19-24•Å ’˜ŽÒi˜ajF - ƒ^ƒCƒgƒ‹i˜ajF - ´˜^i˜ajF
- ƒL[ƒ[ƒhi˜ajF - ŒfÚŽGŽi‰pjF PROCEEDINGS OF THE JAPAN EARTHQUAKE ENGINEERING SYMPOSIUM ’˜ŽÒi‰pjF Stephen K. HARRIS, Charles SCAWTHORN, John A. EGAN ƒ^ƒCƒgƒ‹i‰pjF DAMAGE IN THE MARINA DISTRICT OF SAN FRANCISCO IN THE OCTOBER 17, 1989 LOMA PRIETA EARTHQUAKE ´˜^i‰pjF
All building collapses to occur in San Francisco or Oakland in the October 17, 1989 Loma Prieta earthquake actually occurred in the Marina district of San Francisco, a low-rise wood building neighborhood located approximately 100km from the epicenter of the M¡7.1 event. The Marina district was created with man-made fill between 1893 and 1911, primarily by hydraulic deposition of poorly graded sands. Liquefaction and ground failure occurred throughout the Marina, but primarily in a zone of failure just bayward of the original shoreline, resulting in broken water and gas piping and amplification of ground motion estimated to be up to a factor of four over nearby rock sites. Based on a building-by-building survey of damage, overall building damage in the Marina is estimated at 3%, while average damage to four story, wood-frame corner apartment buildings is estimated at nearly 20%. Building damage was observed to be most severe near the center of the fill, where a large fire broke out in a collapsed building, reulting in one death and the destruction of four buildings. Because of inadequate water supply, due to the broken water mains, the fire could only be suppressed following deployment of San Francisco's fireboat Phoenix, which supplied water from the Marina Lagoon to a special Portable Water Supply System developed by the San Francisco Fire Department. ƒL[ƒ[ƒhi‰pjF - ‹LŽ–‹æ•ªF - ‹æ•ª @@@ˆÏˆõ‰ï˜_•¶W