500 LAUREL DR 2016-01-01 MF Import

Veotechnical Engineering Study Oa-2267 Three Story Addition - 500 Laurel Street, Everett January 31, 2001 Seismic Risk While we did not perform a datailed seismic risk analysis for this project, it is clear that earthquake ground motion response is a partic�lariy important factor and that it should be carefully considered in structural design. Historically, th� Puget Sound Region has been :�ubjected to frequent earthquakes of modeiate intensity, and is designated in the Uri`omi Building Code as Seismic Zone 3. Two earthquakes that resulted in significani damage occurred in 1949 near Olympia, and in 1965 near Seattle. The April 3, 1949 earthquake is the largest recorded earthquake in the region, reachiny a magnitude of 7.1. It was felt over 150,000 square miles, resultiny in $25 million in damages, eight (8) deaths and many injuries. The Ap�il 29, 1965 earthquake of magnitude 6.5 was felt over 130,G00 square miles, and resulted in widespread damage in the Seattle area. The area was also subjected to a Magnitude 5.0 earthquake during January 1995 and a 5.4 earthquake in May of 1996, and more recently a 5.9 earthquake. Based on seismic risk analyses we have performed for similar sites in the Puget Sound region, considering the generally fi��m nature of the majority of the in-situ materials, and using the criteria contained in the City of Seattle Directors Rule 3-93 (the current state of the practice in this area for unsophisticated seismic analyses), we estimate that the design peak horizontal ground acceleration at the site should be considered to be o� the arder of the followiny: ■ Minirnum lateral acceleration = 0.17g Approximate acceleration levels are only estimatable at this time for the state of practice due to complexities of the area ±hat could iiiclude focusirg and other complex concepfs. Figure 16.2 of the 1997 eoiition of the Unifo.m Building Code (UBC) also indicates that the site is located within the seismic area desionated as Seismic Zone 3. For this zone the UBC indicates in Table 16-I that the site has the following zone factor: 1997 UBC Seismic Zone factor, 7 = 0.30 37 J I I � 1 1 I � 1 1 1