King County Courthouse post-earthquake site review




	March 6, 2001 King County Courthouse post-earthquake site review Following is the site review report issued by the structural engineering firm of CoughlinPorterLundeen. The firm inspected the King County Courthouse immediately following the earthquake on Wednesday, Feb. 28, 2001, found no structural damage and determined that the building is safe for occupancy. To: Department of Construction and Facility Management Attn: David Layton 400 Yesler Way Suite 220 Seattle, Washington 98104 Project: King County Courthouse Seismic Upgrade Project No.: S00-0955-01 By: Keith Moore Per your request, Coughlin Porter Lundeen has performed a site review of the King County Courthouse at 516 Third Avenue in Seattle, following the February 28, 2001 Seattle area earthquake. Our observations during our site visits at 1pm on February 28th and 9:30 am on March 1st are as follows: The building is a twelve-story concrete framed building built in 1914/1929. The building has not been seismically upgraded. Observations at the building indicate that the primary structure, consisting of the concrete frames and shear walls, has not suffered damage as a result of the earthquake. We therefore feel the building is in good condition and is safe for occupancy Cosmetic damage has occured throughout the building, particularly as it relates to the movement of clay tile walls. At numerous locations throughout the building, particularly in the stair wells and behind the elevators, reflective cracks were noted in the plaster. At one location, Stair #5 on the third floor, there was a partial collapse of the non-structural clay tile wall into the stair pathway. In several locations, the plaster skim coat has become separated from the wall. The exterior cladding was, in general, in excellent condition. A single exterior window threshold at the south face of the 9th floor cracked. Half of that piece fell to the alley below. Windows in a number of locations were either broken or cracked. At two locations in the building clay tile "stalactites" approximately 4" x 4" in size had broken off and fallen through the ceiling tile. A small section of the decorative marble in the main corridor of the 4th floor has split at a fire extinquisher cabinet. No collapse or other cracking in the marble wall façade was noted. Short Term Recommendations: Replace broken windows. Tape cracked window with duct tape in a diagonal manner with tape at a minimum of 12" on-center. Completely remove the clay tile on the third floor in Stair #5 adjacent to the courtroom. Replace the wall with a 2-hour rated wall to maintain fire rating. Repair plaster cracks. During repair, remove any plaster that has separated from the clay tile. Based upon observations from elevator service personnel, leave elevators #7 and #10 out of service until further observations can be made by Coughlin Porter Lundeen, Inc. and the elevator service personnel. Long Term Recommendations: While the building structure performed well, current information from UW/USGS indicates that ground motions on firm sites in downtown Seattle (such as the Courthouse site) were not nearly as large as would normally be expected for a magnitude 6.8 earthquake centered near Olympia. We continue to strongly recommend completing the seismic retrofit. Based upon our observations, the courthouse is safe for occupancy. Please let us know if you require additional information for either the short-term recovery or long-term repair solutions for the building. Sincerely, Coughlin Porter Lundeen, Inc. Keith Moore, P.E. Structural Engineer cc: Mike Wilkins, King County Updated: March 6, 2001 Executive's home \| Executive's news Executive's e-mail King County \| Executive \| News \| Services \| Comments \| Search Links to external sites do not constitute endorsements by King County. By visiting this and other King County web pages, you expressly agree to be bound by terms and conditions of the site. The details.