6916 BERKSHIRE DR 2016-07-29 - Laserfiche WebLink

Design Build Services, Inc. Engineering & Construction Management 28119-120th St.S.E., Monroe,WA 98272 Phone/Fax:(360)793-9659 E-mail:rheide@dbsmonroe.com March 23, 2015 Jeff Stewart Stewart Company 1242 State Ave. Ste. I—PMB 208 Marysville, WA 98270 (425) 330-1996 Subject: Footing and Concrete backfill @ 6916 Berkshire Dr. SE, Everett As requested by the City of Everett I have reviewed the situation where a crawlspace has been partially excavated for a basement, undermining the existing footings. The excavation is below the theoretical 1:1 stress slope that projects down from the existing footing. This is unacceptable and the access to this location is limited. As a result it is proposed to pump concrete fill to backfill the slope to re-establish the 1:1 slope. The lowest bench is being formed vertically to allow for useful space. As a result this wall will project up above the 1:1 stress plane and has to be treated as a stem wall. The wall is under 4'so it would normally not require engineering, however, the concrete fill on the upper bench will form a surcharge so the wall does require engineering. I have designed with 2,500 psi concrete so no testing is required. It is my understanding the wall will be poured in two pours. The wall, and then the slab and concrete fill. The wall and the footing portion of the slab has to be poured in the first pour. They can be poured as a mono-pour. I am concerned that with the weight of the concrete fill, the upper bench could overstress the lower wall befor:•r'he break-out bars become effective. This should address the co ems of the City. If you have any further questions or I can be of any further assistance please :II me at the above number. 4fIO E te A to I C ,41 , ti Al: 3iZ3115' Rick Heide, P.E. President Attachments