4841 GLENWOOD AVE 2019-01-11 - Laserfiche WebLink

mom LWJ \J i. RILEYGROUP MAR 11 2017 March 21, 2017 CITY OF EVERETT Mr.Chad Slayton Permit S-ervi es Caliber Real Estate Services LLC 6031 Connection Drive,Suite 100 Irving,Texas 75039 RE: Retaining Wall Interim Option 4841 Glenwood Avenue Everett,Washington RGI Project No. 2016-072 References: The Riley Group, Inc. Retaining Wall Recommendations, 4841 Glenwood Avenue, Everett,WA, dated August 16,2016 Dear Mr.Slayton As requested, The Riley Group, Inc. (RGI) is providing this letter to provide an interim option for the retaining wall. RGI previously the referenced letter with recommendations for the design and construction of a replacement wall for the exiting Ultrablock Wall. Understanding We understand the City of Everett Code Enforcement is requiring the wall be addressed now rather than waiting for the dry season to begin work on the replacement of the wall. We also understand that the replacement wall consisting of a cast in place reinforced wall is not yet permitted for installation. Interim Wall Recommendations In order to reduce the height of the wall and therefore the loading on the wall,we recommended removing the top 2 blocks from the top of the wall and installing them as a second wall approximately 15 feet from the face of the existing wall. The top block on the majority of the existing wall is not backfilled with soil but extends above the existing grade. The attached Site Sketch shows the approximate location and the existing and proposed grades. The existing Ultrablock wall is 6 blocks high in the area proposed for removal of the top 2 blocks reducing the exposed wall height to about eight feet in height. This interim solution does not improve the overall stability of the remaining wall to current design standards due to the lack of batter and the poor soil conditions behind the wall, however this will reduce the loading on the lower portion of the wall by removing about two and one half feet of soil from the top of the wall. The soils excavated should be removed from the site if feasible, or stockpiled on plastic and covered with plastic in the area shown on the site sketch. The small trees currently growing between the wall and the existing pavement surface should be chipped on site and spread between the two walls as erosion control over the exposed soil surface. The exposed soil should be compacted to seal the surface prior to placement of the chips. The new wall should be placed on a leveling course ,of 5/8 clean crushed rock and the void between the existing concrete should be backfilled with the same rock to provide drainage to the Corporate Office 17522 Bothell Way Northeast Bothell,Washington 98011 Phone 425.415.0551 4 Fax 425.415.0311 www.riley-group.com