304 SE EVERETT MALL WAY PANERA BREAD Geotech Report 2025-07-25

KA No. 092-12004 August 24,2012 Page No. 13 least 90 percent of the maximum dry density based on ASTM Test Method D 1557. Pipe bedding should be in accordance with the pipe manufacturer's recommendations. The contractor is responsible for removing all water-sensitive soils from the trenches regardless of the backfill location and compaction requirements. The contractor should use appropriate equipment and methods to avoid damage to the utilities and/or structures during fill placement and compaction. Lateral Earth Pressures and Retaining Walls Development plans had not been completed at the time this report was prepared and we do not know if retaining walls are planned for the project. We have developed criteria for the design of retaining or below grade walls. Our design parameters are based on retention of the in-place soils. The parameters are also based on level, well-drained wall backfill conditions. Walls may be designed as "restrained" retaining walls based on "at-rest" earth pressures, plus any surcharge on top of the walls as described below, if the walls are braced to restrain movement and/or movement is not acceptable. Unrestrained walls may be designed based on "active" earth pressure, if the walls are not part of the buildings and some movement of the retaining walls is acceptable. Acceptable lateral movement equal to at least 0.2 percent of the wall height would warrant the use of "active" earth pressure values for design. We recommend that walls supporting horizontal backfill and not subjected to hydrostatic forces be designed using a triangular earth pressure distribution equivalent to that exerted by a fluid with a density of 35 pcf for yielding(active condition)walls,and 55 pcf for non-yielding(at-rest condition)walls. The following table, titled Wall Design Criteria, presents the recommended soil related design parameters for retaining walls with well-drained level backfill. Contact Krazan& Associates, Inc. if an alternate retaining wall system is used. Krazan&Associates,Inc. Eleven Offices Serving The Western United States