3313 OAKES AVE 2020-07-14 - Laserfiche WebLink

GeoTest Services,Inc. December 9,2016 3313 Oakes Avenue,Everett,WA Job No. 16-0659 value. We do not recommend increasing the coefficient of friction to resist seismic or wind loads. Geotechnical Parameters for Preliminary Shoring Design At the time that this report was written, a decision had not been formally made by the project team regarding the inclusion of a shoring wall along the southern side of the subject property. The following soil parameters can be assumed in the preliminary design of a formal shoring system. TABLE 1: Geotechnical Parameters for Preliminary Shoring Design Parameter Value Unit Weight 135 pcf Friction Angle 350 Active Pressure 35 pcf At-rest Pressure 55 pcf Passive Pressure 275 pcf The adjacent southern retaining wall foundation will exert a surcharge on the proposed shoring wall. Adjacent footings that are higher in elevation than the proposed building footings will exert a surcharge on the footings of a new structure if a 1 H: 1V (or steeper) imaginary slope exists between the outside edges of the existing wall foundation and the proposed wall foundation. This will need to be accounted for in the design of the shoring wall. Although the above parameters can be assumed in the preliminary shoring design, a formal shoring design would require additional input from GTS. During the formal design process, it may be necessary to refine some of the above assumptions as the design is being completed. GTS should be given the opportunity to review the final shoring plans to confirm that the parameters given above and the recommendations given in this report have been incorporated into the final design. It is ultimately the governing municipality or jurisdictional body that will accept the final shoring design. Therefore, it must be accepted by the Client that variability exists and that the desired shoring type may not be permitted under the governing jurisdiction, or that the desired shoring type and supporting documentation may be denied, revised, or otherwise rejected through the formal permit process. Foundation and Site Drainage To reduce the potential for perched groundwater and surface water to seep into interior spaces we recommend that an exterior footing drain system be constructed around the perimeter of new building foundations as shown in the Typical Footing and Wall Drain Section, Figure 3. The drain should consist of a minimum 4-inch diameter, rigid, perforated PVC pipe, surrounded by a minimum 12 inches of filtering media with the discharge sloped to carry water to a suitable collection system. The filtering media may consist of open-graded drain rock wrapped by a nonwoven geotextile fabric (such as Mirafi 140N or equivalent) or a graded sand and gravel filter. The drainage backfill should be carried up the back of wall to within approximately 1 foot of the ground surface and contain less than 3 percent by weight passing the U.S. Standard No. 200 sieve (based on a wet sieve analysis of that portion passing the U.S. Standard No. 4 sieve). Page 11 of 17