4937 SEA BREEZE WAY 2017-01-13 - Laserfiche WebLink

� � Geotechnical Engineering Evaluation NGA File No. 916915 Pepe Retainin� Wall April 27, 2015 Everett, Washington Page 8 should be used to control ecosion. Areas disturbed during construction of wall repair or replacement should be protected from erosion. Erosion control measures may include diverting surlace water away fro�r� the stripped or disturbed areas. Silt fences and/or straw bales should be erected to prevent muddy water from leaving the site or flowing down the sloping �;round surface or over the wall. Stockpiles sho�ild be covered with plastic sheeting during wet weather. All undoc�nnented fill and trash iound oi� the slopc should be removed. Disturbed areas should be planted as soon as practical and the vegctation should be maintained until it is establishcd. "I,he crosion potential for areas not stripped of vegetation should be low to moderate. Protection of slope areas should be performed as required by the City of Everett Specifically, we recommend that the slope not be disturbed or modified through placement of any Iill or re�noval of the existing vegetation e�cept for dangerous trees that may pose safety risks to the house. No additional material of any kind should be placed on the slope or be allowed to reach the slope, s�ich as excavation spoils, lawn clippings, and other yard waste, trash, and soil stockpiles. Replacement of vegetation should be performed in accordance with the City of Everett code. Any proposed development within the slope sho�ild be the subject of a specitic geotechnical evaluation. Under no circumstances should water be allowed to concentrate on the slope. '�ite Preparation and Grading If the st�-uctural en�ineer determines that the wall co�ild be repaired, most of the existing wall components should remain in place. Erosion control ineasures should be implemented and site ��reparation could consist of only removing the top two feet of soil f'rom the area in front of the house, along the driveway, and behind the wall. This should take place after all of�the wall repairs have taken place. If the steel rods are encountered, they should be cut off and removed. The soil should be removed fi•om the site and not used as backfill materiaL The exposed surface should be compacted to an unyielding condition, and then backfilled with pit r�in material compacted to structural fill specifications. If the exposed soils are loose even after compaction, we recommend that a 12-inch layer of rock spalls be placed prior to placing tkle pit run. If significant surface water flow is encountered during c��nstruction, this flow should be diverted around areas to be developed, and the exposed subgrades should be maintained in a semi-diy condition. The prepared subgrade should be protected from c��nstruction t�raffic and not ove�- load the wall. Extreme care should be taken to not undermine the existing walkway and house foundations. NELSON GEOTECHN/CAL ASSOCIATES, INC.