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

• Geotechnical Engineering Evaluation Pepe Retaining Wall Everett, Washington NGA File No. 916915 April 27, 2015 Page 13 from the structures. Surface water should be collected by permanent catch basins and drain lines, and be routed into an appropriate discharge syste�r� at the bottom of tl�e slope. We did not observe evidence of footing drains around tlle residence. We recommend that a drainage contractor evaluate this condition and implement drainage systems as warranted. We observed vertical drains near the walkways and also below tl�e wall. We recommend that roof drains not be allowed to discharge into the wall backfilL These drains sho�ild be investigated to deteri��ine if they are fui�ctioning p�-operly. Also, the o�itlets of the pipes on the slope should be evaluated to determine that they are not causing instability on the slope. An e��ergy dissipater s�ich as a bed ofi rock spalls may be needed at the discharge point. A specifiic design can be determined during the drainage evaluation. Other Considerations There are other serious issues at the site that were not part of this study, but also should be addressed. The area to the south of the residence has experienced slope failures in the past and will continue to be unstable. We recommend that the retaining wall be extended along the soutllern portion of the property to protect the residence from any future sliding. Also, due to the presence of undocumented fill throughout the property and the cracki��g and fo�mdations undermining observed, we recommend that the southern and caste�•n found�tion lines be underpinned to prevent any additional settlement related issues. Roof drains sho�ild continue to be routed through the wall and down the slope. Water should not be allowed to saturate the wall backfill. USF, OF THIS REPORT NGA has prepared this r•eport for Mr. Mark Pepe and his agents for use in the planning the repair of the existing rctaining wall on this site only. There arc other serious iss��es within this site that need to be addt-essed. Some of the issues have been mentioned in this report, but additional concerns may at•ise. The scope of our work does not include services related to construction safety precautions and our recommendations are not intended to di�-ect the contractors' methods, techniques, sequences, or procedures, eYcept as specifically described in our report for consideration in design. There are possible variations in subsui•face conditions between the explorations and also with ti��e. Our repoT•t, concl�isions, and interpretations should not be construed as a warranty of subsurface conditions. A contingency for unanticipated conditions should be included in the budget and schedule. NELSON GEOTECHN/CAL ASSOC/ATES, INC.