5902 EVERGREEN WAY HOUSING HOPE 2018-01-01 MF Import

! � Sub.rurface Erplorarion, Geofogic Ha�ard, and Norcring Hape Pharr!1 PrNiminary Geotuhnica!Englnetring Rtparr Errrrrr, {4'ashirtgran D[rign Recommendnt(nns � The latersl pr�ssures presented above are based on the conditions of a uniform backfill consiseing of on-site, glacial soils compacted to 90 percent of ASTM:D 1557. A higher degree of compaction is not recommended, as this will inerease the pressure acting on the wall. A � low•er compaction may resul[ in setdement of the slab-on-grade above the walls. Thus, the com�action level is critical and must be tested by our firm during placement. Perimeter � foo�ing drains should be provideci for all retaining walls as discussed under the section on Drninage Consideratrons. � It is imperative that proper drainage be provided so that hydrostatic pressures do not develop against the wall. This would involve iustallation of a minimum 1-foot-wide washed gravel blanket drain, which is continuous with the perimeter footing drain and eztends to within 1 � foot of the ground surface. _ 12.2 Passi��e Resistance nnd Friction Factors � Lateral loads can be resisted by fric[ion benveen the foundation and the natural glacial soils or supporting structural 6ll soils, or by passive ear[h pressure acting on the buried portions of the � foundations. The foundations must be backfilled with compacted structural fill and compacted to at least 95 percent of the maximum dry densiry to achieve the passive resistance provided � beloa•. �Ve recommend the foliowing desien parameters: • Passive equivalent fluid = 250 pcf ( � Coefficient of hiction = 0.30. i The above values are allowable and include a safery factor of atleast I.S. � I?.3 GeoeridT`� Reinforced Fill 1 Based on our review of the site topography, soil conditions, and intended use of the proposed � building area, the western slope could be buttressed with GeogridTN reinforced fill. Using � proven technology, fill is reinforced in horizontal layers with a very strong, plastic GeogridT" mat that exrends into the hillside filL This reinforced fill may be faced with a property designed mociular block wall or rockery. It should be noted that the facing will not be required � to provide any lateral suppoR for the fill; the entire support is developed ttuough thc GeogridT`+ mat layers. The facing is to protect the reinforced soils from erosion. For this project, the reinforced fill wedge would be keyed into the medium dense recessional outwash ' soils at an approximate depth of S to 7 feet below existing toe-of-slope grades. We have attached a diagram of a GeogridT'" reinforced fill s(ope with a rockery facing, for informational purposes only, as Figure 3. The actual engineering design of this fill and the desired facing Irype wili be completed once a wall type is chosen and grading plans are developed. AESI can provide site-specific �esign plans for insertion into the permit package upon request. � Frbruary 1/, 1CO2 ASSOCfATED 6,1RTH SCIENCE$ lNC. sc�r,ld-XFA1:�9A:.ProJreiCL17/719iKFlWp.µ:g Page 13 / I ' /�