1415 75TH ST SW BASE FILE 2016-01-01 MF Import

O'Donnell, Origt�am & Partner�, N. W. May 19, 1907. Volume Shrinl:age of Fill For estimating volumes, we recommend shrinkage factor of 4 to 5 percent be use in-place volumes to fill compacted to 95 compaction. ' Cut and Fill Slopes E-154U Page 12 that an average d wlien converting percent relative The maximum depth oE cul is anticipated to be about twenty- three (23) feet, and the maximum anticipated fi.il heiglit ie to be approximately twenty-seven (27) feet. We recommend all temporary slope� in till be cut at 111:2V or flatter depending upon exposed soil and groundwater condi- tions. All other soils will require slupes of 311:2V. Perma- nent slope� in till and oCher soils should be sloped at lII:1V and 211:1V, respectively. 'Phe high fill slopes planned for the western parcel and the norCheast corner of the east site should be sloped no steeper tl�an 211:1V, but siiallow (less tlian five (5) feet) structural fill slopes may be graded at 1.751I:1V. We recommend that all excavated s.lopes be examined by a representa- tive of Carth Consultants, Inc. to evaluate the ccndition of the exposed soils and groundwater seepage. All permanent exposed slopes should be planted with a suitable species of rapid yrowl•li veqetation as soon after acl�ieving the final grade as possible L-o reduc�• �_iie potentiel for erosion. Any temporary slo�e surface sliould be protected �3uring construction with visgueen or some other mr_thod oE erosion control. ' Groundwater Control The subject site contains Eine grained soils that will iiake grading operations difficult during wet weatlier. The test pits also encountered seepage generally perche�l upon tlie dense till. For tliis reason, it is important that groundwater be controlled wherever possiUle. Seepage should be�anticipated fr�m cuts. Surface interceptor ditches may have L� be placed along the toe or top of all cuts nnd deep fille, whichever loca�iun appears to be tnore Ceasible. Dased on our test pits it appears that subsur- face drains will be requiced alor�3 the top of all cuts extending at least six (6) inclies into tl�e Li_'1. We suggest tliat final locatiors and depths of subcurface drains be established during gradinq operations by a represenCative of Earth Consultanls, Inc., at which time the seepage areas will be more cl,�urly defined. The �ite should be graded to drain at all times and all loose surfaces sea:ed at nigtit to prevent the inEiltration of molsture into tlie soil. Afl:er a rainfall, equipment sliould G1fII1 COI15lIIIdI1L5, Inc.