6920 SEAWAY BLVD Geotech Report 2018-01-02 MF Import

i ( All fill placed on sl.opes which are steepar [han �S: l (horizon[al to ver[ical) should be properly keyed into the existing site soils. This could � be accomplished by cu[[ing a series of 5- to 8-foot-wide benches into [he slope surface as the fill is being nlaced. Particular c;ire should be [aken ! to strip all vegetation and root systems from [he slope pr.ior [o fill placc- 1 ren[. Fill surfaces should ha crowned at all times to preven[ [he punding I �f water. l.'e recommend Chat 2 representative from our firm observe the placement and compactio» of s[ructural fill. M adequate number of in-place density Itests should be performed as the fill is be_ng placed to determine iE che required degree oE compaction is being achieved. IPermanent Slopes: We recort¢nend that permanent cu[ and fill slopes in all areas except for the new detention pond ear[h dike be constructed at 2: l t (horizontal to vertical),or flatter. Fill slopes for the new detention pond ! earth dike should be somewhat flatter. We recommend that [he ups[ream and � downstream faces oE [he ear[h dike be inclined at 1: 1 and 2�: 1, respectively. The existing side slopes along the portion of the western drainage within tha area of the new detention pond are inclined as steep as 2: L 'fhese slopes I :cay axperience some sloughing and raveling as a result of [he repetitive :illing and empyting of the detention pond. 'fhis could require some main[en- � ance of the slopes. If excessive sloughing is esperienced, we sugrest L'ha[ ce be consulted to evaluate the problem and assist in developing appropriate I remedial r�easures. Unprotected cut and fill slooes will be subjected to erosion until a I aege[ative cover is established. Therefore, we reco�mnend [hat all slope sur- faces be planted as soon as practical to minimize the potential for eroston. Curbs, berms, drainage ditches or swales should be installed along [he Ieop of cut and fill slopes to intercept surface runoff down the face of these slopes and reduce the poCen[ial for erosion. Swales or drainage ditches should be �� ins[alled at [he base of cut slopes, where necessary, to in[ercept any ground �.ater seepage. Collected water should be routed to appropriate disposal poin[s. SPREAD FOOTI:IGS We recoromend that the proposed new building and other Phase 2 struc[ures be supported on shallov �pread footings. These Eoo[ings should be Eounded either on the ^edium dense to very dense na[ive glacial till, ou[wash sand and �� - 8 - G@OEt191fl@@f5 Incorporoted