1600 121ST ST SE 2016-01-01 MF Import

� � Dccember 15 1992 9 923-1184 � In areas whcre the existing (ills and peats arc Icfl in placc, we remnunend Ihe following: • Preload/Surchar�e: The remmmendations presenled in Section 5.G should be � implemmiled and will minimize post conslruction selUemenl. • Subgrade SupporL• The intent of our remnunendations is to provide a � subgradc capablc of supportin� a loaded dump truck wilh limiled ground disturbance prior lo placing Ihe design pavement seclion (asphall and grave�rock subbase. Seclion 5.G provides conslniclion recommendalions for � meeting Ihis perfonnance criteria. During dry wealher, lhis can probably be accomplished though a combinalion of proof-rolling, subgradc compaction and localized over-excavalion o( so(l areas. In areas whem the rcquimd re,ise in � grade is more than about 2(eGf,_minimal subgrede preparalion is mquired since lhe netv f'I should br. ids;c aiiy sofl arcas. � 5.4 Utililics � In arcas whcre the cxisting loose fills and peal arc removed, arc o( limiled deplh, or do not exist, the ulililies can ba designed and constructed in a normal mannec Il may be prudenl lo locate lhe major deep truck lines such as waterand sewer in areas o( limiled unsuitable soils � and simply oververcavale in Ihe trenches and place lhe ulility on grevel backfdl over till. Depending on Utie local pennilling a�encies, il may be a requiremenl lo place these main ulililies on competenl ground. � Ulililics, parlicularly thc on-site lines, can bc fowided in the exisling fill or lhc pcat provided lhe preluad/sulcharge recommendalions presented in Section 5.G have been implemenled in advancc of Ilic utility installalion. Any sofl, unsuilable soil exposed at lhe boUom of ulility' � trenclies slioiild bc over-excavaled to a minimum deplh of t}velve-inches below design inverl and replaced with strucluraf fill or pea grevel. If lhe deplh lo Ihe bollom of Ihe peat is less ihan about hvo feet, it is proUably prudent to ovcr-excavalc anyway. Prior to lhe placemenl � of the fill or pea gravel on soft soils, it may be prudenl lo �lace a.geolextile separation (abric on the botlom and sides of thc excavation if lhc ground is unslable. � In arcas tvhere lhe utilily will be undcrlain by pcat, wc recommend Ihal flexible joinls and cut-ouls be provided tvhcre lhe ulililies enier thc pilc supported buildings. h� addilion, all ulilily installalions should salisfy the rcquiremenls of the local governing agencies. � Utility trench excavalions below the groundwaler fable will probably encounler cavin� condilions and will require temporary shorin�; or a Irench box lo mainlain sidewall slabilily. � Dewatering of lhe excavalions can probably be accoiuplished �vith sump pumps. � � Golder Assoeiales