11419 19TH AVE SE Geotech Report 2018-01-02 MF Import

� 1 � II Geotechnical Gnbineering I:ecommendatia�s 6.0 Introduction � Based on the findings of our study, it is our opinion, from a geotechnical s?andpoint, that the subject propeny is suitabie for the proposed development, provided the recommendations pro�✓ided herein � are properly followed. The dense native sediments, or properly placed structural fill placed on the native sediments will be capable of providing suitable foundation support for the proposed structures utilizing conventional spread footing foundations. One area(around EP-6) where unsuitably soft �I � silt was encountered, will require overezcavation to reach a suitable bearin� stratum. Slab on grade floors may also be supported on thc natural bearing sediments or structural fill. � 7.0 Site Preparation ' Old foundations presently on site should be completely temoved. Any buried utilities should also � be removed or relocated if they are under building areas. R.es!ilting depmssions should be brought back to grade with structural fill (Section 8.0) � Site preparation of[he planred building and road/parking areas should include removal of all trees, brush, debris and any deleterious material. Additionally, tl�e upper organic ropsoil should be � sfipped and remaining roots grubbed. Based on our exploration pits, topsoil s'sipping depth should be from two to hvelve inches. Existing asphalt should be removed and disposed of off site in accordance �vith local regulations. The entire site should the� be rolled to compact any toose or disturbed soils. Finally, :lie site should be proof rolled with a heavy, fully loaded dump truck to � delineate any soft areas susceptibfe to settlement. Proof rolling should be wimessed by our soils engineer. Soft or loose areas evident during proof rolling should be excavated to frm soils and � replaced�vith structural fill (Section 3.0). [f gading takes place during the wet winter months, exposed subgrade soils should be protected witl-, � a layer of clean sand and gravel, (ean concrete, or asphalt-treated base. Should subgrade soils become excessively wet or disturbed, they should be'removed and replaced with compacted structural fill containing less than five percent (5%) fines. Where underlying soils are escessively iwet, it may be necessary to stabilize the irea with a layer of quarry spalls or a layer of geotexti(e - fabric (such as Mirafi �OOx) between tne subgrade and structural fill. Wet surficial soils were � encountered near the pond at the south end of proposed building C and will require such stabilization. � In our opinion, stabie construction slopes should be the responsibility of the contractor and should be determined during construction. For estimating purposes,however,we anticipate that temporary, i � unsupported cut slopes in the dense glacial till can be made at a maximum slope of O.�H:1 V �I � (Horizontal:Vertical). Temporary cut slopes in topsoil and sands and gravel should be sloped back to 1 H:1 V. As is typical with earthwork operations, some sloughing and raveling may occur and cut slopes may have to be adjusted in the 6eld. In addition, WISHA/OSHA regulations should be � followed at all times. � �b ' MAYES TESTING ENGINEERS