6807 EVERGREEN WAY 2016-01-01 MF Import

GE01'ECiiNICAI. ENGINEE�i1NG STUDY JML` F��chitectwe April 19, 1999 E-8689 Page 5 ;Ju*ing dn; wiaacher, rr,ost soils which are compactible and non-organic can be used as ;;;.fi.�Citlral f�l•.. Etased on the results of our laboratory tests, the on-site soils at the time of ou� ,>,;;��l,,r•,_ior� ;��ear to be near their optimum moisture content and should be suitable for us. ir, t�:�ir ;�,e�cn� condition as structural fill, provided the grading operations are conducted dusing dry weather. However, laboratory testing indicates the riati�ee silty sand with gravel Y��s on the order of 20 percent fines passing the No. 200 sieve. Soil with fine:; in excess of fiive percent will degrade if exposed to excessive moisture, and compaction and grading will be difficult if the soil moisture increases significantly above its optimum condition. If the native soil is exposed to moisture and cannot be adequately compac:ed, then it may be necessary to import a soil which can be compacted. During dry weather, any non-org2nic compactible soil with a maximum grain size of six inches can be used. Fill for use during wet weather should consist of a fairly well graded granular material having a maximum grain size of six inches and no more than five percent fines passing the �Jo. 200 sieve based on the minus 314-inch fraction. A contingency in the earthwork budget should be included for !his possibiiity. Foundations Based on the results of our study, it is our opinion the proposed building can be supported on a conventionai spread and continuous footing foundation system bearing on the existing fill, competent native soil or structural fill used to modify site grades. Our borings indicate the upper three to five feet of the site soils are loose. If loose soils are encountered at the footing subgrade elevation, they should be compacted in place to the requirements of structural fill. For frost protection considerations, exterior foundation elements should be piaced at a minimum depth of eighteen (18) inches below final exterior grade. Interior spread foundations can be placed at a minimum �epth of twelve (12) inches below the top of slab, except in unheated areas, where interior foundation elements should be founded at a minimum depth of eighteen (18) inches. Continuous and individual spread footings shouid have minimum widths of eighteen (181 snd twenty-four (24) inches, respectively. With foundation support obtained as described, for design, an allowable soil bearing capacity of two thousand five hundred (2,500) psf can be used for the existing fill, competent native soil or structural fill. Loading of this magnitude would be provided with a theoretical factor-of- safety in excess of three against actual shear failure. For sh�rt-term dynamic loading conditions, a one-third increase in the above alio�evable bearing capacities can be used. Earth Con�ultenu. Inc.