Laserfiche WebLink
i <br /> 3 <br /> 4 <br /> File No. 20-3855-01.1301 KLEIN F E L D E R <br /> May 3, 1995 <br /> In areas to receive asphaltic concrete pavements, we recommend that the top 12 inches of <br /> Engineered Fill be compacted at or near optimum moisture content, to a minimum of 95 <br /> percent of the maximum dry density'as determined by the above-referenced test method. We <br /> recommend the structural and trench backfill be placed in the same manner as Engineered Fill. <br /> 3. Foundations <br /> ry In our opinion, once the site has been graded as recommended in the previous subsection, the <br /> structures can be supported on spread and/or continuous foundations bearing on the properly <br /> placed Engineered Fill. We recommend that foundations extend minimum depths of 12 inches <br /> for one-story and 18 inches for two-story structures below the lowest adjacent finished soil <br /> subgrade, interior or exterior, whichever controls. The recommended minimum width of <br /> foundations is 12 inches. <br /> With the above provisions, we recommend a maximum allowable bearing pressure of 2,000 <br /> pounds per square foot for dead plus live loads be used in design. This value can be increased <br /> where foundations are underlain by at least 4 feet of Engineered Fill. However, because of the <br /> lightly-loaded nature of residential structures, minimum width requirements will likely control <br /> foundation design, and a higher bearing value-will likely not be needed. The above value can <br /> be increased by to for the total of all loads, including wind and seismic forces. The above <br /> value can also be used in foundation design for the sound wall on top of the berm. <br /> With foundations supported on properly placed Engineered Fill prepared as recommended in- <br /> the "Site Preparation and Grading" subsection of this report, the anticipated total settlement is <br /> approximately 'A to 1/a inch. Differential settlement can be assumed to be approximately 'A <br /> these values. The majority of the settlement should occur during construction as building loads <br /> are placed, provided foundations are not exposed to sustained standing water or flooding. <br /> We recommend that the foundation and reinforcing design be provided by the structural <br /> engineer. We note that the above-stated bearing pressure is a net value, and the weight of <br /> concrete in the portions of the foundations which extend below grade can be neglected in <br /> proportioning the foundations. <br /> 4. Lateral Pressures <br /> Resistance to lateral forces can be provided either by friction between the base of the <br /> foundations and the soil or by passive pressure of the sides of the foundations against the soil. <br /> The recommended coefficient of friction is 0.40. The recommended passive soil pressure for <br /> properly placed Engineered Fill is an equivalent fluid pressure of 450 pounds per square foot <br /> (psf) per foot of depth. <br /> � 5. Concrete Slab-on-Grade Floors <br /> Once the grading- is completed as recommended in the "Site Preparation and Grading" <br /> subsection of this report, concrete slab-on-grade floors (floor slabs) will be underlain by <br /> j Copyright 1995 Kkinfelder,Inc. Page 6 of 10 <br /> i <br />