2530 MADISON ST 2016-01-01 MF Import

AirTouch Celluler 7-91 M-11905-0 3 October19�7 PaBe 11 capacity of 5,000 pounds per square foot (psf). This bearing capacity inccrporates a static safety factor of at least 2.0 and can be increased by one-third for transient loads. �. Uolifi Resistance: We anticipate that uplift loads will be resisted by the dead weight of the mat foundation, as well as the soil materials covering the mat. Native soils used to cover t the mat, if compacted to a minimum of 90 percent of the Modified Proctor maximum dry � density, may be assumed to have a unit density of 120 pcf. C L �- l_ Laterai Resistance: Lateral loads on the foundation caused by seismic or transient loading conditions may be resisted by a combination of passive soil prossure against the side of the foundation and shaar friction res�stance along the base. An allowable base friction value of 0.45 and an allowable passive earth pressure of 250 pcf, expressed as an equivaient fluid unit weight, may be used for that portion of the foundation embedded more than 1 foot below finished exterior subgrade elevation. Settlements: We i;stimate that total post-construction settlements of properly designed footings beariny on properly prepared subgrades will not exceed 1 inch, with differential settlements approaching one-half of the total. � 4_4 Structural Fill The following comments, recommendatior;s, and conclusions regarding the use of structuralfill are provided for design and construction purposes. 1- Ma ri I�: "Structural fill" includes any fill materials placed under footings, pavements, � driveways, and other permanent structures. Typical materials used for str�cturai fill include clean, well-graded sand and gravel (pit-run1; clean sand; crushed rock; c,ontrolled- density fill (CDF); lean-mix concrete; and various soil mixtures of silt, sand, z.nd gravel. � Recycled concrete derived from crushed parent material is also useful as structural fill. Soil Comoosition: Soils used for structural fill should not contain individual particles greater � than about 6 inches in diameter and should be free of organics, debris, and other deleterious materials. Given these prerequisites, the suitability of eoils used for structural fill depends primarily on the grain-size distribution and moisture content of the soils when � they are placed. As the "fines" content (that portion passing the U.S. No. 200 Sieve) � increases, soils 6ecome more sensitive to small changes in meisture content. Soils � containing more than about 5 percent fines (by waight) cannot be consistently compacted to a firm, unyielding condition when the moist�re content is more than about 2 percentage points above optimum. The use of "clean" soil is necessary for fill placement during � wet-weather site work. Ciean soils are defined as granular soils that have a fines content of less than 5 percent (by weightl, based on the soil fraction passing the U.S. No. 4 Sieve. 7•91M41B06-0