2000 TOWER ST ARTS AND SCIENCES BLDG 2018-01-02 MF Import

and in temporary cut slope areas for the first floor level should extend through wall backfill and be embedded in native soils, unless designed to be supported on structural fill. Foundation Settlement We estimate that the total postconstruction settlement of footings founded on the dense to very dense till deposits or structural fill extending to the very dense glacial deposits, as recommended above, should be less than 3/4 inch. Differential settlement between comparably loaded column footings or along a 25-foot section of continuous wall footing should be less than %, inch. We expect most of the footing settlements will occur as loads are applied. Loose or disturbed soils not removed from footing excavations prior to placing concrete will result in additional settlement. Construction Considerations Immediately prior to placing concrete, all debris and loose soils that accumulated in the footing excavations during forming and stcei placement must be removed. Debris or loose soils not removed from the footing excavations will result in increased settlement. if wet weather construction is planned, we recommend that all :boting subgradcs be protected using a lean concrete mud mat. The mud mat shoud be placed the same day that the footing subgrade is excavated and approved for foundation suppri-t. Lateral Resistance Lateral loads can be resisted by passive resistance on the sides of the footings and by friction on the base of the footings. Passive resistance should be evaluated using an equivalent fluid density of 350 pef where footings are poured neat against native soil or are surrounded by structural .-ll compacted to at least 95 percent of MDD, as recommended. Resistance to passive pressure should be calculated from the bottom of adjacent floor slabs and paving or below a depth of 1 foot where the adjacent area is unpaved, as appropriate. Frictional resistance can be evaluated using 0.35 for the coefficient of base friction against footings. The above values incorporate a factor of safety of about i.5. if soils adjacent to footings are disturbed during construction, the disturbed soils must be recompacted, otherwise the lateral passive resistance value must be reduced. Footing Drains We recommend that perimeter footing drains be installed around the Art and Science building. The perimeter drains should be installed at the base of the exterior footings. The perimeter drains should be provided with cleanouts and should consist of at least 4-inch-diameter perforated pipe placed on a 4-inch bed of, and surrounded by, G inches of drainage material enclosed in a non -woven geotextile fabric such as btirafi 140N (or approved equivalent) to prevent fine soil from migrating into the drain material, as shown on Figure 3. The footing drain pipe should be installed at least 18 inches below the top of the adjacent floor slab. The drainage material should consist of washed 3/8-inch to No. 8 pea gravel or "Gravel Dackfill for Drains" per Section 9-03.12(4) of the WSDOT Standard Specifications. We recommend that the drainpipe consist of either heavy -wall solid pipe (SDR-35 PVC, or equal) or rigid corrugated smooth interior polyethylene pipe (ADS N-12, or equal). We also recommend against using 0 c o 1: n g i n c c r s 13 File No. 5836.002-00/040204