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26 <br /> Axial Capacity. Allowable axial pile capacities are provided on Plates 38 <br /> through 40. The allowable pile capacity curves for locations underlain by glass <br /> are recommended for the turbine and boiler foundations. Expected settlements <br /> were discussed in a preceding section of this report. <br /> Lateral Sliding. Lateral forces transmitted to the foundation mat will be <br /> resisted by the lateral pile capacity, passive earth pressure against the mat, <br /> and friction along the base of the mat. Lateral pile capacities for locations <br /> underlain by glass were provided previously. <br /> The allowable passive earth pressure against the mat should be computed <br /> based on value of 200 pcf, which is applicable for compacted soils. The passive <br /> resistance of the top foot of material, however, should be ignored. <br /> Friction along the base of the mat should be computed based on a coefficient <br /> of friction of 0.2 if the base of the mat is in contact with native materials at <br /> their natural condition. If the base of the mat is in contact with at least 1 ft <br /> of material compacted to structural fill criteria, the coefficient of friction <br /> can be increased to 0.3. The passive earth pressures and coefficients of <br /> friction, noted above include a factor of safety of 2. <br /> If the total lateral resistance is not adequate, we suggest that a lateral <br /> pile load test be conducted to re-evaluate the allowable lateral capacity for a <br /> pile. If after the load test it is not considered appropriate to upgrade the <br /> allowable lateral pile capacity, the sliding resistance of the mat could be <br /> improved by adding a turned down skirt around the perimeter of the mat. <br /> Transformer Deaerator, Pipe Rack, and Other Equipment with Point and Area Loads <br /> Structure Description. Numerous equipment and pipe racks are customarily <br /> founded on pads and individual footings. Pad sizes are as large as 20 by 30 ft <br /> for the main transformer and 41 by 11 ft for the compressor. Gross bearing <br /> pressures are typically between 600 and 1200 psf beneath the pads. In addition, <br /> pipe rack supports impose point or small area loads. Typically gross pressures <br /> range from 1200 to 2000 psf, depending on the size of footing pad beneath the <br /> support. <br /> Foundation Options. We recommend the major equipment and loaded areas of <br /> the site be improved with DDC or partial removal and replacement. After improve- <br /> ment, it is anticipated to be feasible to found these equipment and structures on <br /> shallow foundations. <br /> 1144A/CC-26 <br /> CMcClelland <br />