Laserfiche WebLink
Geotechnical Engineering Report lierracon I <br /> Proposed Flight Line Steam Line Project <br /> Boeing Everett Facility Everett, Washington <br /> January 17, 2012 ■ Terracon Project No.: 81115085 <br /> pressures will be influenced by structural design of the walls, conditions of wall restraint, <br /> methods of construction and/or compaction and the strength of the materials being restrained. I <br /> Two wall restraint conditions are shown. Active earth pressure is commonly used for design of <br /> free-standing cantilever retaining walls and assumes wall movement. The "at-rest" condition 111 <br /> assumes no wall movement. The recommended design lateral earth pressures do not include a <br /> factor of safety and do not provide for possible hydrostatic pressure on the walls. <br /> For active pressure movement I <br /> S = Surcharge —0 '4—(0.002 H to 0.004 H) <br /> S For at-rest pressure I <br /> 'r - No Movement Assumed <br /> Horizontal I <br /> Finished <br /> Grade i <br /> H <br /> Horizontal I <br /> Finished Grade <br /> I <br /> 14—p2 -pi-♦1 Retaining Wall <br /> I <br /> EARTH PRESSURE COEFFICIENTS FOR HORIZONTAL BACKFILL <br /> EARTH COEFFICIENT FOR EQUIVALENT SURCHARGE EARTHI <br /> PRESSURE BACKFILL TYPE FLUID DENSITY PRESSURE 1,2 PRESSURE, <br /> CONDITIONS (pcf) Pi(psf) P2(psf) <br /> Active (Ka) Granular- 0.28 35 (0..44)S (35)H <br /> At-Rest (Ko) Granular- 0.44 55 (0.44)S (55)H <br /> Passive (Kp) Granular-3.0 375 --- --- I <br /> 1. Static surcharge pressures should be calculated as indicated for At-Rest conditions if the <br /> surcharge loads are imposed after the wall has been backfilled and the wall has rotated about base. I <br /> 2. Retaining walls should also be designed to resist seismic lateral earth pressures, as appropriate. <br /> Uniformly distributed pressures of 6.5H and 10.5H in pounds per cubic foot (rectangular distribution) <br /> may be applied to yielding and non-yielding retaining walls, respectively, to account for seismic I <br /> pressures. <br /> Applicable conditions to the above include: I <br /> For active earth pressure, wall must rotate about base, with top lateral movements of about <br /> 0.002 H to 0.004 H, where H is wall height I <br /> Responsive • Resourceful • Reliable 16 <br />