1810.9.1.2 Design details.
BC § 1810.9.1.2
Moments, shears and lateral deflections used for design of deep foundations shall be established considering the nonlinear interaction of the shaft and soil, as recommended by the engineer. Where the ratio of the depth of embedment of the center-to-center diameter or width of deep foundations is less than or equal to six, the deep foundation may be assumed to be rigid. Group effects from soil on lateral deep foundation nominal strength shall be included where deep foundation center-to-center spacing in the direction of lateral force is less than eight diameters. Group effects on vertical nominal strength of deep foundations shall be included where deep foundation center-to-center spacing is less than three diameters. The uplift soil nominal strength of deep foundations shall be taken as the uplift strength as limited by the frictional force developed between the soil and the deep foundation. Where a minimum length for reinforcement or the extent of closely spaced confinement reinforcement is specified at the top of the deep foundation, provisions shall be made so that those specified lengths or extents are maintained after deep foundation cutoff.
