General Order 95
Section IV
Strength Requirements for All Classes of Lines
48.6 Tower or Pole Foundations and Footings
In calculating the resistance of foundations or footings of towers,
poles and pole line structures to uplifts, the weight of concrete shall be
taken as not more than 145 pounds per cubic foot and the weight of earth
(calculated 30 degrees from the vertical) shall be taken as not more than
90 pounds per cubic foot. The resistance of soil to the depression of foundations
or footing shall be calculated from the best available data on the soil in
question. In lieu of calculation, the strength of foundations or footings
against uplift or depression may be determined by tests under the soil conditions
prevailing.