A unified theory for the design of pole foundations

A new ultimate pressure distribution model around the embedded part of a pole, under the action of a lateral load, is proposed. By introducing a new term called the lateral coefficient of contact pressure and applying the principles of equilibrium, a formula for the depth of embedment in soils is derived. For small pole rotations (less than 1°) it is shown that the coefficient of contact pressure is a function of the lateral coefficient of subgrade reaction. Thus a unified formula is obtained for the depth of embedment in any soil. A `normal pole foundation´ is defined and a design chart is presented for the rapid design of these foundations. This formula gives excellent results when compared with the empirical and semiempirical data published in statutory regulations, overseas codes of practice, as well as the complex methods presented in textbooks on geotechnical engineering. Two worked examples illustrate the application of the formula