For calculating the natural frequency of structures such as buildings, chimneys, bridges and silos appropriate analytical formulas exist. However, in the case of retaining walls undergoing the
3 Calculation Methods of Earth Pressure for Retaining Wall with Gentle Back Surface 3. 1 Approximate Solution Based on Coulomb Theory There are two sliding surfaces in the backfill, but \(\Delta ABC\) and \(\Delta BCD\) are still regarded as a complete wedge, so the earth pressure of retaining wall is in full compliance with Coulomb theory.
method is described in Section 5: Retaining Walls in the Standard Specifications for Highway Bridges, Adopted by the American Association of State Highway and Transportation Officials