Lateral Earth Pressure
4.1.1 Lateral Earth Pressure Introduction
I heard a structural engineer bragging, “Active earth pressure, passive earth pressure, ‘at-rest’ earth pressure, who needs them? I use the Rankine active earth pressure and it works fine for me, why do I need anything else?”
Are you confused about which earth pressure to use, or which earth pressure theory to use, Rankine or Coulomb? What about intermediate earth pressures between active and passive? Have you ever heard of prestressing the soil to reduce lateral strains developed during lateral loading? How do you include seismic lateral stresses into determination of the design loading for a retaining wall? Do you use an equivalent fluid pressure of 30 pounds per cubic foot for all of your retaining wall designs?
Determination of the lateral earth pressure is a problem that must consider the lateral soil strains that develop in the soil mass. Calculation of lateral earth pressures by exclusive use of active earth pressure coefficients or by use of an equivalent fluid pressure of 30 pounds per cubic foot can lead to problems.
4.1.2 Lateral Earth Pressure – The Problem
Selecting the correct lateral earth pressure for use in retaining structure design is another perennial issue of confusion with engineers. I receive on average about one call per month about problems involved with determining the appropriate lateral earth pressure.
As we discussed in Section 2.6, lateral earth pressure equations were developed ...