Exploitation of Foundation Stiffness and Resulting Ground Pressure.

In addition to the basic knowledge of structural theory there is also a need to keep in mind the basic pressures which develop in various ground conditions and the effect of the foundation stiffness on these pressures (see Fig. 10.14).

Again armed with this knowledge the engineer should exploit the conditions to his advantage.

For example, the stiffness of a foundation should only be sufficient to distribute the applied load down to a suitable bearing capacity and accommodate the resulting settlement, since the bending moment developed would be much smaller on the flexible foundation than the rigid foundation. The flexible foundations will result in higher pressures directly under the load and when the stiffness and pressures are taken into account the resulting bending moments produced are much smaller.

Fig. 10.14 Foundation stiffness and resulting ground pressure.