Chapter 15 Substation and Overhead Line Foundations 15.1 INTRODUCTION The design of overhead line tower or substation gantry structure foundations must be such as to safely sustain and transmit to the ground the combined dead load, imposed load and wind load in such a manner as not to cause any settlement or movement which would impair the stability of the structure or cause damage. The settlement is a result of the transfer of load from the structure to the soil layers. Essentially settlement must be minimized to an