Transmission And Substation Foundations - Technical Design Manual (TD06088E)

DESIGN EXAMPLES

Figure 7-17 GROUP ® Results

With the two layouts determined, it is now possible to analyze and ensure that the piles have the required capacity with the intended spacing. Because the pile cap will not be truly rigid and the fact that the piles can continue to deflect and carry their ultimate capacities, beyond the location they reach ultimate capacity, it will be assumed the capacity of each pile is 100 kips ultimate (50 kip working). To ensure the FS=2 kip will be used as the capacity of each of the 9 piles. Because there are 3 piles that will not be taking any axial load from the moment in both cases, it is assumed that that axial load will be transferred through these piles and not through the other piles in the concrete cap. It is now possible to calculate the amount of moment that can be resisted by the layout. This can be conducted by using a summation of moments about the center of the cap (location where load is applied).

Page 7-28 | Hubbell Power Systems, Inc. | All Rights Reserved | Copyright © 2017