A. PROJECT DESCRIPTION – FOUNDATION PILE CONFIGURATION
This article presents a pile foundation design for a monopole electricity transmission tower. This type of tower is commonly subjected to high overturning moments. The foundation is a 26’x12’ rectangular concrete cap supported on helical piles (Figure 1). Table 1 below presents the maximum ultimate loads on the pile cap on each direction. Table 2 presents the soil properties and stratigraphy that has been estimated and used within the DeepFND software.
B. DEEPFND/HELIXPILE SOFTWARE – SOIL TYPES AND BORINGS
C. DEEPFND SOFTWARE – PILE SECTION PROPERTIES
An 8in diameter steel pipe (PP8x0.5) helical pile is selected with three 24’ inch diameter plates. Table 3 presents detailed pile properties. Figures 4 and 5 present the pile type and length, and the pile section properties respectively.
D. PILE GROUP – DIMENSIONS AND LOADS
The pile cap is defined a 26ft x 12ft concrete slab with a 3ft thickness, supported by 10 vertical helical piles (Figure 6). Both the transverse and the longitudinal external load combinations on the pile cap, as well as a case with 50% of the design loads on both directions are considered. Figure 7 presents the external loads applied on the cap centroid for each load combination.
E. PILE GROUP – PILE LOCATIONS AND GENERATED MODEL
Finally, the pile configuration is illustrated in the figures bellow. Figure 8 presents the piles layout (pile center local x and y coordinates), while the 3d generated Model is illustrated in figure 9.
F. PILE GROUP ANALYSIS – TRANSVERSE LOAD COMBINATION
G. PILE GROUP ANALYSIS – LONGITUDINAL LOAD COMBINATION