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.
![Power Transmission Tower - Helical Pile Foundation](https://static.wixstatic.com/media/b53ca0_2385b3a5ff494bb89d396c47e9f69151~mv2.png/v1/fill/w_80,h_30,al_c,q_85,usm_0.66_1.00_0.01,blur_2,enc_auto/b53ca0_2385b3a5ff494bb89d396c47e9f69151~mv2.png)
![Power Transmission Tower - Helical Pile Foundation](https://static.wixstatic.com/media/b53ca0_24b8ad15d46f4ffd82c99233d3a32969~mv2.png/v1/fill/w_80,h_13,al_c,q_85,usm_0.66_1.00_0.01,blur_2,enc_auto/b53ca0_24b8ad15d46f4ffd82c99233d3a32969~mv2.png)
![Power Transmission Tower - Helical Pile Foundation](https://static.wixstatic.com/media/b53ca0_98b92fdec3c7414d9a814a065293def0~mv2.png/v1/fill/w_80,h_30,al_c,q_85,usm_0.66_1.00_0.01,blur_2,enc_auto/b53ca0_98b92fdec3c7414d9a814a065293def0~mv2.png)
B. DEEPFND/HELIXPILE SOFTWARE – SOIL TYPES AND BORINGS
![Power Transmission Tower - Helical Pile Foundation](https://static.wixstatic.com/media/b53ca0_b40061bf69a34aab92428b88f3996288~mv2.png/v1/fill/w_80,h_30,al_c,q_85,usm_0.66_1.00_0.01,blur_2,enc_auto/b53ca0_b40061bf69a34aab92428b88f3996288~mv2.png)
![Power Transmission Tower - Helical Pile Foundation](https://static.wixstatic.com/media/b53ca0_d76a46926ec94e0e9fe84f81b9d18866~mv2.png/v1/fill/w_80,h_54,al_c,q_85,usm_0.66_1.00_0.01,blur_2,enc_auto/b53ca0_d76a46926ec94e0e9fe84f81b9d18866~mv2.png)
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.
![Power Transmission Tower - Helical Pile Foundation](https://static.wixstatic.com/media/b53ca0_4ed970bb333c4c28b85f5b8a3a495ca7~mv2.png/v1/fill/w_80,h_12,al_c,q_85,usm_0.66_1.00_0.01,blur_2,enc_auto/b53ca0_4ed970bb333c4c28b85f5b8a3a495ca7~mv2.png)
![Power Transmission Tower - Helical Pile Foundation](https://static.wixstatic.com/media/b53ca0_7a6161929ffa465aa487fbf81c5fa463~mv2.png/v1/fill/w_80,h_35,al_c,q_85,usm_0.66_1.00_0.01,blur_2,enc_auto/b53ca0_7a6161929ffa465aa487fbf81c5fa463~mv2.png)
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.
![Power Transmission Tower - Helical Pile Foundation](https://static.wixstatic.com/media/b53ca0_d033551057cf4d6c827ce471dd959dc7~mv2.png/v1/fill/w_80,h_40,al_c,q_85,usm_0.66_1.00_0.01,blur_2,enc_auto/b53ca0_d033551057cf4d6c827ce471dd959dc7~mv2.png)
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.
![Power Transmission Tower - Helical Pile Foundation](https://static.wixstatic.com/media/b53ca0_d0491e7932e64cc79ff4faf2459341b7~mv2.png/v1/fill/w_80,h_26,al_c,q_85,usm_0.66_1.00_0.01,blur_2,enc_auto/b53ca0_d0491e7932e64cc79ff4faf2459341b7~mv2.png)
![Power Transmission Tower - Helical Pile Foundation](https://static.wixstatic.com/media/b53ca0_3793e0c57d0747e4a664b0464f8d3169~mv2.png/v1/fill/w_80,h_50,al_c,q_85,usm_0.66_1.00_0.01,blur_2,enc_auto/b53ca0_3793e0c57d0747e4a664b0464f8d3169~mv2.png)
F. PILE GROUP ANALYSIS – TRANSVERSE LOAD COMBINATION
![Power Transmission Tower - Helical Pile Foundation](https://static.wixstatic.com/media/b53ca0_4738e1ba269641168e58788fd6d48492~mv2.webp/v1/fill/w_144,h_82,al_c,q_80,usm_0.66_1.00_0.01,blur_2,enc_auto/b53ca0_4738e1ba269641168e58788fd6d48492~mv2.webp)
![Power Transmission Tower - Helical Pile Foundation](https://static.wixstatic.com/media/b53ca0_88cb0ad7a8a64791b2900ef09acf68b4~mv2.png/v1/fill/w_80,h_45,al_c,q_85,usm_0.66_1.00_0.01,blur_2,enc_auto/b53ca0_88cb0ad7a8a64791b2900ef09acf68b4~mv2.png)
G. PILE GROUP ANALYSIS – LONGITUDINAL LOAD COMBINATION
![Power Transmission Tower - Helical Pile Foundation](https://static.wixstatic.com/media/b53ca0_2c17fb56976f4cbfbbc94d4d3f22589a~mv2.png/v1/fill/w_80,h_40,al_c,q_85,usm_0.66_1.00_0.01,blur_2,enc_auto/b53ca0_2c17fb56976f4cbfbbc94d4d3f22589a~mv2.png)
![Power Transmission Tower - Helical Pile Foundation](https://static.wixstatic.com/media/b53ca0_88d5cf5fe45b46e4a2f34f746fca6922~mv2.png/v1/fill/w_80,h_38,al_c,q_85,usm_0.66_1.00_0.01,blur_2,enc_auto/b53ca0_88d5cf5fe45b46e4a2f34f746fca6922~mv2.png)
![Power Transmission Tower - Helical Pile Foundation](https://static.wixstatic.com/media/b53ca0_15a1a82fb2bd4051a6d579a3e0b7ed37~mv2.png/v1/fill/w_80,h_43,al_c,q_85,usm_0.66_1.00_0.01,blur_2,enc_auto/b53ca0_15a1a82fb2bd4051a6d579a3e0b7ed37~mv2.png)
![Power Transmission Tower - Helical Pile Foundation](https://static.wixstatic.com/media/b53ca0_79769634dff249729567053a3865976d~mv2.png/v1/fill/w_80,h_49,al_c,q_85,usm_0.66_1.00_0.01,blur_2,enc_auto/b53ca0_79769634dff249729567053a3865976d~mv2.png)
![](https://static.wixstatic.com/media/d323f9_ba0a932f1db3481297c0e6141c536895~mv2.png/v1/fill/w_62,h_43,al_c,q_85,usm_0.66_1.00_0.01,blur_2,enc_auto/d323f9_ba0a932f1db3481297c0e6141c536895~mv2.png)