Alternative Support Systems for Cantilever - National Transportation ...
Alternative Support Systems for Cantilever - National Transportation ...
Alternative Support Systems for Cantilever - National Transportation ...
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
2.3 <strong>Alternative</strong> Foundations from Other Industries<br />
An investigation into transmission line foundations, cellular tower foundations, wind<br />
turbine foundations, and large advertising sign foundations was completed. While investigating<br />
these fields it became apparent that despite the similarities in foundation requirements, the large<br />
torsion experienced by cantilever sign/signal foundations is not typically present in other<br />
industries and is not designed <strong>for</strong>. Because of this, the other industries’ alternatives would most<br />
likely not be viable <strong>for</strong> the cantilever sign and signal applications. The following section will<br />
describe what was found in these other industries.<br />
2.3.1 Transmission Line Foundations<br />
An investigation into transmission line foundations showed that they often use cast-in-<br />
place concrete designs that are similar to the current anchor bolt design, using anchor bolts to<br />
connect the superstructure to the foundation; see Figure 2-8c (9). The other cast-in-place designs,<br />
Figure 2-8a, Figure 2-8b, are disparate from the current anchor bolt design. However, these are<br />
not viable alternative options because they are typically exposed to primarily axial and shear<br />
loads. The sizes of the members make direct embedment a more suitable option <strong>for</strong> their<br />
foundations than a cantilever sign/signal foundation. See Figure 2-9 <strong>for</strong> the loading that<br />
transmission line foundations are subject to (9). This loading pattern is similar, but not the same<br />
as the loading that cantilever sign/signal foundations are subject to. The torsional load that a<br />
cantilever superstructure induces on a foundation creates additional concerns <strong>for</strong> transferring<br />
load to the foundation that these foundations cannot address.<br />
Other alternatives investigated in the transmission line industry seem unsuitable <strong>for</strong><br />
sign/signal foundations because of construction sequencing, cost, and most importantly because<br />
they are unlikely to successfully transfer the torsional loading a sign/signal superstructure is<br />
13