Civil Engineering Reference
In-Depth Information
FIGURE 13.11
Excavation for the grade beam that will span
between the two piers.
Usually this foundation system is designed by the structural engineer. The geotechnical
engineer provides various design parameters, such as the estimated depth of the bearing
strata, the allowable end-bearing resistance, allowable skin friction in the bearing material,
allowable passive resistance of the bearing material, and any anticipated downdrag loads
that could be induced on the piers if the upper loose or compressible soil should settle under
its own weight or during the anticipated earthquake. The geotechnical engineer also needs
to inspect the foundation during construction in order to confirm the embedment conditions
of the piers.
13.3.3
Prestressed Concrete Piles
Introduction.
Common types of prestressed concrete piles are shown in Fig. 13.18.
Prestressed piles are typically produced at a manufacturing plant. The first step is to set up
the form, which contains the prestressed strands that are surrounded by wire spirals. The
