FEMA P55 Coastal Construction Manual, Fourth Edition - Mad Cad

8 DETERMINING SITE-SPECIFIC LOADS Volume II
Figure 8-8.
Vertical (buoyant) flood
force; buoyancy forces
are drastically reduced
for open foundations
(piles or piers)
8.5.8 Wave Loads
Calculating wave loads requires the designer to estimate expected
wave heights, which, for the purposes of this Manual, are limited
by water depths at the site of interest. These data can be estimated
using a variety of models. FEMA uses its Wave Height Analysis for
Flood Insurance Studies (WHAFIS) model to estimate wave heights
and wave crest elevations, and results from this model can be used
directly by designers to calculate wave loads.
Wave forces can be separated into four categories:
From nonbreaking waves – can usually be computed as hydrostatic forces against walls and
hydrodynamic forces against piles
From breaking waves – short duration but large magnitude
From broken waves – similar to hydrodynamic forces caused by flowing or surging water
CROSS
REFERENCE
For additional guidance
in calculating wave loads,
see ASCE 7-10.
8-20 COASTAL CONSTRUCTION MANUAL