47.5 MB - The Whole Building Design Guide

m Breaking wave loads, which are most likely to occur in coastalareasm Impact loads resulting from floating debris striking a buildingor building elementm Long-term erosion and localized scour, which can increase theeffects and magnitudes of other loads2.1.2.1 Design Flood DepthWater depth associated with the design flood is computed by determiningthe DFE (see Section 2.1.1.3 or 2.1.1.4) and subtractingthe elevation of the ground at the building site. Since theseelevation data usually are obtained from different sources, it is importantto determine whether they are based on the same datum.If not, standard corrections must be applied.Flood depth is the most important factor required to computeflood loads, because almost every other flood load calculation dependsdirectly or indirectly on this factor. In riverine areas, theflood depth rarely accounts for waves. In coastal areas, the totalflood depth is composed of a “stillwater” depth, plus the expectedheight of waves (see Figure 2-6).Figure 2-6:Definition sketch—waveheight and stillwater depth2-18 MAKING CRITICAL FACILITIES SAFE FROM Flooding