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2.3.4 PILE AND PIER FOUNDATIONS Three to scven feet of vertical erosion at the seaward row of piles Wd$ common (see Figure 2-7). This erosion, coupled with insufiicient penetration of the piles on many structures, led to structural damage to or collapse of primarily pre-FIRM structures. Undersized piles (6-inch diameter limber in some instanccs) were not sufiicient to resist storm forces; they generally failed and resulted in structural damage or collapse. Piers constructed of concrete blocks on shallow footings frequently collapsed as a result of erosion. Well-designed and well-constructed pile and pier foundations withstood the lorces exerted by the storm. Use of splicing techniqucs was also observed on some eroded piles (see Figure 2-8). Although the splicing of piles placed tllese structures at increased risk of failure, no failures related to spliced piles were obscrved. 2.3.5 FRAMING SYSTEMS The BPAT found many examples of poor framing of timber /loor beams andjoists in platform-type construction. In particular, poorly fashioned beam-tn-beam andjoist-to-bcam connections were common. Typical problems included the following: . pile notching greater than 50 percent of pile cross-section . poor alignment of piles, which resulted in unsupported beams at piles . use of wooden shims to support beams (i.e., to compensate for notches cut too low) . overreliance on nails and thin metal straps/hangers Glue-laminated beams and joists were observcd in cxterior applications in some recent post- FIRM residential construction. The use of laminated sUllCtural members in exlerior applicalions ~.~ ~ ....; -~ -.. ...J ~. - ""- ill -, ..~,. ~- .. - -, lit ---- :-- ,..-- ," A ~ , . Figure 2-7 These piles were not embedded deejJ en(mgh to survive the erosion oj the sand. As a lPSUlt, there is now a large gap between the bottoms oj the pilings and the gnmnd sU1fare. 2-6 SITE OBSERVATIONS