Driving Laminated Timber Piles at Auburn University-PPT Presentation

PPT Presentation

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The Auburn University study investigated glue-laminated timber as a modern deep-foundation material. Traditional timber piles are cost-effective and used in applications such as docks, small bridges, and residential structures, but their size, variability, and susceptibility to degradation can limit performance. Laminated timber can form larger, more consistent sections from smaller wood pieces.<br /><br />Researchers modeled axial capacity, lateral behavior, and driveability to select piles for field testing. Three untreated, untapered piles with balanced laminations were fabricated: two measuring 18 × 18 inches and 50 feet long, and one measuring 24 × 24 inches and 50 feet long. The tests took place at Auburn University’s National Geotechnical Experimentation Site. Piles were instrumented with strain gauges and accelerometers at multiple locations to monitor driving.<br /><br />Using an ICE I-19v2 diesel hammer, the two 18-inch piles were driven to depths of 35 and 33 feet. Their driving performance was strong, and the hammer caused negligible damage to the pile tops. The 24-inch pile was not driven because the hammer and reaction system were considered insufficient after the smaller piles’ performance.<br /><br />End-of-initial-drive measurements were analyzed using CAPWAP. The analysis estimated axial capacities of 628–640 kips and a pile elastic modulus of approximately 2,650 ksi. The study’s authors concluded that laminated timber is a viable deep-foundation material, while noting that this work was, to their knowledge, the first of its kind.

Keywords

glue-laminated timber

deep foundation

timber piles

axial capacity

lateral behavior

driveability

CAPWAP analysis

diesel hammer

geotechnical testing

Auburn University