Experimental and Analytical Forensic Investigation of Bridge Timber Piles under Eccentric Loads

This study examines the structural behavior of bridge timber piles under eccentric compression loading. A collapsed rural concrete bridge supported on timber piles was used as a prototype in this study. Samples of the collapsed piles were retrieved and experimentally tested under compression and combined compression and flexure. The experimental timber pile response was used to calibrate an numerical model of the full timber piles of the prototype bridge, including material and geometric nonlinearity as well as soil-structure interaction. The numerical results illustrated that the pile strength was significantly reduced under eccentric load compared to concentric load. It was concluded that the effect of compression-flexure interaction on bridge timber piles must be checked during design, especially in the case of simply-supported superstructures where loading on one span may lead to eccentric loading on a timber pile group.