Experimental study of structures subjected to hydrodynamic and debris impact forces

An accurate estimation of tsunami-induced forces on nearshore structures is an important step towards the design of tsunami-resilient buildings. The University of Ottawa, in collaboration with the Canadian Hydraulics Centre (CHC) of the National Research Council, located in Ottawa, has established a comprehensive experimental and numerical modeling program focusing on tsunami-structure interaction with the ultimate goal of improving tsunami mitigation methods and strategies. As part of this experimental program, the authors conducted laboratory tests on the impact of extreme hydrodynamic forces and floating debris on two structural models with different cross sections (square and circular). These structures were subjected to supercritical hydraulic bores that are similar to ones generated by broken tsunami waves advancing inland. The structural models were instrumented with sensors capable of recording time histories of the hydraulic bore depth, as well as the lateral displacement, acceleration, pressures, forces, and moments imposed on the two structural models. The bore depth and bore velocity were recorded and analyzed, and the bore-structure interaction was also investigated. The time histories of the impact force resulting from wooden debris hitting the structural models were also recorded and analyzed. The authors further investigated existing formulas provided by the most recent tsunami-resistant engineering design guideline (FEMA P-646, 2012) and the Coastal Construction Manual (FEMA P-55, 2011) to compare the experimentally-recorded hydrodynamic and debris impact forces with current prescriptions.Peer reviewed: YesNRC publication: Ye