Hydraulic Experiments on Impact Forces from Tsunami-Driven Debris

Abstract

Impact on a column by an idealized 1:5-scale shipping container propelled by tsunami flow was modeled in a large-scale wave flume. Results from hydraulic experiments were compared with corresponding data from in-air impact experiments using the same experimental configuration to assess the hydrodynamic effects on impact force and duration. Experiments were conducted by varying flow conditions, velocity, and nonstructural mass. An aluminum specimen was tested empty and with the addition of nonstructural mass to simulate partially loaded shipping containers. The measured peak impact forces from the longitudinal test in water were observed to have an increase no greater than 17% of the corresponding measured peak impact forces from the longitudinal test in air. The impact duration measured from the in-air test provided a lower bound for the impact duration measured for the in-water tests. Hydraulic effects were shown to increase the impact duration by an average of 20%. The additional nonstructural mass was shown to have no significant impact on the measured peak impact force, but was shown to increase the overall impulse on the column, as expected.