Dynamic behaviour of a flexible membrane tsunami Barrier with Dyneema®

Abstract

Proof-of-concept model tests on a novel self-deploying on-shore tsunami barrier were executed. The tsunami barrier consists of a membrane, floater and cables that are stored underground. Due to buoyancy the barrier self-deploys when struck by a tsunami. The membrane and cables consist of the strong, flexible and light-weight material Dyneema that can resist a 20 m high water column. A novel tsunami generating method was applied to generate a high-velocity initial bore, followed by a long duration high water level, using a normal piston type wave maker in a wave flume. Numerical calculations using a numerical Volume-of-Fluid code were used to tune the tsunami generation. The tests showed that the tsunami barrier indeed automatically deployed and completely blocked a 19 m high (reflected) tsunami for bore velocities up to 7.5 m/s. For higher bore velocities the barrier still deployed. For larger tsunamis (with a 33 m reflected water depth) the barrier remained erected, although overflow evidently occurred.