Simultaneous measurement of wave forces and pressures on a double-chamber perforated caisson

Abstract

Accurate measurement of wave forces and pressures on coastal and offshore structures is extremely important for the evaluation of the structure stability against wave loading. This study introduced a hybrid measurement technique of using S-beam load cells and disc-type pressure transducers simultaneously. A novel instrumentation of tiny load cells together with pressure transducers were developed to measure the wave loading on a double-chamber perforated caisson. After carrying out experiments with great care, a detailed comparison is given between the directly measured forces and those estimated from the integration of the pressure records. Excellent agreement was observed between the wave forces that were obtained by the two methods, showing the index of agreement of 0.96 on average. Although this technique is very simple to apply, it has an advantage of measuring the wave force acting on the entire structure, while obtaining the forces and pressures on the individual components of the structure at the same time. Hence, this method can provide crucial information required for the design of coastal and marine structures having many elements, such as coastal bridges, refuge buildings against tsunamis, offshore platforms, as well as perforated caissons.