Experimental spatial correlation of wave loads on front decks

Abstract

The large-scale experiments described herein were carried out at Forschungs-Zentrum Küste (FZK), Hannover (Germany) by a research team of the Universities of Bologna, Edinburgh, Southampton, Plymouth, HR Wallingford and the Coast and Harbor Engineering, Inc. (USA). Wave-induced loads on close-to-prototype jetties were measured. Experimental evidence indicates the presence of force peaks with a short space–time correlation structure, carried by convective processes with a velocity of the order of the wave celerity. The important limitations imposed by the imperfect spatial resolution of pressure transducers on the integrated force are discussed. The finding may be of interest to design laboratory tests involving rapidly-varied processes such as impact waves and the subsequent analysis phase, which may lead to gross errors in the evaluation of the integral process. A guideline to select the cutting frequency is provided

Uplift Forces on Wave Exposed Jetties: Scale Comparison and Effect of Venting

“…• Calculation of the deck force requires pressure integration (according to influence areas). Lamberti et al (2011) shows that integration of pressures logged at 4 kHz leads to a large overestimation of the maximum force, since the spacing between pressure sensors is insufficient to describe the rapidly varying process of the wave impacts. Sampling at the higher frequency the spatial correlation is much smaller than the transducers spacing and pressure readings ( Figure 6), only valid in the close proximity to the point of measurement, cannot be extended to the whole region between sensors.…”

Wave Loads on Exposed Jetties: Description of Large Scale Experiments and Preliminary Results

“…Of course, in order to avoid aliasing, a low-pass filter must be inserted before the acquisition system. This conclusion is argued in Martinelli et al (2010, in Italian) and in Lamberti et al (2010b): when the load is derived by pressure integration, the resolution in time and space must be related to each other to avoid misinterpretations. As a consequence, the incredibly large amount of stored data do not add much information to the load process.…”

Effects of Wave Loading Conditions on the Fragility of Pile-Supported Wharves/Piers

“…For instance, hurricanes Katrina (2005) and Wilma (2005) caused significant structural damage to pile-supported piers (Gutierrez et al 2006) and wharves (Bardi et al 2007), respectively. The problem becomes more pressing as the hazard exposure of these structures evolves with sea level rise caused by climate change (Lamberti et al 2011). Thus, in light of gaps in the risk assessment of these structures in hurricane prone regions, Balomenos and Padgett (2018a) proposed the first probabilistic framework for developing analytical fragility models for pile-supported wharves/piers vulnerable to hurricaneinduced storm surge and waves.…”