Characterization of the scour cavity evolution around a complex bridge pier

Abstract

A study on the time development of local scour around a complex pier was developed using a small-scale model embedded in a sediment bed. A total of 15 laboratorial tests were performed at the Hydraulics Laboratory of the Faculty of Engineering of the University of Porto. The duration of each experiment was previously established to progressively characterize the scour cavity. After each experiment, the flume was gradually emptied to facilitate the application of closerange photogrammetry. The scour depth values resulting from the application of photogrammetry at the pile cap front agree well with the values obtained experimentally. The temporal development of the scour cavity is presented and discussed. Empirical formulas for the scour cavity time development and for the relation of scour depths to scour cavity volumes were obtained. The obtained threedimensional models can also be used for calibration and validation of numerical models.

Application of Structure-from-Motion photogrammetry in laboratory flumes

“…SfM techniques have already been used and tested in a wide array of field applications (e.g., Westoby et al, 2012;Fonstad et al, 2013;Micheletti et al, 2015), but few studies have used SfM in a laboratory setting (Marra et al, 2014;Kasprak et al, 2015;Ramos et al, 2015;Wang et al, 2016). This technology is becoming increasingly popular, but to our knowledge there have been no studies explicitly evaluating the relative performance of SfM against other methods of topographic measurement in a laboratory flume environment (but see Nouwakpo et al 2014), and there is a general lack of guidelines for SfM application in flume settings.…”

Hydrodynamics of a bordered collar as a countermeasure against pier scouring

“…it develops almost linearly if time is put in the logarithmic scale [43][44][45]. Recent studies nevertheless demonstrated that for protected piers (tests T1 and T2) scour develops through various stages at different rates, depending on the initially landfilled geometry that gradually emerges [33,[46][47][48]. Figure 4 shows the temporal evolution of d s for all tests.…”

Remote sensing of laboratory rivers

“…Numerous experimentalists have adapted the method to the remote sensing of model topography, most commonly with convergent cameras mounted on a rolling instrument cart above the experiment. Laboratory 'SfM' has been used to monitor experiments with braided rivers (Javernick et al, 2018;Kasprak et al, 2015;Leduc et al, 2019;Middleton et al, 2019;Peirce et al, 2018Peirce et al, , 2019, alluvial fans and steep unconfined flows (Leenman & Eaton, 2021;Leenman et al, 2022;Piton et al, 2018;Vincent et al, 2022), estuaries (Braat et al2019;Leuven et al, 2018), step-pool channels (Wang et al, 2021;Zhang et al, 2020), Martian valley evolution , bridge scour (Ramos et al, 2016), bedforms (Adams & Zampiron, 2020;Bankert & Nelson, 2018;Nelson & Morgan, 2018;Polvi, 2021), alluvial cover (Buechel et al, 2022;Papangelakis et al, 2021;Welber et al, 2020), and the effects of plants and wood (Spreitzer et al, 2020b(Spreitzer et al, , 2021Wang et al, 2016).…”