Further Results to Time-Dependent Local Scour at Bridge Elements

Oliveto, Giuseppe; Hager, Willi H.

doi:10.1061/(asce)0733-9429(2005)131:2(97)

Cited by 181 publications

(110 citation statements)

References 5 publications

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“…densimetric Froude number at the tailwater section with V cross sectional flow velocity, g = g( s )/ modified gravitational acceleration,  mass density of water,  s mass density of bed sediment, and For unsteady flows, eqn (1) could be applied by using an analogous approach as in Oliveto and Hager [21] in case of bridge piers. The computation of scour depth can proceed as follows:…”

Section: Methodsmentioning

confidence: 99%

The Temporal Scour Progress Downstream of Low-Head Stilling Basins Under Unsteady Flow

Oliveto

2017

WIT Transactions on Ecology and the Environment

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This paper deals with the temporal evolution of local scour downstream of low-head stilling basins. In comparison to previous companion papers the most real conditions of unsteady approach flow are considered here. In this aim, experiments were carried out in a 1 m wide and 20 m long rectangular channel. Free overfall jets plunging into a horizontal apron were caused by an ogee-crested spillway. A nearly-uniform sediment with median grain size d509 mm was used as mobile bed. The temporal effect of six different hydrographs on local scour depth was investigated under clear-water scour condition. Based on the data collected and the previous results for steady flow conditions a predictive model is proposed to simulate the temporal progress of the scour depth along the channel axis as function of tailwater densimetric Froude number, relative submergence, and dimensionless time.

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Section: Methodsmentioning

confidence: 99%

The Temporal Scour Progress Downstream of Low-Head Stilling Basins Under Unsteady Flow

Oliveto

2017

WIT Transactions on Ecology and the Environment

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“…Experimental data were compiled from available studies in Chabert and Engeldinger [58], Zanke [10], Franzetti et al [59], Oliveto and Hager [14,19], Sheppard et al [60], Grimaldi [61], Alabi [62], Simarro et al [63], Meyering [64], Lança et al [65], Link et al [22] and Pizarro et al [21]. Altogether, results corresponding to 137 experiments were analyzed.…”

Section: Data Characterization For λ Estimationmentioning

confidence: 99%

“…Validation runs are plotted on Figure 7a-d, presenting the timedependent evolution of the measured scour depth in contrast to the BRISENT model calibrated and estimated according to the proposed equations (Equations (22), (26) and (27)). ) present measured scour depths over time, BRISENT model calibrated using a steady run, BRISENT model calibrated using unsteady runs, and BRISENT model considering Equation (13) to Equation (14) and Equation (19) to Equation (22) for experiments 2017LINK01U and 2017LINK02U, respectively. Table 5 summarizes the model benchmarking in terms of RMSE for experiments "2017LINK01U" and "2017LINK02U", and the results show that the proposed equations correctly reproduce the main dynamic of the time-dependent scour depth.…”

Section: Brisent Validation: Highly Unsteady and Multi-peaked Hydrogrmentioning

confidence: 99%

BRISENT: An Entropy-Based Model for Bridge-Pier Scour Estimation under Complex Hydraulic Scenarios

Pizarro

Samela

Fiorentino

et al. 2017

Water

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Abstract:The goal of this paper is to introduce the first clear-water scour model based on both the informational entropy concept and the principle of maximum entropy, showing that a variational approach is ideal for describing erosional processes under complex situations. The proposed bridge-pier scour entropic (BRISENT) model is capable of reproducing the main dynamics of scour depth evolution under steady hydraulic conditions, step-wise hydrographs, and flood waves. For the calibration process, 266 clear-water scour experiments from 20 precedent studies were considered, where the dimensionless parameters varied widely. Simple formulations are proposed to estimate BRISENT's fitting coefficients, in which the ratio between pier-diameter and sediment-size was the most critical physical characteristic controlling scour model parametrization. A validation process considering highly unsteady and multi-peaked hydrographs was carried out, showing that the proposed BRISENT model reproduces scour evolution with high accuracy.

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“…Fig. 1(a) also plots the predictor of Oliveto and Hager (2005), as a solid line, by assuming a shape factor of 1 (cylindrical pier), as well as the AE25% band around the predictor. Similar plots were produced for the other seven d=D p groups; they do not substantially differ from Fig.…”

Section: Data Characterizationmentioning

confidence: 99%

Clear-Water Scour at Comparatively Large Cylindrical Piers

et al. 2013

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New long-duration clear-water scour data were collected at single cylindrical piers with the objective of investigating the effect of sediment coarseness, D p =D 50 (D p = pier diameter; D 50 = median grain size) on the equilibrium scour depth and improving the scour depth time evolution modeling by making use of the exponential function suggested in the literature. Experiments were carried out for the flow intensity close to the threshold condition of initiation of sediment motion, imposing wide changes of sediment coarseness and flow shallowness, d=D p (d = approach flow depth). The effect of sediment coarseness on the equilibrium scour depth was identified; existing predictors were modified to incorporate this effect for U=U c ≈ 1.0; D p =D 50 > ≈60 and d=D p ≥ 0.5; the complete characterization of a known scour depth time evolution model was achieved for U=U c ≈ 1.0, 60 < D p =D 50 < 500 and 0.5 ≤ d=D p ≤ 5.0.

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Further Results to Time-Dependent Local Scour at Bridge Elements

Cited by 181 publications

References 5 publications

The Temporal Scour Progress Downstream of Low-Head Stilling Basins Under Unsteady Flow

The Temporal Scour Progress Downstream of Low-Head Stilling Basins Under Unsteady Flow

BRISENT: An Entropy-Based Model for Bridge-Pier Scour Estimation under Complex Hydraulic Scenarios

Clear-Water Scour at Comparatively Large Cylindrical Piers

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