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1

Interference of an upstream pier on local scour at downstream piers

Khaple S., Hanmaiahgari P. R., Gaudio R., Dey S.

Acta Geophysica

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2017

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Vol. 65, no. 1

29--46

EN

In this study, three kinds of pier arrangements were tested. They are (i) two piers in tandem, (ii) two piers in staggered arrangement, and (iii) three piers in symmetrically staggered arrangements. In the arrangement of two piers in tandem, the equilibrium scour depth at downstream pier decreases with an increase in downstream distance up to approximately eight times pier diameter and then increases with further increase in downstream distance. However, the scour depth at downstream pier is always smaller than that at upstream pier. In the arrangement of two staggered piers, the scour depth at the downstream pier for L/b = 4, where L is the offset distance and b is the pier diameter, is the same as that of the upstream pier at S = 8b, where S is the streamwise spacing or distance between piers. Further, for three piers in staggered arrangement, as the lateral spacing between downstream piers increases, the equilibrium scour depth at downstream pier decreases.

2

Experimental study on local scouring at pile-supported piers

Moreno M., Birjukova O., Grimaldi C., Gaudio R., Cardoso A.H.

Acta Geophysica

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2017

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Vol. 65, no. 3

411--421

EN

In spite of the increasing importance of complex piers for bridges, the number of studies on these piers is comparatively small and the predictors of scour depth at complex piers are only a few, derived from limited experimental evidence. The main purpose of this paper is to share with the hydraulics community the results of 67 tests on scouring at pile-supported piers (including complex piers) aligned with the flow, under clear-water conditions close to the threshold of beginning of sediment motion, while contributing to shade some more light on the influence of the pile-cap thickness on the equilibrium scour depth, the reliability of the superposition approach, the contribution of each one of the complex pier components to the equilibrium scour depth of the ensemble, and the performance of existing predictors of local scour at complex piers.

3

Sediment particles and turbulent flow simulation around bridge piers

Pasiok R., Stilger-Szydło E.

Archives of Civil and Mechanical Engineering

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2010

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Vol. 10, no 2

67-79

EN

Scientific surveys regarding the mechanisms of transportation of bed material grains from the scour hole are undersupplied in literature. This work takes into account the mechanisms behind a local scour, associated with a bridge pier impact. In order to gather information about the flow field, an appropriately formulated numerical model of flow was used, the so-called LES (large-eddy simulation). The numerical analyses carried out in this work, examining the mechanisms of the transportation of bed material grains by means of a suitably formulated flow model, constitute theoretical background for the analysis of velocity fields around bridge piers. Those analyses will come in handy during hydraulic computations of bridges.

PL

Brakuje w literaturze opracowań naukowych z zakresu badań mechanizmów transportu ziaren materiału dna z dołu rozmycia. Niniejsza pracę należy zaliczyć do prac nowatorskich. Rozpatruje ona mechanizmy rozmywania lokalnego, związanego z istnieniem filaru mostowego. Do zdobycia informacji o polu przepływu wykorzystano odpowiednio sformułowany numeryczny model przepływu, tzw. symulację dużych wirów (LES - large-eddy simulation). Przeprowadzone w niniejszej pracy analizy numeryczne, badające mechanizmy transportu ziaren materiału dna z wykorzystaniem odpowiednio sformułowanego numerycznego modelu przepływu, stanowią teoretyczne podstawy analiz pola prędkości wokół filarów mostów. Analizy te będą pomocne przy obliczeniach hydraulicznych mostów.