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You are here : eLibrary : IAHR World Congress Proceedings : 36th Congress - The Hague (2015) ALL CONTENT : Sediment management and morphodynamics : Influence of column width on the equilibrium scour depth at a complex pier
Influence of column width on the equilibrium scour depth at a complex pier
Experiments on local scouring around complex bridge piers were performed in steady clear-water conditions to evaluate
the effect of the relative column width, 􀜦􀯖 /􀜦􀯣􀯖 (􀜦􀯖 = column width; 􀜦􀯣􀯖 = pile cap width), on equilibrium scour depth, 􀝀􀯦􀯘,
for different pile cap positions, 􀜪􀯖/ℎ (􀜪􀯖 = distance from the initial bed level to the top of the pile cap; ℎ = approach flow
depth). Two complex pier models were tested for this purpose. These models were designed with a round-nose column
founded on a rectangular round-nose pile cap, supported by two rows of cylindrical piles. In both models only 􀜦􀯖 was
changed, obtaining two relations of D􀭡/D􀭮􀭡 (0.55 and 0.40). A total of fourteen tests, run for 15 to 25 days, were carried out
in a 40 m long and 2 m wide rectangular sand-bed tilting flume. A total of eight tests were performed with Model 1
(D􀭡/D􀭮􀭡 = 0.55) for different H􀭡/h ratios and six tests were performed with Model 2 (D􀭡/D􀭮􀭡 = 0.40) for the six most
relevant positions analysed with Model 1. The dependence of the equilibrium scour depth on the relative pile cap position
was identified, corroborating the findings of other studies. The results of both complex pier models allow the conclusion
that the scour depth evolution and the equilibrium scour depth depend directly on 􀜪􀯖/ℎ and 􀜦􀯖 /􀜦􀯣􀯖. The relative increment
in 􀝀􀯦􀯘 values, observed from the tests with Model 2 to the tests with Model 1, is influenced by the increment of the column
width (i.e., increase in 􀜦􀯖 /􀜦􀯣􀯖 ratio), as the other geometric dimensions of the complex pier remain fixed.
File Size : 812,206 bytes
File Type : Adobe Acrobat Document
Chapter : IAHR World Congress Proceedings
Category : 36th Congress - The Hague (2015) ALL CONTENT
Article : Sediment management and morphodynamics
Date Published : 12/08/2015
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