Revised Clear-Water and Live-Bed Contraction Scour Analysis Training Manual

This paper presents the results of an experimental study investigating the effect of skew angle on clear-water contraction scour under a bridge deck at partially and fully submerged flow conditions. Two bridge deck models without a pier, one of which was located perpendicular to the flow while the other one was located with skewness of 15°, were used in the study. Forty experiments were performed for each deck model, 24 of which were under partially submerged and 16 were under fully submerged flow conditions. Analysis of the experimental data showed that as the discharge and approach flow depth increased, the maximum scour hole depth under the skewed deck model increased up to 25%–66% for fully submerged flow and 17%–57% for partially submerged flow conditions. Furthermore, the effect of skew angle significantly enlarged the width of the scour hole as you move along the skewed deck.

Download Full-text

Clear-Water Scour around Bridge Abutments under Backwater Conditions

Transportation Research Record Journal of the Transportation Research Board ◽

10.1177/0361198196152300124 ◽

1996 ◽

Vol 1523 (1) ◽

pp. 196-202 ◽

Cited By ~ 2

Author(s):

Terry W. Sturm ◽

Aftab Sadiq

Keyword(s):

Flow Distribution ◽

Scour Depth ◽

Clear Water ◽

Bridge Abutments ◽

Bridge Abutment ◽

Rectangular Channels ◽

Contraction Ratio ◽

Bridge Approach ◽

Contraction Scour ◽

Abutment Scour

An experimental study was conducted of the depth of clear-water scour around the end of a square-edged bridge abutment terminating in the floodplain of a compound channel. The study's purpose was to improve current techniques of abutment scour prediction, which are based primarily on laboratory studies in rectangular channels. It is indicated that a discharge contraction ratio arising from a theoretical contraction scour analysis for equilibrium conditions can be used for explaining the effect of flow distribution on the local abutment scour depth in the case where significant backwater occurs from bridge contraction. The use of reference values of approach flow depth and velocity in the floodplain for undisturbed conditions without the bridge is shown to collapse experimental results for scour depth in both the case of a contraction with negligible backwater, and the case of a contraction with significant backwater in the bridge approach section.

Download Full-text

Clear-Water Contraction Scour at Selected Bridge Sites in the Black Prairie Belt of the Coastal Plain in Alabama, 2006

Scientific Investigations Report ◽

10.3133/sir20075260 ◽

2008 ◽

Author(s):

K.G. Lee ◽

T.S. Hedgecock

Keyword(s):

Coastal Plain ◽

Clear Water ◽

Contraction Scour

Download Full-text

Experimental study of clear-water contraction scour

Water Science & Technology Water Supply ◽

10.2166/ws.2020.014 ◽

2020 ◽

Vol 20 (3) ◽

pp. 943-952 ◽

Cited By ~ 4

Author(s):

Ravindra Kumar Singh ◽

Manish Pandey ◽

Jaan H. Pu ◽

Srinivas Pasupuleti ◽

Vasanta G. Kumar Villuri

Keyword(s):

Experimental Study ◽

Reasonable Agreement ◽

Time Dependent ◽

Scour Depth ◽

Clear Water ◽

Equilibrium Conditions ◽

Bridge Abutment ◽

Water Conditions ◽

Contraction Scour ◽

Equilibrium Scour Depth

Abstract In this paper, experimental results of clear-water scour on a sand bed under short contractions were studied. Sequences of test runs were performed under clear-water conditions for three different contraction ratios. The outcomes of the experiments were employed to define the effects of various parameters on equilibrium scour depth under clear-water scour conditions. In this work, the precision of three maximum scour depth equations was tested from previous studies for contraction scour cases. Two new analytical equations were proposed to calculate time-dependent scour depth and maximum scour at equilibrium conditions, respectively, from the study. The proposed equations were validated using measurements from the present study as well as from previous literature, and the equations show a reasonable agreement between measured and computed values of scour depth under clear-water conditions in short contraction. The presented equations can be used for studying protection of the submerged portion at a bridge abutment or any similar structure.

Download Full-text