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Showing 1 to 20 of 141 for “"scour"”.
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Local scour at bridge piers
Local scour at cylindrical bridge piers in both uniform and non-uniform cohesionless sediments was investigated experimentally. The aim of the study was to improve understanding of local scour around bridge piers with sediment transport. Three empirical functions which relate the equilibrium depth …
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Scour at bridge piers and abutments
… formulae that have been put forward to predict scour are examined and some of their limitations pointed out in an attempt to clarify some of the research work that has been done on scour. The formulae are applied to two known bridge failures and their accuracy in those particular situations …
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Determination of scour susceptibility through rapid assessment
… existed to efficiently predict the potential scour that could be expected at nearly 20,000 existing off-system bridges in the State of Kansas to assign a National Bridge Inspection Standards (NBIS) Item 113 coding. A customized methodology for scour evaluation was developed through the …
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A vibration-based bridge scour monitoring technique
… most common cause of bridge failure has been “scour” – the gradual erosion of soil around bridge foundations due to rapid water flow. A reliable technique to monitor scour could potentially guide timely repair and, in turn, mitigate the risk of future scour-induced bridge failure. Currently, …
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Modelling local scour around bridge piers using TELEMAC
Scour at bridge crossings is a major cause of bridge failure. There are several different types of scour such as general scour, constriction scour and local scour. One of the most serious types is local scour which occurs as a result of vortex formation around bridge piers and abutments (Hoffmans & …
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Physical modeling of local scour around complex bridge piers
Local scour around bridge foundations has been recognized as one of the main causes of bridge failures. The objective of this study is to investigate the relationships among field, laboratory, and numerical data for the purpose of improving scour prediction methods for complex bridge piers. In this …
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Erosion behavior and scour risk of extremely coarse streambeds
Bridge scour, which is the erosion of soil and rock around bridge abutments and piers, is the principal cause of bridge failure in the United States and around the world. Previous investigations of scour have focused mostly on fine sediments such as sand, silt, and small gravel, because such …
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Scour in regions of flow separation with free-surface effects
… the flow regime is important because diving-jet scouring rates are substantially faster than surface flow scouring rates, and diving-jet scour holes form nearer to the structure. A bi-stable region exists in which either flow is possible with the same upstream and downstream flow conditions. …
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Scour under air entrained jets below dams and flip buckets
… used over the last 50 years for estimating scour under falling jets is: D=Kqx Hy/dz There is, however, disagreement between Authors concerning which values should be used for K, x, y and z. It was. surmised by the writer that plunge pool air entrainment could also be a relevant parameter and …
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Evaluating Shallow-Flow Rock Structures as Scour Countermeasures at Bridges
… that shallow-flow rock structures are not viable scour countermeasures at bridges.</p>
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The Effect of Wall Jet Flow on Local Scour Hole
… measurements and measurements of the evolving scour hole shape were made. Detailed descriptions of the turbulent flow field over a fixed rough bed and for scour holes at equilibrium were obtained for a range of initial jet conditions. Fully turbulent, multiphase flow was modelled using the …
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Numerical modelling of local scour in rivers using fluent 6.2
Scour and deposition are natural processes which take place in a river as the stream profile adjusts to changing flow rates, sediment loads and other environmental conditions. Man-made obstacles to the stream flow such as bridge piers and abutments and other hydraulic structures alter flow patterns …
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Data-Driven Risk Assessment of Bridges Subject to Corrosion and Scour
… degradation events, such as corrosion and scour, creates safety issues in the structural system and can lead to possible bridge failures. Collecting and analyzing inspection data provide a way to monitor and assess the safety condition of bridges. This thesis presents new methods for …
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A SHM-based decision support system for risk management of bridge scour
Flood-induced scour, the erosion of material around bridge foundations due to flowing water ,is by far the leading cause of bridge failures worldwide. Although recent developments in sensor technology have resulted in more structures being monitored, practical applications of scour monitoring …
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Combined abutment and contraction scour in compound channels for extreme flood events
… the combination of abutment and contraction scour is investigated to better understand the scour mechanisms and scour patterns for extreme floods. Close-toreality scour events were physically simulated using models built at 1:45 and 1:30 geometric scales of two-lane bridge prototypes. Scour …
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