Nonuniform Transient Sediment Transport Modeling
A numerical model based on Lai's (1991) multimode scheme for fully coupled simulation of water and sediment movement in mobile-bed alluvial channels with nonuniform bed materials has been...
Top Width of Pier Scour Holes in Free and Pressure Flow
The maximum top width of the local scour holes at piers is shown to be a simple function of the scour depth and the angle of repose of the bed material in water. Knowledge of the top width...
Video Analysis of Gravel Saltation
Experimental results concerning saltation characteristics of gravel particles in a movable bed channel are analyzed by using video imaging techniques. Ensemble averaged values of saltation...
Scour Development at Isolated River-Bed Obstacles
Development of local scour was investigated for isolated obstacles on movable beds subject to clear-water scour. The resulting maximum scour depths, scour volumes, and obstacle displacements...
n Values for Shallow Flow in Rough Channels
Manning's friction factor n has been developed from flume data for very shallow open channel flow in a high-gradient channel with large bed material. n values are presented as a function...
Problems with Numerical Modeling of Gravel-Bed Rivers
Inherent to one-dimensional numerical models are the assumptions that hydraulic parameters can be assigned a characteristic average value, and that the flow is gradually varied so that...
The Control and Monitoring of Local Scour at Bridge Piers
A series of flume experiments revealed a possible method of reducing local river bed scour at bridge piers, thereby, reducing the risk of bridge failure. Three prototype schemes were installed...
Shape Effect on Bed-Load Transport in Pipes
The nature of part-full flows in pipe sewers produces different channel shapes resulting in non-uniform shear stress distribution on the wetted perimeter. New experimental data were utilized...
A Method of Managing Floating Debris
The device described offers a promising approach to a new method of managing floating debris. It modifies the surface flow of water from a submerged location. The modified flow reduces...
An Application of Nonhomogeneous Poisson Process in Sediment Infiltration Into Gravel Bed
The compound homogenous Poisson process (CNHPP) model (Shen & Todorovic, 1971 ) is found applicable in sediment infiltration into gravel bed due to the unsteady and nonuniform...
Riprap Coverage Around Bridge Piers
Experiments were conducted to examine the effect of riprap size and coverage on reducing local scour at bridge piers. Pier diameter, bed material size, riprap size and diameter were varied...
Sediment Deposition from Debris Flow on a Gentle and Wide Slope
Motion of sediment grains in the deposition process from debris flow on a gentle and wide slope was examined. A model of the deposition was presented on the basis of an analysis of grain...
Pier Scour on the South Saskatchewan River
A continuing program to measure river bed scour near bridge piers and abutments on the Alberta rivers has been on going for over thirty years. The objectives are to verify the existing...
Measurement of Bridge Scour at the SR-32 Crossing of the Sacramento River at Hamilton City, California, 1987-92
A study of the State Route 32 crossing of the Sacramento River near Hamilton City, California, is being made to determine those channel and bridge factors that contribute to scour at the...
Overmining Causes Undermining(
Instream aggregate mining has caused significant problems and expense to California bridges. Riverbed degradation on the order of 3-5 m (9-15 ft) beneath waterway crossings within actively...
Scour Inspection Using Ground Penetrating Radar
This paper examines the capabilities of Ground Penetrating Radar (GPR) for river bed scour inspection based on a study carried out by Clarkson University, Potsdam, New York in association...
Local Scour Measurements at Bridge Piers in Alberta
A summary of local pier scour data collected by Alberta Transportation and Utilities (AT & U) over the past 30 years is presented. Several methods used to gather this data are...
A New In-Stream Aerator
Experiments on microporous, polymeric, hollow fiber membranes are being conducted for application to in-stream aeration. The hollow fibers are scaled on one end and connected to an oxygen...
Sediment and Water Quality Control Devices in Small Watersheds
The physical behavior and health of an alluvial stream depends on the extent of man's interferences in its tributary areas. In its natural setting a stream provides three main functions...
Highlights of the New ASCE Standards on Composite Deck Floor Slabs
This paper presents highlights of the newly approved and printed ASCE Standard on the design and construction of composite floor deck slabs utilizing cold-formed steel. In 1992 four documents...
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