A Model for Low-Drag Landslides
Field observations and experimental records indicate that the primary mode of motion of many large landslides is that of sliding rather than flowing. Most of the shear during sliding is...

Simulation of Subsurface Drainage of Highway Pavements
An analysis of the drainage of a pavement system from initial saturation incorporates a realistic assessment of the drainable porosity of the base. This analysis indicates that if a granular...

San Francisco Bay and Delta Oil Spill Fate Studies Part I: Hydrodynamic Simulation
A two-dimensional vertically-averaged finite element model was used to simulate the hydrodynamics in San Francisco Bay and Delta to support oil spill fate studies. Simulations were performed...

San Francisco Bay and Delta Oil Spill Fate Studies Part II: Oil Spill Simulation
Because of the presence of oil refineries and significant tanker and barge traffic in the bay and delta region, the possibility of a moderate or major spill in the area must be considered....

Incipient Motion in Gravel-Bed Rivers
Incipient motion processes are reviewed for bed material in gravel-bed rivers. Prediction difficulties are identified. Research results are reported for field and flume studies to investigate...

Sediment Budgets in Gravel Bed Streams
A sediment budget/mass balance technique is presented for use in assessment of sediment transport by river reach in gravel bed streams. Selection of appropriate gravel bed transport equations,...

Density Currents in Pollutant Transport and Mixing
A buoyant spreading model for the current-advected plume is formulated including several distinct mechanisms: convective spreading, interfacial friction spreading, entrainment at the density...

Criticality of Density Intrusions
Previous analyses of density intrusions indicates that a steady interface cannot be maintained if the front propagates at a speed greater than that of long interfacial waves. Supercritical...

Bed Sediments Size Changes, Atchafalaya River
During low flows of 1989 and 1991, we collected bed sediment samples from the thalwegs of the Mississippi River from Cairo, Illinois, to Head of Passes and along the Atchafalaya River...

A Study of Lateral Bed Slopes Developed at Bend
A study was conducted to compare seven actual cross section profiles of Philip Bayou Realignment with the lateral bed slopes estimated from the model derived by Ikeda titled `Sediment...

Effect of Grain Size on Sediment Transport Calculations
The U.S. Army Corps of Engineers is currently developing a `Hydraulic Design Package for Flood Control Channels' (SAM). SAM is capable of computing sediment rating curves and stable channel...

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...

A Model for Vertical Transport at a Sheared Density Interface
A physically based model for vertical mixing and transport at a sheared density interface is presented, based on high-resolution measurements from laboratory experiments. It is found that...

Mixing Characteristics of a Transitional Stratified Two-Layer Flow
Small scale structures in a stably stratified two-layer flow are investigated. The flow configuration has the initial velocity interface displaced with respect to the density interface....

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...

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...

Fluid Mechanics Aspects of Ocean Outfalls
Prediction of the environmental effects of ocean outfalls requires understanding of some complex fluid mechanical phenomena. These include the dynamics of merging plumes in flowing, density-stratified...

Sediment Disposal and Transport in Central SF Bay
The relocation of dredged material from navigation channels in the Francisco Bay is crucial to the movement of deep-draft shipping and shallow-draft recreational vessels. The margins of...

Survival of Atlantic Salmon Smolts Bypassed Through Ice-Log Sluices Determined by the HI-Z Turb'N Tag
The HI-Z Turb'N Tag was used to assess injury and mortality incurred by Atlantic Salmon (Salmo salar) smolts bypassed through ice-log sluiceways at two stations. Both sluiceways were similar...

The Influence of Protective Material on Local Scour Dimensions
Protective materials installed around the base of a bridge pier can reduce or prevent local scour. The performance of four materials: grout mats, grout bags, footings, and riprap, are...

 

 

 

 

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