Pier Scour at Wide Piers
Scour at relatively wide piers in shallow water is not explicitly accounted for in the current HEC-18 scour equation. The scour estimated for this case is often overpredicted. In this...

Small Inocula Can Effect In Situ Biodegradation
This is the first report of colonization of soil by small numbers of a genetically engineered microorganism. The study suggests that the addition of small inocula of D5 to contaminated...

Numerical Modeling of Water Flow over Porous Media
The momentum transport phenomena at the interface of porous media and fluid are numerically investigated. The single domain approach is used with matching boundary conditions; i.e., the...

Sediment Removal from Stormwater Runoff
Sediment traps, also known as baffle boxes, are being used throughout the state of Florida to remove sediment from stomiwater. A baffle box is divided into three compartments by two bathers,...

An Experimental Study on the Use of Constructed Wetlands for Stormwater Management
The purpose of this study is to compare the pollutant removal effectiveness of selected wetland vegetation such as cattails, reeds, and bulrushes by using laboratory bucket wetlands. Pollutants...

Scour Around Circular Piers
In certain situations scour classification becomes sensitive. The generalised scour relationships are superior to classification dependent scour relationships. In this study a generalised...

Maryland SHA's Procedure for Assessing Existing Bridges for Scour Vulnerability and for Rating Unknown Foundations
The Maryland State Highway Administration developed a recommended screening procedure for rating existing bridges for Item 113, Scour Critical Bridges, in the National Bridge Inventory...

Hydrodynamic Changes Associated with Navigation Traffic on the Upper Mississippi River System
Research has been conducted at the Illinois State Water Survey for the last five to seven years to collect field data from the Illinois and Mississippi Rivers to determine the extent and...

Field Measurements of Streambed Scour at Bridge Piers in Ohio
Field measurements made from 1989 to 1994 were evaluated to characterize pier scour at 21 bridge sites in Ohio. Pier scour was observed at sites in 45 of 47 real-time scour measurements....

Scour-Hole Dimensions at Selected Bridge Piers in New York
Knowledge of scour-hole dimensions can be used by bridge engineers to deter mine the extent of countermeasures needed to prevent scour at bridge piers. Scour-hole widths at 128 piers,...

Scour Processes Observed in Field Data
River channels scour and aggrade due to complex, interrelated natural processes that are dynamic over space and time. Channel scour is particularly difficult to predict for bridge crossings,...

Entrainment of Eggs and Larval Fish into Propeller Jets
Because larval fish have limited mobility and eggs have no mobility, both are susceptible to entrainment into the propeller jets of passing vessels. Entrainment subjects eggs and larvae,...

Field Verification of Dem-Derived Watershed Response
Rainfall-runoff data from an NAEW Experimental Watershed are used to test the feasibility of deriving the watershed response from the digital elevation model of the watershed. Using Clark's...

Assessment and Implications of Local Channel Instability on the Prediction of Bridge Scour
Current assessments of the potential for scour at existing and new bridges do not include the effects of local channel instability on predicted bridge scour estimates. Local channel instability...

Use of Geomorphic Data for Assessing Stream Stability at Bridge Structures
The authors recently completed a statewide bridge scour evaluation for the Nevada Department of Transportation, which included evaluation of the geomorphic processes of bank erosion and...

Industry Standards for Erosion Control Products�Future Tools for Civil Engineers
In 1990, the International Erosion Control Association (IECA) formed a Cooperative Standards Program (CSP), directed by the IECA Committee on Standards. The purpose of the CSP is to develop...

3D Flow Structures?From Laboratory to Field Applications
One laboratory experiment and one field application have been modeled. For each one different sources of errors in the model results could be detected. It may be concluded that the applicability...

Verification of a 3D Flow Model Using Laboratory Data
The ASCE Task Sub-Committee on 3D Free Surface Flow Model Veri fications has been developing test cases and/or procedures for both computational model developers and users over the past...

Developing a Rating Table for the Central Diversion Dam Radial Gates
The Central Nebraska Public Power and Irrigation District uses radial gates for flow control throughout its system. The rating tables for five radial gates on a diversion dam are in error,...

Discharge Characteristics of Overshot Gates
Overshot gates are becoming increasingly popular for controlling water levels in open channels because of the ability of the gates to handle flow surges with limited depth changes. While...

 

 

 

 

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