Tetrapods as a Scour Countermeasure
Few materials have been studied for their effectiveness in protecting bridge piers and abutments from local scour other than riprap. Recent research conducted at the FHWA research facility...
Threats to Bridge Stability from Scour Related Failures of Drop Structures
Catastrophic failure of bridge foundations may occur when channel bed elevations are lowered unexpectedly. Bridges to be constructed in channels that are known to have bed degradation...
Wind Induced Circulation in Shallow Lakes
Clear Lake is a relatively shallow lake in Northern California. Natural flows are small but at times they do transport heavy metals into the lake. In order to predict water quality constituent...
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...
Scour Retrofit Case Studies for Arizona
Scour retrofit involves a coordinated analysis and joint determination of action by several engineering disciplines: typically, geotechnical, hydraulic and structural engineering. The...
An Improved Method for Measuring System Performance of Hydraulic Infrastructure Systems
Due to the public awareness of the importance of functioning of hydraulic infrastructure systems and the serious consequences caused by their failure, many researches were undertaken to...
Integration of Environmental Management with Reservoir and Power System Operations
Two examples related to the Tennessee Valley Authority's reservoir and power systems operation with environmental performance and management as major goals are given in this paper. One...
Methods for Prediction of Maximum Scour at Coastal Structures
The most common coast scour-related problems are toe scour at rubble mound structures and vertical seawalls, and scour at the base of piles and horizontal pipelines. Existing scour prediction...
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...
Hydrologic Design: Extending Traditional Methods
A review of traditional hydrologic design shows that it is inadequate. The continued adaptation of manual techniques into computer software without a major change in fundamental assumptions...
Using Geophysical Data to Assess Scour Development
The development of scour holes in the Connecticut River near the new Baldwin Bridge has been documented by comparing geophysical records collected before (1989), during (1990), and after...
Local Scour at Bridge Piers in Alberta?Case History
A two span steel truss bridge with a rectangular concrete central pier was built over the Oldman River near Brocket in south-west Alberta in 1954. Initially the bridge was built square...
Reliability Analysis of Levee System of a River
The levee height is determined by the summation between computed water level and an assumed freeboard. The water level is computed by given discharge in the steady conditions. Therefore,...
Risk and Uncertainty in Flood Damage Reduction Project Design
The recent emphasis on partnership between the Federal government and local sponsors in the development of flood damage reduction projects has promoted considerable interest in the application...
Modeled Hydraulic and Salt Transport Patterns in the Sacramento-San Joaquin Delta
Modeled hydraulic and salt transport patterns in the Sacramento-San Joaquin Delta have been summarized as the basis for detailed environmental assessment of proposed water management projects...
Structure of Coastal Upwelling on a Sloping Bottom
A large eddy simulation of coastal upwelling on a sloping bottom is carried out. The structure of the upwelling consists of a persistent primary front, a temporary secondary front which...
The Courant Number and Unsteady Flow Computation
The Courant number C, the key to unsteady flow computation, is a ratio of physical wave velocity, ?, to computational signal-transmission velocity, ?, i.e., C = ?/?. In this way, it uniquely...
Evaluation of Historical Scour at Selected Stream Crossings in Indiana
Geophysical data were collected by means of ground-penetrating radar and tuned transducer systems to estimate the historical scour at ten bridges in Indiana. These geophysical data were...
Variability in Solutions of Constrained Optimization Problems: Ocean Outfall Design Case
Uncertainty in optimization model resulting from parameter uncertainty has not been well studied in the hydraulics and water resources areas. To make valid decisions, knowledge of the...
Three-Dimensional Modeling of the Coastal Region Offshore from Sydney, Australia
Care must be taken in model formulation to ensure that unwanted internal circulation cannot be induced. Extensive model testing must be carried out on possible distorted element shapes...
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