AASHTAASHTO Flashcards
A general and progressive buildup or raising of the longitudinal profile of the channel bed as a result of sediment deposition.
Aggradation—
An unobstructed, relatively flat area beyond the edge of the traveled way for the recovery of errant vehicles. The traveled way does not include shoulders or auxiliary lanes.
Clear Zone—
An unobstructed horizontal or vertical space.
Clearance—
A general and progressive lowering of the longitudinal profile of the channel bed as a result of long-term
erosion.
Degradation—
Maximum flow of water a bridge is expected to accommodate without exceeding the adopted design constraints.
Design Discharge—
The flood flow equal to or less than the 100-yr flood that creates the deepest scour at bridge foundations.
Design Flood for Bridge Scour—
The peak discharge, volume, stage, or wave crest elevation and its associated probability of exceedence that are selected for the design of a highway or bridge over a watercourse or floodplain.
Design Flood for Waterway Opening—
A storm water management facility that impounds runoff and temporarily discharges it through a hydraulic outlet structure to a downstream conveyance system.
Detention Basin—
Linear depression in the bottom of components to cause water flowing on the surface to drop.
Drip Groove—
The flood due to storm and/or tide having a 0.2 percent chance of being equaled or exceeded in any given year.
Five-Hundred-Year Flood—
Scour in a channel or on a floodplain that is not localized at a pier or other obstruction to flow.
General or Contraction Scour—
The science concerned with the behavior and flow of liquids, especially in pipes and channels.
Hydraulics—
The science concerned with the occurrence, distribution, and circulation of water on the earth, including precipitation, runoff, and groundwater.
Hydrology—
Scour in a channel or on a floodplain that is localized at a pier, abutment, or other obstruction to flow.
Local Scour—
Flood flows derived from two or more causative factors, e.g., a spring tide driven by hurricane- generated onshore winds or rainfall on a snowpack.
Mixed Population Flood—