underdrain


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underdrain

[′ən·dər‚drān]
(civil engineering)
A subsurface drain with holes into which water flows when the water table reaches the drain level.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

underdrain

underdrain
A drain, installed in porous fill, for drawing off surface water or water from the soil, as under the slab of a structure.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.
References in periodicals archive ?
Updated from a charter 2008 version and available in a free trial, Permeable Design Pro Software v2.0 for permeable interlocking concrete pavement (PICP) generates time-saving cross section drawings with base and subbase thicknesses, plus CAD drawings illustrating calculated hydrologic and structural requirements from user-designated rainfall events, runoff flows from contiguous surfaces, traffic loads, underdrains and soil subgrade characterizations.
The best option to improve subbase drainage and reduce the risk of premature pavement failure in an existing parking lot is to install an underdrain system to allow moisture a point of relief.
Following dewatering, the con tractor installed the geocomposite underdrain and established the subgrade for the liner system.
* The underdrain pipes should be slotted with as many slots as possible, and slots should be as wide as possible.
In an installation with difficult influent characteristics, traveling bridge filters are installed with options that either "surface-wash" the upper layer of the media with jets of water or "air-scour" the full media bed with bubbles forced up through the underdrain along with the backwash water flow.
Topics include debris flow assessment and mitigation; rockfall rating systems; dam sinkhole evaluation; seismic imaging for landslide remediation; photogrammetry for mapping discontinuities, river morphology, and concrete damage; mine subsidence under levees; Laramie formation claystone behavior; underdrains for construction on expansive soils; reinforced soil structures; bedrock settlement under dams; energy foundations; and tunnel rehabilitation.