Design guidance for low-water crossings in areas of extreme bed mobility, Edwards Plateau, Texas.
-
2009-03-23
Details:
-
Alternative Title:Guidance for design in areas of extreme bed-load mobility, Edwards Plateau, Texas.
-
Creators:
-
Corporate Creators:
-
Subject/TRT Terms:
-
Publication/ Report Number:
-
Resource Type:
-
Corporate Publisher:
-
Abstract:The purpose of this report is to present results from a combination of field and laboratory investigations of mobility
of gravel to cobble sized materials in Texas streams on the Edwards Plateau. TxDOT uses low-water crossings for
many of the roadways in the region, particularly where the streams are ephemeral. When the streambed mobilizes,
instances of roadway loss of service, either by deposition of large amounts of bed materials or by structural failure
associated with streambed mobilization are relatively common. The objectives of the project were to determine the
mechanics of streambed mobilization and develop design guidelines (approaches) to mitigate damage associated
with streambed mobilization events. Numerical models were developed and a GIS approach was used to
demonstrate how area subject to streambed mobilization can be identified through application of these tools.
Physical models were used to demonstrate the mechanics of streambed mobilization and test current design
solutions. The physical model identified the mechanics for culvert “self-clearing” and that a porous roadbed results
in changes to the flow dynamics that affect bedload deposition in the low-water crossing area. An offset threeculvert
design was identified by TxDOT engineers as an alternative to the more-common box culvert.
-
Format:
-
Funding:
-
Collection(s):
-
Main Document Checksum:
-
Download URL:
-
File Type: