Establish Guidance for Soils Properties-Based Prediction of Meander Migration Rate

Meander migration costs the Texas Department of Transportation (TxDOT) millions of dollars to protect affected bridges and highway embankments, as illustrated by the case histories accumulated by this research team in phase 1 of this work. These histories include the SH 105 bridge over the Brazos River, the US 105 bridge over the Trinity River, the US 90 bridge over the Nueces River, the SH 105 bridge over the Trinity River, the US 59 bridge over the Guadalupe River, and the SH 80 bridge over the Guadalupe River. One recent meander migration threat (FM 787 at the Trinity River) required a $300,000 emergency countermeasure and a $5.6 million replacement bridge. Several solutions for predicting the movement of meanders have been proposed in the past. This report shows these solutions to be unreliable. The solution outlined in this report considers soil erodibility as an independent parameter influencing meander migration. Other conventional parameters such as flow velocity, meander radius of curvature, river width, and others are part of the proposed solution. Through a combination of well-instrumented large-scale flume tests, quality numerical simulations, and fundamental laboratory erosion tests, a simple and reliable solution is developed.