Wednesday, October 31

Learn All About It: Crucial Role Of Highway Retaining Walls

Have you noticed those big retaining walls that line many of our area's highways? In this post we discuss these walls, in particular the ones being built to reinforce the elevated mainlanes above the frontage roads and surrounding right of way (ROW) along I-10 for the project between La Cantera and Ralph Fair Road.
These walls allow us to use the I-10 ROW as efficiently as possible with multiple lane heights supported by mechanically stabilized earth (MSE) walls. These walls are constructed soil walls with artificial reinforcing, meaning backfill is brought in to stabilize the wall face and provide a sturdy foundation.

The MSE wall’s face is constructed of precast concrete panels stacked in vertical layers. The precast concrete panels stabilize unstable slopes and retain the soil on steep slopes while under crest loads. Due to the mainlane overpasses being higher in elevation than the frontage roads or surrounding ground, these walls are needed to widen the road. Otherwise, there is not enough distance between mainlanes and frontage roads to place the required embankment slopes. Below are some examples of MSE retaining wall we're constructing on this project.

With these new retaining walls in the construction process, it won’t be long until you will be driving on the new and improved lanes they will support. Next time you’re stopped next to a retaining wall, take a quick look and admire how much weight these simple, yet extraordinary walls support. 

In the pictures above, the top two show the retaining wall during the actual construction process. These pictures clearly show the backfill used to stabilize the wall along with the individual precast concrete panels. The bottom two pictures show the retaining wall with several vertical layers of precast concrete panels. Also notice that all the concrete panels have the same unique pattern on the face of the panels. This pattern is specific to MSE retaining walls in the San Antonio district, so keep an eye out for this pattern throughout the city!