Design Build project at Smithsonian National Zoological Park
General Contractors Hensel Phelps and Athena Construction Group worked with Smith-Midland to manufacturer the 850 foot long x 30 foot high simulated stone retaining wall for the Smithsonian National Zoological Park in Washington, DC. M & J Welding completed the welding and wall erection.
Originally designed to be cast in place, Hensel Phelps rethought the process, proposing a design-build project involving the use of a shotcrete wall, and placement of precast concrete panels as a facing. The panels were cast and hand-stained to mimic the look and color variations of a natural stone wall, matching the stone wall located on the nearby Rock Creek Parkway. The wall has all the color variations of a natural wall, and is a permanent penetrating stain that will last indefinitely.
The panels were erected using a crane, and were connected to the shotcrete wall with stainless steel plates and anchors. Seven panels were set per shift, which equaled one panel set per hour. Speed of construction was fast.