Feature by Sean Peterfreund, SE
In March, the United States Patent and Trade Office granted McMillen Jacobs Associates a patent for the Tieback Anchor Alignment and Access Device (TAAD), which makes building tieback walls easier.
Over the years our engineers recognized the need for an improved approach to tieback de-tensioning in deep excavations in urban settings. The default approaches of staging slab and wall construction or by providing “windows” in the permanent walls and waterproofing membrane were proving to be expensive and time-consuming to builders. In addition, these approaches decrease the reliability of the waterproofing system.
The TAAD is a double-wide flange steel insert for concrete shoring walls. It forms a hollow conduit to allow for a drill rig to drill down through the device from the surface and quickly de-tension all tiebacks from the surface. Most importantly, the de-tensioning can take place after the permanent underground structure and waterproofing are complete. When incorporated early in the design process, the device creates the potential for significant savings in schedule for deep, waterproofed excavations associated with tall buildings and cut-and-cover transportation.
McMillen Jacobs Associates has roots in innovation dating back to 1959, when Don Jacobs developed, and later patented, the Jacobs Sliding Floor (aka the “Magic Carpet”). This invention revolutionized drill-and-blast tunneling. Through the development of the TAAD patent, we continue to uphold our reputation for challenging the status quo through innovation in the pursuit of higher quality and more efficient construction, while providing better value in terms of cost and end-product. We embrace and celebrate this philosophy in all our work.