The DigIndy Project is an 18-mile-long tunnel system more than 200 feet below the surface of Indianapolis. When completed, this tunnel system will have the capacity to store over 250 million gallons of sewage. imi is supplying the concrete for this project that will provide lining to the tunnels.
During the early stages of planning for this project, imi began designing and testing mixes that would perform to the project’s needs, including pumping concrete underground for thousands of feet to its final destination, setting timeframe, and strength of the final product.
To place the product, the concrete is pumped from the surface down a 250 foot vertical shaft. It’s then run horizontal until the mixture reaches the forms that will create the walls of the tunnels. Once that strength reaches 1000 psi, the form is removed and moved to the next location for the next pour. Each day, around 210 feet of the tunnel is set using around 510 yards per section (~2.4 yards/foot).
imi will supply roughly 400,000 yards of concrete when the tunnel project is complete.