Pima County Public Service Center & Parking Garage

To address the soil issue, Sundt collaborated with the architects and engineers to evaluate multiple foundation options, ultimately selecting a “compensating mat slab” foundation. A traditional foundation would have been both difficult and more costly. The compensating mat slab foundation was placed by Sundt’s concrete team in two massive overnight operations that were the largest in Tucson’s recent history. Together, the pours required more than 7,800 cubic yards of concrete to create the five-foot-thick, one-acre foundation. To obtain enough concrete, Sundt used trucks from two ready mix companies to manage the delivery. The work took place in two separate weekend pours to make as little impact as possible on local traffic, and the City of Tucson helped coordinate traffic lights along the route to keep the trucks moving. Because the foundation was poured in June in Arizona, crews had to cool and cure the concrete with ice added at the batch plant and burlap blankets with landscape soaker houses running continuously for seven days.

The construction team also had to navigate around existing utilities, including a key fiber optic line for the western United States. There were also pipes and other subsurface construction that were nearly 100 years old, including numerous domestic water connections and pipes that had been abandoned in place without documentation. A forensic investigation was conducted to ensure the work was thorough and no connections were missed.

In addition to the Public Service Center, Sundt also constructed an adjacent $14.7 million parking structure that accommodates 706 cars, including secured judges parking, public and County staff parking, plus integrated retail space fronting on a public plaza shared with the Public Service Center main entrance.