Cedar Rapids Library
In June 2008 a flood devastated downtown Cedar Rapids, Iowa. The public library was among the ruined buildings. The city decided to rebuild the library on a new site, three blocks further from the Cedar River.
Braun Intertec was brought in on the library construction after the geotechnical engineering had been completed, but before work began on the foundations. The existing fill was not suitable for a building of that size and weight — so a specialty contractor installed geopiers, a system where the existing soil is excavated and replaced with crushed stone in a grid pattern throughout the site. Braun Intertec helped by monitoring installation and testing the properties of the geopiers.
This site was in one of the oldest settled parts of Cedar Rapids and excavation unearthed antique structures and items with historic value. We had to work hand-in-hand with the historical society.
Further excavation dug up an old, brick-lined cistern. We drilled soil borings to determine how the cistern and its contents would impact the foundations. Based on the findings, Braun Intertec engineers provided additional geotechnical recommendations for the construction in the vicinity of the old cistern.
New fill was needed to raise grade in several areas of the site, but it wasn’t just a matter of filling with soil or rock. Because this building was designed to achieve LEED Platinum status, the design team wanted to re-use material and use only local materials to raise the grade. To prevent introducing contaminants into the new site, they conducted an environmental survey of the borrow sites to confirm there were no dangerous levels of contamination.
In addition, our Building Sciences team was consulting with OPN Architects and Ryan Companies on the building envelope design.
Once construction commenced, our Non-Destructive Examination (NDE) team analyzed and tested the building itself. We evaluated the steel and its structural strength by studying the beams, welds, bolts, and bolt tightness that held the building together. The Building Sciences group conducted field performance testing of the installed curtain wall windows and skylights as the building was going up. We also completed thermographic inspections of the exterior walls to look for gaps in exterior insulation, thermal bridging, and air infiltration. All of these efforts played a critical role in the library obtaining LEED certification.
The project was an exercise in uncovering and working around (or through, or over) the unknown. Now that the project is complete, Cedar Rapids citizens can enjoy their state-of-the-art library.