Unrestricted Research thanks to modern Construction Methods: The Mansueto Library in Chicago

In 2007, the University of Chicago’s Regenstein Library had reached its capacity. As the university’s wish was to keep storing its books centrally on campus, the decision was made to build a new library: The Mansueto Library, which will be opened in the spring of 2011.

The building, which is named after a donating married couple, was designed by worldfamous Chicago architect Helmut Jahn. It is being built as a four-storey glass and steel dome that will accommodate reading and studying rooms. A five-storey subterranean book vault is located beneath the dome. Thanks to stable temperatures underground, only a minimal amount of energy input is necessary to reach optimum temperatures for conserving the volumes.

The Mansueto Library will be equipped with an automated storage and retrieval system (ASRS) designed to hold up to 3.5 million books and to deliver any of them to the service desk within a mere five minutes. In comparison to most US-American universities that store their books externally, waiting periods of several days can be avoided.

Construction work at Mansueto Library began in September 2008. The oval foundation consists of a slurry wall with a total of 26 panels that touch one another at a slight angle. The construction of the slurry wall was carried out in approximately 2 ½ months, with an average of 3 ½ panels erected per week. The panels’ tops are linked by a cast-in place concrete ring that is approx. 1.5m (5ft) high and approx. 1.7m (5.5ft) wide. This ring will link the dome with the first-floor slab and transfer loads from the dome to the foundation.

Once the slurry wall was finished, the basement was excavated. After completion of the excavation, the perimeter wall was tied back into the surrounding soil using DYWIDAG Strand Anchors that were posttensioned and grouted. As there are no floor slabs to support the outer wall in the Mansueto Library, a total of 334 permanent DYWIDAG Strand Anchors had to be anchored in the soil at depths of up to 30.5m (100ft) for stabilization. The tiebacks were installed in four levels for a 16.7m (55ft) temporary excavation below grade.

In addition to the required strand anchors, DSI USA also provided the equipment necessary for testing and stressing. Following completion of the excavation, an approx. 61cm (2ft) thick reinforced floor slab was cast in place for the basement floor.

For the next 22 years, the University of Chicago will have enough room for new books thanks to the new library.