LiDAR-Guided Masonry Repair and Structural Recovery at the Guggenheim Building in the University of Northern Colorado

In September 2022, a vehicular impact caused severe structural damage to a historic unreinforced masonry wall at the Guggenheim Building on the University of Northern Colorado campus. The SUV strike displaced a load-bearing brick wall by over four inches at the southeast corner, directly beneath two floor levels and a roof structure. Built in 1910, the three-story building is a key architectural feature of the campus, making the structural intervention both urgent and sensitive.

Initial stabilization involved installing strongbacks bolted through the damaged wall. A thorough assessment followed using LiDAR scanning to map the wall’s internal surface and identify precise displacement patterns. These high-resolution scans informed the extent of necessary reconstruction while enabling engineers to develop a support plan tailored to the structural load paths and the brittle nature of the historic masonry.

The engineering team, working in coordination with contractors and the university, developed a temporary shoring system using needle beams to maintain stability during wall reconstruction. Four wide-flange steel beams were placed at two-foot spacing to support the affected masonry and the loads from floors and roof above. The needle beams were supported by shoring towers both inside the building and at an exterior cast-in-place foundation extending below frost depth.

A preload was applied to the needle beams before brick removal to minimize sagging. This preload was calculated to approximate the load transfer from the displaced masonry. A novel aspect of this system included digital load scales originally developed for brewery tanks. Eight load-monitoring scales, four on each side, tracked forces in real-time and were connected to a central station for continuous monitoring.

To maintain structural integrity, surveyors recorded structural movements throughout demolition, shoring, and reconstruction. This dual-monitoring approach of both beam loads and masonry shifts ensured load equilibrium and early detection of any developing instability.

Demolition of the damaged wall sections was done manually to preserve as much of the original material as possible and to protect surrounding components. Replacement bricks were sourced to match the size, texture, and color of the originals. Mortar was selected for compatibility with the historical materials, particularly focusing on stiffness and aggregate gradation to ensure seamless bonding.

Once the new wall section was rebuilt, the temporary shoring was carefully removed after confirming adequate curing and strength. The voids left by the needle beams were filled with matching brickwork to complete the structural restoration.

The completion of this project involved complex coordination and precision execution. It demonstrates effective strategies for supporting unreinforced masonry structures during emergency repair while preserving historical integrity. The outcome is a structurally sound and visually consistent restoration that maintains the architectural identity of the Guggenheim Building.