Industrial Support Column Stabilization at University of Tennessee

The Challenge

100-year old foundation with loose soils under the support columns had poor load-bearing capacity.

The University of Tennessee purchased an historic warehouse structure to consolidate their Facility Support Services department, which had previously been spread around various locations on campus. The 100,000 square foot building dated back to the early 1930s and had once been the site of a nationally recognized marble processing plant. The university undertook a full-scale renovation to transform the building into a state-of-the-art facility with offices, conference rooms, labs, and warehouse space. However, loose soils under the support columns had poor load-bearing capacity. That challenge, along with the condition of the nearly 100-year old foundation, combined to create a difficult situation for the construction firm contracted to transform the warehouse.

Key Facts

The Solution

The Polyurethane Injection process was utilized to stabilize the concrete foundation and support columns without excavation or demolition.

No drawings or other information were available about the existing foundation system. Site investigations revealed poor foundation conditions and undersized foundation elements. The subsurface exploration showed extremely variable sub-surface conditions, with many areas of poor soils with low bearing capacity. To adequately support the code-required building loads, the load-bearing capacity would need to be increased to approximately six kips/square foot. Alternatively,a deep foundation system would need to be added to transfer the building loads to refusal.

The design team initially conceived that they would support each of the 142 column locations by removing the slab, excavating to expose the foundation, installing helical piers, connecting them to the foundation, and then backfilling and re-pouring the slabs. However, after budgeting the proposed work and performing a constructability analysis, it was determined that this approach would be cost-prohibitive and have a major negative impact on the construction schedule.

Groundworks was contacted to evaluate the project and determine its zero-excavation solutions could possibly be a good fit. After site visits, conceptual budgeting, and a review of historical project examples, the contractor’s design team decided that Groundworks’ soil stabilization methods would get the job done in less time and within the project’s budget.

The Impact

The client saved time and an estimated $380,000 in repair costs.

The work was performed successfully in increments over six weeks. The polyurethane injection process was utilized to stabilize the concrete foundation and support columns without excavation or demolition. Four injections per column at multiple depths were performed around and below the 142 column footings. With this technique, Groundworks was able to effectively stabilize the warehouse, displace soft soils, increase the bearing capacity to code requirements, and prevent future settlement. The client saved time and an estimated $380,000 in repair costs by utilizing Groundworks’ repair methods as opposed to the originally proposed alternatives.

Groundworks is proud to have been able to help the University of Tennessee and Johnson & Galyon Construction with this impressive project. The entire warehouse remodel was completed in Spring of 2016, and since completion there have been no indications of settlement.