150 Year Old Chapel Stabilized

The Challenge

Settlement issues caused by soft clay soils.

The Dayton Veterans Affairs Protestant Chapel, an important historical landmark in Ohio, was constructed in the 1860’s. Over the years since, several additions have been completed for the chapel. As the culturally important chapel neared its 150th birthday, a large crack opened on the west face of the original bell tower, running from ground level to the top of the tower. Due to the age and height of the structure, the ominous bell tower crack presented a critical safety issue. The tower footings were constructed from stacked limestone bound with mortar. Engineers knew that fastened systems like push or helical piles would create torsion that would damage or break the footings. Also, project engineers understood that any excavation around the foundations would likely relieve earth pressure and lead to buckling of the stacked stone footings. The historic chapel’s iconic bell tower needed a reliable fix fast, and project engineers reached out to Groundworks.

The soils around the chapel were analyzed following the collection of core samples by a 3rd party contractor. Soil borings showed bedrock at about 12 feet below grade. The foundations varied from six feet to 10 feet below grade. The soil samples indicated that soft clay soils were present above the bedrock and beneath the footings, and likely led to the settlement issues with the bell tower.

Key Facts

The Solution

Polyurethane injections were used to mitigate the settlement issue.

After consultation with project engineers and a review of all soil analyses conducted at the site, polyurethane injections was agreed upon as the best solution for the site and the circumstances. Groundworks crews arrived on site and quickly injected high-density polyurethane into the soils beneath the footings to mitigate the bell tower settlement issue.

The Impact

Groundworks quickly stabilized the tower footings without excavation.

Upon completion of the polyurethane injections, the Dayton VA Protestant Chapel was stabilized, and the dangerous settlement that had threatened the bell tower was addressed to the satisfaction of the project engineers. Polyurethane injections provided a solution that did not cause any torsion in the footings. Most importantly, Groundworks’ solution required no excavation. While each footing injection point required strict assessment, the flexibility of polyurethane injection allowed crews to adjust equipment set-up and injection design to meet the project’s needs.