Project: Immaculate Conception Church
Immaculate Conception Church was built in 1956 and in spite of never going through a major renovation, the construction of the building has held up amazingly well. However, one major structural issue was the deterioration of the 16 stone columns supporting the bell tower. The original columns were installed and anchored with ferrous metal anchors that began to rust causing large chunks of the columns to break off. Large pieces of stone falling 65 feet was a serious hazard but, even more dangerous was the fact that these columns are load bearing and carry the weight of the entire structure above them.
Camarata Masonry Systems, Ltd. (CMS) removed the old columns and replaced them utilizing stainless steel anchors. The first challenge was to build a scaffolding system inside the bell tower that would allow access to all sides of the columns. The floor of the bell tower was only 16’ by 16’ and was four and a half feet below the base of the columns. Therefore, a dance floor was built at the height of the base of the columns and an elaborate scaffold system was constructed allowing two additional platforms around each column. Aluminum I-beams were attached on top of the scaffold system and chain fall hoists were used to lift the 600 pound stone columns into place.
The second major challenge was to remove the old load bearing columns while maintaining the support of the structure above. CMS designed an apparatus that consisted of steel plates that saddle the top of the parapet wall on either side of each column. Scaffolding screw jacks were welded to the saddle plates and 3” pipes were inserted over the screw jacks. Angles were welded to the top of the pipe and two additional angles were bolted to the angles at the top of the pipe connecting the entire apparatus. Two adjustable plates were bolted to the angles connecting the two pipes, allowing the two adjustable plates to slide in the joint above the capitals of the columns and carry the load of the structure. Once this was in place, the existing columns were safely removed and the new columns installed. Due to the limited amount of space and the capacity of the support apparatuses only two columns could be worked on at any given time.
While this project presented new challenges, all 16 columns were replaced in a 30 day period making the bell tower safe and preserving the original design for future generations.