Challenge

Built in 1961 the Westminster Bradenton Manor’s South Elevation was slated for renovation. It was decided to bring the building up to code by removing the entire facade. Hurricane-resistant windows, new stucco with Mediterranean detailing, and a new mansard roof were planned. Due to the renovation generating additional loading to the existing wall footing, it was determined that there would be differential settlement between the new footer and existing. A deep foundation was recommended to transfer the load from the new footer to the limestone below. To minimize vibration and possible damage to the existing structure, Helical Piers were chosen as the deep foundation to support for the new footer

Solution

Helical Piers were chosen as the deep foundation system because they can be installed with smaller equipment, and less vibration and disturbance to the existing structure. LRE Commercial was chosen to install the Helical Pier system for this project. LRE utilized 54 FSI 287 helical piers, with 8”- 10” lead sections, installed to 14-foot average depths. The Helical Piers were installed on 4.5 centers to achieve a design working load of 20 kips per pier. Utilizing a FSI retrofit bracket at each location and hydraulic cylinders, LRE uniformly loaded each bracket. Upon completion, the retrofit brackets and tops of the Helical Piers were encapsulated into the new footer and foundation. The detail of the footer also consisted of doweling into the existing footer and floor slab.

Project Summary

Geotechnical Engineer: Nodarse & Associates

Structural Engineer: McElroy Engineering

Architect: James E. Toth Architecture

Construction Manager: Hennessey Construction

Certified Installer: LRE Commercial

Products Installed: Fifty-four FSI 287 – 8” – 10” Helicals to an average depth of 14 feet 4.5 feet on center.

Helical being hydraulically advanced

Hydraulic cylinder connected to bracket

Uniform load applied to each pier

Building before and after renovation