Helical Tiebacks – Manchester, NH

October 28, 2011

The oldest standing school building in New Hampshire was undergoing major renovations; the addition of three sub levels to the structure. This construction project required extensive shoring along the property line. The site was also on the corner of a busy intersection and site access was relatively limited.

Drillled-Micro Piles: A design consisting of drilled soldier piles and lagging was utilized to support the excavation work and neighboring property. Micropile columns were chosen as the solider piles so to minimize disturbance that driven piles would create.

Helical Piles: Helical tiebacks were installed in the middle of a pair of soldier piles with heavy-duty walers to spread the load. Proof and performance testing was done on the helical tiebacks to ensure performance. The piles were successfully tested and the helical work was completed in 10 working days.