Savings: More than 50% over conventional methods.
The existing sixteen-storey office building, with two levels of basement, was built in 1964. Steel moment frames and some braced bays provided lateral resistance to the existing structure. The foundations are on piles.
A change of occupancy was planned in 1997 to house the provincial police (Surete du Quebec) headquarters. The project structural engineers evaluated that the existing structure was not capable of resisting seismic forces and the storey drifts were excessively high. Over a period of 35 years, the building codes had changed considerably, especially in terms of seismic provisions.
In 1999, the work on seismic rehabilitation was undertaken along with major renovations to protect the original and new investment. Pall Friction Dampers offered the best solution for the seismic upgrade. Since the dampers dissipate a major portion of the seismic energy, the storey drifts and forces acting on the structure are considerably reduced. Hence, expensive and time-consuming work of strengthening existing member and pile foundations was not required. Pall Friction Dampers were incorporated in existing cross bracing and new single diagonal bracing.