Seismic Retrofit of 3 Million
Gallon Reservoir
Sacramento, USA
Savings: More than 60% compared to other structural schemes.
The Freeport water tower, a distinctive landmark visible from Interstate-5, was built in 1956. The steel reservoir stands about 120 feet high. The supporting structure consists of 27 steel columns with two levels of 60 feet long tension cross bracing.
Of the several seismic retrofit options, the scheme with Pall Friction Dampers in tension cross bracing was chosen. When tension in one of the braces forces the damper to slip, the damper’s mechanism shortens the other brace, thus preventing buckling.
Due to high damping provided by the Pall Friction Dampers,
the strengthening of columns and foundations was not necessary. Seismic retrofit
was completed in 1999.
