Pasadena could soon ask residents to foot the bill for the almost century-old Central Library’s nearly $200 million retrofit and upgrade project through a potential parcel tax on the ballot next year.
Closed since last May after a preliminary seismic evaluation found the building was out of compliance with municipal code, the Central Library will need to fortify its structure which was built with unreinforced masonry walls now widely recognized as a safety hazard in even moderate earthquakes.
The evaluation found the library’s walls, built in 1927, were already showing significant cracks, and were not fastened to the structure’s foundation, floor beams or roof.
At their Aug. 22 meeting, the Pasadena City Council received a presentation from Gruen Associates — which the city contracted in February to provide planning and environmental documents for the project — on possible approaches that will upgrade the building listed on the National Registry of Historic Places as well as bring it up to code.
Gruen recommended employing a ‘concrete shear wall” approach to the project, which would replace the building’s inner bricklayer with a concrete wall that will reinforce the library’s outer brick layer, floors, and roof.
According to Gruen the method, estimated to cost around $175 million, was the most cost effective that met design standards, and offered the quickest approval and construction times compared to other retrofit approaches that were considered.
While a different method, the base isolation approach, would have offered more seismic protection — raising the library’s foundation to add isolators underneath ground floor columns that absorb earthquake impacts — it would also be more time consuming and expensive, adding about nine months to the project and requiring additional support structures to be constructed on the second floor.
The City Council, like the Library Commission, Historic Preservation Committee and Design Commission…
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