Biggs Cardosa was tasked under an As-Needed Structural Engineering Services Contract with SFPW to perform a seismic vulnerability assessment of the Peace Pagoda, identify the seismic deficiencies and develop retrofit options to enhance its expected seismic performance.
Biggs Cardosa performed seismic evaluation of the Peace Pagoda based on the ASCE 41-17 Tier 1 and Tier 2 methodologies, Collapse Prevention Structural Performance Level and BSE-2E seismic hazard level. Results of seismic analyses indicated that the existing structure had significant deficiencies, with most of its beams and columns highly overstressed in shear, flexure or both. The assessment concluded that the existing Pagoda structure was vulnerable to partial or total collapse and was deemed to have an expected Seismic Hazard Rating (SHR) of 4.
A seismic retrofit was recommended in order to reduce the potential earthquake damage and to prevent the possibility of a partial/total collapse. Currently, Biggs Cardosa is developing retrofit concepts to remedy the seismic deficiencies in the Pagoda’s lateral system. The task of retrofitting an iconic monument structure of historical importance is challenging indeed, as there are stringent limitations on adding new seismic strengthening elements. Any proposed retrofit solutions must preserve, to the greatest extent possible, the architectural integrity, historic fabric and character of this San Francisco icon.
