Extracting the Response of the Bay Bridge, California, from the Application of Multichannel Deconvolution to Earthquake-Induced Shaking

Engineered structures, such as bridges, are excited by earthquakes at the base of the towers and the endpoint of decks. The different structural units of bridges, such as the towers and decks, are coupled. We extract the response of the towers and decks of the Bay Bridge in California from the motion of the bridge that is caused by earthquakes. This constitutes a multichannel deconvolution problem, which is, in general, ill-posed. We use the redundancy of the western half of the Bay Bridge, with near-identical towers and decks, to estimate the response of the upper towers, lower towers, and decks, from the transverse motion recorded in the bridge after four earthquakes. The extracted response functions for the four earthquakes show consistent wave arrivals that correspond to the waves that propagate through the towers and the decks. This method can, in principle, be used to monitor changes in the structural response.