Originally built in 1933, the North Torrey Pines Road Bridge was deemed structurally and seismically deficient in 1990. To bring the historic structure up to current seismic standards, the project team had to deal with structural irregularities, varying soil conditions and a tight sight—all while keeping the bridge open during construction.
The nonlinear retrofit plan involved isolating the superstructure from the existing columns and prestressing the entire bridge for continuity. This allowed contractors to keep the classic facade of the bridge intact while providing a seismically stable design. At the same time, the entire superstructure was removed and replaced with precast girders to architecturally match the existing structure.