Retrofit of seismically designed steel-concrete composite structures to withstand progressive collapse

This work addresses the need for buildings to sustain structural damage without excessive propagation to the rest of the elements. Four element retrofit strategies are proposed and assessed on their effectiveness in increasing the progressive collapse resistance of seismically designed steel-concrete composite buildings. The cost-effectiveness of the designs determined by the proposed strategies is evaluated by comparison against the solutions defined using structural design optimization. The results yielded are indicative of the trade-off between total retrofit cost and performance under the considered damage scenario.