Retrofitting bridges to accommodate single point interchanges on the Gauteng Freeways Improvement Project

William Nicol Bridge originally consisted of a four span reinforced concrete deck with circular void formers. The deck was 30 m wide and had a total length of 73 m. For the new design the deck was widened on both sides to create the approaching flares for the single point intersection (see figure 1)

3.2 Design philosophy and methodology

The widening works consisted of in-situ outer spans and precast middle spans.