This Snack & Learn webinar explores the emergency rehabilitation completed on the M2 highway, a mushroom type pier bridge with drop in slabs in which the pier with extreme ASR in the shear zone. This highway carries significant traffic and had to be repaired in a consolidated timeline.
The design commenced with temporary works design of steel jacking towers. The towers were installed under the drop-in slabs and used to jack the slabs up off the piers, which remained in that position due to congested workspace. The towers were designed to take the slabs load as well as some additional live loading from the workers on site.
The existing piers were demolished and replaced with new piers. The new piers were designed to withstand the South Africa real loading based of TMH7, NA, NB and NC vehicles. Due to the emergency nature of the project, importing of Dywidag bars to use in the pier head was not allowed for so the design used only reinforced concrete as opposed to the existing piers. The bases of the piers were reused, and mechanical couplers and chemical anchors were used to tie the new pier to the existing bases. The design consisted of the new pier columns, the mushroom head and the half joints which supports the drop-in slabs.
This webinar explores how WSP provided a quick solution for its client, providing the design and some construction supervision services.
Jared Da Silva - Engineer: Structures, WSP in Africa