JACOBS TEMPORARY SLOPE STABILISATION

The Quality Street bridge which spans the M4 Southern freeway, has in recent years experienced a major increase in traffic volume. A large percentage of this traffic volume includes articulated trucks travelling between the 3 lane, M4 Southern freeway and the Jacobs industrial area. To cope with this increased traffic volume, the Ethekwini Roads Provision Department & their consultant, VelaVKE / Eyethu Engineers Joint Venture prepared a design which required Quality Street bridge and the existing approaches to be widened. Extending the existing bridge required the widening of the bridge support structures. To extend the reinforced concrete bridge support, the existing material had to be excavated using heavy plant machinery. The roads had to remain open to traffic during construction, which posed several problems to the contractor, one been that access to the slope adjacent to the busy freeway and Quality Street was difficult. Furthermore, the excavation of the slopes that supported Quality Street had to be near vertical, in order to keep the road open to traffic, whilst allowing the base of the retaining wall and bridge support structure to be built. The cut slopes which varied between 1m and 8,5m required temporary support during construction.