Construction World December 2023

CONSULTING ENGINEERS

DISTILLERY ROAD BRIDGE REHABILITATION PROJECT T he Distillery Road Bridge crosses the Plankenbrug

River and serves as the only public access road to Bosman’s Crossing, a small mixed development community within Stellenbosch. Its location has historic significance since the original bridge was constructed in 1691. It was the first formalised entrance from the Cape to Stellenbosch along the old Cape wagon road, with the last bridge upgrade dating back to the mid-20 th century. Due to concerns regarding the structural integrity of the existing bridge, it was decided to replace the bridge with the careful retention and detail integration of the existing central stone pier and stonework salvaged from the embankments. Phased demolition of the existing structure allowed traffic accommodation during half-width construction. The bridge was supported on deep piled foundations and was successfully upgraded to a single carriageway with two cantilever pedestrian walkways. Additional upgrades included the water main supplying potable water to the area and new stormwater, electrical and fibreoptic infrastructure. Erosion protection measures and river rehabilitation efforts were implemented during construction. AECOM was appointed in August 2019 by the Stellenbosch Municipality to design and upgrade the new Distillery Road Bridge. AECOM developed several options for the proposed remedial works and established its associated viability in terms of technical and cost considerations for each option. In conjunction with Stellenbosch Municipality, it was confirmed that, due to the overall condition of the existing bridge, its replacement was considered the most feasible solution. AECOM provided the following engineering services on this project: • Geotechnical design (analysis, reporting, preliminary and detail design) • Bridge design (visual bridge inspections, detailed assessment report, preliminary and detail design) • Pavements and materials (full services) • Geometric design (preliminary and detail design) • Two-dimensional flood study of the Plankenbrug River and Bosman’s Crossing area and hydraulic design of all road drainage infrastructure (visual inspections, analysis, reporting, preliminary and detail design) • Documentation and procurement • CMCS (construction monitoring, client’s

representative, project management) Stellenbosch Municipality received initial concerns about the structural integrity of the Distillery Road Bridge, setting in motion the process to rehabilitate or upgrade it. The bridge crosses the Plankenbrug River and is located on the western edge of Stellenbosch, near the point where Adam Tas Road/R310 crosses the railway line. The Distillery Road Bridge is about 20 m in length and consists of a single carriageway. It is the only access road into Bosman’s Crossing, a small mixed development area within Stellenbosch comprising various commercial developments and apartment complexes. The original Steenenbrug at Bosman’s Crossing was constructed in 1691 as the first public works project in the Stellenbosch District. It was the first formalised entrance from Cape Town to the growing town of Stellenbosch along the old Cape wagon road leading to lower Dorp Street. The site sits adjacent to the Stellenbosch Archaeological Reserve. Over 300 years later, the bridge has been upgraded on several occasions, with the most recent upgrade dating back to the mid-20 th century. The upgraded bridge design has been duly informed by the heritage significance of the structure. Heritage considerations included the retention and detail integration of the existing central stone pier (non structural), reuse of the stonework salvaged from the embankments for landscaping and design of cantilever walkways that are a visual reminder of the original bridge. An existing bollard at the approach of the existing bridge was repainted, reinstated and used as a spatial marker, with a plaque conveying the historical importance of the site and the retention of the stone pier. 

64 22 nd Best Projects Awards 2023