COVER STORY
Launching
THE ASHTON ARCH Showcasing construction at its best, the iconic Ashton Arch, designed by AECOM, sets a new benchmark for innovation as South Africa’s first concrete tied-arch bridge constructed using a transverse launching method. The bridge programme was executed by main contractor H&I Construction, working alongside a highly talented team of design and product specialists.
Ashton Arch in its offset position prior to launch
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IMIESA January 2022
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ituated at the base of the Langeberg mountain range, Ashton is a bustling town that forms par t of the Western Cape’s wine and fruit growing region. The routes passing through Ashton ultimately join the N2 at Worcester and the N1 at Swellendam, making the integrity of the town’s bridge a crucial interconnecting link. The new Ashton Arch features a cablesupported concrete deck that spans 110 m between supports, with arching ribs rising 22 m above the asphalt road sur face. The twin parallel arch ribs are connected via five 15.5 m wishbone beams, providing lateral stability to the arch ribs. Post-tensioned tiebeams complete the arch’s structural form, and the final design makes provision for a dual-carriageway layout of four 3.4 m lanes and two 2.4 m sidewalks.
PROJECT TEAM • Main Contractor: H&I Construction • Client: Western Cape Department of Transport & Public Works, Roads Branch • Structural Engineer & Bridge Designer: AECOM • Launch System Designer: Nyeleti Consulting • Temporary Works Designer: Maffeis Engineering
SPECIALIST SUPPLIERS & SUBCONTRACTORS • Sika South Africa • Form-Scaff • Amsteele Systems