{"id":104092,"date":"2026-06-04T15:35:12","date_gmt":"2026-06-04T13:35:12","guid":{"rendered":"https:\/\/www.maccaferri.com\/za\/success-stories\/zanzibars-first-double-carriage-flyovers-a-reinforced-earth-solution-for-constrained-urban-approach-embankments\/"},"modified":"2026-06-04T15:35:12","modified_gmt":"2026-06-04T13:35:12","slug":"zanzibars-first-double-carriage-flyovers-a-reinforced-earth-solution-for-constrained-urban-approach-embankments","status":"publish","type":"stories","link":"https:\/\/www.maccaferri.com\/za\/success-stories\/zanzibars-first-double-carriage-flyovers-a-reinforced-earth-solution-for-constrained-urban-approach-embankments\/","title":{"rendered":"Zanzibar\u2019s First Double-Carriage Flyovers: A Reinforced Earth Solution for Constrained Urban Approach Embankments"},"content":{"rendered":"
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Challenge<\/h3>\n <\/div>\n <\/div>\n <\/div>\n <\/div> \n <\/div>\n
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The Zanzibar urban roads upgrade required the delivery of the island\u2019s first double-carriage flyovers at Mwanakwerekwe (Flyover 1) and Adani\/Amani (Flyover 2) to support growing transport demand and urban development. In both locations, the critical geotechnical challenge was not the bridge substructure itself, but the need to retain high approach embankments within a constrained urban footprint. The MSE wall heights varied from near zero at the start of the approaches to approximately 9 m at the abutments, while the bridge abutments themselves were piled, leaving the retained approach fills to be supported by the earth-retaining system.<\/p>\n

A conventional retaining solution would have increased footprint demand, reduced constructability flexibility and imposed a less efficient solution for long, variable-height urban approaches. The project also had to address:<\/p>\n