To help rebuild infrastructure in war-torn Angola, Armando Rito Engenharia was retained to design the EUR 26 million 4th of April cable-stayed bridge to replace an antiquated one-way bridge between the cities of Benguela and Lobito. Located in the heart of the Catumbela village amid complex urban surroundings, the bridge had to ensure a low profile, with short pronounced curves, slim deck, and piers outside the main river to minimize environmental impact. To accommodate these geometric constraints, Armando Rito required detailed construction drawings and accurate 3D modeling and analysis software.
Armando Rito used Bentley’s RM Bridge for bridge design and analysis to develop its cable-stayed solution, and MicroStation to produce construction drawings. Using Bentley software, the team conducted a tri-dimensional model analysis, defined pylon geometry, designed stay cables, determined installation forces, and optimized cable stay tensioning throughout the project lifecycle. The comprehensive modeling and analysis capabilities offered by RM Bridge enabled the project team to deliver a modern, aesthetic, and culturally symbolic structure with an impressive engineering design.
Bentley software enabled the team to make more informed decisions throughout the construction process, saving time and money. Using RM Bridge to develop the innovative saddle design for the stays allowed a reduction in steel quantities and slimmer concrete masts, resulting in an immediate savings of almost 15%. To overcome challenges optimizing cable-stay forces, combined with the bridge’s complex geometry, Armando Rito worked with Bentley’s Professional Services team to accelerate the process, delivering the project timely and within geometric requirements. The completed bridge reduced travel time from over 2 hours to less than 30 minutes.
The comprehensive modeling and analysis capabilities of RM Bridge and the assistance provided by the software developers were instrumental to the innovation and success of this project. RM Bridge was used to create a 3D structural model of the cable-stayed bridge, including pylon geometry and cable stays, and to perform construction stage analysis. The RM Bridge Addcon optimization module allowed for stress operations and time-dependent behavior. All construction drawings were created with MicroStation.