14.08.2018
Impressive proof loads on the Maputo-Katembe bridge successfully finalized
In the frame of an all-encompassing quality monitoring during the construction of the longest suspension bridge of Africa in Maputo, two independent proof loads on the suspension bridge as well as the northern foreland bridge were mandatory. As Gauff Engineering is responsible not only for the quality monitoring and control but also for the review of the design and the consultancy on-site for this infrastructure project, this procedure has been a very elaborate and an extraordinary challenge. The suspension bridge itself has access bridges of various construction types on the north and south part of the bay of Maputo and therefore consists of three bridges.
The evidence of functionality given via static and dynamic proof loads are generally required by contract for suspension bridges, especially for a complex structure as the Maputo-Katembe bridge. The bridge can only be handed over to the builder, the state-owned company EDMS (Empresa de Desenvolvimento de Maputo Sul), after having successfully completed those tests. For that purpose, 56 trucks - each vehicle with a gross weight of 25 tons – have been driven on the bridge conforming to the standard static load tests. In addition, dynamic tests have been carried out. This has included brake tests, driving with steady speed, driving over bumps as well as deceleration and repeated starts.
The proof loads of the bridge did occur preferably in still air conditions during the night, to exclude the influence the high temperature differences occurring during the day could exert on the measured values. The tests performed with extensive measurements on the cables, suspensions, pylons and inside the steel liners, have been conducted during a total of five nights and were accompanied by representatives of two Chinese universities. Due to the less temperature-sensitive properties of concrete in comparison to steel, the test loads on the northern foreland bridges could be undertaken during the day. The original design of the bridge having been adapted during the construction period, specific proof loads on defined spots of the roadway, the cables etc. ensure that the bridge will work according to the original calculations during later operation.
The successful acceptance of the proof loads by GAUFF Engineering and the builder, following the submission of the report, sets another milestone on the path to the inauguration of the bridge.
