Diaphragm wall and piles set record in Africa: Foundation for Africa’s largest suspension bridge in Mozambique

Abstract

As part of the master plan for the infrastructure of the road network in the southern Africa area, a suspension bridge is being built in Maputo, Mozambique. The bridge over the Maputo Bay has an open span of 680 m between pylons and is anchored on the north and south side of the Bay by massive anchor blocks that are built in deep shafts constructed by circular diaphragm walls. With an outer diameter of 50 m and an excavation depth of 15 m and 36 m respectively, these shafts are among the largest presently being built in the world for a suspension bridge. The diaphragm wall panels of the walls reach down to a depth of 56 m into the fine sandstone and siltstone.The pylons and the approach bridges north and south are founded on piles with diameters of 1.50 m to 2.20 m and reach a maximum depth of 110 m. Construction material has been carefully selected and the use of local material as well as approved imported material and products to guarantee a 16-hour retarding time needed for the concreting procedure of the foundation elements.