This ‘eruption’ on Mozambique’s N260 is a ‘structural instability of the soil’, says ANE – report

The defect, which began to appear yesterday, already extends about 30 metres in length and nine metres in width, and presents a severe rupture with uplift, extensive cracking, and lateral displacement of the road pavement. ANE says its technicians conducted a visual observation from which they noted that a partial collapse of the road edge is occurring, exposure of the lower layers, and the presence of water on the surface. In addition, they report having observed damage to the lined side ditch, the presence of longitudinal and transverse cracks, soil saturation, and surface water coming from beneath the pavement, instability of the adjacent slope, and significant deformation of the embankment body.

They add that a technical diagnosis was carried out, indicating that the phenomenon corresponds to a geotechnical failure of the type known as embankment sliding, associated with loss of strength and subgrade cutting due to water saturation, probably caused by the existence of a water source that is triggering movement of the slope mass as a result of water impact. Among other factors, the ANE delegation in Manica identifies as probable causes the high rainfall and, consequently, the recharge of groundwater sources. In view of this situation, ANE recommends the removal of the unstable material, reconstruction of the embankment with suitable and well-compacted material, and the implementation of an efficient drainage system and soil stabilization.

It also points out that drains should be constructed to remove water from the pavement structure and reduce neutral pressures, among other measures. While these interventions are awaited, local authorities have decided to maintain a police presence to protect the site because, in the eyes of the local population, this eruption is synonymous with the existence of a gold deposit.