Gov�t defends contractor in Moshupa bridge fall
Isaac Pinielo | Wednesday January 18, 2017 15:49
The contractor, Elsamex-ITNL JVCA who were engaged to rehabilitate the road from Mmankgodi junction to Jwaneng, removed concrete erosion protection covers from the two bridges as part of the works.
Engineers knowledgeable with the project said the removal of the covers had exposed the sand-based bridge support to floodwaters leading to the bridges’ collapse. Several vehicles were damaged in the collapse, while festive travellers were forced to use longer routes that eventually became crowded due to the detour.
Transport and Communications permanent secretary, (PS) Elias Magosi told journalists on Monday that the contractor had indeed removed the concrete that was preventing erosion on the bridge. He said however the contractor could not be blamed as the removal was part of the works needed for the road expansion.
“As part of the adjudication process, the contractor was found to be technically and financially qualified to undertake this project,” Magosi said. “The assessment of capability of the contractor was done together with the World Bank from whom the government sourced a loan. “Due to the heavy intensity of the rains and high floods on the 25th December and 7th January, a bridge on the A10 highway (Gaborone-Kanye road) in Moshupa collapsed.”
According to the PS, the bridges collapsed after flash flooding in the water channel due to heavy rains in the upstream.
The water, he said, eroded the soil in the inlet and embankments, which resulted in the weakening of the road layers and hence failure of the load.
“The culverts were under construction and the contractor had removed the concrete preventing erosion for purposes of expanding the road which aided in scouring of the embankment to some extent.
“The existing road embankment could not take the water pressure for too long and hence the two culverts were washed away,” he said.
Magosi said road designs take into account climate changes, and that the roads have a 20-year design lifespan, while culverts and bridges have a 25 to 50 years design life respectively.
Commentators over the festive period noted that authorities monitoring the contractor and the contractor itself had underestimated the strength of the rains forecast by the Department of Meteorological Services. The department had forecast flooding in the area in September, before confirming the forecast again early in December.