Pedestrian safety alongside roadways and near to railways is an area often overlooked in infrastructure planning, but the City of Ekurhuleni, together with the Passenger Rail Agency, launched their Tembisa Pedestrian Underpass Bridges Project in April 2022 so that pedestrians and cyclists have a safer environment for walking and cycling. The development of an attractive, safe and user-friendly pedestrian and cycle underpass by the Thami Mnyele and Golden Gate rail crossings in Tembisa will also reduce fatalities.

Rocla, South Africa’s iconic manufacturer of pre-cast concrete infrastructure solutions was appointed to supply 42 3.0m x 3.0m Jacking Culverts for the Tembisa pedestrian and cyclist underpass project by Esor Construction.

“One of the major challenges at site were the soil conditions. During the jacking phase, the backfill material causing collapses inside excavations. The friction in turn caused high jacking pressures when jacking. The jacking walls with support by 4 x 18m anchors and piles in the ground ensured the walls remained in place whilst the use of Bentonite - an absorbent aluminium phyllosilicate clay - used to cover the culverts limited friction during the jacking process” said Hendrik Ferreira, Construction Supervisor at Esor Construction.

“We have worked with Rocla on many projects over the years and always found their technical assistance invaluable. The technical team is renowned for custom designed solutions” said Ferreira.

Rocla’s Civil Engineer, Mohammad Bodhania commented that with each culvert having a mass of about 10.5 tonnes, 250 tonnes (24 culverts) were jacked into the first channel and a further 190 tonnes (18 culverts) jacked into the second channel.

“The project engineers specified that the 3m x 3m culverts were to be jacked at a depth of 4m below an existing rail embankment. We at Rocla then set about customising elements of the culvert design to accommodate this”.

Rocla specialises in the design and manufacture of pre-cast concrete infrastructure products from a variety of pipes, culverts, manholes, concrete poles, wingwall units and sanitation and bespoke products.

Rocla is part of the IS Group which also includes Technicrete.

ISG