Culverts: integral to water, road and mining infrastructure projects

20 March 2019

The main function of culverts is to manage the flow of
water from one side to the other of an ‘obstruction’. This can be a road,
railroad, trail or other structure constructed in either the natural or
designed flow path of the water.

Factors to be considered before design and
installation are the site specific application, environmental impact ensuring
that erosion is minimised and structural damage avoided. Incorrectly placed or
designed culverts can result in culverts failing, becoming dislodged and in
extreme pollution cases being clogged with vegetation and sediment.

Rocla, one of South Africa’s leading precast concrete
product manufacturers, is a supplier of a wide range of culverts for
infrastructure and other water flow related projects. Their production
experience, quality controls and technical design expertise in project
assessment and product design has been successfully utilised for custom-designed
culverts and many major infrastructure developments such as Polokwane Eastern
Ring Road and the rehabilitation of the D528 in George’s Valley, Limpopo.


Along with custom designed culverts for once-off
projects, Rocla offers two distinct ranges of culverts, differentiated by the
type of loading requirements, both available with associated precast base

For Heavy Loading Applications, such as to provide a
waterway below railway tracks, Rocla’s SATS SAR Rectangular Portal Culverts can
be used. These, or custom units are also utilised in any application with
excessive fill requirements with the culvert tunnel at the base of the fill
zone, allowing either conveyor or vehicle access.

The standard SAR culverts are supplied in lengths of
1,22m and designed for up to 10m of fill.  Culverts required for loading
heights greater than 10m are handled individually and designed in-house at
Rocla Head Office.

For traditional loading applications, creating
waterways below roads, trails or even drainage channels, Rocla’s Standard
Rectangular Portal Culverts are the preferred solution.

These standard culverts range in size from a span of
450mm to 3600mm, and heights from 300mm to 3000mm. The strength classes
for these culverts are 75S, 100S, 150S, 175S and 200

If time constraints are a factor for any project, the
Precast Culvert option, along with the Precast Base, as opposed to casting
in-situ, will save on project duration and provide quality assurances on final

units for culverts

Rocla’s Precast Wingwall units can be used at both the
inlet and outlet of any channeled system making use of circular or rectangular
portal culverts for stormwater applications. The natural flow path of water
upstream of a construction is often wider than the culvert or pipe structure.
Transition sections are then required to receive and direct the flow of this
upstream water through the culvert/pipe. The same is true of the downstream end
of the culvert/pipe section. The precast concrete wingwall unit is the most
effective structure to use for the effective transfer of this water,
eliminating erosion and creating a smoother flow of water. .

Rocla manufactures a wide range of precast concrete
products that are effective and cost efficient for all infrastructure and
general construction projects requirements. They have representation in Namibia
and Botswana in addition to their South African presence.

Rocla is part of the ISG which also includes

Further information is available from Malebusa Sebatane,
Tel: 011 670 7600 Cell: 078 803 9863, email: [email protected]

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