Sir Lowry's Pass Viaduct:

The Sir Lowry's Pass to the east of Cape Town is one of the oldest South African passes and carries the busy N2 national highway. HHO Africa were appointed to design the upgrade for the pass from a single carriageway road to a four lane undivided freeway. Included in the upgrading was a major geotechnical investigation for all aspects of the deisgn and construction.

Among the features of the project were:

	The viaduct design included a road over rail bridge to accommodate the railway line which climbs the pass, above and below the road
	Variable geological conditions presented several rock anchoring challenges
	Groundwater was found to be aggressive. The rock anchors had to be double-corrosion protected (a first on road bridges in South Africa)
	The curvilinear alignment of the road presented several challenges in the location of the support piers. Footings were secured with rock anchors
	The confined working space led to the decision to precast all the viaduct beams
	Rail traffic had to be accommodated at all times and no delays were permitted during the fruit harvest seasons.
	The need to maintain a reasonable and safe traffic flow during construction

The project won the SAICE Regional Award for Engineering Excellence and Innovation

For further information or queries please contact terence@hho.co.za