December 2013
CONSTRUCTION WORLD
74
Professional Services
C
Tshelimnyama pedestrian bridge project
Project information
• Name of project: Tshelimnyama pedestrian bridge project
• Company entering: SMEC SA
• Client: SANRAL
• Main contractor: JT Ross
• Steel fabricator: JH Gouws Engineering
• Architect: GAPP
T
he Tshelimnyama Pedestrian Bridge Project showcases how a
unique lookingbridge canbe createdusing engineering ingenu-
ity and technical expertise. Positioned on National Route 3 (N3)
just north of Pinetown, the asymmetrical, cable stayedbridge provides
a striking landmark for road users and pedestrians. The structure is
part of larger pedestrian facilities upgrading projects along the N3
between Westville and the Mariannhill Toll Plaza.
The bridge is a two span structure with a total length of
89,75mand a back span length of 34m.The 3,2mdeck is constructed
from reinforced and prestressed concrete and is supported by 10
sets of stay cables. A 32 m long inclined, twin legged structure steel
tower supports the cables by means of spade and fork connections.
The final design of the bridge is direct response to the site and
the required functionality. Although the overall structural form was
decided by in a design competition, the close collaboration of engi-
neers and architects enabled a unique visual form to be created for
the tower. It is hoped that the bridge achieves the goal of creating a
positive landmark for both the client and local community.
SMEC South Africa’s lead consultant on the project John Anderson
says that the Tshelimnyama Pedestrian Bridge Project is a key link in
the larger SANRAL pedestrian facility upgrade project.
The Tshelimnyama Township, which is located on the south side
of the N3, is home to many low-income families – a large portion of
who have found work in the nearby industrial areas of Mahogany
Ridge and Westmead on the northern side of the N3. Due to a lack
of shorter, more direct routes, many of the residents chose to cross
the N3 freeway to access these work opportunities, risking their lives
in the process.
The challenge of the site was to attract pedestrians onto the bridge
and to design a structure which integrated itself into the surrounding
landscape. SMEC was appointed as the consulting engineer for the
project and produced a design that was functional as well as aestheti-
cally pleasing. The slender deck floats over the N3, supported by the
stay cables and anchored to the central tower and the rock cutting on
the adjacent slopes. The bridge was constructed by JT Ross.
There are many unique elements on this project, including the
sculpted structural steel tower, which leans forward at an angle
of 14 degrees with a continually varying cross section. The tower
geometry is complex but aesthetically pleasing and testament towhat
is achieved with a strong collaboration between architect, engineer
and employer.
