Expertise

Vela VKE has designed and supervised the construction of hundreds of bridges in South Africa and internationally. We have developed a specialized team of bridge design engineers capable of designing to the highest technological standards. Vela VKE also carries out the design of bridge repairs and rehabilitation for maintenance and to extend bridge life. We are experienced in carrying out bridge inventories and related assessments as well as to assess structures for abnormal loads.

Vela VKE's design capabilities extend across a broad spectrum of building structures and material types including steel, reinforced concrete, prestressed concrete and timber.  Our structural engineers have assessed many building structures and are fully conversant with the latest techniques for repair and rehabilitation of structures.
 
The objective of the Structural Division of Vela VKE is to provide appropriate design expertise and innovation and a prompt and efficient service.  A full range of services is offered, from site investigations and foundation design through site civil engineering to building structural design and design of building services.

Many innovative solutions to particular problems have been devised, these have ranged from a student's hostel constructed from old containers for Simon’s Town School, through a  6-storey marble clad steel staircase suspended by steel cables at Siemens Office Park to the design of intricate steel domes for Emperor's Palace in Gauteng.

Detailed Capabilities:

• Incremental Launching
• Balanced cantilever construction
• Bridge jacking
  
• Advancing shoring
  
• Composite construction
  
• Cable-stayed decks
  
• Internal and external prestressing and post-tensioning
  
• Design for earthquake loading
  
• Pre-cast Segmental construction
  
• Floating concrete caissons for river bridge pier foundations
  
• A bridge pulling technique for installing a major freeway bridge under a 25m high embankment
  
• Pretensioned concrete bridge handrails designed to replace vandalized aluminium handrails
  
• Epoxy-bonded steel plating to improve resistance to shear and bending stresses
  
• Strengthening by the grouting in of bending and shear bars
  
• Stabilisation of abutments with ground anchors and shear connectors
  
• Construction of replacement deck slabs
  
• Strengthening of reinforced concrete members using carbon fibre reinforced polymers
  
• Construction of additional supports
  
• Crack sealing by resin injection
  
• Transverse strengthening by means of additional diaphragms
  
• Provision of external prestressing to beams
  
• Sealing of concrete against moisture ingress
  
• Jacking up of deck structures to increase vertical clearance
  
• Replacement of bearings and deck joints

Barend Christiaan Viljoen obtained a Hons. B. Eng (Cum Laude) degree from the University of Stellenbosch.  Chris has since accumulated 25 years of experience in a variety of engineering disciplines.  In particular he has several years of design, supervision and project management experience on railway, tunnelling and water projects.  He is presently working on the Lesotho Highlands Water Project Further Phases Study and the Mokolo Crocodile West Water Augmentation Project.  Recent projects include the Prevention of Water Ingress into the Gold Mines of the Witwatersrand, the upgrading of the Ash River and the Nuwejaarspruit river upgrading projects.  He started his career with the then South African Transport Services on the Coal Line project in 1981 and in 1988 joined the Lesotho Highlands Water Project Phase 1 design team where he later became the Chief Design Engineer for the Delivery Tunnel North portion of the project.

Chris is presently head of the Vela VKE Structures division and is a member of EXCO.  He is a registered professional engineer.  He represents Vela VKE at the South African Association on Tunnelling (SANCOT), the South African National Committee on Large Dams (SANCOLD) and is a member of the structures, railways and harbours and geotechnical divisions of SAICE. When not at work Chris enjoys travelling, hiking, Koi fish keeping and gardening with his family.

Email :  viljoenc@velavke.co.za