144 Oxford Street Rosebank

 

The steel structure for the 144 Oxford Street project acts as support for a composite roof slab, but more significantly supporting a glass curtain wall to a nine-story atrium.

The architectural brief for the project was to create an atrium space with minimal structural impact, and optimum visibility through the glass curtain wall, which encapsulates the entrance. Only slender structure, specifically box sections and rods, could be used to support the glass.

Why was steel used for this project?

Due to the extreme sensitivity of any deflections, large spans and large point loads as a result of the glass support structure, steel was the only viable choice from conception.

The glass curtain-wall that spans 25m wide by 9 stories high, and 4 meeting pods had no traditional support work due to the brief, and had to be hung from a hidden steel structure spanning over the atrium space. In both the case of the pods and the curtain wall support, high-tension rods were used to connect to the structure above. These rods fitted the aesthetic brief ,      could be produced in higher grades of steel, and due to the simple one-directional load acting upon them, the basic geometrical shape was fully utilized. The rods connected to the steel roof structure, which consisted of a 25m lattice girder spanning over the atrium onto concrete supports.

As the girder was supporting a long glass facade, minimal deflections were allowed for when under load. The deflection requirement along with the large compressive forces present in the girder was best satisfied with the use of large H-section members in the girder. The curtain wall plane was offset from the girder plane, which resulted in large horizontal tension forces. These forces were resisted by tying the girder vertical members via tension rods to the concrete cores. The tension rods allowed for simplified connections with high loads onto the cores due to the simple rod shape.

Overcoming challenges

From a fabrication point of view, and due to the large section sizes being used in the girder for the high loads it was to carry, the welding at the joints was a critical aspect of the fabrication where pre-heating of the parent material at the joints was necessary and 100% non-destructive testing to confirm suitable welds had been laid down.

Although there were numerous sections of steelwork to be installed on the site the installation of the Atrium girder presented the main challenge since it was not possible to gain access for a crane onto the site and the tower cranes could not lift the weight of the girder which was 12.2 tonnes.

A 500ton heavy lift crane with 105 ton of counterweight was therefore hired in to install the girder from Oxford Street at an installation radius of 52m.

The coordination for this lift was critical since one carriageway of Oxford Street needed to be closed off to traffic to allow the setup of the crane which was planed through from midnight on a Friday and for the balance of the weekend.

The road closure was installed at midnight on the Friday with the heavy-lift crane being set up and ready to lift the girder by 9:00AM on Saturday morning.

The whole operation went to plan and the crane was off the street by 5:00PM on the Saturday afternoon.

What makes this project impressive from a technical perspective?

An extremely large area of glass and structure is hanging from the long-span steel structure above. This required technical expertise to not only understand how the structure will move during loading, but how its performance would translate from design models into the actual fabricated and erected steel structure. Large efforts were made to calculate and refine the expected loading, to accommodate for the expected movement.

What is special/ unusual/ innovative/ aesthetic about the steelwork in this project?

The girder had a camber that would absorb most of the movement, however just as maximum allowable deflection was a concern, so was over cambering. If at any time the girder did not perform and deflect as expected unwanted secondary issues would arise in the glass curtain wall and thus three adjustable deflection phases were built into the installation.

The first phase being in its unloaded state by means of packer plates to adjust the curtain wall supporting beam levels. The second with all permanent loads being applied to it, except the glass, and adjusting deflections by means of shortening the high tension rods with their threaded connections. And the last phase being with jacks used to lift the entire curtain wall into place.

How does this project demonstrate the benefits of Steel as a material?

Steel was the only material that could be manufactured and erected with a  tolerance of only a few millimetres, and also perform precisely as modelled. This was aided by the low number of manufacturing variables for steel, as opposed to other materials used in construction.

How did the project team work together?

The project team held several planning meetings, with the contractor included, occurred well before the fabrication of the steelwork even started. This helped the entire team to understand the challenges each member faced and how they would influence the team as a whole. The steel work was modelled and coordinated between consultants via 3d modelling in Revit. Since the steelwork in the Revit model was accurate, it was exported directly to the steel detailer for shop drawings.  Inspections of the fabricated steelwork occurred while the steel was still in the factory, due to the extreme time-sensitivity of the erection date.

Project motivation editorials are provided by the project nominator. If any technical details, company names or product names are incorrect, please notify the SAISC so that the error can be corrected.

PROJECT OVERVIEW 

Physical address of the project       

Street Address  

Town  

Province 

144 Oxford Street , Rosebank. 
Google Maps link   

 

STRUCTURAL STEELWORK 
Completion date of steelwork  August 2019 
Completion date of full project  November 2019 
Tonnage and steel profiles used  75 ton of various profiles + 990m2 of Bondek 

 

 

Project Team Role Company
Nominator TASS Engineering P/L
Client/ Developer Growthpoint
Architect Paragon Architects
Structural Engineer Sutherland Engineers
Engineer Sutherland Engineers
Quantity Surveyor RLB Pentad / Farrow Laing JV
Project Manager Origin Project Managers
Main Contractor WBHO / Tiber JV
Steelwork Contractor TASS Engineering P/L
Steel Erector Van Rensburg Steel
Cladding Manufacturer  –
Cladding Supplier  –
Cladding Contractor  – 
Corrosion Protection  –
Galvanising  –
Corrosion Protection  –
Paintwork Contractor DRAM Industrial Painters
Photographer, Photo competition Sutherland Engineers
Photographer, Other submitted images TASS Engineering P/L

 

 

 

 

 

If you were a part of this project, and your company details are incorrect or missing – please notify the SAISC so that the error can be corrected.

PX5 Warehouse Conveyors Structures

 

 

The PX5 Warehouse and conveyor structures project entailed the construction of fertilizer storage and distribution building.

The building consists of concrete bases and retaining walls with a structural frame comprised of castellated sections.

Due to the very onerous nature of fertilizer on the corrosion protection, as well as the adverse effect of fertilizer to galvanizing, the team was forced to use a very onerous paint specification.

Project motivation editorials are provided by the project nominator. If any technical details, company names or product names are incorrect, please notify the SAISC so that the error can be corrected.

PROJECT OVERVIEW 
Physical address of the project     

Street Address  

Town  

Province 

South Coast Road, Rossburgh, Durban 
Google Maps link    

 

STRUCTURAL STEELWORK 
Completion date of steelwork  30/8/2019 
Completion date of full project  10/10/2019 
 Tons of structural steel used  2,500 Tons 
Structural profiles used  Combination of Rolled Profiles and Tubular 

If you were a part of this project, and your company details are incorrect or missing – please notify the SAISC so that the error can be corrected.

Tshwane Regional Mall

Tshwane Reginal Mall is a new mall in Mamelodi Pretoria. Steel was integral to architectural look and design of the mall, especially with the bold steel entrances and pop out roof along the mall.

 

 

Structural framing

The main mall roof structure mainly consisted of I-beam rafters with Metsec purlins, allowing for long spans and a reduced overall tonnage to the structure.

The Large entrances were constructed of large curved box sections. Fabricated out of plate. Top and bottom flanges laser cut to shape, and side web plates rolled to suit.

Split tee sections with rolled CHS sections creating the fanning sun screens along the outside.

Inside the mall supporting these entrance roofs are huge CHS struts impressively supporting the roofs.

This theme is continues throughout the mall with large concrete columns and CHS “tree structures” supporting pop out roofs along the main mall areas.

The food court have stainless steel pipes like “sticks” decorating the area.

Outside all along the front of the mall, there are heavy I beam canopy structures adding to the bold look of steel as you approach the entrances.

The entire parking lot roof was erected on top of the fourth floor slab. So this required spider cranes to be able to work on top of these slabs.

Then on the other hand the heavy entrance box sections required large 50ton cranes to be able to lift the large sections into place.

The benefits of using steel

In a mall like this most of the structure is build out of concrete and bricks. But the appeal to the mall is the Bold steel sections used in the entrance, External walkways, and large steel pipes supporting the roofs inside the mall walkway areas. This can only be achieved by the architectural use of steel.

Project motivation editorials are provided by the project nominator. If any technical details, company names or product names are incorrect, please notify the SAISC so that the error can be corrected.

Physical address of the project  

 

 

 

 

Street Address  

Town  

Province 

 

 

 

 

 

Tsamaya Avenue 

Mamelodi 

Gauteng 

Google Maps link  https://goo.gl/maps/dsdMcjCMxm6m5dENA  

 

STRUCTURAL STEELWORK 
Completion date of steelwork  June 2020 
Completion date of full project  2021 
Tonnage and steel profiles used  500t – Hot Rolled, Tubular and Metsec Profiles 
Project Team RoleCompany
NominatorFerro Eleganza (Pty) Ltd
Client/ DeveloperIsibonelo Property Services (Pty) Ltd
ArchitectSVA International (Pty) Ltd
Structural Engineer Pure Consulting (Pty) Ltd
Engineer  
Quantity Surveyor (PQS)Nonku Ntshona & Associates
Project ManagerLMKV Management Consultants
Main ContractorGD Irons Construction (Pty) Ltd
Steelwork ContractorFerro Eleganza (Pty) Ltd
Steel ErectorFerro Eleganza (Pty) Ltd
Cladding Manufacturer 
Cladding Supplier 
Cladding ContractorChartwell Roofing (Pty) Ltd
Corrosion Protection 
GalvanisingArmco Superlite (Pty) Ltd
Corrosion Protection 
Paintwork ContractorJokes Building Construction CC
Photographer, Photo competitionFerro Eleganza (Pty) Ltd

If you were a part of this project, and your company details are incorrect or missing – please notify the SAISC so that the error can be corrected.

 

Whale Trail Staircase


ParaMatic was commissioned by a contractor on behalf of CapeNature to measure the site then conceptualise and detail the new steel stairway to Stilgat at the De Hoop Nature Reserve in the Western Cape. ParaMatic used a 3D scanner to capture the site and modelled and detailed the new stairway in Tekla Structures.

The De Hoop Whale Trail is a world-famous long-distance hiking trail in the De Hoop Nature Reserve administered by CapeNature. The 54 km trail has overnight stops along the trail and runs through mountain and coastal regions. Part of the trail runs along a coastal ridge with a detour down a steep valley to a renowned swimming cove and picnic spot at Stilgat. The hiking path runs approximately 100 m from the sea and is subject to daily exposure to sea air, mist and wind borne salt spray. The original timber and wire rope ladders on the mountainside have long since decayed from rot and corrosion and the climb from the mountain path to the sea is perilous. With an increasing trend in the average age of hikers, the client realized that the route either had to be closed or made safe. Cable or chain ladders were considered too risky for the profile of the hikers and a stairway was approved for the path to Stilgat.



The brief

The owner proposed and approved a stairway but stipulated that the stairway had to be aesthetically unobtrusive, sympathetic with the area, modular and lightweight and make a minimal use of cement works. Maximum off site manufacture was required.

No survey data on the site was available.

The remoteness of the site makes regular maintenance impractical. The site is far from the Reserve main offices on a rough road and is in a pristine, undamaged coastal zone. On-site contractors are hard to manage on such a large site as De Hoop and the owner wanted site activities to be as short as possible and with the smallest possible labour force. The project was also on a tight deadline so as not to affect the 2020 Summer hiking calendar.

Morning mist, wind spray and heavy early morning condensation are regular environmental considerations. Softwood rots quickly and is wholly unsuited to the climate. Uncoated steel corrodes within days.

Wherever possible, the staircase had to follow the mountainside to allow it to blend in with the undergrowth and avoid breaking the silhouette of the cliff.

The stairway had to allow for perennial river flow in the stream bed and not block the stream in full flow. Access to a lookout point was discussed.

Road access close to the site is only possible using a small four-wheel drive vehicle, with a rough climb from the unloading point to the installation site. All components therefore had to be suited to portage over rough terrain without endangering the installation contractor’s staff.

Site welding had to be eliminated or minimized. Drilling using battery packs would be acceptable, so anchor foundations into existing rock was considered the preferred route for fixing wherever possible.

Heavily burdened hikers must be able to descend the stairs without slipping on wet surfaces.

The area does experience intermittent fires, but is remote and considered inaccessible to fire fighters with other priorities during a fire. It was not practical to route the stairway away from flammable vegetation. The structure must be essentially fire proof and if a component is fire damaged, the design should allow for replacement without welding. Fire damage should not compromise the immediate stability of the structure.

The cost of a stainless steel structure was beyond the budget of the project. A structural, duplex hot dip galvanized solution was considered the most likely functional and economic solution.

Why steel?

The owner proposed and approved a stairway but stipulated that the stairway had to be aesthetically unobtrusive, sympathetic with the area, modular and lightweight and make a minimal use of cement works. Maximum off site manufacture was required.

No survey data on the site was available.

The remoteness of the site makes regular maintenance impractical. The site is far from the Reserve main offices on a rough road and is in a pristine, undamaged coastal zone. On-site contractors are hard to manage on such a large site as De Hoop and the owner wanted site activities to be as short as possible and with the smallest possible labour force. The project was also on a tight deadline so as not to affect the 2020 Summer hiking calendar.

Morning mist, wind spray and heavy early morning condensation are regular environmental considerations. Softwood rots quickly and is wholly unsuited to the climate. Uncoated steel corrodes within days.

Wherever possible, the staircase had to follow the mountainside to allow it to blend in with the undergrowth and avoid breaking the silhouette of the cliff.

The stairway had to allow for perennial river flow in the stream bed and not block the stream in full flow. Access to a lookout point was discussed.

Road access close to the site is only possible using a small four-wheel drive vehicle, with a rough climb from the unloading point to the installation site. All components therefore had to be suited to portage over rough terrain without endangering the installation contractor’s staff.

Site welding had to be eliminated or minimized. Drilling using battery packs would be acceptable, so anchor foundations into existing rock was considered the preferred route for fixing wherever possible.

Heavily burdened hikers must be able to descend the stairs without slipping on wet surfaces.

The area does experience intermittent fires, but is remote and considered inaccessible to fire fighters with other priorities during a fire. It was not practical to route the stairway away from flammable vegetation. The structure must be essentially fire proof and if a component is fire damaged, the design should allow for replacement without welding. Fire damage should not compromise the immediate stability of the structure.

The cost of a stainless steel structure was beyond the budget of the project. A structural, duplex hot dip galvanized solution was considered the most likely functional and economic solution.

Structural framing

Steel is the material most suited to manufacture of varying lengths and geometries. Standard hot rolled sections were used for the stair stringers and platforms. All elements were limited in mass to ensure they could be hand carried onto site for bolted assembly.

The client provided a typical section for the handrail detail which had to be modified to suit hot dip galvanising after welding.

The client agreed that standard stair treads had an industrial appearance and that non slip grating types treads could be painful in a fall. The final stair tread concept was a carcass of a thin plate with bolted-on machined timber stair inserts, selected for their anti-slip properties. Treads are replaceable, using counter sunk bolts. A damaged insert would not affect the short term usability of the stairway. Hardwood or recycled plastic treads were specified as these do not require treatment or maintenance.

Site Survey: No information on the site was available. ParaMatic used a Leica BLK360 to scan the site and obtain a point cloud. Before the scan, we identified and marked the most probably route using barrier tape and pegs and scanned this path. The Leica is small and portable and is easy to place in awkward positions. A typical scan takes 2-3 minutes and approximately 40 scans were made. The pointcloud and panoramic photographic detail allowed us to identify practically every surface and feature of the rock faces and digitise the routing for the stairway. No physical measurements were taken. Individual scans are composited to make up a single point cloud model of the site. All the decisions regarding final stair dimensions were made in the drawing office

Before installation, we returned to site with foundation drilling templates and marked the positions of each of the stair components for drilling of the holding down bolts. Using exposed rock surfaces wherever possible.

Cost and Speed: The owner’s budget for detailing was even lower than that of a standard structural steel frame supplied at standard fabrication rates. Detailing in Tekla allowed the model to be developed over the point cloud, eliminating the iterative testing which slows projects and delays detailing. Tekla Stuctures is especially powerful for detailing of special details and configurations and facilitated rerouting after the model was reviewed. Tekla produces consolidated bills of material which allowed us to quickly check that we were within our mass budget and provided detailed cutting lists and component drawing to ensure that the manufacturer was able to purchase accurate materials and bolts requirements and deliver precisely the detailers intent.

 After two days of scanning, we were able to produce the model and detail drawings within 10 days of drawing time

Installation:

What is most impressive about this project from a technical perspective?

The owner had originally anticipated that the finished material would be delivered by helicopter, owing to the remoteness of the site. By detailing accurate, finished sub-assemblies in small, portable, site bolted frames, the owner was able to eliminate helicopter transport and more importantly inspect prior to delivery and confirm that components met the required dimensions, reducing site corrections to a minimum.

ParaMatic were able to deliver on the promise of a purpose designed stairway with a limited budget quickly and effectively by importing a point cloud into the model. Traditionally, a point cloud is data heavy and is used to generate a model which is then used for further detailing. Tekla Structures systems architecture allows for modelling and viewing in realtime without delays and machine crashes.

How does this project demonstrate the benefits of steel as a material?

Steel is a perfect building element for elaborate builds – the ready availability of structural sections and the ability to bend and weld stock plate from the same material for a cost effective yet unique and hardy product. Joining and coating processes are simple and well understood and relatively simple. Further, steel allows for relatively simple site alterations and welding without significant quality compromise.

What is special/ unusual/ innovative/ aesthetic about the steelwork in this project?

Absolutely no measurements were taken on site and the modeller was totally reliant on the output of the scanner.

Usual practice is to visit site with a clipboard, camera and a tape measure. The nature of the site makes this impossible. Steep, loose slopes break up lines of sight and the only practical site solution without a scanner would have been to build modular frames and cut and weld them on site to suit the topography. While surveying has a role, the data returned by the surveyor has no “look and feel” and does not provide for determining better alternatives in the second round of design.

Using prefabricated frames changes the nature of the project, eliminating the need for boilermakers and welders to be given safe working plaftorms and converts the project into a simple erection sequence carried out by competent steel erectors.

It is unusual for handrails to be fully detailed and manufactured prior to delivery to site. Scannign made this possible.

How did the project team work together (e.g. contractor involved early, challenges/ ease of communication etc.)

The ParaMatic team visited the site with the Project Originator and Champion, employed by the Owner, and the project Engineer. On a cold, windy and wet day we marked out the best route with barrier tape and discussed alternatives. After the routing was finalised and agreed and paced out we scanned the route from cliff top to beach level. On returning to the offices, we prepared a first model which was forwarded to the client for comment and approval. Overlaying the model on the point cloud allowed all parties to visualise the routing and issue approval to continue. Without the scan of the site, we would have to rely on tape measure and photographs, normally problematic on a complex site. The scanner allowed us to plan around vegetation and decide when vegetation could be easily removed for later regrowth, again taking decisions up front which would have been referred to the field engineer during the construction.

Project motivation editorials are provided by the project nominator. If any technical details, company names or product names are incorrect, please notify the SAISC so that the error can be corrected.

PROJECT OVERVIEW
Physical address of the project Street Address Town Province De Hoop Nature Reserve, Bredasdorp, Western Cape
Google Maps link  
STRUCTURAL STEELWORK
Completion date of steelwork 31/03/2020
Completion date of full project 15/04/2020
Tonnage and steel profiles used 5.8 tons of Channels, Tubes and Platework
   

If you were a part of this project, and your company details are incorrect or missing – please notify the SAISC so that the error can be corrected.

Thelle Mogoerane Hospital – Doctors & Nurses Accommodation, Creche & Training Centre

The client required safe and secure access from the accommodation site to the new Thelle Mogoerane Hospital. Hospital staff working late-night shifts require safe access to both sites. Access to the bridge which spans Nguza Street is by way of biometric access control. The bridge and ramps are wheelchair friendly. This necessitated longer ramps at acceptable falls as well as shorter horizontal rest areas on both sides of the bridge. The design was to be aesthetically pleasing. The hospital site had not made provision for any bridge or ramps and this posed problems for the designers to get the ramped structure accommodated on the hospital property. The end result is, however, a practical and aesthetically pleasing solution to the many physical problems on both sites.

PROJECT OVERVIEW
Location of the
project
Nguza Street, Vosloorus, Gauteng
Tons of steel used Bridge & Walkways = 72 Tons
Building Steel = 201 Tons
Structural profiles used Hollow Sections, Hot Rolled Sections &
Cold Formed Sections
Type of cladding Bridge Walkway Vertical Cladding – Clearvu
Project Team Role Company
Client/ Developer Gauteng Department of Infrastructure
Development
Architect AFFRIARCH CC.
Structural Engineer Aurecon Group (Pty) Ltd
Quantity Surveyor Bakhele Consulting Quantity Surveyors
Project Manager Ado Architects & Project Managers
Main Contractor Liviero Construction (Pty) Ltd
Steelwork Contractor Tass Engineering (Pty) Ltd & Khombanani Steel (Pty) Ltd
Structural Steel Detailer 3D Struct Cc
Steel Erector Lazzy Steel Erectors (Pty) Ltd
Cladding Manufacturer Clearvu (Pty) Ltd
Cladding Supplier Clearvu (Pty) Ltd
Corrosion Protection /
Paintwork Contractor
Dram Industrial Painting Contractors (Pty) Ltd

Project motivation editorials are provided by the project nominator. If any technical details, company names or product names are incorrect, please notify the SAISC so that the error can be corrected.

Camp Jao

The completely rebuilt and revamped Jao Camp will retain the same high stilted main area built into the tree canopy, with more private areas in amongst the trees. The camp will comprise two villas and five twins with private plunge pools, lounge and dining areas, kitchen facilities plus en-suite bathrooms, including indoor and outdoor showers. The new Jao Villas, accommodating four people each in the two identical guest rooms, which share the main area, will feature a private vehicle, guide, chef and butler.

Why Steel was chosen

 “Over the years traditionally camps have been built using local hardwood and tinkers. This was not good as the forestation is a real issue. Certified plantation tinkers treated were the next step in the evolution of the Bush camp….. However, The CCX treated tinkers request a lot of maintenance and stress on the roads, service people, low of income dining maintenance and general frustration.

For this reason, we have worked to use pre-manufactured steel structures by SE Steel. This gives us a maintenance free structure that is manufactured off-site and assembled on our pristine site.”

“Having to replace our old substructures provided us with the opportunity to enhance the special features that we always loved about Jao, to make improvements and incorporate extra touches. We are making the most of our camp environment, with buildings set to blend into the tree canopy whilst offering stunning views and honouring our commitment to be as eco-sensitive as possible”, says co-owner of the Jao Reserve, Cathy Kays.

Lead architects, Silvio Rech and Lesley Carstens, who designed the original Jao in 1999, shared their approach to the rebuild: “We have taken a fresh and contemporary approach to the sense of adventure Jao always had – creating a feeling of not knowing what to expect around the next corner, and the element of surprise and delight in this ever evolving sculptural architectural language. The architecture is a collection of different spaces that take the visitor on a spatial adventure as one enjoys being in the Delta The everchanging architectural structures take their clues from forms found in nature but in a fresh innovative way. Conventional materiality is replaced with a more eco- sensitive palette as the bouquet of spaces and sculptures evolves.

The way one is couched, protected from the environment, is blended into a series of highly sculptural emotive spaces that amplify the blur between the concept of shelter & art/ sculpture & architecture.

The visitor’s poetic mental space is taken to a higher level. The choreography of 24 hours in the Delta has been crystallised into structures that artistically house and heighten each event and ritual experienced when visiting Jao. A family of concepts have been evolved by the architects specifically for the Jao concept”.

The main area will feature both indoor and outdoor lounges, dining areas, a satellite kitchen and several private dining areas, along with a fire deck. The spa at Jao will be tucked in amongst the palms for privacy and is surrounded by water to provide a calming and tranquil atmosphere. The gym will be built on the edge of the island, presenting stunning views over the lush waterways, while the main pool, with its unique canopy pavilion providing shade, will project out into the floodplain with 270-degree views of the Delta.

A colour palette of creams, greens, soft purple and splashes of yellow will be used, incorporating a unique botanical theme with special emphasis placed on the water lily. A range of beautiful new furnishings will be crafted to reflect the theme. A mix of wood and light-coloured Eva-tech decking will contrast with the red balau wooden walkways and lighter floors in the internal areas. The walkways reflect the old camp and provide a striking difference to the room interiors, which will be more refined in appearance. Comfort is provided through cooling and heating systems, complementing the camp design. Using Climate Wizard, an Australian cooling system, the suites and villas will be cooled with an indirect evaporative cooler that delivers a large amount of cold air with no added moisture, for a fraction of the energy used by conventional air conditioning systems. Self-igniting Calore stoves will provide heating during the colder months.

Design choices amplify the eco-sensitivity of the structure. The steep angling back wall and roof are made with fibre roofing material, with the interior clad in fibre reed and the exterior clad in fibre palm tiles. The rest of the walls are constructed from a combination of canvas and gauze, with minimal glass in front of the bed and bath. Using aluminum frames, large parts of the front of the room will open up. The main structures are all made out of steel that is painted a gum pole colour. The roofs will also feature gum poles and latte poles to support the fibre roofing on the inside, with wooden plyboard to which the reed is attached. For maximum eco-efficiency, built walls will feature Cavitybatt insulation and an added board of plywood, with waterproofing and fibre palm attached to the top layer. We have made great use of natural lighting – parts of the roof feature sky lights covered with latte poles to provide shaded, dappled lighting. All buildings will have a latte verandah roof to provide extra shade.

A key feature is the museum and gallery, described by Rech and Carstens as follows:

“Imagine a building that houses all our thoughts pertaining to visiting the Okavango Delta This is how the concept of the Gallery and Museum was borne. This creates a centre where visiting scientists and researchers can present their research, and where items can be displayed for educational purposes. There are also always a large number of found objects that are interesting from a guest perspective as they give a greater understanding of the area such as local plants and animal bones, as well as geographical maps and artworks of the region. We are building a double volume structure that has the Gallery on the upper level- where these items can be displayed to greater effect, rather than just render them décor items and the Shop on the lower level. Among the Gallery items will be a series of prints from the National herbarium in Pretoria of Botanical pressing made by Cathy Kays great grandfather- E.E Galpin- who was one of the pre-eminent botanists of his time and has been called the ‘Prince of Collectors”. He left 16000 sheets to the herbarium and a number of plant species have been named after him. We are selecting plants of the region that he identified. Other items on display will be a series of animal skeletons, mounted and displayed like a museum, for educational purpose. The current plan is for a giraffe skeleton. Obviously, these are skeletons of animals that have died from natural attrition, so they take some time to source.” From waterways and lagoons to dry Kalahari grasslands, Jao’s location on a remote island in one of the most picturesque concessions in the Delta provides both land and water Okavango experiences, with day and night game drives all year round.

“We are delighted with the progress of the rebuild to date, and look forward to welcoming our guests back to our new and enhanced Jao Camp in 2019”, Cathy concludes.

STRUCTURAL STEELWORK
Completion date of steelwork March 2019
Completion date of full project June 2019
Tons of structural steel used 330 Tons
Structural profiles used Tubes and I-Beams all cold rolled
Project Team Role Company
Nominator SE Steel Fabrication (PTY) Ltd
Client/ Developer Ngamiland Adventure Safaris (Pty) Ltd
Architect silvioRECH + lesleyCARSTENS Architecture and Interior Architecture
Structural Engineer PLB Engineers
Engineer PLB Engineers
Quantity Surveyor Q24U
Project Manager SE Steel Fabrication SE Steel Fabrication SE Steel Fabrication

QS4U

Main Contractor Lodge Builders Botswana
Steelwork Contractor SE Steel Fabrication

(PTY) Ltd

Steel Erector SE Steel Fabrication (PTY) Ltd
Cladding Manufacturer Fibre Roofing
Cladding Supplier Fibre Roofing
Cladding Contractor Fibre Roofing
Nomination Document Submission KRU Detailing CC
Structural Steel Detailer KRU Detailing CC

 

If you were a part of this project, and your company details are incorrect or missing – please notify the SAISC so that the error can be corrected.

Christian Revival Church

Christian Revival Church (CRC) on Witkoppen road in Douglasdale Johannesburg features structural steel in the main auditorium roof, the spiral ramp and the feature ring structure supporting the main staircase.


The structural framing

The lower and upper gallery seating accommodates 4500 congregants and is enclosed with a curved structural steel roof consisting of triangular radiused roof trusses spaced 10m apart over an area of 80m x 68m. The seven unique structural steel triangular space frame trusses (also referred to as ‘Toblerone trusses’) are manufactured from circular hollow sections with varying spans up to 50 m. These radiused trusses support the purlins, roof sheeting, insulation, air-conditioning ducts, a service walkway, and audio-visual systems.

The auditorium roof structure was analysed using the Prokon frame analysis program with loading modelled in 20 different load combinations. The Toblerone trusses which span across the entire main auditorium building, are supported by reinforced concrete columns with corbels at each end of the trusses as well as by an intermediate reinforced concrete ring beam. The trusses are constructed from a variety of circular hollow sections with two top chords and one bottom chord connected with diagonal members along the span. The top chords, which under most load combinations are in compression, are braced together with horizontal circular members. The trusses are roughly 1.9 m deep and 2.4 m wide in plan and are curved to provide a curved roof profile and suitable slope for rainwater disposal. 

Each of the seven space trusses is unique as these have intermediate support from a ring beam which is curved in plan and which forms the rear perimeter of the auditorium. The intermediate support point of each of the trusses consequently occurs at a different point along its length resulting in changes to the arrangement of each truss.

The size of the steel trusses makes thermal expansion and contraction a significant consideration which was dealt with by providing movement joints and flexible connections thereby allowing the trusses to move freely when expansion and contraction occurs. These movement joints, which consist of steel plates with PTFE sheets between, have been provided at the steel to concrete connections on the corbels for each bottom chord and at the ring beams above for the top chords on each end of each truss.

Due to the length of the steel trusses, each truss was constructed into 3 or 4 units to facilitate transport to site. Each unit was welded together in the workshop and provided with connection plates at each of its ends so that these could be bolted together during erection on site. The steel connections consisted of steel end plates and stiffener plates welded to the ends of the two top chords, one bottom chord and two diagonal chords. The plates were provided with bolt holes of varying number and diameter bolts determined by the maximum load being transmitted through each connection.

The spiral ramp is a significant architectural and structural feature in the entrance hall of the church. The ramp starts in the lower parking basement and provides safe and comfortable vertical access to all floors for all users including those in wheelchairs.

One central reinforced concrete column in the center of the spiral ramp supports a circular reinforced concrete beam and slab system at the roof of the spiral ramp. This slab and beam system is braced by perimeter columns and beams which also support the glass facade. 55mm Diameter steel hangars with adjustable couplers are hung from the slab and beam system and support the inner steel stringer channels. The outer steel stringer channels are connected to the inner stringers with I-beams and are braced at various points to the columns surrounding the ramp. A reinforced concrete slab forms the floor of the ramp and is supported between the two stringers and intermediate I-beams for the length of the spiral ramp.

 

The steel ring structure was added to overcome an aesthetic challenge encountered during the initial design of the concrete staircase. In order to achieve the required aesthetic outcome, the design of the staircase was modified by removing the reinforced concrete columns which initially extended from the first landing to the second landing and replacing these with a circular hollow section steel ring structure.

The steel ring structure is supported at its base on either side of a reinforced concrete column beneath the landing of the first flight. This is the base of the circular structure and from here it circumvents the first flight’s staircase landing and meets the base of the second staircase at the apex of the circle. The steel structure is fixed to the base of the second flight staircase landing where it provides support to the staircase. The steel structure is connected at either side of the landing of the first flight for stability.

The steel ring solved an aesthetic challenge and provides a unique structural and architectural feature in the building and introduces a fun element on the side where the children’s church is located.

From the Project Manager’s  Perspective

Main Roof.

The first issue we had from an erection point of view was that the tower crane was in the wrong position and hence caused issues when erecting the final 3 bays.

  • Transporting of the sections to site was also a logistical challenge to the amount of trips required.
  • The setting out and drilling of the M30 anchors on the concrete ring was also a challenge which was overcome by the use of templates and coring the holes.
  • Working out and erecting a support scaffold for the 3rd and 4th truss bay was a challenge and we overcame that by allowing for scaffold jacks and timber batons on the top of the scaffold so we could fine tune the support structure.
  • The installation of the last section of each truss was difficult due to the tight 50mm (design) tolerance from the back of the truss to the RC upstand this was often down to 15mm.
  • Doing tandem lifts on the last 3 trusses with a tower crane and a mobile crane and having to walking though the truss that was partially suspended to connect the splice connection. This often took a few hours as the trusses where picked up with a 4 sling rigging system and caused deflection of the truss sections when suspended. The use of mechanical lifting and pulling equipment assisted greatly in ensuring every splice had no gaps.

Spiral Ramp

Setting out of the levels of the eyelets on the hanging rods was a challenge due to access and when installing a section below a section that as set we found that rotation was happening and changing the levels.

  • Installation of the spiral stringer sections was difficult due to access and don’t being able to use a mobile crane for the first ring due to head clearance from the soffit above.

We overcame this by having cast in sleeves positioned in the slab above to allow for lever hoists to do the lifting and manipulating of the ramp sections.

  • The access scaffolding had to be adjusted and lowered for every section to be installed.
  • Once all sections where installed we noticed significant creep was happening on the ramp which in turn caused the handing robs to be out of plumb. This was overcome by shortening and lengthening the ramp sections and cutting off and rewelding the fin plates that connected the ramp sections to the eyelets on the hangers.
  • Finishings to create an aesthetically pleasing structure took a significant amount of finesse with the grinder and body putty work.

Construction Director’s Perspective

The CRC Church developments roof structure looks simple at first glance until one realises that it is made up of curved triangular “Toblerone” main support structures with varying spans brought about by an intermediate, curved in plan, concrete support beam which heads the back wall of the main auditorium.

The seven number Toblerone trusses span an opening of 68 meters and are made from circular tubular sections of varying diameters and wall thicknesses to match the varying spans and in order to make them all to the same curved shape they were fabricated incrementally in a layout jig approximately 30m in length in the workshop.

These trusses were further complicated by walkways which are in the lower ‘V’ of the truss mounted on welded on brackets on the bottom chord at approximately 920mm.

The Toblerone trusses were fabricated in transportable lengths taking into account their shape and curvature which are bolted together using stiffened pipe flanges of varying thicknesses.

Erection of the trusses was fairly straightforward using the site tower crane and mobile cranes where the tower crane was unable to reach with the only real problem being the close tolerance between the perimeter ring beams which required some interesting manoeuvring of the suspended sections to coax them onto their holding down bolts.

A second more interesting structure from a constructability point of view is the spiral ramp at the car park entrance to the church. This ramp starts at basement level and services three levels through the structure.

The spiral structure is suspended from the concrete roof by suspension bars on its inner stringer with the outer stringer bolted to perimeter concrete and steel columns in unsymmetrical locations.

The ramp structure was fabricated in a specially designed jig framework in our workshops which allowed for the various unsymmetrical support locations to be accommodated.

Due to the inner stringer of the ramp being supported on suspension bars the structure had to be erected from the top down which presented some really difficult challenges in terms of headroom to get the top sections in and the entire structure wanting to rotate as more sections and weight were added.

Cast in sleeves in the roof slab with tirfor cables passing through were utilised to install the initial sections and the entire structure had to be installed first and then aligned from top to bottom to get the rotation out such that all the suspension bars were vertical in the final setup.

A third interesting feature on the Project is the “Feature Ring” supporting the mid landing of the concrete access stair at the one end of the entrance lobby. Although not particularly challenging from a fabrication and installation point of view it does provide a unique structural solution for supporting the stairways second landing which is aesthetically pleasing and provides an interesting talking point for the congregants.

Project motivation editorials are provided by the project nominator. If any technical details, company names or product names are incorrect, please notify the SAISC so that the error can be corrected.

STRUCTURAL STEELWORK
Completion date of steelwork November 2018
Completion date of full project February 2019
 Tons of structural steel used 200 tons
Structural profiles used Hollow sections, hot rolled sections, CFLC
 SA content – if this is an export project 100% SA Content
CLADDING
Cladding profile/ type used 0.53mm ISQ550 Novotexi 440 profile sheeting
Cladding area/ coverage and tonnage 8520 m² (47 tons)
PROJECT TEAM ROLE COMPANY
Nominator and Steelwork Contractor Tass Engineering
Client/ Developer Christian Revival Church 
Architect DBM Architects JHB (Pty)Ltd.
Structural Engineer Fortem Consulting Engineers (Pty)Ltd.
Civil Engineer Tekciv Consulting Engineers  

 

Quantity Surveyor Mellet Quantity Surveyors
Project Manager Deo Gloria Developments (Pty) Ltd
Electrical Engineer NALA Consulting Engineers(Pty)Ltd
Mechanical Engineer PV3 Engineers
Main Contractor Mike Buyskes Construction (Pty)Ltd

If you were a part of this project, and your company details are incorrect or missing – please notify the SAISC so that the error can be corrected.

Durban Christian Centre – New Auditorium Campus

The “Jesus Dome” roof structure at the Durban Christian Centre was a well-known feature roof very visible on the sweep of the N2 coming into Durban. The auditorium burnt to the ground in a devastating fire in 2016 leaving the local congregation, some 3500 strong, without a place of worship. The rebuilt was commissioned in 2017 and the Team was gathered.

The Concepts

The Client wished to retain the memory of the original dome into the future, unfortunately, a shape which belies the modern understanding for acoustic performance. To produce a world-class auditorium the Architects, EPA, threw the memory of the dome up into the air and a tri-bifurcated arch was conceived. Simple, smooth extruded box shapes rising over a sheeted, duo-pitched and acoustically attenuated free-spanning roof structure. On plan confined onto a hexagonal concrete ring beam squeezed to focus on the stage.

There seemed little purpose, other than feature, for the arches if they were not to be used to hang the roof below. So two possible schemes were followed in parallel. One with no arches – the roof structure truss grillage made deep enough to free span, and a second with the arches used to hang the primary apex girder so economizing on the truss grillage. This gave cost comparisons to the Client in respect of the spend to achieve the arches over a more conventional structure.

Taking it to the Ground

Steel arches need pouncing points – for our structure, these were some 15m off the ground. Off shutter concrete prisms seemed to fulfill the need in every way. The primary arch buttresses needed to be slimmed to allow access on a restricted footprint so this arch was tied – the primary girder running under the primary arch forms the arch tie, interconnected in a bold move through large welded steel elbows set into the 2.5m wide reinforced concrete buttresses.

The secondary arch buttresses were free to sweep to ground along the steel arch thrust lines, or thereabouts.

For the balance of the roof structure, a chunky concrete ring beam sits atop 7m high concrete columns and tied into the double story structures at front and back of house.

Making the Geometry Work

The arches are, as a trio, wedged from a single sphere, with the origin deep below the floor slab. Each arch is the rind of a perfect slim slice through the origin of the sphere and as such, in radial section, is very slightly trapezoidal – this variation was so small that the shape could easily be rationalized to rectangular allowing the designers and fabricators to select UC sections radiussed about the major axis. The Hulabond cladding box adopted the final trapezoidal form. Round tubes were used for the lacing in combination with web plates.

With the concept realized and agreed with the Architect, the structural design team got to work developing a parametric algorithm in the visual programming environment of Dynamo, which works seamlessly with Revit. This was then used to solve the geometry of all of the arches by iterating through the parameters of the sphere, and the arch truss centerlines imported into the global OASYS analyses and REVIT models and ultimately into TEKLA.

Getting the Design Done

The internal truss grillage is a simple 6×6 grid, allowing the designers some latitude to offer up future-proofing for spot loads at the intersections, as well as providing a sensible patchwork for the arrangement of acoustic lining, services reticulation and suspended acoustic blades above the 3500 seated auditorium array.

Simple IPE purlins set up a bottom flange shelf frame for the acoustic lining and a platform for the Klip-Tite sheeting system. A clamped bracket was devised for all the in-roof services so that post erection drilling or screwing could be prohibited globally.

A series of global analysis models were set up, augmented by a suite of simpler two-dimensional model checks. The primary software used was the OASYS GSA Building Suite program allowing the import and export of geometry into and out of both Revit and Tekla.

Global buckling considerations paid attention to the arch arrangement, and overall stability, as well as serviceability for pre-cambers, and interim construction step models incorporating temporary support towers to protect the geometry during erection.

All the arches end with exactly the same “cheese wedge”, terminating on articulating pot bearings designed to resist pull-off (when the wind blows).

Getting to the Fabrication

Negotiating with a chosen fabricator, Impact Engineering was hotly debated at the outset. For such an iconic structure it is our view that this was a primary factor in the success of the project. Agreeing on fabrication methodology and understanding fabrication economies with the fabricators during the design development is a process most designers would wish for. We applaud our Clients and fellow Professionals for engaging in this way.

NJV decided from the outset to partner with a selected detailing house, Strutech 3D Modelling. The final negotiation TEKLA model became the fabrication model in a fluid process which eliminated in our estimate 4 to 6 weeks of critical path time.

Impact Engineering fabricated the arches as a whole, one in each of their fabrication sheds. Once complete they were carved up for blasting and painting. The arch crossover units were then preassembled for fit in the sheds before transport to site.

Innovating for Erection

Steffanuti Stocks have been exemplary in their attention to setting out of the large HD bolt sets ( note from Author: in 30 years of practicing as a structural engineer both here and abroad the use of survey and delivery of accuracy by both Steffanuti Stock and Impact Engineering was at a level of excellence I have not witnessed before).

Program necessitated that the arch pieces be pre-clad with the Hulabond panels almost entirely prior to lifting, this required coordination and care between Façade Solutions and Impact with only a small window of time after the fact to access the arches utilizing cherry pickers for snags and joint sealing.

An erection plan well considered reduced the temporary tower suite to two, one under each hanger intersection. To say that site access was tight would be an under-exaggeration, and every truss piece lift brought the site action to a halt and a gathering audience. Each piece was maneuvered into position, lifted and slipped into place – no double lifting, no cladding damaged and no site work required. After each lift pre-set survey points were checked and structural behavior deflections matched with expectations of the analytical OASYS models.

The eight tubular hangers lay green at the fabrication works until the primary girder was de-propped and then each was site measured and purpose made to fit. Once the arches were de-propped and the roof was hanging the trusses could be completed below the arch formation and the cladding installed.

The arches will be accessed for cleaning by rope access cleat methods devised under consultation, the cleats having been installed prior to the arch cladding.

Project motivation editorials are provided by the project nominator. If any technical details, company names or product names are incorrect, please notify the SAISC so that the error can be corrected.

STRUCTURAL STEELWORK
Completion date of steelwork March 2019
Completion date of full project October 2019
Tons of structural steel used 280
Structural profiles used Hot rolled sections, nominal tubular
CLADDING
Completion date of cladding March 2019
Cladding profile/ type used Klip-Tite 700 0,53mm CIS
Cladding area/ coverage and tonnage 3300m2
Nominator NJV Consulting (Pty)Ltd
Client/ Developer Durban Christian Centre
Architect Elphick Proome Architects Incorporated
Structural Engineer NJV Consulting (Pty)Ltd
Quantity Surveyor Abakali
Quantity Surveyor (Lead) RLB Pentad Quantity Surveyors
Project Manager M3 Africa Consulting
Main Contractor Steffanuti Stocks Building KZN
Steelwork Contractor Impact Engineering (Pty)Ltd
Steel Erector CMGS Projects CC
Cladding Manufacturer Global Roofing Solutions
Cladding Contractor Impact Engineering (Pty)Ltd
Corrosion Protection
Galvanising
Phoenix Galvanising
Corrosion Protection
Paintwork Contractor
Top Coat
Fabrication detailing Strutech 3D Modelling
Corrosion Consultant          T.H.C.P.S.
Bearing Supplier Nova Engineering Works (Pty)Ltd
Access Consultant Façade Solutions
Arch Cladding Sub Contractor Scope Of Work

If you were a part of this project, and your company details are incorrect or missing – please notify the SAISC so that the error can be corrected.

Fezile Dabi Stadium, Parys

The roof structure provides protection from the elements to the main grandstand and adjoining stands.  The stadium was officially opened in 2013 but without a roof. As part of the upgrade of the stadium, a new roof was proposed.


What was the brief to the architect?

Provide a roof on the existing stands that is both practical as well as aesthetically pleasing on the eye.

Was the project envisaged in steel from the start? If not – why was it built in steel in the end?

Yes proposed as steel from the beginning

Give a brief description of the structural framing. What type of sections were used (e.g. hollow, cellular, I beams etc) and why?

The roof trusses and supporting columns are made entirely from Circular Hollow Sections (CHS)

Give a brief description of the cladding process (complexity, difficulty, innovation etc)

The bull-nose on the stadium roofs were a concern. A mock-up was carried out at the steelwork fabricator’s premises and approval was given to continue as planned

Were there any challenges in the fabrication of the project from the engineer’s design – if yes, please tell? Tell more about fabrication and erection process if it was complex, difficult, innovative etc.

The fabrication process required several fabrication jigs to be made up to accommodate the 84-no trusses required for the project. The tubular sections were rolled into various radii and the cross bracing were individually profiled cut to allow a stub-on connection to the main truss struts. The challenges faced during erection involved fitting a new roof onto an existing structure. Interface connections that were not in the envisaged locations, resulted in modifications having to be carried out on new steelwork.

What is special/ unusual/ innovative/ aesthetic about the steelwork/cladding
in this project?

The project is aesthetically appealing in that a previous stadium is now provided with a roof which enables the spectators to have some protection from the elements.

How did the project team work together (e.g contractor involved early, challenges/ ease of communication etc.)

Constant communication between the Steelwork Contractor and the Structural Engineer was critical to get agreement on being able to fit the new roof to the existing stadium stands.

STRUCTURAL STEELWORK
Completion date of steelwork March 2019
Completion date of full project April 2019
Tons of structural steel used Approx. 300 tons
Structural profiles used Tubular Steelwork up to 220mm diameter in roof
CLADDING
Completion date of cladding March 2019
Cladding profile/ type used 0,58mm IBR Chromadek® Sheeting
Cladding area/ coverage and tonnage 7920 m2
Nominator CADCON (Pty) Ltd
Structural Engineer Aecom
Quantity Surveyor WBHO
Main Contractor WBHO
Steelwork Contractor CADCON (Pty) Ltd
Steel Erector CADCON (Pty) Ltd
Steel Detailer MONDO CANE
Cladding Supplier Clotan Steel
Cladding Contractor CADCON (Pty) Ltd
Corrosion Protection
Paintwork Contractor
Dram Industrial Coatings

Fourways Mall – Promotions Court

As part of the upgrade of the Fourways Mall, a new roof was proposed. The fabrication process required several fabrication jigs to be made up to accommodate the roof design for the project. The roof was built on ground level and erected on temporary roof support steelwork. tubular sections were rolled into various radii and the cross bracing was individually profiled cut to allow a stub-on connection to the main truss struts. The challenges faced during erection involved fitting a new roof onto the temporary structure and accuracy of fabrication & erection was of the essence.

What was the brief to the architect?

Provide a roof on the new Mall extension that is both practical as well as aesthetically pleasing on the eye.

Was the project envisaged in steel from the start? If not – why was it built in steel in the end?

Yes proposed as steel from the beginning

Give a brief description of the structural framing. What type of sections were used (e.g. hollow, cellular, I beams etc) and why?

The roof trusses are made entirely from Circular Hollow Sections (CHS), Cruciform Columns supporting the roof was made out of plate

Give a brief description of the cladding process (complexity, difficulty, innovation etc)

Cladding to the roof was done by TDS, the roof was covered with Shutter board, Spider-P waterproofing & Synthetic TPO membrane

What is special/ unusual/ innovative/ aesthetic about the steelwork/cladding
in this project?

The project is aesthetically appealing in the shape of this roof design.

How did the project team work together (e.g contractor involved early, challenges/ ease of communication etc.)

Constant communication between the Steelwork Contractor and the Structural Engineer was critical to get agreement on being able to fit the new roof.

STRUCTURAL STEELWORK
Completion date of steelwork 28-02-2019
Completion date of full project TBA
Tons of structural steel used 160t
Structural profiles used Tubes, UB, UC & CFLC
SA content – if this is an export project 100% local procured
PROJECT TEAM COMPANY
Nominator CADCON (Pty) Ltd
Client/ Developer Azrapart (Pty) Ltd
Architect Boogertman + Partners
Structural Engineer WSP Africa
Engineer WSP Africa
Quantity Surveyor Quanticost QS
Project Manager SIP Project Managers
Main Contractor Mota-Engil Construction South Africa
Steelwork Contractor CADCON (Pty) Ltd
Steel Erector Ijaca
Cladding Contractor Hulabond Cladding
Skylight Rainbow Skylight S.A. (Pty) Ltd
Corrosion Protection
Paintwork Contractor
TDS Contractors