APPLICATION OF PROJECT:

Community Gathering hub, Shelter and Performance stage.

PROJECT DESCRIPTION:
Highly Complex, Triangulated, Polycarbonate roof structure, with a complete 3-Dimensional form.

86m2 total roof surface including both structures.

DESIGN / FABRICATION / INSTALLATION BRIEF

Design Intent

Technical challenges from our perspective where mainly based around design intent and ensuring we could maintain this, whilst managing the overall buildability of the structure to ensure we could build within councils limited budget. We achieved this by working with Council and discussing design changes openly to ensure everyone involved was on the same page. The total Surface area of the Polycarbonate roof panels is 86 m2.

 

A big factor was in reducing the weight of the overall roof which was originally specified as Glass, the original roof weight alone dropped by 68%. This was reduced without sacrificing strength as the impact resistance of the polycarbonate panel was higher than the specified glass paneling.

Our team played a pivotal role with liaising between Brisbane councils structural engineering and architecture team.

Allot of focus and energy was put into developing highly accurate engineering detailing, to allow buildability of structure, whilst achieving architectural design intent, we assisted here through our third party engineer and the Brisbane Councils Engineering team.

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Workshop Drawing and Detailing

Workshop drawings of all elements including polycarbonate and timber works to ensure seamless integration onsite.

Fabrication detailing of steelwork, Including Hot dip galvanizing ventilation collaboration throughout design as most members had multiple sections welded together in order to create the shape but minimize connections.

Electrical works integration, including access routes, through the steelwork.

Design of all capping channels, mounting rails, polycarbonate panels, Flashings and waterspouts.

In all the workshop drawing package consisted of:

278 pages for structural steelwork.

183 pages for the roofing.

And approximately 80 pages of sketches, markups, timber detailing, flashings and gutter detailing.

STRUCTURAL SYSTEMS

Geometry

Structure 1: 2 post Cantilever Triangulated roof structure. 8 x roof faces.

All columns and rafters were pitched or leaned to both channel water and enhance the overall aesthetic.

All edges are Asymmetrical meaning ever steel member, polycarbonate panel, capping channel, rail, timber batten, connection cleat and gutter was unique. This makes for a highly challenging design and fabrication process.

Structure 2: 4 post Cantilever Triangulated roof structure. 16 x roof faces.

This structure is also curved in plan view, meaning a greater number of unique items.

Another challenge with the geometry specifically for this structure is related to the column-footing connection, the column base plates had to neatly marry up to the footpath F.S.L. which was also sloping, this meant the footing locations for the structure moved further out in a 3-Dimensional alignment as you worked down the slope. Particular attention related to the surveying both pre and during construction was critical here.

MATERIALS

Roofing

The architectural team wanted to maintain an acute triangle theme throughout the roofing structure. This was to highlight the upcoming, modern theme of West End, Timber was to clad the underside of the structure to Remind us of the history that still lives there.

This meant Textile based solutions were ruled out, as the rigidity required to the surface was not easily achievable, along with the appearance that could be achieved with Glass.

Originally Glass was looked into as the preferred option for the roofing element. After numerous meetings with Council weighing up the pro’s and con’s, we put forth an alternate solution to utilize solid, Tinted, Polycarbonate sheeting, which is also extruded locally in Brisbane by an Australian company, EGR Plastics.

This reduced the weight by 68%. Provided better impact Resistance, Provided Higher UV protection whilst also achieving the same design intent.

Steelwork was Mild steel, Hot Dipped Galvanised and 2Pac paint finished to specification.

FABRICATION

Fabrication of the steelwork was highly complex, so to ensure when we arrived at site, that the steel would fit together, we built the entire structure at our fabricators workshop, cross checking dimensions and adjusting accordingly.

Over 3 weeks both structures were meticulously assembled, tacked and welded out.

This meant when we were at site, with cranes, our in house rigging team and council performing an inspection, the steelwork connected seamlessly, much to the delight of the council personnel.

COLLABORATION, CONSTRUCTION AND MAINTENANCE

Throughout the design, fabrication, programming, and construction processes, collaboration and communication between all elements were key. We achieved mutual collaboration by openly sharing ideas and thoughts with one another, setting meetings between the different elements to run through scenarios and potential challenges on a solutions based agenda. This meant together we could tackle even the most difficult tasks.

Construction

Our team onsite for the duration of the build consisted of 3 riggers, 2 carpenters, 1 boilermaker, plus contracted crane companies etc. the entire build for our scope was completed in 2 weeks onsite including all finishing works.

Timber works followed on for another 2 weeks after this with 4 carpenters on site. Each piece of timber carefully prepared and finished to fit perfectly into position.

Due to the extra effort put in place at fabrication time, the installation of the structural steel was relatively straight forward, as it was the second time to be putting the structure together.

Extreme care had to be taken to avoid scratching or damaging the polycarbonate panels.

All panels were routed to shape offsite, fixed together into their respective group on ground level and lifted into position where they were fixed off to preinstalled fixing rails.

Overall project scale from head contractors point of view was quite complex, the site was small with difficult access and 2 extremely intricate structures.

Credits

Entrant:  Versatile Structures
Role played by Entrant:  Designer, Fabricator, Installer, Project Manager

Location:  West End, QLD 
Completed:   October 2017

Client:  Brisbane City Council

Architect:  Brisbane City Council
Engineer:  Brisbane City Council, Brisse Engineers
Builder:  Dig It
Fabricator:  Versatile Structures, Ruffles Engineering