Structural Systems - Steel Construction Research Programme

Steel construction research projects are evaluated by the HERA's Steel Research Panel consisting of leading structural engineers and fabrication industry members. For many years the Panel has had many more projects proposals on their list than can be funded and most projects have had outputs which end up in the New Zealand structural steel design standard and HERA guidelines.

Structural Steel Connections Guide
The development of the Structural Steel Connections Guide led to a standardization of connections used in steel construction across New Zealand, reducing design efforts and risk, simplifying detailing, cost estimating and through facilitating CNC machine programming. This has led to significant cost saving estimated to be several million dollars each year.David Moore, General Manager Grayson Engineering says: "The Connection Guide is probably the most effective development provided by HERA for the Steel Construction Industry. It makes the steel detailing side a lot easier and allows us to configure our CNC machinery with a range of connection plates that we can pre-load the cutting data for and that this ultimately cuts down programming and processing time which translates into greater efficiencies and enhanced levels of productivity across the board."

Fire Engineering Programme Example - Slab Panel Method
Application of the Slab Panel Method and SPM software developed by HERA allows designers of steel framed buildings to value optimise the fire and structural engineering to avoid wasteful expenditure on applied fire proofing to those parts of the structure that do not need it. This is of substantial benefit in terms of reduced cost, reduced construction time and efficient utilisation of the country's resources in the construction industry sector.Martin Feeney, Principal and Senior Fire Engineer, Holmes Fire says: "The application of the Slab Method in the last few years resulted in cost savings in the order of $1.8 million on projects that our practice alone has been involved with. Application of the associated Radiation Barrier software - also developed by HERA - yields further average annual savings through optimised fire protection costs in the order of $1.5 million."

HERA Invited on a Major European Fire Research Programme
Structural Systems Manager Dr Stephen Hicks was invited as the only non-European representative toparticipate in the European Cooperation in Science and Technology (COST) action entitled Integrated Fire Engineering and Response(IFER), which includes researchers and specialists from 18 European countries. It aims at providing specific applications on the performance-based fire safety design methods to practitioners, and introduces the latest international research into Standards for fire design. It is hoped that the output from this work can be used in the development of the new fire section in NZS3404, which is currently underway, together with the update to the HERA Slab Panel Method(SPM).

Seismic Research Programme
The Northridge and Kobe earthquakes raised concerns as to the performance of seismic structural steel frames used in NZ. The HERA seismic research program led to assurance that NZ systems are safe to design level in earthquakes and to the development of new more effective seismic resisting frame systems. Today, NZs structural steel design standards and guidelines which incorporate HERA research, are world-leading in respect to design against seismic and fire hazards with overseas countries adopting parts of them. The HERA contribution to predictable seismic design of steel structures played the principal role in structural steel increasing its market share in multi-level steel construction from basically 0% in the 80 th to close to 50% today.Geoff Bird, Senior Structural Engineer, Beca: "For many years, I have been involved on the HERA Steel Research Panel and have had input to the focus of the HERA research program. The work undertaken by HERA in the seismic behaviour of structural steel buildings is leading edge and world class. In particular, the FBJ (Flange Bolted Joint) and SHJ (Sliding Hinge Joint) research and subsequent design methodology has provided significantly improved design efficiencies for steel buildings in New Zealand. There is now some $2.5bn of structures using this methodology, with associated design, construction, cost, and performance benefits."

Steel Bridge Development Programme
Steel-concrete composite bridges has a market share of 50%, or more, in many international markets. The current market share within New Zealand is less than 20% indicating that the cost benefits of composite bridges are not being realized. Since 2004, HERA has embarked on a long term program of providing guidance to bridge designers by providing technical advice, development of design aids, seminars and updating NZ Standards to reflect the opportunities for composite design. Examples of recent achievements include the 440m multi-span Contact Energy Bridge and the 100m single span Waikato River Network Arch Bridge, both part of the Eastern Taupo Arterial Bypass Project.

Says Phil Gaby, Project Director Bridges, at Holmes Consulting: "Through inspiration from a HERA seminar, we were able to win several bids for steel bridges based on novel designs used in other countries. In the Eastern Taupo Arterial Bypass Project alone, the use of steel solutions provided a significant direct cost saving in comparison to conventional concrete only bridge designs. Particularly relevant was the reduction in construction programme as a result of the steel composite bridges being 40 % lighter than concrete alternatives and therefore much quicker and easier to construct particularly in sites with difficult access like Contact Energy and the Waikato River crossing.

Other HERA-inspired structures designed by Holmes Consulting Group include 2 no. 100m long ladder deck steel composite bridges at Okura. The structures carry SH4 over the erosion prone Mangawhero River. A saving of 15% on construction cost was realised over the conforming all concrete bridge design. Seminars held by HERA have inspired other Holmes Consulting Group projects including Mangamahu Bridge, an 85m span network arch bridge. This bridge was significantly easier to construct and 30% cheaper than the conforming design. This bridge scheme won an ACENZ gold medal award. Currently under construction is the HERA inspired and Holmes designed Matahorua Gorge Bridge north of Napier. At 140m long with a central span of 52m long, this bridge is one of the longest span steel girder bridges in the country. Again the structural form was significantly cheaper than any of the other tenders submitted a direct result of ladder bridge simplicity of form and ease of construction when compared to the other forms of construction."

Design Guide on Composite Bridges
Through generous support from the New Zealand Transport Agency (NZTA) and the steel industry, the first draft of the New Zealand Composite Design Guide was launched at a series of national seminars. The publication is prepared by Raed El Sarraf, David Iles of the UK Steel Construction Institute and David Easey of AECOM. The Design Guide is based on AS5100 and when completed, will be complimented by a number of worked examples.