دانلود رایگان مقاله طراحی ساختاری سه پست تنیده و چوبی ساختمان هنرهای رسانه ام ام آی تی

Abstract

The NMIT Arts & Media Building in Nelson, New Zealand is the first in a new generation of multi-storey timber structures. It employs a number of innovative timber technologies including an advanced damage avoidance earthquake design that is a world first for a timber building. Aurecon structural engineers are the first to use this revolutionary Pres-Lam technology developed at the University of Canterbury. This technology marks a fundamental change in design philosophy. Conventional seismic design of multi-storey structures typically depends on member ductility and the acceptance of a certain amount of damage to beams, columns or walls. The NMIT seismic system relies on pairs of coupled timber shear walls that incorporate high strength steel tendons post-tensioned through a central duct. The walls are centrally fixed allowing them to rock during a seismic event. A series of U-shaped steel plates placed between the walls form a coupling mechanism, and act as dissipaters to absorb seismic energy. The design allows the primary structure to remain essentially undamaged in a major earthquake while readily replaceable connections act as plastic fuses. With a key focus on sustainability the extensive use of timber and engineered-wood products such as laminated veneer lumber (LVL) makes use of a local natural resource, all grown and manufactured within an 80 km radius of Nelson. This IstructE award winning project demonstrates that there are now cost effective, sustainable and innovative solutions for multi-storey timber buildings with potential applications for building owners in seismic areas around the world.

4. Conclusions

To date few commercial multi-storey timber buildings in New Zealand have been designed or built that would compete with a similar concrete or steel building. This is not necessarily due to lack of capability oftimber products, but rather through lack of opportunity and industry misconceptions. The latest trends in building design, especially in the European Union, are seeing a rapid growth in multi-storey timber buildings. This is primarily for reasons of sustainability, where timber is used as a carbon sink but more recently because of improving design techniques and knowledge. Timber is now promoted for its affordability and speed of construction. The success of the NMIT Arts & Media project (Fig. 7) has proven that with innovative design multi-storey timber construction is a viable option which can compete with traditional steel and concrete options. The engineered structural system has been evaluated as being very cost competitive, and has subsequently been adopted in a number commercial building developments. The NMIT building project offered a unique opportunity for Aurecon structural designers. The first commercial use of the Pres-Lam post-tensioned rocking-dissipative timber system marks a fundamental change in timber design. The PerformanceBased Engineering philosophy ensures that the building will continue to function after the design level seismic event. In the wake of the 2011 Canterbury Earthquakes this project demonstrates to building owners that a fully functioning building post-earthquake can be achieved in a cost effective manner.