Ruby’s Restaurant, Al Raha Beach Resort
In Abu Dhabi, the location for Ruby’s restaurant, the most common structural material is reinforced concrete. The architect’s (Broadway Malyan UK) concept for the restaurant featured significant curved structural elements. While possible to construct in other materials these curved members were particularly suited to the use of glue-laminated timber, a structural material familiar to the New Zealand construction industry.
Mark L Batchelar Consulting Engineers was engaged to develop an initial timber structural system to establish the feasibility of the concept. Based on this preliminary investigation Global Timber Homes Ltd, a New Zealand based consortium with experience in glue-laminated timber manufacture and the construction of timber buildings, was successful in securing the construction contract. Detailed structural design was then progressed, maximising the use of New Zealand timber products. A total of ten container loads of New Zealand certified renewable resource timber was used in the project.
The main structural frames for the building envelope, first floor and deck areas are designed in glue-laminated radiata pine manufactured by McIntosh Timber Laminates Ltd Auckland. The first floor secondary framing is a truss joist system using Mitek parallel chord trusses. There is also a high level mechanical services concrete platform on slender concrete columns. This introduces an additional structural element to be integrated into the main building system comprising glue-laminated timber frames with plywood diaphragm roof, floor and wall elements.
The unusual geometry of the structure with asymmetry in both elevation and plan made a full three dimensional computer model of the structure essential. Structure loadings were based on British Standards for dead, live and wind loads while seismic design was required to comply with the American Unified Building Code UBC. The different structure elevations required wind load to be assessed for maximum loads on each of the four faces of the building.
A one hour fire resistance rating was required for the restaurant. All timber structural members were checked for adequate residual strength after fire while sustaining live load and reduced wind loads. In consideration of combinations of structure dead load, live load, wind load, seismic load and after fire stability a total of twenty independent load combinations needed to be reviewed.
Connections between glue-laminated timber floor beams and round timber glue-laminated columns required an innovative approach. Substantial load transfer was required at these connections without reducing either column or beam capacity. Strength reduction of the beams and columns by notching or rebating was avoided by the development of curved steel collars screw fixed to the timber columns. The curved steel collar contains a large integrated steel shear pin that engages with a bearing seat plate screw fixed to the beams. This detail is illustrated in the display submission. The connection was easily installed and appropriate for both vertical and sloping timber columns. The curved brackets could be readily positioned on the columns to ensure that the shear pin was at the correct elevation to receive the floor beams.
NZ Wood Timber Design Awards 2010
Highly Commended – Commercial Engineering Excellence
Clever Wood Solution Award