3D Wireframe screen shot - Novotel
The Novotel 'Australia On Collins' Hotel is situated on
The first part of the project was to produce the shop drawings for the crane grillage which was to support the main construction crane on top of the existing south wing hotel roof, at level fourteen. Although not a complicated structure in itself, the awkward part arose due to the strengthening columns required in the hotel rooms directly below the grillage.
Steel columns were installed and connected back to the existing concrete columns in order to strengthen them. The tops of the new steel columns were drilled so as to install ‘through bolts’ through the hotel roof and into the grillage leg base plates. There was a great deal of survey work carried out during the detailing of this structure, in order to ensure the grillage legs landed exactly where required.
The loads involved in the crane were very large, and there was little tolerance available in them. This made the positioning of the new steel with respect to the existing structure extremely important.
3D Wireframe screen shot – Crane Grillage
The grillage project was awarded to us based on the fact I
was able to make an immediate start. The timescale was critical as
Main Construction Crane Installed on Grillage
We were then in the process of bidding for the main hotel refurbishment contract, along with several other detailing companies. We were awarded this contract primarily based on the quality and speed at which I completed the grillage works.
Due to the complicated nature of tying into an existing building, and the fact that the design was not complete at the start of the project, the client specifically requested that we be employed in more of a consultancy role, so as to be able to liaise with the other relevant disciplines on the hotel project. I attended several 'workshops' with the client and various trades, where I was able to show my 3D model to aid conceptual ideas from the architect and engineer and follow on trades such as the cladding and mechanical contractors.
The redevelopment project itself consists of adding a further 60+ hotel rooms to the current hotel. To achieve this, an additional five storeys, plus roof, will be installed on top of the existing level nine roof at the rear of the hotel.
The upper structure is a simple column and beam design, it is the supporting structure that complicated the project.
The hotel is, in effect, a cube with a void on the centre. The north-west and south wings carry on up to level fifteen, whilst the existing east wing terminates at level nine. Above this level is the glass wall of the existing atrium within the 'void'.
The new addition sits on top of the east roof, the existing glazed wall becomes one side of the new wing and a new facade is installed to the east face.
East Roof Prior to Transfer Steel Installation
To support this new structure, a new transfer level is created. This transfer level is a grid of 1000 & 1200 WB's. The new structure is completely independent of the old structure above this transfer level in order to maintain sufficient space for resonance should a major earthquake hit Melbourne CDB.
The transfer steel level is supported in two ways. The primary supports being new columns which penetrate through the existing stair wells and carry the load direct to the basement footings. Although the columns themselves are simple, the complications arise in the survey requirements to ensure the columns are installed in the correct location, are close enough to the stair walls to allow for connections to those walls and end up in the correct location at the top for the transfer steel. Penetrations were opened at every landing in each stair well in order to pass the columns through from the existing roof level.
East Roof – Northern Transfer Beams Installed
East Roof – North & South Transfer Steel Installed
The second system of support for the transfer steel was the installation of strengthening columns within the level immediately below the new transfer steel level. Although not a huge amount of steel, there was a substantial amount of work required in bringing together the various surveys and engineering details, along with maintaining adequate space for the architects brief and ensuring the steel could actually be fitted due to access issues.
Underside of Transfer Steel
Currently, the strengthening columns, main support columns and level ten transfer steel have all been installed, and all with great success. The high degree of accuracy provided by the survey team, along with the ability to accurately model the survey data into Tekla Structures made it possible to be as best prepared as could be with the interfacing of the new steel requirements and the existing structural elements of the building.