Structural Openings

Geostructural Solutions Ltd possesses the flexibility in their approach to form an opening by which ever method is safest most economic and most practical. This can be by use of a sacrificial stooling technique to form the opening in concrete or steel or by use of a conventional needling system. The conventional needing system sometimes presents complications in causing damage to the building or simply by difficulty in gaining access.

Sacrificial Steel Stools V Needling

The temporary support system for creation of an opening by use of sacrificial steel stools is inherently safest when it comes to risk of damaging the building. This is because the load-path always follows the same line to the foundations as for the permanent structure. With a needling system the load is transferred to a secondary system often with temporary foundations and back into the wall once the frame has been installed. This can lead to considerable movement, and in particularly sensitive buildings i.e. Listed Buildings and buildings having multi-ownership this can be unacceptable.

Speed of Construction

Generally installation of a beam or frame by use of sacrificial stools is quicker than an equivalent needling system. The works can be carried out entirely by one contractor without the need to worry about temporary foundations, making good of floor and ceilings, or making good of needle positions. For concrete beams and frames there is no need for fire proofing.

Cost of Sacrificial Stools V Needling

At the out-set the cost of needling appears to cost less than an equivalent system using sacrificial stools. However once making good, fire cladding, temporary foundations, disruption to other works is taken into account then the cost is at least the same and often less for sacrificial stools. Where this system often wins out is speed of construction and the fact that only one trade is involved.

Applications:

• Shop Fitting
• Building Refurbishment
• Opening up a building for more space
• Change of use for a building.

Gaining Access to the Location of the Beam/Frame

For large frames in buildings having restricted access a heavy steel beam can present difficulties for gaining access. There are safety concerns in terms of manoeuvrability/lifting. Reinforced concrete can be pumped and the reinforcing steel manhandled into the site. When a frame is required to be installed at ceiling level and within the depth of the floor then needling is sometimes precluded as an option especially when access to the upper and lower floors is prevented.

Simple Beam, Beam and Columns, Complete Frame or Entire Floor.

Especially by use of RC work the complete floor of an entire building can be framed out to make open space. For example a labrynth of small rooms within an old masonry building can be opened up for use as a public area such as a bar, office or assembly area. Reinforced concrete has inherent stiffness and is particularly useful when it is necessary to carry the moment around the joists.

Predeflection

Any of the above systems whether it be a steel or RC frame can be preloaded by hydraulic jacking before creating the opening.

Structural Openings
Kensington House
London W8

The Clients requirement

Kensington Court is a typical London Victorian development of purpose built flats. In this case the building comprises of four stories of heavily loaded masonry divided into a labyrinth of small rooms forming individual flats at each floor level.

Although the layout of the building and the flat itself suited our client he found the rooms in his ground floor flat too small and confined, he wished to remove some load-bearing walls to make an open-plan layout which was more suited to his needs. His difficulty was in confirming the feasibility of the project given the difficult access conditions and the fact that he occupied the ground floor only of the 4 storey building.

The Consulting
Engineers View

Ian Jones Associates of Mortimer Hill, Tring, were approached with the task of finding an appropriate solution to meet the client’s requirements. Once the solution had been formulated he then had to find a contractor who could be relied to undertake the work without causing unnecessary inconvenience to the people occupying the neighbouring flats and without causing detriment to the building itself during or after formation of the openings.

The engineers solution was to form a series of structural box frame openings in concrete or in steel within the existing local-bearing walls. The depth of the beams was to be kept as shallow as possible. Although the engineer came up with this solution relatively quickly he could not find a contractor willing and reliable enough to undertake the work economically whilst satisfying his requirements in respect of the building itself and the access restrictions. When Geostructural Solutions Ltd was formed the engineer believed he had found such a contractor.

The Solution and the Work on Site

Although a series of box frames were required at isolated locations it was felt that a common upper beam would serve to tie the frames together whilst limiting the risk for differential movement by spreading the load. The frames were formed by introducing sacrificial stools and jacking them into position using a sacrificial stooly technique. In general reinforced concrete was chosen due to its inherent stiffness and rigidity but at certain locations where circumstances permitted steel columns were used for speed and economy.

The project was carried out on budget and on time to the total satisfaction of the client and the consulting engineer.

The Outcome

The client got his desired effect within his budget. He was delighted with the result. The engineer was able to recommend Geostructural Solutions Ltd to the client with confidence and he was not disappointed. The neighbours suffered the minimum of disruption to their every day lives.

We are delighted to present the attached letter from our client following completion of our works on site.

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info@geostructuralsolutions.co.uk