Tuesday evening, 15th August, saw over 25 IDE members and guests gather at the Oak Hotel, Hockley Heath, Birmingham for an evening sponsored by DSM Demolition Limited and hosted by Robin Powell FIDE.
Robin Powell welcomed everyone to the meeting and commented that he was pleased to see so many people in attendance.
The evening then started with a presentation from Steve Tamplin from Controlled Scaffolding who gave us an insight into the changes in regulations covering scaffolding and what we, as Demolition Engineers, need to consider when using scaffolding on projects. Steve made mention of the differing competencies required when erecting, adjusting and dismantling scaffolding and that system scaffolding requires a different design and erection procedure and HSE will require evidence of full competency when using system scaffolds. He emphasized that the loadings are key to the design and we should remember that 45 dry scaffold boards weigh one tonne and will, therefore impose a loading of their own onto the scaffold and that loading will increase when the boards are wet. Ties must be designed prior to erection and must be installed as the design and Steve emphasized that point with a good video of a scaffold collapse caused by ties being removed by the building contractor to “make it easier to work”. Steve’s talk concluded with a round of applause and then questions from the floor including a need for him to clarify who can dismantle a “demolition scaffold”.
The second presentation of the meeting was from Ricky Hay, Managing Director of Dem-master Limited who are collaborating with DSM on the demolition of St James Centre, Edinburgh. The demolition is complex and difficult as the brutalist architecture of the buildings on site has led to a number of methods being used whilst keeping John Lewis and the adjacent bus station open at all times.
Demolition methods used are – Traditional Top Down, High Reach, Ultra High Reach and Crane deconstruction.
The buildings are mainly of precast panel construction (similar to the infamous Ronan Point) which determines how they can be demolished. The temporary works to install props to every panel is a complex job on it’s own without the added pressures of demolition of those panels at height. Following a long lead in period and extensive discussions with structural engineers it was decided that Ultra High Reach demolition was the best way forward as it was the safest method for both the operatives on site and the public and it could be demonstrated that the work was done as the HSE guidelines of risks being ALARP (As Low As Reasonably Practicable). To allow the work to commence the podium of the shopping complex had to be strengthened to take the additional loading from the temporary works and the loadings from the props. It was essential to maintain operator sightlines at all times whilst maintaining the structural integrity of the structures. Ricky spoke about an uncontrolled collapse to one of the car parks on site and how the site team changed the methods to ensure ALARP by checking areas daily for overloading and ensuring that the buildings remained structurally sound at all times. An idea of the complexity of the work can be found by clicking one of the following links:-
The final presentation of the evening was by Robin Powell who showed a short film of a Demolition in France by designed collapse mechanism using “Verinage” – a computer controlled hydraulic jacking system. Watch the video here:
Robin Powell commented “Contrary to the opinions of many, verinage does not:
1. Use explosives of any kind.
2. Employ cables to pull the building down to the ground.
Hydraulic Jacks or cables are used to remove or deflect structural walls on collapse floors to initiate the process … Gravity does the rest.”
Author: John Woodward FIDE
The content of this article represents the personal views of the author and nothing is to be taken as representing the views, opinions, policy or position of any other persons or organisations mentioned herein or of the Institute of Demolition Engineers.