Risk of disproportionate collapse is avoided
||South Wiltshire UTC
Before the former Wiltshire Police HQ could be converted into the new South Wiltshire University Technical College, the building had to undergo a full structural survey and risk assessment. This was to establish whether any areas were considered to be at risk of disproportionate collapse and needed strengthening in order to comply with Building Regulation A3. Four areas of the building were identified as being possible areas of risk, due to critical load conditions affecting the external corners, the front elevation and internal load bearing walls.
The Helifix solution
Calculations were carried out by Helifix engineers to analyse the reinforcement requirements and a final programme of strengthening was agreed with the project engineers.
- Around the entire exterior of the four storey building and along the internal load bearing central spine wall, three HeliBars were bonded into mortar beds at two different levels between all the windows with a total of 2,190m being used. These reinforced the brickwork, creating continuous masonry beams that helped to support and spread the structural loads, particularly in the large masonry panels at the building's corners.
- Further HeliBars secured the external elevations to the internal concrete floor slabs. The HeliBars were inserted through clearance holes in the masonry and bonded into channels cut into the concrete, with the outer ends bent and bonded into the external mortar beds.
- SockFix heavy duty grouted anchors were installed at the corners, at a 45° angle, through the mid depth of the wall to secure the panels and allow the corners to cantilever. Once the building had met all its mandatory requirements to avoid any risk of disproportionate collapse it was transferred and able to become the new South Wiltshire UTC.