St. Helens College, Merseyside
Partial Demolition of St. Helens CampusConnell Brothers were appointed as demolition contractors for the partial demolition and enabling works for stage 1 of the redevelopment of the St. Helens College Campus in the centre of St. Helens on behalf of the college.
The project called for the demolition of a number of different structures situated within a live campus environment. All of the structures to be demolished were attached to the retained buildings and therefore required careful hand demolition at the interfaces. In addition new access for disabled students and staff had to be constructed prior to the demolition commencing.
Services passing into the areas to be demolished were terminated or diverted and all access to these areas sealed by timber hoardings, this included ensuring that service tunnels were sealed to prevent unauthorised access after the buildings were demolished. A live sub-station located in one corner of the site also required protection during the works.
The building to the west end consisted of a 5 storey reinforced concrete frame with concrete cladding panels to the external walls. The floors were of a concrete beam and block infill construction. The ground floor was used as a car park and the upper floors were classrooms. The building was connected to the rest of the college by a double staircase and a service riser that both needed to remain. This required the corridor to be infilled at each floor with blockwork. Scaffold was erected to the front where the entrance to the remaining sections of the college was still in use and to assist in the hand separation of the buildings.
There was a central corridor and an end staircase providing structural support to the building and therefore demolition was carried out by combination of high reach and traditional demolition specification excavators working from both sides to progressively demolish the building floor by floor. At the ground floor level against the retained building there was a plant room that required protection during the works.
Once demolition had been completed the exposed face of the retained building was fully clad to provide weather protection.
The central part of the site comprised a 4 storey teaching block, the ground floor being partially below ground level. Within the block was a gymnasium and attached to the south side was the barrel vaulted sports hall. The gymnasium was in turn connected to a 6 storey teaching block and a theatre with a squash court above. These buildings were constructed of a reinforced concrete frame with a mixture of in-situ reinforced concrete waffle floors at low level and pre-cast reinforced concrete planks at high level. Again scaffold was erected to allow for hand demolition at the interfaces with the retained structure.
No detailed drawings were available and therefore demolition along the cut line was carried out by hand to expose the different structures and to determine the final demolition line. The upper floors to the west side were connected to the main building by a corridor and the classrooms contained the computer teaching facilities.
The ground floor slab was built on an elevated area of fill and this required removing in order to break out the foundation of the building. The underground service ducts were also removed before being blocked up.
Once the buildings were separated demolition was carried out by a combination of high reach and traditional demolition specification excavators.
The west elevation of the retained building required a number of different finishes. The upper floors were fitted with new glazing sections to match the existing windows and allow light into the computer classroom. Below this the openings were infilled with an insulated brick and block wall.
The remaining section of the ground floor was fitted with a combination of brickwork and glazing panels and was used as site offices for the following construction company.
The rear of this area contained the 6 storey block, theatre and squash court. Scaffold was erected once again in order to carry out hand demolition to separate the structures. Propping was carried out to the squash court and mini-excavators lifted onto the roof to remove the roof. The roof beams were removed by the use of a mobile crane.
Scaffold was also erected to the end elevation which stood on the back of the pavement. Opposite the building was a new art studio with full height glazing. Demolition of these blocks was carried out by a combination of high reach and traditional demolition specification excavators.
Behind these blocks part of the hair dressing teaching area was demolished to facilitate the new construction.
Propping was installed to the floors and the end section of the building carefully removed by initially saw cutting to separate the structures and then a combination of hand and mechanical demolition. These works were carried out in close proximity to the live sub-station. Once completed this area and the area behind the former theatre were fully clad to provide weather protection.
All the suitable demolition arising were crushed on site using Connell Brothers own crusher to provide construction material for the following development.