Colemans were appointed by BAM to deliver a programme of complex cutting, hydro demolition, robotic demolition and traditional demolition within a five-storey below ground structure at Three Snowhill, Birmingham.

This work would facilitate the complex construction of new walls, cores and structural strengthening below ground so the new 17 floor ‘Three Snowhill’ office development could be constructed in the heart of Birmingham’s business district.

As part of the adaption of the existing structure, one level of above ground reinforced concrete structure was also demolished using a selection of techniques, including extensive propping. The above ground concrete was in poor condition and required temporary support during the sequential demolition process. Large beams could not be demolished using traditional techniques because of slab loading limits, so propping and cutting techniques were utilised so large sections of concrete could be released and lifted.

Various methods of hydro demolition below ground were utilised including hand lance demolition, excavator mounted hydro demolition and robotic hydro demolition. This method of demolition was adopted so existing rebar could be exposed, allowing new walls to be tied into the existing structure. During the hydro demolition process, extensive protection zones were set up to facilitate complex phasing requirements as well as a water treatment and correction plant to deal with around two million litres of water produced during the project.

To facilitate the safe delivery of the project, in excess of 70 different designs were completed and thousands of different prop configurations utilised to ensure the global stability of the structure remained sound throughout. Due to the building’s proximity to the adjacent Two Snow Hill office building, the tram line and Snowhill Queensway, complex jacking and bespoke temporary propping was also designed and installed.

Works facilitated the completion of one of Birmingham’s most striking architectural buildings that now houses key businesses including BT.