The project included the examination works on a 30m long wall that was situated on top of a 14m high retaining wall structure, and involved the installation of around 12,500 bricks, while trains continued to run under the scaffolding.
Sheffield
While working on behalf of Network Rail Eastern CAM, QTS were undertaking wall examinations on the TJC1 line in Sheffield. Through the examination works on a 30m long wall that was situated on top of a 14m high retaining wall structure, a fault requiring an emergency response was discovered.
Quick mobilisation from the QTS team meant that the installation of sensors and 24-hour monitoring were in place within the hour. Sensors were attached to the wall
to monitor remotely for seven days. The smallest vibration of equipment was causing the wall to move, so a solution had to be found quickly.
Ground conditions at the top of the parapet posed issues, as weight distribution meant further movement and collapse of the wall was high risk. Cantilever scaffold was ruled out for this reason.
The wall was at great risk of collapse due to the trigger levels reported from the monitoring. This meant that our team had to come up with an engineering solution that would not impact on the line or the travelling public.
A scaffold was designed to enable load capacity to be reduced and to withstand a possible wall collapse. This also provided reassurance that the ground conditions were stable for the scaffold that had been designed. QTS RRV’s with trailers were utilised to help get the scaffold materials to site through a possession. Also through the use of possession, the scaffold was erected to a suitable point, the remainder could be completed during day shift working.
Having the scaffold in place then allowed the remaining brickwork to be removed. Even though the weather caused issues, tarpaulin was installed that allowed our bricklaying team to continue working under this shelter. The rebuild ran smoothly, with around 12,500 bricks installed, while trains continued to run under the scaffolding.