The 1 Victoria Street redevelopment project comprises the retention of the two-story basement and demolition of existing building above ground level, and construction of a new building. The new building will comprise the retained basement, and ground and nine upper floors for use as retail, restaurant, leisure/experience, medical, and office uses together with associated ancillary spaces to those uses. The structural proposals include the reuse of existing raft foundation and underream piles with strengthening in the form of settlement-reducing bored piles
Martello employed one our MP4000 series rigs using the Martello technique to bore the 600mm piles to depths of up to 20m through the void between the B2 suspended slab and the B3 level. The 20t operating weight with a small footprint of 5.8m x 2.4m of the MP4000 series rig allowed the ease of manoeuvring around the existing furniture withing the piling area such as 6 number existing lift shafts, ground supporting columns and walls.
One of the biggest challenges for this contract was the need to pass height restrictions of 2.2m situated on the existing ramp leading into the basement. As our MP4000 series rig sits at 3.1m tall in transport mode this posed a large issue.
With the help of our in house design, fabrication and plant departments we over came this issue by designing and building a bespoke sledge system that could be attached to the towing hitch of the JCB 525-60 telehandler. This sledge was designed to carry the components that form the rig such as the power pack, mast section, rotary head and the rigs handling crane as these items needed to be removed to allow us to reach the 2.2m restriction. The sledge was then adapted on site to allow the stacking of the reinforcement cages that assisted us to transport a larger amount of sections at one time.