Temporary Structures – EKAP2

Demolition project background

As part of the second phase of the East Kent Access Scheme, VolkerFitpatrick installed one of the world’s largest Jacked Box structures to date.

Six sections with individual masses of 2500t were cast on site and installed using hydraulic jacks, skid rails and thrust blocks. DDS were awarded the contract to demolish these temporary structures, following successful completion of other demolition works involved at earlier stages of the scheme.

Specification

  • Demolish 2no skid rails (approx. 140lm in length) and 2no thrust blocks, shear keys  used for the installation of the Jack box tunnel.
  • Hydro demolition and diamond sawing, leaving reinforcement bar in exposed, on the cutting edge elevation of the tunnel for the next phase of the construction works to connect to..
  • Remove retaining walls on both sides of the casting yard and casting yard slab.
  • Excavate slab in preparation for surfacing formation of the new highway.
  • Remove all arisings from site
  • Leave the site clean, safe and tidy on completion.

Achievements & Successes

  • The confines of the working area proved to be one of the biggest challenges to overcome on this site, as the site itself was a section of a busy site highway, used regularly by site traffic. Logistics plans had to be created sequencing the works in such a way all site traffic could pass through unhindered at all times. This also had to allow for the constant flow of road haulage vehicles removing demolition arisings.
  • In order to successfully remove the concrete to cutting edge elevation of the tunnel, leaving the reinforcement bar in situ, DDS employed specialist Hydro Demolition Equipment. This equipment used over 25,000 litres of water per day. As such DDS bunded that specific working area to prevent flooding to the rest of the site. The working area itself was carefully monitored throughout the works.
  • The thrust blocks and skid rails were heavily reinforced, however the full extent of this was not known prior to commencing the works. A flexible approach was taken in order for us to adjust our resources and programme in order to meet our client’s deadline, should the initial stages of the work fall behind.
  • DDS recycled 100% of all demolition arisings.
  • The removal of 500 tonnes of reinforcement and over 6000 tonnes of concrete.
  • Achieving an accelerated program to from 6 weeks to 3.5 weeks
  • Complete client satisfaction.