Cliff stabilisation, Brighton Marina
Following a significant earlier collapse, a 230m long section of the 30m high cliffs at Brighton Marina required permanent stabilisation to protect the public, as well as apartments, shops and a superstore in the Marina Village, from any future cliff falls.
At the base of the cliffs is a paved walkway bordering the marina developments while at the top, the cliff edge is only some 20m from the busy A259 coast road. This meant that access to carry out the work was very difficult. By using specialist plant and experienced personnel, all drilling and installation work was carried out by means of abseiling techniques.
Re-grading of the top section of the cliff face and removal of any loose areas of chalk was undertaken by CJ Thorne & Co Ltd. Long reach drill-mounted rigs based on top of the cliffs were then guided by abseiling personnel to ensure careful rock drilling and enable the installation of 600 x 6m grouted rock bolts.
For areas of deep fractured chalk 55 x 7.5m heavy duty rock anchors were required and drilling for these had to be undertaken from a wheeled cradle lowered down the face. To complete the stabilisation, the whole section of cliff was covered with 6,000m² of netting, secured with profile pins, to contain any future loose chalk.
Technical Details:
- Stabilisation of 230m long section of 30ft high chalk cliffs
- Restricted access
- Abseiling installation
- Long reach drill-mounted rigs from top of cliff for installation of 600 x 6m grouted rock bolts
- Drilling for 55 x 7.5m heavy duty rock anchors from wheeled cradle lowered from cliff top
- 6,00m² of netting secured with profile pins
