Newquay Rockface Stabilisation

Securing the cliff – understanding the needs of the residents and wildlife

Cormac has decades of in-house expertise which makes managing the entire process more efficient and cost effective: from geotechnical investigations, through the design process, to the often complex logistical aspects of stabilising collapsed slopes and cliffs. Major landslips occurred at access points to two of Newquay’s beaches, and one of them was on a private access road to Tolcarne Beach, used year-round for locals and visitors alike. This road is also adjacent to the Tolcarne Hotel, sitting at the base of the cliff.

Our client, Cornwall Council, has responsibility for the cliff above the road and appointed Cormac to manage the soil and rock slippage. As with all coastal works, the project had to be planned around the bird nesting seasons, and the tourism season. There are a multitude of other restrictions that might crop up concerning wildlife legislated by other government agencies, as well as traffic management restrictions to consider.  This particular slippage occurred during the winter, so immediate remedial works could be carried out.

‘The first phase was to install a combination of rock anchors and soil nails, to make the area above the access road safe, so that it could be open to traffic again’, explains Jim Driscoll. ‘Under the advice and guidance of specialist ecologists, we then netted the affected cliff section to prevent birds from nesting in the works area, so that we would be able to continue the stabilisation later on in the year, without conflict with the wildlife.’

The second phase of the scheme was to stabilise the cliff face, which started in the October, once the busiest part of the holiday season was over. Around four hundred and thirty rock bolts, were drilled eight metres deep into the cliff, along with one hundred and eighty soil nails. Due to its location, and access difficulties, the bulk of the work was carried out by rope access from the road above, employing one of our regular sub-contractors.

Jim Driscoll explains: ‘One of the many difficulties of drilling by rope access is not having machine mounted drills. This increases the risk of hand-arm vibration syndrome to the operatives. To reduce this risk, a small hand drill is set up on a skid-rig, which is hung by ropes down the rock face, eliminating the manual handling of the vibratory drill.’

The works ran from October to January, and were completed with minimal disruption to the local residents and businesses.

Behind the Great Western hotel in Newquay is a narrow public access road, leading down to Great Western beach. As at Tolcarne, a naturally occurring landslip, blocked all access to the beach, and opened up a crack in the road, within feet of the hotel.

Jim describes the process: ‘We had to close pedestrian access to the beach. Then, all the slipped material had to be removed. The only other access was at the far end of the beach, which therefore led to close liaison with the Marine Management Organisation, and Environment Agency, to obtain the permissions required to transport the material by tractor and trailer across the beach, ensuring no damage to the wildlife or marine environment’.

Once again, we employed rope access contractors along with a very high elevated work platform known as a ‘giraffe’, to enable us to reach the entire work area.

For our Council client, we are required to achieve a design life of one hundred and twenty five years for the majority of strengthening and stabilisation schemes. ‘The rock anchors and soil nails on this scheme, were all stainless steel,’ says Jim Driscoll, ‘ This is far more expensive than galvanised steel, but has a much longer design life in this type of environment. Materials are chosen through the design process to ensure the most robust solution for the area in which they will be located ’ 

Absolutely key in this kind of coastal work is liaison with the businesses that depend on tourism. We spent a lot of time working with the Great Western Hotel, to ensure disruption to their business was minimised, and all access was reinstated as soon as possible. 

The crack that had opened in the road within feet of the hotel, was secured with a combination of vertical piles, a reinforced pile cap, and rock anchors. 

Again, the location made this difficult: ‘We were literally outside the dining room of the hotel,’ says Jim, ‘And the road itself is only about 4m wide.’