A ten week project to prevent further landslips on part of Rye’s Military Road has just started. The work will see the creation of a web of cables held together by around 100 pins driven into the cliffs.
In February, there were several landslips in parts of the bank to the north of the Military Road and to the east of the Globe Inn. This was attributed in part to the aftermath of heavy rainfall which resulted in ground water entering the escarpment to loosen the surface soil, causing several tons of debris to slip and block the road.
With the risk of more frequent bouts of extreme rainfall, landowners have been considering what could be done to stabilise the bank in an attempt to prevent further events.
An expert team from Optera has recently embarked on a project set for around ten weeks to stabilise one of the slip areas, above 77 Military Road.
Optera explain on their website how bank or slope failure is typically associated with increased weight at the top of the slope caused by water saturation, leading to a loss of skin friction and subsequent slip.
The engineering work under way in the Military Road area involves the creation of broad steps with integral drainage to allow the slope to better resist any movement. In addition, around one hundred pins are being driven in to the rock underneath, as an anchor system to restrain any future slope movement.
The installation uses a “spider” rig which operates on the steep bank suspended by cables anchored at the top of the slope. At the very top of the slope, where the escarpment is very steep, engineers may need to abseil down to complete the process.
Once the slope is drilled and pinned “geo-mats” will be installed to complete the stabilisation. Given the specialist equipment and the techniques involved this is a significant piece of civil engineering by skilled engineers.
The approach could be used in other parts of Rye, where landslip is a risk.
Image Credits: Anthony Kimber .