Cliff Reinforcement/Rock Netting Weldgrip Gripforce ® Rockbolts & Drilling Equipment
The Connaught Garden Cliffs at Sidmouth are 15m to 18m high, overlooking the sea. Weathering of the red sand-stone cliffs has made the footpath below the cliff face dangerous for public access. Major work was carried out to reinforce areas of the cliff face and to secure the top section by Rock Netting over a length of 140m, to prevent any loose weathered rock from free fall. Vegetation was cut back at the top of the cliff and a Polyester Geogrid - overlaid by a plastic coated wire mesh - was secured to the face by Weldgrip Fibregrip ® Rockbolts. To re-establish the vegetation Hydroseed was used on the top section of the cliff. The rockbolts used were 22mm diameter x 1m long, with an 80kN nut and a 150mm diameter high load plastic end plate. The rockbolts were installed into 42mm diameter holes and grouted with a ratio of 0.4% water to O.P.C. (Ordinary Portland Cement). The holes were drilled using a Weldgrip Turmag pneumatic hand held rotary drilling machine and turbine scroll auger rods with 42mm wing bits. All the holes up to 3m in length, both for the reinforcing and rock netting, were drilled using this method. All the work carried out on the cliff face was by rope access. The lightweight construction of the Weldgrip drilling equipment and Fibregrip ® Rockbolts gave better handleability and therefore improved safety for the rope access work. Other advantages of using Weldgrip Fibregrip ® Rockbolts were:-
|
©
2008 Weldgrip Geotechnical , All Rights Reserved |