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Soil nailing with Klemm
00:00 25 May 1995
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A Klemm KR 80302 anchor drilling rig from Ingersoll-Rand is being
used to drill holes for soil nailing on the A31 Ashley Heath Grade
Separated Junction contract near the coastal town of Bournemouth in
Dorset.
The soil nailing is being carried out by subcontractor BRC Mining and Land Reinforcement on behalf of main contractor, Wimpey Engineering and Construction.
It is part of a œ6.7 million contract to divert the A31 into a cutting between retaining walls and under the Ashley Heath roundabout at the point where the road meets the A338 Ringwood to Bournemouth spur road.
The task, a central part of the contract being run for the Highways Agency, provides earth wall support so that the contractor can excavate vertical faces in the loose sand/gravel mixture underlying the A31.
The 2,800-hole nailing project, one of the largest of its kind in the UK, is said to minimise the amount of excavation and land required for the scheme on a site where space is a premium.
Features of the crawler-mounted Klemm KR 80302 rig include a 200V gear feed drilling mast with a Klemm0-4053A hydraulic drifter unit. Additional equipment includes a Hiab 027 hydraulic crane for handling large casings of up to 3m. If required, the unit's hydraulics can run a water flushing pump.
On this particular project, Ingersoll-Rand's P600 portable compressor supplies compressed air for air flushing in the drilling process.
Soil nailing is a similar process to rock anchoring, where steel bars are inserted into the face of an earth wall and grouted in to tie the surface back and stop the wall from collapsing.
The construction of a vertical wall begins with excavation of panels 12m long and one metre deep. For each 1m deep section, the soil face is trimmed to make it vertical and then a layer of reinforcing mesh is fixed to the trimmed soil face.
Sprayed concrete is then applied in a 100mm layer of concrete on to the mesh which reinforces the face of the earth wall.
Sleeves are set into the concrete which can then be used as guides for drilling through the concrete into the earth behind.
Once the drill hole has been formed using the Klemm rig, a 7.3m long high tensile steel soil nail is pushed into the hole and grouted in. A tightening nut on the exposed end of the rod anchors the nail to the wall, tying back the concrete face. Once the first 1m deep section is completed, another metre is excavated and the process repeated until the maximum depth of 8m is reached.
Details: enter 701 on card
The soil nailing is being carried out by subcontractor BRC Mining and Land Reinforcement on behalf of main contractor, Wimpey Engineering and Construction.
It is part of a œ6.7 million contract to divert the A31 into a cutting between retaining walls and under the Ashley Heath roundabout at the point where the road meets the A338 Ringwood to Bournemouth spur road.
The task, a central part of the contract being run for the Highways Agency, provides earth wall support so that the contractor can excavate vertical faces in the loose sand/gravel mixture underlying the A31.
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The 2,800-hole nailing project, one of the largest of its kind in the UK, is said to minimise the amount of excavation and land required for the scheme on a site where space is a premium.
Features of the crawler-mounted Klemm KR 80302 rig include a 200V gear feed drilling mast with a Klemm0-4053A hydraulic drifter unit. Additional equipment includes a Hiab 027 hydraulic crane for handling large casings of up to 3m. If required, the unit's hydraulics can run a water flushing pump.
On this particular project, Ingersoll-Rand's P600 portable compressor supplies compressed air for air flushing in the drilling process.
Soil nailing is a similar process to rock anchoring, where steel bars are inserted into the face of an earth wall and grouted in to tie the surface back and stop the wall from collapsing.
The construction of a vertical wall begins with excavation of panels 12m long and one metre deep. For each 1m deep section, the soil face is trimmed to make it vertical and then a layer of reinforcing mesh is fixed to the trimmed soil face.
Sprayed concrete is then applied in a 100mm layer of concrete on to the mesh which reinforces the face of the earth wall.
Sleeves are set into the concrete which can then be used as guides for drilling through the concrete into the earth behind.
Once the drill hole has been formed using the Klemm rig, a 7.3m long high tensile steel soil nail is pushed into the hole and grouted in. A tightening nut on the exposed end of the rod anchors the nail to the wall, tying back the concrete face. Once the first 1m deep section is completed, another metre is excavated and the process repeated until the maximum depth of 8m is reached.
Details: enter 701 on card
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