ABSTRACT
Excavate sloped bank to vertical to receive retaining or stabilization treatment priced below; allow 1.00m working space at top of bank; backfill working space and remove balance of arisings off site; Measured as length along the top of the bank Bank height 1.00m; excavation by 5 tonne excavator
10° m 68.00 30° m 21.00 45° m 12.10 60° m 7.00
Bank height 1.00m; excavation by 5 tonne excavator; arisings moved to stockpile on site
10° m 11.70 30° m 5.85 45° m 3.40 60° m 1.95
Bank height 2.00m; excavation by 5 tonne excavator 10° m 270.00 30° m 82.00 45° m 48.00 60° m 28.00
Bank height 2.00m; excavation by 5 tonne excavator but arisings moved to stockpile on site
10° m 77.00 30° m 23.00 45° m 13.50 60° m 7.75
Bank height 3.00m; excavation by 21 tonne excavator 20° m 255.00 30° m 160.00 45° m 89.00 60° m 48.00
As above but arisings moved to stockpile on site 20° m 40.00 30° m 25.00 45° m 10.30 60° m 5.60
£ Excluding site overheads and profit
EROSION CONTROL MATS
Bank stabilization; erosion control mats Excavate fixing trench for erosion control mat 300× 300mm; backfill after placing mat selected below m 6.20
To anchor trench above; place mat to slope to be retained; allow extra over to the slope for the area of matting required to the anchor trench By machine; final grade only of excavated bank by excavator; lay erosion control solution; sow with low maintenance grass at 35 g/m2; spread imported topsoil 25mm thick incorporating medium grade sedge peat at 3 kg/m2 and fertilizer at 30 g/m2; water lightly
unseeded Eromat Light m² 2.75 seeded Covamat Standard m² 3.40 lay Greenfix biodegradable pre-seeded erosion control mat; fix with 6 ×300mm steel pegs at 1.0m centres m2 3.85 Tensar open textured erosion mat m² 5.40
By hand; final grade only of excavated bank by hand; lay erosion control solution; sow with low maintenance grass at 35 g/m2; spread imported topsoil 25mm thick incorporating medium grade sedge peat at 3 kg/m2 and fertilizer at 30 g/m2; water lightly
unseeded Eromat Light m² 3.20 seeded Covamat Standard m² 3.85 lay Greenfix biodegradable pre-seeded erosion control mat; fix with 6 ×300mm steel pegs at 1.0m centres m2 4.35 Tensar open textured erosion mat m² 5.90
Cellular retaining systems; Excavate vertical bank to slope; Grade to even grade; Lay imported topsoil 200 thick; Slope angle 20°
excavation by 21 tonne excavator m 310.00
SOIL REINFORCEMENT
Geogrid soil reinforcement (Note: measured per metre run at the top of the bank)
Backfill excavated bank; lay Tensar geogrid; cover with excavated material as work proceeds 2.00m high bank; geogrid at 1.00m vertical lifts
10° slope m 600.00 20° slope m 335.00 30° slope m 240.00
2.00m high bank; geogrid at 0.50m vertical lifts 45° slope m 63.00 60° slope m 50.00
3.00m high bank 10° slope m 600.00 20° slope m 335.00 30° slope m 240.00 45° slope m 520.00
£ Excluding site overheads and profit
RETAINING WALL SYSTEMS
Note: The following models do not allow for excavation to the existing bank in preparation of the retaining system; Please amalgamate with the ‘Grading and preparation’ section above
Excavate trench and lay foundation concrete 1:3:6; 600×300mm deep By machine m 29.00 By hand m 40.50
Concrete block retaining walls; Stepoc Excavate trench 750mm deep and lay concrete foundation 600mm wide×600mm deep; construct Forticrete precast hollow concrete block wall with 450mm below ground laid all in accordance with manufacturer’s instructions; fix reinforcing bar 12mm as work proceeds; fill blocks with concrete 1:3:6 as work proceeds
Walls 1.00m high type 190; 400×225×200mm m 190.00 type 256; 400×225×256mm m 210.00
As above but 1.50m high type 190; 400×225×200mm m 235.00 type 256; 400×225×256mm m 270.00
Walls 1.50m high as above but with foundation 1.80m wide×600mm deep type 190; 400×225×200mm m 295.00 type 256; 400×225×256mm m 330.00
Walls 1.80m high type 190; 400×225×200mm m 320.00 type 256; 400×225×256mm m 360.00
On foundation measured above, supply and RCC precast concrete L shaped units, constructed all in accordance with manufacturer’s instructions; backfill with approved excavated material compacted as the work proceeds 1250mm high× 1000mm wide m 200.00 2400mm high× 1000mm wide m 420.00 3750mm high× 1000mm wide m 145.00
Gabion walls; excavationcosts excluded; see ‘Grading and preparation of banks’ above
Gabions 500mm high; allowance of 1.00m working space at top of bank; backfill working space and remove balance of arisings off site; lay concrete footing; 200mm deep×1.50m wide height retained
500mm m 92.00 1.00m m 140.00 1.50m m 200.00 2.00m m 250.00
£ Excluding site overheads and profit
RETAINING WALL SYSTEMS – CONT
Timber log retaining walls
Excavate trench 300mm wide to one third of the finished height of the retaining walls below; lay 100mm hardcore; fix machine rounded logs set in concrete 1:3:6; remove excavated material from site; fix geofabric to rear of timber logs; backfill with previously excavated material set aside in position; all works by machine 100mm diameter logs
500mm high (constructed from 1.80m lengths) m 71.00 1.20mm high (constructed from 1.80m lengths) m 110.00 1.60mm high (constructed from 2.40m lengths) m 160.00 2.00mm high (constructed from 3.00m lengths) m 210.00
150mm diameter logs 1.20mm high (constructed from 1.80m lengths) m 200.00 1.60mm high (constructed from 2.40m lengths) m 230.00
200mm diameter logs 2.00mm high (constructed from 3.00m lengths) m 305.00
Timber crib wall Excavate trench to receive foundation 300mm deep; place plain concrete foundation 150mm thick in 11.50N/mm² concrete (sulphate-resisting cement); construct timber crib retaining wall and backfill with excavated spoil behind units
timber crib wall system; average 5.0m high m 1000.00 timber crib wall system; average 4.0m high m 730.00 timber crib wall system; average 2.0m high m 320.00 timber crib wall system; average 1.00m high m 160.00
REVETMENTS
Gabion mattress revetments Construct revetment of Maccaferri Ltd Reno mattress gabions laid on firm level ground; tightly packed with broken stone or concrete and securely wired; all in accordance with manufacturer’s instructions
gabions 6 ×2×0.17m; one course m² 33.50 gabions 6 ×2×0.17m; two courses m² 56.00
Grass concrete; bank revetments; excluding bulk earthworks Bring bank to final grade by machine; lay regulating layer of Type 1; lay filter membrane; lay 100mm drainage layer of broken stone or approved hardcore 28-10mm size; blind with 25mm sharp sand; lay grass concrete surface (price does not include edgings or toe beams); fill with approved topsoil and fertilizer at 35 g/m2; seed with dwarf rye based grass seed mix
Grasscrete in situ reinforced concrete surfacing GC 1; 100mm thick m² 60.00 Grasscrete in situ reinforced concrete surfacing GC 2; 150mm thick m² 75.00 Grassblock 103mm open matrix blocks; 406×406×103mm m² 57.00
£ Excluding site overheads and profit
Neoweb; Cellular slope retention; clear existing bank of light scrub shrubs and grasses; spray with glyphosate; grade to even grade; lay soil retaining system backfilled with excavated material
100 deep m2 13.60 200 deep m2 23.00
backfilled with ballast 100 deep m2 15.80 200 deep m2 27.50
backfilled with concrete 10Nmm 100 deep m2 19.10 200 deep m2 35.00
backfilled with imported topsoil and seeded 100 deep m2 20.00
