ABSTRACT
There are so many factors, apart from design considerations, which influence the cost of tunnelling that it is only possible to give guide prices for a sample of the work involved. For more reliable estimates it is advisable to seek the advice of a Specialist Contractor. The main cost considerations are:
* the nature of the ground * size of tunnel * length of drive * depth below surface * anticipated overbreak * support of face and roof of tunnel (rock bolting etc.)
* necessity for pre-grouting * ventilation * presence of water * use of compressed air working
The following rates for mass concrete work cast in primary and secondary linings to tunnels and access shafts are based on a 5.0m depth of shaft and 15.0m head of tunnel Apply the following factors for differing depths and lengths:
HEAD LENGTH: 15m 30m 60m 90m Shaft depth 5m +0% +10% +20% +32½% Shaft depth 10m +5% +12½% +27½% +35% Shaft depth 15m +10% +17½% +32½% +40% Shaft depth 20m +15% +20% +37½% +42½%
EXCAVATION NB: Rates +25% or −10% Dependent on Ground Conditions Excavating tunnels in rock
1.5m dia. – – – – m3 538.56 3.0m dia. – – – – m3 336.60
Excavating tunnels in soft material 1.5m dia. – – – – m3 255.25 3.0m dia. – – – – m3 140.25
Excavating shafts in rock 3.0m dia. – – – – m3 207.57 4.5m dia. – – – – m3 173.91
Excavating shafts in soft material 3.0m dia. – – – – m3 120.61 4.5m dia. – – – – m3 103.78
Excavating other cavities in rock 1.5m dia. – – – – m3 538.56 3.0m dia. – – – – m3 336.60
hours £ £ £ rate £
Excavating other cavities in soft material 1.5m dia. – – – – m3 255.25 3.0m dia. – – – – m3 140.25
Excavated surfaces in rock – – – – m2 19.64 Excavated surfaces in soft material – – – – m2 19.64
IN SITU LINING TO TUNNELS
Notes The following rates for mass concrete work cast in primary and secondary linings to tunnels and access shafts are based on a 5.0m depth of shaft and 15.0m head of tunnel See above for additions for differing shaft depths and tunnel lengths. NB: Rates +10% or −10% Dependent on Ground Conditions
Mass concrete; grade C30, 20mm aggregate Cast primary lining to tunnels
1.5m dia. – – – – m3 325.38 3.0m dia. – – – – m3 280.50
Secondary lining to tunnels 1.5m dia. – – – – m3 378.68 3.0m dia. – – – – m3 300.13
Formwork; rough finish Tunnel lining
1.5m dia. – – – – m2 52.73 3.0m dia. – – – – m2 52.73
IN SITU LINING TO ACCESS SHAFTS
Notes The following rates for mass concrete work cast in primary and secondary linings to tunnels and access shafts are based on a 5.0m depth of shaft and 15.0m head of tunnel See above for additions for differing shaft depths and tunnel lengths. NB: Rates +10% or −10% Dependent on Ground Conditions
Mass concrete; grade C30, 20mm aggregate Secondary linings to shafts
3.0m int dia. – – – – m3 300.13 4.5m int dia. – – – – m3 291.72
Cast primary lining to shafts 3.0m int dia. – – – – m3 319.77 4.5m int dia. – – – – m3 305.75
hours £ £ £ rate £
IN SITU LINING TO ACCESS SHAFTS – cont
Formwork; rough finish Shaft lining
3.0m int dia. – – – – m2 79.66 4.5m int dia. – – – – m2 53.86
IN SITU LINING TO OTHER CAVITIES
Notes The following rates for mass concrete work cast in primary and secondary linings to tunnels and access shafts are based on a 5.0m depth of shaft and 15.0m head of tunnel See above for additions for differing shaft depths and tunnel lengths. NB: Rates +10% or −10% Dependent on Ground Conditions
Mass concrete; grade C30, 20mm aggregate Cast primary lining to other cavities
1.5m int dia. – – – – m3 328.19 3.0m int dia. – – – – m3 280.50
Secondary linings to other cavities 1.5m int dia. – – – – m3 378.68 3.0m int dia. – – – – m3 300.13
Formwork; rough finish Other cavities lining
1.5m int dia. – – – – m2 52.73 3.0m int dia. – – – – m2 52.73
hours £ £ £ rate £
PREFORMED SEGMENTAL LININGS TO TUNNELS
Precast concrete bolted rings; flanged; including packing; guide price/ring based upon standard bolted concrete segmental rings; ring width 610mm
Under current market conditions the reader is currently advised to contact specialist contractors directly for costs associated with these works
PREFORMED SEGMENTAL LININGS TO SHAFTS
Precast concrete bolted rings; flanged; including packing; guide price/ring based upon standard bolted concrete segmental rings; ring width 610mm
Under current market conditions the reader is currently advised to contact specialist contractors directly for costs associated with these works
PREFORMED SEGMENTAL LININGS TO OTHER
Precast concrete bolted rings; flanged; including packing; guide price/ring based upon standard bolted concrete segmental rings; ring width 610mm NB: Rates +10% or −10% Dependent on Ground Conditions Linings to tunnels
1.5m int dia.; Ring 1.52m ID×1.77m OD; 6 segments, maximum piece weigth 139 kg – – – – nr 575.04 3.0m int dia.; Ring 3.05m ID×3.35m OD; 7 segments , maximum piece weight 247 kg – – – – nr 1029.67
Linings to shafts 3.0m int dia.; Ring 3.05m ID×3.35m OD; 7 segments, maximum piece weight 247 kg – – – – nr 814.84
Lining ancillaries; bitumen impregnated fibreboard Parallel circumferential packing
1.5m int dia. – – – – nr 5.71 3.0m int dia. – – – – nr 11.41
hours £ £ £ rate £
PREFORMED SEGMENTAL LININGS TO OTHER – cont
Lining ancillaries; PC4AF caulking compound Caulking
1.5m int dia. – – – – m 9.86 3.0m int dia. – – – – m 9.86
SUPPORT AND STABILIZATION NB: Rates +15% or −5% Dependent on Ground Conditions Rock bolts
mechanical – – – – m 27.33 mechanical grouted – – – – m 42.67 pre-grouted impacted – – – – m 41.04 chemical end anchor – – – – m 41.04 chemical grouted – – – – m 29.19 chemically filled – – – – m 45.92
Internal support steel arches; supply – – – – t 1200.78 steel arches; erection – – – – t 473.77 timber supports; supply – – – – m3 349.69 timber supports; erection – – – – m3 301.50 lagging – – – – m2 25.85 sprayed concrete – – – – m2 29.58 mesh or link – – – – m2 9.55
Pressure grouting sets of drilling and grouting plant – – – – nr 1296.22 face packers – – – – nr 57.42 deep packers – – – – nr 98.44 drilling and flushing to 40mm dia. – – – – m 21.75 re-drilling and flushing – – – – m 17.25 injection of grout materials; chemical grout – – – – t 689.13
Forward probing – – – – m 22.41
