Pipe Roofing

PIPE ROOFING

the solution for tunnel construction

hollow, self-drilling

PIPE ROOFING

New Austrian Tunnelling Method (NATM) The principle of the NATM is a temporary (flexible) distribution of the rock pressure around the tunnel excavation until stabilized by the final concrete tunnel lining. Based on convergence monitoring, the thickness of shotcrete and the spacing between the bolts es determined in such a way, that an increase of convergence is reduced.

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Characteristics for the NATM are: an immediate sealing of the tunnel surface after excavation by support through shotcrete against further tension relief, as well as bolting the soil layers with anchors to create a shear resistant bearing ring for the rock.

PIPE ROOFING

· the cohesion is increased by grout injection Self-drilling, hollow TITAN rock bolts for pipe roofing, · they are drilled and grouted without casing facilitate and extend the use of the NATM method to gravelly, shisty, sandy and even coarse clay soils because · the same drilling equipment can install longer bolts

cross section reinforced grout columns

crown

support soil

TITAN Rock Bolts

bottom stabilization with TITAN Micro Piles

tunnel axis

bottom bench

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PIPE ROOFING

min. 3m

15 m

1,5 D 1m

D 10 m

passive zone lane slip p

TITAN Micro Pile 40/16, 15 m long p

shotcrete

h

a < 5 - 10°

<3m groutbody

1m D

p

p

Please ask for the complete calculation 4

PIPE ROOFING

TIT AN pipe roofing offer numerous advantages TITAN · The drill jumbo (HL 550/ COP 1238) can be used for the installation, no special equipment is needed · TITAN hollow self drilling bolts offer the same bearing capacities as traditional pipes, e.g. 121 x 10 mm or 114 x 7,1 mm · The grout cover is guaranteed, as drilling and grouting is carried out simultaneously · In addition soil and rock reinforcement and consolidation flushing are effected by a 0,8 to 1,0 W/C flushing ratio which deeply penetrates into loose areas, cracks and fissures (see cross section below)

Soil, loose gravel

Gout infiltration (grey/black colour) through thin flushing, stabilisation of the annulus and consolidation of the loose soil is effected

Final grout W/C 0,4 - 0,5 (red colour) TITAN rock bolt 40/16

660 kN ultimate load

Directional stability of ± 2 % of the total length according to VOB regulations of typically 15 m = ± 0,3 m is accomplished by the special directional stability carbide drill bits.

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PIPE ROOFING

further applications of the TITAN rock bolts: spiling (forepoling) - radial bolting face bolts - bench micro piles tension piles (anti heaving) soil nails to stabilize the tunnel entrance.