The advantages of the CT-Bolt™ Combines the benefits of immediate point anchor support anda post groutable fixture.

The polypropylene sleeve seals the bolt against corrosion whengrouted.

Long term support for fully mechanised or hand installation.

Vik Ørsta AS P.O. Box 193 N-6150 Ørsta Теl.: +47 70 04 70 00 www.vikorsta.no

www.ct-bolt.com

Grouted bolt CT-Bolt

Quickly installed, easily grouted

The CT-Bolt is in many ways a typical combination mechanical bolt, installed as a temporary rock support and later grouted to becomepermanent. But there are important differences.It’s quick and easy to install, simple to grouteven with varying consistency and the polypropylenesleeve seals the bolt against corrosion.

The bolt can be installed manually or fullymechanised with rock bolters, which have beendeveloped for the CT-Bolt.

Special hemispherical domeThe CT-Bolt has a special hemispherical domeat the end, which serves both to hold the rockloading on the plate and as a grouting chamber.The grout is pumped into the hemisphericaldome and flows through the polypropylenesleeve. At the end of the bolt, the grout flowsout of the sleeve and spreads back between thesleeve and the rock.

Unique corrosion protection When the bolt is grouted, it can take loadsalong its full length as well as at the bearingplate. The polypropylene sleeve also sealsthe bolt against corrosion. The buttons on thesleeve transfer the load from the rock to the boltand centre the bolt in the borehole.

The CT-Bolt is anchored with an expansionshell and is prestressed during installation. Theload is maintained because the bearing plateneedn’t be removed for grouting. If the area has to be shotcreted before the boltis grouted, it is possible to attached tubes to thehemispherical dome and the plate and grout thebolt after shotcreting. Many underground rockstabilisation jobs have proved the efficiencyand reliability of the CT-Bolt since its first use in1993. It has been specified on projects such assub-sea tunnels, road and rail tunnels, sewertunnels and mines.

CT-Bolt - The optimal solution for rock support

The CT-Bolt is installed in abore hole of 44-51mmdiameter, using the expansionshell. The hole is drilledto at least the length of thebolt.The bolt is pressurised sothe plate gives immediatesupport

When the grout flows outtrough the hole in the plateand sets, you have solid full-length anchorage.

The polypropylene sleeveseals the bolt against corrosion.

To grout the bolt, use aninjection nozzle on the grouthose. Insert the nozzle inthe hole in the hemisphericaldome and pump the grout. Itflows up inside the polypropylene sleeve and back down between the sleeve and the drill hole.

Installation

CombiCoat® is a combination of hot-dip galvanizing, zinc phosphatizing and powder coating. The treatment gives unique protection against corrosion and wear and tear as well as giving the surface a classy finish.

Protec ts . Conserves . Beaut i f ies .

Zinc phosphating

Hot dip galvanizing

Steel

Powder coating

Combi Coat®

The charts at right show results of tensile tests byindependent laboratories. They show displacementand load characteristics for two bolt sizes ondifferent applications, point-anchored and fully- grouted.

The CT-M20 has a yielding load of 157kN (31400lb.) and a failure load of 188kN (38100 lb.) aftergrout.

The CT-M22 has a yielding load of 237 kN (51600lb.) and a failure load of 296 kN (65000 lb.) aftergrout.

Bolt lengths range from 1,5m-6m

Technical information

Grouted bolt CT-BoltCorrosion protection of

rockbolts For many years various methods of fullcolumn grouting have been considered asacceptable corrosion protection for rockbolts.Overcored samples from fully grouted boltshave revealed varying quality of the grouting.

Section D-D: Fully groutedSection C-C: Loss of grout in wet areaSection B-B: Eccentric boltSection A-A: Air Pocket

Australia, Cudgen Road tunnelAustralia, M2 road tunnel, SydneyAustralia, M5 Joint Venture road tunnel, SydneyAustralia, Jindabyne valve House, h. power tunnelAustralia, WMC Olympic Dam, underground mineAustralia, Kanowna Belle, underground mineAustralia. Newcrest Telfer, underground mineCosta Rica, San Jose, hydro power tunnelFinland, Kemi underground mineFoeroy island, NordoyatunnelenIceland, Karahnjukar PowerStationIceland, Faskrudsfjardargong, Road TunnelIceland, Hvalfjordur, sub sea tunnelIceland, Hedinsfjordur road tunnelItaly, Naturno, railway tunnelItaly, Foligno, road tunnelItaly-France, Mont Blanc, road tunnelItaly, Frejus railway tunnelNorway, OPS E39 Trøndelag road tunnelsNorway, Jong-Asker, railway tunnelNorway, Snøkvit LNG, sub sea tunnelNorway, Frøya sub sea tunnel

Norway, Hitra sub sea tunnelNorway, Romeriksporten railway tunnelNorway, Mongstad North, gas cavernsNorway, Halsnøysambandet sub sea tunnelNorway, Eiksundsambandet sub sea tunnelNorway, Ringveg Vest Bergen sub sea tunnelNorway, Finfast, Sub sea tunnelNorway, OPS E18 Kristiansand road tunnelNorway, E18 Winterbro road tunnelSpitsbergen, Svea nord transport tunnelSpitsbergen, seed storagePortugal, Sines LPG rock cavernSingapore, rock cavernsSweden, Trollhattan railway tunnelSweden, Botniabanen, railway tunnelsSweden, Limhamn rock cavernSweden, Hallandåsen, railway tunnelSwitzerland, Kirchenwald, highway tunnelSwitzerland, Löstschberg Basis tunnelTurkey, Inmet underground mineUSA, Chattahoochee sewer tunnel, AtlantaUSA, Lake Mead water tunnel

References