CT-Bolt Combination Rock Bolt
2
Contents Introduction... 3 Fields of Application... 4 Main Advantages... 4 System Description... 4 System Components... 5 Specifications... 5 Installation Procedure... 6 Technical Features... 6 Further References... 6 Introduction The CT-Bolt TM is an unique combination rock bolt system. It offers the combined advantages of an immediate point anchorage and subsequently a fully grouted rock bolt. A two-step installation procedure allows fast installation and immediate anchorage, separate and independent grouting provides flexibility in regard to working cycles. Due to the controlled grouting procedure and different bar coatings available, the CT-Bolt TM is a reliable ground control system for underground applications. The working ability of the CT-Bolt TM has been proven throughout various underground construction projects; the system has become a standard in today s state-of-the-art ground control procedures. 3
Fields of Application Systematic permanent reinforcement of underground excavations Ground support for areas with limited or no access during operational lifetime Permanent roadways and excavations Hydropower and underground oil or gas storage caverns Sub-sea and sewer tunnels Main Advantages Efficient, practically proven, and reliable rock reinforcement system Combination of an immediate point anchorage and a fully grouted rock bolt Immediate load-bearing capacity after installation by the mechanical anchor Fast installation and flexible postgrouting behind the working face Double corrosion protection due to a polyethylene sleeve and grout coverage Easy adjustment of the corrosion protection level to customer demands Semi-automated or manual installation procedure System Description Combination rock bolt Immediate point anchorage by activation of an expansion shell anchor Post-grouting assembly features double corrosion protection 4
System Components Polyethylene sleeve Corrugated, with inner centralizers Dome-shaped grouting adapter With grouting hole and welded-on sleeve Nut Expansion shell Plate Incl. bore for grout discharge Rebar rock bolt Cold rolled threads on both sides for mounting expansion shell and nut Specifications Characteristic Value / Type Unit CT-M20 CT-M22 Outer rebar diameter [mm] 20 21.7 Thread designation [mm] M20 M22 Characteristic yield load 1) [kn] 140 230 Characteristic ultimate load 1) [kn] 170 290 Borehole diameter range 2) [mm] 44-51 Delivery lengths 3) [m] 1.5-6.0 1) After grouting 2) Expansion shells for larger borehole diameters available upon request 3) Delivery lengths up to 8.0 m are available upon request 5
Installation Procedure Borehole drilling Drilling of a borehole: Ø 44-51 mm Recommended borehole length: about 100 mm longer than the bolt length Bolt installation Insertion of the assembled CT-Bolt into the pre-drilled borehole Pressing the bolt plate firmly against the excavation surface Activation of the expansion anchor by pre-stressing of the anchor nut provides immediate point anchorage Typical required torque: 200-300 Nm Flexible bolt grouting Preparation of cement grout according the given specifications Connection of an injection adapter to the grouting adapter of the CT-Bolt Primary grout flow inside the sleeve towards the bolt s toe (expansion shell) - complete grout coverage of the rebar Secondary grout flow outside the sleeve until the grouting medium flows out at the bore for grout discharge at the hemispherical bolt plate Further References Load indicators and rock bolt testing equipment available upon request Technical Features Combination rock bolt Active reinforcement by pre-stressing of the expansion anchor Allowance of a certain amount of elastic deformation of the rebar induced by displacements of the rock mass Flexible grouting behind the working face allows an optimum adoption of the CT-Bolt to given ground and operating conditions Optimum alignment and assurance of complete grout coverage of the rock bolt by the polyethylene sleeve Unique choice of the corrosion protection level Protection of the components of the CT-Bolt according to given levels of corrosive environments Bolts are available black, hot dip galvanised, or with a special Combi Coat (combination of hotdip galvanizing, zinc phosphate, and powder coating) Indicated lifetimes for load-bearing components of the fully-grouted CT-Bolt by accelerated corrosion tests performed by Vik Ørsta AS from 50 (black type) to 150 (Combi Coat type) years 6
7
EMEA DYWIDAG-Systems International GmbH Alfred-Wagner-Strasse 1 4061 Pasching/Linz, Austria Phone +43-7229-610 49 0 Fax +43-7229-610 49 80 E-mail alwag@dywidag-systems.at www.alwag.com North America DSI Underground Systems Inc. 9786 S Prosperity Road West Jordan, UT 84081, USA Phone +1-801-973 7169 Fax +1-801-973 7172 E-mail dsiunderground@dsiunderground.com www.dsiunderground.com South America DSI Chile Industrial Ltda. Las Encinas #1387, Valle Grande Lampa, Santiago de Chile, Chile Phone +56-2-596 96 20 Fax +56-2-596 96 69 E-mail informaciones@dywidag-systems.cl www.dsi-chile.com APAC/ASEAN DYWIDAG-Systems International Pty. Ltd. 25 Pacific Highway Bennetts Green, NSW 2290, Australia Phone +61-2-49 48 90 99 Fax +61-2-49 48 99 56 E-mail dsi@dywidag.com.au www.dsiminingproducts.com/au Please note: This brochure serves basic information purposes only. Technical data and information provided herein shall be considered non-binding and may be subject to change without notice. We do not assume any liability for losses or damages attributed to the use of this technical data and any improper use of our products. Should you require further information on particular products, please do not hesitate to contact us. ALWAG (AM 952/79), AT (AM 6138/2003), AT-SYSTEM (AM 6139/2003), DYWI (4197869), LSC (AM 4326/2008), OMEGA-BOLT (3258282), POWER SET (AM 6163/2002), and TUBESPILE (AM 4328/2008) are registered trademarks of DYWIDAG-Systems International GmbH. Combi Coat and CT-Bolt TM are trademarks of Vik Ørsta AS. DYWIDAG-Systems International GmbH is a partner of Vik Ørsta AS. Austria Argentina Australia belgium Bosnia and herzegovina Brazil Canada Chile Colombia Costa Rica Croatia Czech republic Denmark Egypt estonia Finland France Germany Greece GUATEMALA HONDURAS Hong Kong Indonesia Italy Japan Korea Lebanon Luxembourg Malaysia Mexico Netherlands Norway Oman Panama Paraguay Peru POLAND Portugal Qatar Saudi Arabia singapore South Africa Spain Sweden Switzerland Taiwan Thailand Turkey United Arab Emirates United kingdom Uruguay USA Venezuela 04314-1/08.12-web he