A Combined Rock Bolt System for Immediate Support and Permanent Reinforcement
Cuttable Combination Rock Bolt is an integrated ground support system combining mechanical point anchoring and full-length grouting anchorage for underground engineering projects. It ensures safety and speeds up construction cycles.
Combination Rock Bolt System
CT-Bolt combines two support mechanisms in one bolt system: immediate mechanical anchoring and long-term grouted reinforcement.
Mechanical Point Anchoring
The expansion anchor head is activated by pre-tensioning, forming a reliable point anchorage with the borehole wall immediately after installation.
Full-Length Grouting Anchorage
After installation, grout can be injected through the bolt system to fill the gap between bolt and borehole, creating a permanent full-length anchoring structure.
ONE BOLT SYSTEM, TWO SUPPORT STAGES
CT-Bolt provides immediate mechanical anchoring for early ground control and full-length grouting reinforcement for long-term underground stability.
Ready to upgrade your underground support system?
Learn MoreCommon Ground Support Problems in Tunneling, TBM Excavation and Permanent Underground Projects
Traditional rock bolt systems often slow down construction, interrupt excavation rhythm, restrict TBM operations, and create long-term durability concerns in demanding underground environments.
Waiting for Grout Curing
Traditional grouted rock bolts require curing time, delaying support activation. Result: Support cannot work immediately.
Support and Excavation Cannot Run in Parallel
Coordination is hard when waiting for curing. Result: Construction rhythm becomes slower.
Steel Bolts Limit TBM Cutting
Steel bolts interfere with TBM cutterheads. Result: Higher cutterhead risk.
Long-Term Durability Risk
Corrosion risks in harsh environments. Result: Reliability reduced.
High Maintenance Costs
Frequent inspections and repairs required for non-integrated systems. Result: Increased operational expenditure.
Complex Installation Logistics
Managing multiple components and curing stages complicates site management. Result: Higher logistical overhead.
Why these problems matter
Get Technical SolutionsWhy CT-Bolt Is Valuable for Modern Underground Support Projects
CT-Bolt combines immediate mechanical anchoring with long-term grouted reinforcement, improving safety and efficiency.
Immediate Load-Bearing Support
Works immediately without waiting for grout curing. Immediate Support, No Curing Wait.
Post-Grouting for Permanent Reinforcement
Creates full-length anchorage for structural stability. Post-Grouting, Permanent Support.
Support and Excavation Parallelism
Faster workflow coordination. Faster Workflow, Parallel Operation.
Active Ground Control
Controls rock earlier to reduce loosening risk. Ground Stability, Active Control.
Cost-Effective Lifecycle
Reduced maintenance and faster cycles lower total project costs. Value: Lower OpEx.
Streamlined Logistics
All-in-one system simplifies transportation and on-site handling. Value: Logistical Efficiency.
Why CT-Bolt matters in underground engineering
View Technical AdvantagesHow CT-Bolt Works from Immediate Anchoring to Permanent Grouted Support
CT-Bolt works in two stages: immediate mechanical point anchoring after installation, followed by full-length post-grouting reinforcement for long-term underground stability.
Stage 1: Immediate Point Anchoring
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Insert: Position the bolt within the pre-drilled borehole.
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Activate Expansion Head: Torquing the nut expands the head against rock walls.
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Apply Pre-Tension: Tensioning provides active pressure to stabilize fractures.
Result: Immediate load-bearing capacity secured upon installation.
Stage 2: Full-Length Grouting
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Connect Grouting: Utilize the specialized hemispherical nut for grout injection.
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Inject Grout: Fill the borehole and the hollow core for full bonding.
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Form Permanent Anchorage: Hardened grout creates a monolithic structure.
Result: System upgrades to permanent, corrosion-resistant support.
Drill
Install/Anchor
Early Control
Inject Grout
Permanent
Discover how our two-stage system optimizes your workflow
Learn More About PrincipleCT-Bolt Options for Immediate Support, TBM Compatibility and Permanent Ground Reinforcement
We provide multiple Cuttable Combination Rock Bolt solutions for standard underground support, TBM tunneling, corrosion-resistant applications, and project-specific permanent reinforcement requirements.
Steel CT-M20
Standard high-tensile steel CT-Bolt designed for versatile ground control and reliable point anchoring.
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Steel CT-M22
Higher-capacity structural steel variant engineered for heavy-duty tunnel support and deep rock reinforcement.
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GFRP Cuttable CT Bolt
Glass Fiber Reinforced Polymer body, providing a TBM-friendly solution that can be easily excavated.
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TBM Cuttable CT Bolt
Specialized construction solution for TBM projects, ensuring continuous advance without cutter head damage.
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Anti-Corrosion CT Bolt
Enhanced coating technology for corrosive mining environments, ensuring 50+ years of design life.
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Project-Custom CT Bolt
Tailor-made bolt specifications for unique geotechnical conditions or specific project requirements.
Send RequirementsNot Sure Which CT-Bolt Fits Your Project?
Get Product RecommendationIntegrated CT-Bolt Components for Immediate Anchoring and Long-Term Grouting Support
The Cuttable Combination (CT) Rock Bolt is engineered for high-performance ground support in mining and tunneling. Its dual-function design provides immediate point-anchor stability and full-length permanent grouted reinforcement.
Steel / GFRP Bolt Body
Available in high-tensile steel or cuttable Glass Fiber Reinforced Polymer (GFRP) for TBM excavation compatibility.
End Expansion Anchor Head
Mechanical expansion mechanism that provides immediate load-bearing capacity upon installation torque.
Polyethylene Sheath
Corrosion protection layer that ensures the integrity of the bolt body in aggressive acidic or saline environments.
Grouting Interface
Precision-engineered inlet for high-pressure grout injection to fill the annulus and rock fractures.
Plate
Heavy-duty load distribution plate designed to conform to uneven rock surfaces and maintain surface tension.
Anchoring Nut
High-torque drive nut that activates the expansion anchor and secures the bearing plate against the rock face.
Need a detailed structural breakdown for your engineering submittal? Download our full component documentation.
Request Component Data SheetSteel CT-M20 / CT-M22 and GFRP Cuttable CT-Bolt Specification System
Select the optimal anchoring system based on ground conditions, required load capacity, and excavation methodology. All specifications meet ISO standards for mining equipment.
Steel CT-M20
Steel CT-M22
GFRP Cuttable
| Specification Parameter | CT-M20 | CT-M22 | CT-GFRP |
|---|---|---|---|
| Material Grade | B500B / Gr 75 | B500B / Gr 75 | Composite |
| Elongation (%) | ≥ 12% | ≥ 12% | ≤ 2% |
| Outer Ø (mm) | 20 mm | 22 mm | 25 mm |
| Thread Pitch | R20/10 | R22/10 | Full Thread |
| Corrosion Prot. | Galvanized/PE | Galvanized/PE | Inherent |
Configure your custom bolt system today. Our engineering team can customize length, thread type, and coating based on your specific geological survey data.
Get Engineering QuoteA GFRP Cuttable CT-Bolt System Designed for TBM Tunneling and Advance Ground Support
The GFRP Cuttable CT-Bolt is engineered for tunneling projects where advance support is required before TBM breakthrough, while maintaining cutterhead-friendly cutting performance.
GFRP Cuttable Body
High-strength GFRP material allows for structural support while being easily sheared by TBM cutters.
Direct Cutterhead Cutting
Cutterhead can directly pass through the supported zone without halting excavation cycles.
Reduced Equipment Risk
Significant reduction in tool wear and risk of damage to the TBM cutterhead disc cutters.
Advance Support
Ideal for providing immediate stability in unstable faces, faults, and broken geological zones.
GFRP Mechanical Strength: 1000+ MPa tensile strength, maintaining cuttable ductility for TBM interference.
TBM EXCAVATION CONTINUITY WORKFLOW
Identify Weak Ground
Install GFRP CT-Bolt
Maintain Ground Stability
TBM Cutterhead Cuts Through
Continue Tunneling
This solution helps combine advance support needs with TBM excavation continuity in complex tunneling conditions.
Learn More About TBM SolutionsMulti-Layer Protection System for Long-Term Underground Service Life
CT-Bolt can be designed with polyethylene sheath protection, grouted encapsulation, and different surface treatment options to improve durability.
Black Steel Option
Standard high-tensile steel for temporary applications or environments with minimal corrosion risk.
Hot-Dip Galvanized
Enhanced protection for humid and moderately corrosive underground environments according to ISO 1461.
Combi Coat® Composite
The ultimate epoxy-powder coating system for extremely high-corrosion or permanent support infrastructure.
Double Protection
PE Sheath combined with grouted encapsulation provides 50-150 years of design service life.
Designed for long-term underground durability in water tunnels, sewage tunnels, and permanent caverns.
Request Durability Data
Standard CT-Bolt Installation Process from Drilling to Post-Grouting
A sophisticated two-stage logic ensuring immediate excavation support followed by permanent structural reinforcement through high-pressure grouting.
01. Borehole Drilling
Percussive or rotary drilling to specified depth and diameter in rock mass.
02. Depth Allowance
Verification of hole cleanliness and depth to accommodate the full bolt length.
03. Bolt Insertion
Manual or mechanized insertion of the CT-Bolt assembly into the prepared borehole.
04. Immediate Mechanical Anchoring
Expansion of the anchor head providing instantaneous point-anchor support.
05. Pre-Tension and Plate Contact
Tightening the nut to compress the bearing plate against the rock surface.
06. Post-Grouting Operation
Injection of cementitious grout through the tube to fully encapsulate the bolt.
From Immediate Support to Permanent Reinforcement
View Installation GuideReliable CT-Bolt Quality Control from Factory Inspection to Grouting Verification
Ensure maximum safety and long-term performance with our rigorous quality control and precise grouting verification processes.
Immediate Anchoring
Testing of mechanical expansion torque to ensure reliability before grouting phases.
Grouting Channels
Internal inspection of the injection tube to ensure unobstructed fluid flow through the bolt.
Reverse Filling
Validation of the bottom-up filling sequence to eliminate air pockets and ensure full encapsulation.
Grout Overflow Check
Visual confirmation of grout exiting the borehole mouth as a proxy for successful filling.
Dimension Inspection
Rigorous geometric checks on thread precision, sleeve thickness, and anchor head expansion.
Batch Consistency
Material traceability and heat number tracking for every production lot to ISO standards.
GROUTING VERIFICATION PROCESS FLOW
Injection Start
Pump connection
Tube Filling
Internal flow
Bottom Entry
Rock contact
Upward Rise
Annulus filling
Overflow
Full verification
QUALITY CONTROL FOR RELIABLE PERMANENT SUPPORT
Download QC ManualCombination Rock Bolt Application Scenarios
Providing robust dual-stage reinforcement across diverse global infrastructure and mining environments where standard support systems fall short.
Deep Hard Rock Mining
Supplying immediate stability to drifts under intense lithostatic pressure, enabling continuous advancement in deep-level extraction zones without waiting for grout to cure.
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Squeezing Ground Tunnels
Pre-tensioned mechanical anchors control early rock deformation, followed by full-grouting to solidify the surrounding weak strata and prevent long-term structural failure.
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Subsea Tunnel Projects
Dual protection utilizing polyethylene sleeves and high-grade grout encapsulation to guarantee permanent structural integrity against high-pressure saline groundwater.
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TBM Fault Zone Recovery
Rapid deployment of GFRP cuttable variants allows crews to secure collapsible rock faces ahead of the TBM without damaging cutterheads during forward progress.
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Hydropower Caverns
Creating deep, permanent anchorage points in massive subterranean power stations to prevent arch collapse during sequential cavern enlargement.
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Mountain Highway Tunnels
Reliable reinforcement for drill-and-blast operations transitioning between hard granite and weathered rock bands, ensuring consistent progression safety.
View ApplicationNeed to assess whether combination rock bolts fit your specific geological challenges?
Request Project ConsultationGet Custom CT-Bolt Solutions Directly from China Factory
Send us your tunnel type, borehole size, support depth, or TBM cutting requirements. Our engineering team will help recommend a suitable Cuttable Combination Rock Bolt solution.
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Factory Direct CT-Bolt Supply
Direct communication with a China manufacturer for faster quotation and direct-from-source pricing.
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Steel & GFRP Options
Steel CT-M20/M22 and GFRP cuttable options tailored for TBM and permanent ground support.
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Tailored Geotechnical Support
Bespoke bolt lengths, diameters, and coatings engineered for weak rock, caverns, and mining roadways.
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Technical & Export Support
Comprehensive support for batch inspection, test reports, and global project delivery.
Request Direct Factory Quotation
Connect directly with our engineering team to get custom-designed solutions that minimize downtime and cut procurement costs.