In an era of expanding underground infrastructure and complex geotechnical challenges, engineers are constantly seeking reliable, durable, and efficient reinforcement solutions. SupAnchor, a globally recognized manufacturer of advanced anchoring systems, has answered that call with the official release of its SupFRP® GFRP Hollow Injection Bolt—a versatile, high-strength bolt designed to excel in the most demanding ground conditions. From tunneling in soft ground to permanent slope stabilization, this innovative hollow bar anchor combines the functions of a rock bolt and injection system, setting a new benchmark for productivity and long-term performance.
The SupFRP GFRP Hollow Injection Bolt emerged from SupAnchor’s extensive R&D efforts to address a critical need in geotechnical engineering: a lightweight, corrosion‑free anchor that can withstand high injection pressures while providing robust tensile reinforcement. Made from glass‑fiber reinforced polymer (GFRP), the hollow bolt allows grout to be pumped through its core under pressures up to 30 MPa (in select models), ensuring complete filling of the borehole and excellent bonding with the surrounding rock or soil. This full‑grouting capability not only improves load transfer but also protects the anchor from environmental degradation, making it ideal for permanent applications and aggressive ground conditions.
The SupFRP series features a waved‑thread outer profile that maximizes mechanical interlock with the grout, while the hollow core enables efficient injection without requiring a separate grout tube. After installation, the bolt itself becomes part of the load‑bearing system, working in conjunction with a plate and nut to secure the face. The result is a genuine geotechnical reinforcement system that simplifies logistics, reduces installation time, and improves overall project quality.
SupAnchor offers the hollow injection bolt in a comprehensive range of diameters and load capacities, tailored to different ground conditions and engineering demands. Key models and their core specifications are summarized in the table below.
| Model | Outside Diameter (mm) | Guaranteed Tensile Load (kN) | Pressure Resistance (MPa) | Weight (kg/m) |
|---|---|---|---|---|
| H22/230 | 22 | 230 | 18 | 0.58 |
| H25/220 | 25 | 220 | 5 | 0.64 |
| H25/300 | 25 | 300 | 30 | 0.79 |
| H28/320 | 28 | 320 | 5 | 0.88 |
| H32/360 | 32 | 360 | 5 | 1.20 |
| H38/490 | 38 | 490 | 5 | 1.50 |
These parameters highlight the bolt’s exceptional engineering: guaranteed tensile loads up to 490 kN, a tensile E‑modulus of 45 GPa, and an ultimate strain of 2.0%. The waved thread design increases the bonding surface area, while the hollow core with a diameter as small as 8 mm (internal) still permits high‑pressure injection. The GFPR material ensures a low weight—starting at 0.58 kg/m—which dramatically eases handling on site, especially in confined spaces or when manual installation is required. Moreover, GFRP’s inherent cuttability allows the bolt to be trimmed on the fly, a critical advantage in tunneling where protruding ends must be removed quickly.
Corrosion resistance is another standout feature. Unlike traditional steel anchors, the GFRP hollow injection bolt is immune to rust and chemical attack, making it the definitive choice for permanent applications in coastal, acidic, or high‑humidity environments. This longevity reduces lifecycle costs and enhances safety over decades of service.
SupAnchor’s hollow injection bolt is already earning trust across a wide spectrum of geotechnical applications. In tunneling, it serves as a reliable forepole and face support element, particularly in soft or squeezing ground where full grouting prevents loosening and water ingress. For TBM operations, the lightweight, cuttable bolt accelerates cycle times and improves crew safety. On open slopes, the bolt acts as a high‑performance soil nail, integrating with mesh and shotcrete to stabilize cut faces, embankments, and landslide‑prone slopes. Its ability to inject grout under pressure fills fissures and reinforces the ground mass, turning a simple nail into an active geotechnical reinforcement system.
Other niche uses include stabilization of mine openings, foundation pits near sensitive structures, and even seismic retrofitting where ductile yet stiff reinforcement is required. The bolt’s compatibility with all standard cementitious and resin grouts gives engineers the flexibility to design for project‑specific conditions.
The global shift toward sustainable infrastructure and the growing complexity of underground works in urban areas have increased the demand for advanced anchoring solutions. A drill‑and‑grout bolt like the SupFRP GFRP Hollow Injection Bolt directly addresses the industry’s pain points: it reduces the number of components on site, speeds up installation through integrated injection, and eliminates the need for corrosion protection coatings. For contractors on tight schedules, this means fewer delays and lower overall costs. For asset owners, the promise of a maintenance‑free, 100‑year design life is compelling, especially in highway tunnels, rail corridors, and hydropower projects.
Market analysts note that the global geotechnical reinforcement and soil nailing market is projected to grow at a steady pace, driven by rehabilitation of aging infrastructure and expansion of transportation networks. In this context, manufacturers that can deliver certified, high‑performance GFRP anchors stand to gain significant traction. SupAnchor, as a seasoned soil nail system manufacturer and ground anchor bolt factory, is well positioned to capture this opportunity through its comprehensive product line and technical support.
Behind the new hollow injection bolt lies SupAnchor’s unwavering commitment to R&D and quality. The company operates state‑of‑the‑art manufacturing facilities with ISO 9001 and ISO 14001 certifications, and its products are tested to international standards such as EN and ASTM. SupAnchor’s self drilling anchor system and self drilling anchor bolt ranges have already been deployed in landmark projects across Europe, Asia, and the Americas. The addition of the SupFRP GFRP Hollow Injection Bolt reinforces the brand’s reputation for engineering excellence and collaborative problem‑solving with clients.
“Professional, innovative, collaborative” is more than a motto—it is the philosophy that has guided SupAnchor’s evolution from a local manufacturer to a global player. By continuously refining materials and designs, the company ensures that geotechnical challenges—whether in a tunnel beneath a metropolis or a remote mountain slope—are met with reliable, economical, and forward‑thinking solutions.
For project managers and design engineers seeking a fully‑grouted, corrosion‑free anchor that performs under pressure, the SupFRP GFRP Hollow Injection Bolt offers a compelling package: high tensile strength, easy handling, and the confidence of a factory‑backed warranty. As SupAnchor expands its distribution network, this innovative product is set to become a staple in the geotechnical toolkit worldwide.
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