Coal mine roadways are often excavated through stratified and heterogeneous rock masses. Soft roofs, bedding planes, fractured ribs, groundwater and stress from mining operations can create stability challenges in underground openings.
Roof and rib support systems help strengthen surrounding rock strata, control loose rock and allow safe passage through underground roadways. Roof bolts and cable bolts are installed to reinforce rock masses. Bearing plates, steel mesh and rock straps are installed to help contain loose rocks at the excavation surface.
Wanfeng produces roof and rib support components to meet your specifications. Our roof and rib support products are made to your drawings and technical specifications, as well as installation requirements.
Weak or Stratified Roof Rock
Coal mine roofs can be composed of shale, mudstone, sandstone or other stratified layers. Separation along bedding planes can cause sagging, cracking or localized roof failure.
Systematic roof bolting can effectively bridge weaker layers together creating a stronger overall structure.
Loose and Broken Ribs
Coal and surrounding strata may break away from roadway ribs due to excavation, mining induced stress or variations in moisture conditions. Mesh and rib bolts help to secure loosened material and minimize exposure to rib falls.
Fluctuating Ground Stress
Mining-induced stress concentrations can change as development progresses, especially near intersections, coal pillars, longwall gateroads and entries near previously-mined areas. Support should be installed with appropriate load capacities and deformation properties.
Large Roadways and Cross-Cuts
Roadway intersections, equipment chambers and loading pockets may require longer spans of exposed support than typical development headings. Additional reinforcement or higher-capacity support may be necessary.
Moisture
Groundwater or high humidity conditions can impact the performance of steel support components over time. Galvanized components or alternative corrosion protections may be specified where necessary.
Timely Mine Development
Installation of roof and rib support is one aspect of the mine development cycle. Support components with uniform dimensions and compatibility with bolting equipment allows for streamlined underground installation.
Component Compatibility
Correct fit between bolt threads, nuts, couplers and bearing plates is essential. Poorly matched components can lead to installation issues or reduced support performance.、
In ground support for coal mines, roof reinforcement is generally installed along with rib retention systems. Wanfeng provides the components necessary to build these systems based on the customer’s specification. Support systems may include:
1. Roof bolts – These anchor into the immediate roof.
2. Rib bolts – These are installed into the sidewalls of the roadway.
3. Cable bolts – Longer length anchors used where required for intersections or other high-stress areas.
4. Bearing plates / Steel straps – Metal plates that are installed across the face to help distribute the load.
5. Mesh – Wire mesh can be installed across the roof or ribs between bolts to help contain smaller rocks.
6. Hardware – Nuts and coupling pins used to tension and secure the system.
Each support job is different and will use a combination of the above products. Tunnel geometry, geologic conditions, mining method, expected loads, installation method and desired lifespan will all factor into the final support design. Support design should be done by a mining or geotechnical engineer familiar with the mining conditions.
1.Roof Bolts
Roof bolts are inserted into holes drilled into the mine roof to help stabilize weak or fractured rock layers. They can be mechanically anchored, resin anchored or fully grouted depending on the approved support design.
Wanfeng has the capability to produce roof bolts in various diameters, lengths, thread profiles and steel grades per confirmed specifications.
Common uses:
* Development roadway roof support
* Gateroad reinforcement
* Mine entry support
* Underground intersection support
* Local weak- roof reinforcement
* Roof rehabilitation
Available roof bolt configurations may include:
* Threaded rebar roof bolts
* Resin-anchored roof bolts
* Fully threaded roof bolts
* Forged- head bolts
* Mechanical anchor bolts
* Customized roof bolts
Important product parameters to consider when selecting a roof bolt:
* Bolt diameter
* Overall length
* Thread type and thread length
* Steel grade
* Yield and tensile strength requirements
* Head or nut configuration
* Surface treatment
2. Rib Bolts
Rib bolts help support unstable coal ribs and roadway sidewalls. Mesh, plates, or straps are commonly installed in conjunction with rib bolts to help control loose materials.
Common uses:
* Coal roadway rib support
* Sidewall stabilization
* Gateroad rib reinforcement
* Intersection support
* Rib rehabilitation
Rib-bolt lengths and configurations should be selected based on assessed rib conditions, expected rib deformation and approved mine support design.
3. Cable Bolts
Cable bolts are used to provide longer, deeper support than traditional roof bolts. Cable bolts may be suitable to stabilize geological features that extend beyond the zone of influence of a conventional roof bolt, or in underground openings that require a wider support reach.
Common uses:
* Wide roadway intersections
* Equipment chambers and loading pockets
* Longwall gateroad support
* Weak or separated roof zones
* Deep roof support
* Areas requiring mine rehabilitation
Cable-bolt configurations can vary by strand structure, length, anchoring method and whether grouting is required. Load capacities will vary based on applied design parameters.
4. Mine Support Mesh
Mesh is installed over the roof or ribs and works with bolts and bearing plates to retain loose coal and rock between reinforcement points.
Mesh can be supplied in different sizes, wire diameters, aperture dimensions and surface treatment options.
Common uses:
* Roof surface retention
* Coal rib support
* Development roadway support
* Intersection reinforcement
* Loose-rock containment
* Mine rehabilitation
Mesh options may include:
* Welded wire mine mesh
* Galvanized support mesh
* Custom cut mesh panels
* Reinforced mesh panels
If flame resistance, antistatic performance, or any other mine-specific certification is required, the appropriate standard and certification parameters must be verified before requesting a quote.
5. Bearing Plates
Bearing plates are placed over roof bolts to help transfer load to the surrounding roof or rib surface and help secure mesh or straps.
Different bearing plate profiles can be selected based on the overall support design, mine surface conditions and roof bolt configuration.
Options may include:
* Flat bearing plates
* Domed bearing plates
* Ribbed/profiled plates
* Combination plates
* Galvanized plates
* Custom stamped plates
Parameters that can be customized to your specifications include:
* Length and width
* Plate thickness
* Center hole diameter
* Plate profile
* Material grade
* Surface treatment
6. Steel Straps
Steel straps can be installed across the roof or ribs to connect adjacent reinforcement points and help distribute applied loads across a wider surface area.
Straps are commonly used in the following applications:
* Roof support for layered or fractured roofs
* Roadway intersection reinforcement
* Support and load distribution for mesh
* Localized crack / bedding control
Strap length, width, thickness, hole spacing and surface treatment can be customized to your specifications when applicable.
7. Nuts, Couplers and Accessories
Correctly matched accessories allow for efficient installation and reliable performance of the support system.
Available accessory items:
* Hex nuts
* Spherical nuts
* Flange nuts
* Threaded couplers
* Washers
* Mesh fasteners
* Bolt installation accessories
* Custom metal fabrications
Thread profile(s) and dimensional tolerances should be verified to ensure compatibility with corresponding roof bolts and installation equipment.
| Ground condition or application | Typical requirement | Relevant product categories |
| Layered roof with bedding separation | Reinforcement across multiple layers | Roof bolts, plates and straps |
| Loose roof material | Reinforcement and surface retention | Roof bolts, steel mesh and plates |
| Unstable roadway ribs | Rib reinforcement and containment | Rib bolts, mesh and plates |
| Wide intersection or chamber | Longer and deeper reinforcement | Cable bolts and surface support |
| Wet or humid roadway | Improved corrosion protection | Galvanized or coated components |
| Fast development cycle | Consistent, equipment-compatible products | Roof bolts, nuts and matched plates |
| High-stress or deforming area | Verified load and deformation capacity | Site-specific yielding or dynamic products |
| Rehabilitation area | Reinforcement of existing support | Bolts, cable bolts, mesh and straps |
NOTE: This chart is intended to show general guidance only. Project specific support needs should be based on geotechnical conditions and engineering analysis.
Uses include supplying Wanfeng ground support products for:
Products needed by coal mines and ground support distributors must often comply with predetermined support plans, bolting equipment and local mining specifications.
Wanfeng can assess the feasibility of custom specifications with drawings, samples or written technical specifications.
The following attributes are available for customization:
Customers wishing to produce customized products need to provide detailed drawings, dimensions tolerances, material specifications and performance requirements.
Dimensions and interchangeability of ground support equipment components should be maintained between production lots. Wanfeng follows manufacturing and inspection processes based on ordered requirements.
Processes may consist of:
1. Over 10 Years Production Experience
With years of manufacturing experience, we know how to appreciate dimensional consistency, thread match, and stable batch production.
2. One-Stop Support Components
Our customers are able to source roof bolts, cable bolts, mesh, bearing plates, straps, nuts and couplers from one responsible supplier.
3. Made to Your Specifications
We can manufacture products to your drawing, sample or verified technical specifications.
4. Consistent Batch Quality
Our production and inspection processes allow us to ensure batch quality matches from order to order for large volume contracts.
5. Supply International Markets
We work with export customers to provide packaging, product labeling and delivery coordination.
6. OEM & Distributor Partners
Wanfung collaborates with mining companies, importers, distributors and existing ground support companies who need a long-term manufacturer.
Technical information allows us to determine product suitability and process your quotation faster and more accurately.
Please include::
Q1: What is the difference between roof support and rib support?
Roof support refers to ground support installed for the express purpose of supporting strata above a mine roadway. Rib support is installed into the sidewalls of the roadway for control of loose coal or rock. Roof & rib supports can utilize bolts, mesh, plates, and straps. Sizes and spacing vary based on local ground conditions.
Q2: What products are typically used for coal mine roof support?
Roof bolts, cable bolts, bearing plates, steel straps, and mine support mesh are all used in roof support applications. Product selection and design should be completed through the mine’s approved ground control plan.
Q3: How do roof bolts and mesh work together?
Roof bolts help support rock layers surrounding a roadway. Mesh is applied to the exposed roof surface and acts to help contain rock fall or loose material between bolts. Bearing plates are used to secure mesh to the roof and help develop load from the bolts into the surrounding rock.
Q4: When would cable bolts be used in a coal mine?
Similar to roof bolts, cable bolts can be used in roof support applications that require longer support depths. Cable bolts are beneficial for use in wide intersections, equipment chambers, weak- roof areas or other applications where greater depths of reinforcement are beneficial. A geological assessment should always be performed before utilizing cable bolts to ensure they are needed and appropriate for the given conditions.
Q5: Can roof bolts be made to custom dimensions?
Yes. Wanfeng offers customized diameters, lengths, thread, material grades, head styles and coatings. Our Engineering team can evaluate most requests per customer provided drawings or technical specifications.
Q6: Does Wanfeng offer matching nuts and bearing plates for roof bolts?
Matching nuts, couplers, washers, and bearing plates can most likely be provided. Please confirm bolt thread and other accessory dimensions prior to beginning production to ensure compatibility.
Q7: Do you have galvanized roof support products?
Galvanized bolts, mesh, plates, and straps may be available upon request. Please consult with a Wanfeng engineer to determine appropriate coating type/thickness based on the application and related standards.
Q8: Can Wanfeng manufacture roof support products to an existing sample?
Sample-based manufacturing can be accommodated. However, having proper drawings and engineering designs are still recommended by Wanfeng. Material grade, dimensional tolerances, thread profile and engineering load requirements may not always be determinable by a part’s appearance.
Q9: Does Wanfeng design roof support systems for customers?
Wanfeng does not typically design ground support systems. We will supply ground support products as specified by the customer. Roof or rib support systems should be designed by a qualified mining professional or engineer.
Q10: What certifications are needed for coal mine roof support products?
Certification requirements vary widely based on location, client and individual products. Customers should confirm the appropriate standard, testing method and certification documentation required prior to purchasing. Once we have determined the requested certification can be applied to the product, we will gladly produce mining hardware to those specifications.
