Longwall Support Resistance
Screen longwall resistance against supplied pressure×area factored load; canopy contact, dynamic roof behavior and hydraulic reliability are external.
Description
Longwall support resistance can be screened against a supplied roof-pressure load acting over a tributary area.
Longwall support resistance can be screened against a supplied roof-pressure load acting over a tributary area. A caller-selected factor scales that load before comparing available resistance.1
The tool returns requiredResistanceKn, resistanceMarginKn, meetsCallerLoad. The computation uses supplied observations and parameters rather than acquiring measurements.
When to use Longwall Support Resistance
Use this for the following task: Screen longwall resistance against supplied pressure×area factored load; canopy contact, dynamic roof behavior and hydraulic reliability are external. Prepare observations and calibration parameters on the same unit and reporting basis.
How to use Longwall Support Resistance and understand its results
- Prepare the measured quantities and supplied model parameters. Match the units and align paired lists before calculating.
- Enter roofDesignPressureMpa, tributaryRoofAreaM2, designFactor, availableSupportResistanceKn according to the field table, then run the tool.
- Read requiredResistanceKn, resistanceMarginKn, meetsCallerLoad. Use the calculation below to interpret the selected mean or the model’s signs, units and comparison flags.
- Review the supplied assumptions and calibration before comparing or reporting the result.
| Input field | Meaning | Value type and bounds | Requirement |
|---|---|---|---|
| roofDesignPressureMpa | Roof design pressure mpa | number | Required |
| tributaryRoofAreaM2 | Tributary roof area m2 | number | Required |
| designFactor | Design factor | number | Required |
| availableSupportResistanceKn | Available support resistance kn | number | Required |
Use a positive area, nonnegative pressure and available resistance, and a design factor at least one. Equality meets the supplied load.
required kN = 1000×pressure MPa×area m²×factor; margin = available−required The symbols and boundary conditions refer to the supplied fields and the implementation described above.
| Output field | Meaning | Value type |
|---|---|---|
| requiredResistanceKn | Required resistance kn | number |
| resistanceMarginKn | Resistance margin kn | number |
| meetsCallerLoad | Meets caller load | boolean |
{
"input": {
"roofDesignPressureMpa": 0.5,
"tributaryRoofAreaM2": 8,
"designFactor": 1.5,
"availableSupportResistanceKn": 5000
},
"output": {
"requiredResistanceKn": 6000,
"resistanceMarginKn": -1000,
"meetsCallerLoad": false
}
}Limitations and assumptions
The pressure, area and factor require an appropriate design basis. Canopy contact, transient roof behavior and hydraulic reliability are outside this arithmetic screen.
Numerical inputs must be finite. Input-shape and calculation checks do not establish measurement quality or the validity of a supplied calibration.
Alternative or Complementary methods
Choose Ground Support Interaction when you need its operation: Intersect piecewise-linear supplied ground/support curves within bounds; missing, multiple and coincident equilibria are errors, not stability certifications. Choose Ground Reaction Curve for the complementary operation: Evaluate calibrated linear-unloading ground reaction with a residual floor; not an elastoplastic solution or an uncalibrated prediction.
Background reference: Pillar and Roof Span Design Guidelines for Underground Stone Mines.
References
-
Pillar and Roof Span Design Guidelines for Underground Stone Mines — NIOSH, Centers for Disease Control and Prevention
Similar or alternative tools
- Ground Support Interaction
Intersect piecewise-linear supplied ground/support curves within bounds; missing, multiple and coincident equilibria are errors, not stability certifications.
- Ground Reaction Curve
Evaluate calibrated linear-unloading ground reaction with a residual floor; not an elastoplastic solution or an uncalibrated prediction.