Lava Tube Roof Thickness Stability Checker
Screen a caller plate-bending lava-tube roof idealization and invert allowable stress to thickness; coefficient depends on support geometry, and hot/cracked roof stability or access safety is not certified.
Description
A spanning roof can develop bending stress under distributed load.
A spanning roof can develop bending stress under distributed load. A plate coefficient represents the chosen support geometry.
Screen a caller plate-bending lava-tube roof idealization and invert allowable stress to thickness; coefficient depends on support geometry, and hot/cracked roof stability or access safety is not certified.
When to use Lava Tube Roof Thickness Stability Checker
Use this tool to screen a caller plate-bending lava-tube roof idealization and invert allowable stress to thickness; coefficient depends on support geometry, and hot/cracked roof stability or access safety is not certified.
Gather the relevant observations and fitted model parameters. Use the stated units and time basis; keep paired observations aligned.
How to use Lava Tube Roof Thickness Stability Checker and understand its results
- Gather the relevant observations and fitted model parameters. Use the stated units and time basis; keep paired observations aligned.
- Enter unsupportedRoofSpanM, roofThicknessM, distributedDownwardLoadPa, plateBendingCoefficient, callerAllowableTensileStressPa using the field table and calculation rules, then run the tool.
- Read modelBendingStressPa, allowableStressMarginPa, modelRequiredRoofThicknessM. The explanation below defines the units, signs, ordering and any flags or placeholder values.
- If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.
| Input field | Meaning | Value type; see rules below | Requirement |
|---|---|---|---|
| unsupportedRoofSpanM | Unsupported roof span m | number | Required |
| roofThicknessM | Roof thickness m | number | Required |
| distributedDownwardLoadPa | Distributed downward load Pa | number | Required |
| plateBendingCoefficient | Plate bending coefficient | number | Required |
| callerAllowableTensileStressPa | Caller allowable tensile stress Pa | number | Required |
Use positive span, thickness, plate coefficient and allowable tensile stress, with nonnegative load. Return modeled stress, allowable-minus-modeled margin and the thickness that would meet the supplied allowable stress.1
stress = coefficient × load × (span/thickness)² Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| modelBendingStressPa | Model bending stress Pa | number |
| allowableStressMarginPa | Allowable stress margin Pa | number |
| modelRequiredRoofThicknessM | Model required roof thickness m | number |
{
"input": {
"unsupportedRoofSpanM": 2,
"roofThicknessM": 0.5,
"distributedDownwardLoadPa": 1000,
"plateBendingCoefficient": 0.75,
"callerAllowableTensileStressPa": 10000
},
"output": {
"modelBendingStressPa": 12000,
"allowableStressMarginPa": -2000,
"modelRequiredRoofThicknessM": 0.5477225575051661
}
}Limitations and assumptions
Hot, cracked rock and support conditions need independent assessment; no access or stability certificate is produced.
Numbers and computed results must be finite; overflow produces an error. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.
Alternative or Complementary methods
Use Roof Load Ash Collapse Risk Checker: Audit independently measured wet ash loads against caller remaining zone capacities and sum physical ash mass; capacities must account for other loads and this is not a collapse forecast or structural/access-safety certificate. For a complementary task, use Hydrothermal Alteration Weakening Factor: Summarize paired laboratory alteration strength changes with both pooled-strength and unweighted paired conventions; retained fractions above one and negative weakening are preserved, not assumed unsafe flanks.
References
Similar or alternative tools
- Roof Load Ash Collapse Risk Checker
Audit independently measured wet ash loads against caller remaining zone capacities and sum physical ash mass; capacities must account for other loads and this is not a collapse forecast or structural/access-safety certificate.
- Hydrothermal Alteration Weakening Factor
Summarize paired laboratory alteration strength changes with both pooled-strength and unweighted paired conventions; retained fractions above one and negative weakening are preserved, not assumed unsafe flanks.