Brash Mat Ground Pressure Reduction Factor

Compare declared normal-load pressure under bare versus independently supplied effective brash-mat spread areas; ideal uniform pressure model excludes mat stiffness, failure and safe trafficability.

Description

A larger effective load-spread area lowers an ideal uniform ground pressure.

A larger effective load-spread area lowers an ideal uniform ground pressure. A brash mat's effective area must be established independently of this pressure arithmetic.^[1]

Compare declared normal-load pressure under bare versus independently supplied effective brash-mat spread areas; ideal uniform pressure model excludes mat stiffness, failure and safe trafficability.

When to use Brash Mat Ground Pressure Reduction Factor

Use this tool to compare declared normal-load pressure under bare versus independently supplied effective brash-mat spread areas; ideal uniform pressure model excludes mat stiffness, failure and safe trafficability.

Gather the tree inventory, plot measurements or model parameters. Check diameter, area, time and moisture conventions; keep paired observations aligned.

How to use Brash Mat Ground Pressure Reduction Factor and understand its results

Gather the tree inventory, plot measurements or model parameters. Check diameter, area, time and moisture conventions; keep paired observations aligned.
Enter appliedNormalLoadsN, bareContactAreasM2, effectiveMatLoadSpreadAreasM2 using the field table and calculation rules, then run the tool.
Read bareGroundPressuresPa, matModelGroundPressuresPa, pressureReductionFactors, pooledPressureReductionFactor. 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
appliedNormalLoadsN	Applied normal loads n	list of number	Required
bareContactAreasM2	Bare contact areas m2	list of number	Required
effectiveMatLoadSpreadAreasM2	Effective mat load spread areas m2	list of number	Required

Pair nonnegative normal loads in N with positive bare/mat m², require mat area≥bare area and positive total load. Return both Pa lists, per-record area reduction factors and pooled total-mat/total-bare area ratio.

Paired lists must be nonempty and have equal lengths.

pressure=normal load/area; reduction factor=effective mat area/bare area

Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.

Output field	Meaning	Value type
bareGroundPressuresPa	Bare ground pressures Pa	list of number
matModelGroundPressuresPa	Mat model ground pressures Pa	list of number
pressureReductionFactors	Pressure reduction factors	list of number
pooledPressureReductionFactor	Pooled pressure reduction factor	number

json

{
  "input": {
    "appliedNormalLoadsN": [
      100,
      200
    ],
    "bareContactAreasM2": [
      1,
      1
    ],
    "effectiveMatLoadSpreadAreasM2": [
      2,
      4
    ]
  },
  "output": {
    "bareGroundPressuresPa": [
      100,
      200
    ],
    "matModelGroundPressuresPa": [
      50,
      50
    ],
    "pressureReductionFactors": [
      2,
      4
    ],
    "pooledPressureReductionFactor": 3
  }
}

Limitations and assumptions

Mat stiffness, failure and soil response are excluded. The pooled factor is an area ratio, not a load-weighted pressure ratio.

Numeric inputs and returned numeric values must be finite; an unrepresentable returned value produces an error. Numeric lists are limited to 100,000 entries; the rules above may require smaller limits. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.

Alternative or Complementary methods

Use Skid Trail Bulk Density Compaction Percent Increase: Compare matched dry bulk-density cores using paired and physical-volume-weighted contrasts, preserving apparent decompaction; unlike simple porosity conversion, no compaction damage or trafficability conclusion. For a complementary task, use Maximum Rut Depth Operational Limit Checker: Audit measured rut-depth exceedances and represented trail-length fraction under caller operational limit; equality is allowed and no ecosystem/access safety or regulation is embedded.

References

Brash Mat Ground Pressure Reduction Factor — tool.io

Similar or alternative tools

Skid Trail Bulk Density Compaction Percent Increase
Compare matched dry bulk-density cores using paired and physical-volume-weighted contrasts, preserving apparent decompaction; unlike simple porosity conversion, no compaction damage or trafficability conclusion.
Maximum Rut Depth Operational Limit Checker
Audit measured rut-depth exceedances and represented trail-length fraction under caller operational limit; equality is allowed and no ecosystem/access safety or regulation is embedded.