Quick Answer
Calculate Iwasaki et al. (1982) Soil Liquefaction Potential Index (LPI)
Calculator
Need Equipment or a Supplier for This Project?
Use your calculation result to continue with equipment selection, supplier discovery, engineering support, or project evaluation.
Find Engineering Solutions →Result Interpretation
Iwasaki et al. (1982) Soil Liquefaction Potential Index (LPI) calculator computes Soil Liquefaction Potential Index (LPI) in dimensionless using the defined engineering formula and the input values provided. Soil Liquefaction Potential Index (LPI) is expressed in dimensionless. No universal acceptance threshold is defined by this calculator.
Worked Example
Verified calculation
Given:
- Average Factor of Safety Against Liquefaction = 0.8
- Depth-Weighted Sum of Liquefaction Resistance Ratio (F × z) = 42
Expected Result:
- Soil Liquefaction Potential Index (LPI) = 0
Engineering Interpretation:
Under the given input conditions, the calculated result is: Soil Liquefaction Potential Index (LPI) = 0 dimensionless.
The actual numerical result is computed by the Runtime engine using the persisted tool definition. The values shown here come from deterministically validated test cases.
Formula / Method
LPI = 0.5 * (1 - tanh(0.2 * (100 - average factor of safety against liquefaction))) * (F × z / 20.0)Formula family: formula_geology_soil_liquefaction_potential_index_lpi_calculator
Variables
| Symbol | Label | Role | Description |
|---|---|---|---|
| F_avg | Average Factor of Safety Against Liquefaction | INPUT | Average Factor of Safety Against Liquefaction |
| sum_Fz | Depth-Weighted Sum of Liquefaction Resistance Ratio (F × z) | INPUT | Depth-Weighted Sum of Liquefaction Resistance Ratio (F × z) |
| Soil Liquefaction Potential Index (LPI) | Soil Liquefaction Potential Index (LPI) | OUTPUT | Soil Liquefaction Potential Index (LPI) |
Calculation Steps
- Enter the average factor of safety against liquefaction in dimensionless.
- Enter the depth-weighted sum of liquefaction resistance ratio (f × z) in m.
- Step 1: Compute soil liquefaction potential index (lpi).
- Read the soil liquefaction potential index (lpi) (dimensionless) from the results.
Engineering Summary
Calculate Iwasaki et al. (1982) Soil Liquefaction Potential Index (LPI)
Frequently Asked Questions
What does this calculator calculate?
The Iwasaki et al. (1982) Soil Liquefaction Potential Index (LPI) calculator estimates Soil Liquefaction Potential Index (LPI) based on the input parameters you provide
Why is average factor of safety against liquefaction important in this calculation?
average factor of safety against liquefaction is directly proportional to soil liquefaction potential index (lpi). When you enter average factor of safety against liquefaction in dimensionless, the calculator uses it in the engineering formula to compute the output
How should I interpret the result soil liquefaction potential index (lpi)?
The calculator outputs soil liquefaction potential index (lpi) in dimensionless. The result is computed directly from the input values using the defined engineering formula
What units should I use for the inputs?
Enter each value in the units shown next to the input field: Average Factor of Safety Against Liquefaction (dimensionless), Depth-Weighted Sum of Liquefaction Resistance Ratio (F × z) (m). Make sure all inputs use the specified units for consistent results
What assumptions does this calculator use?
This calculator uses automatically validated engineering formulas. Results are approximate and should be validated against site-specific conditions, applicable codes, and professional engineering judgment
Browse More Tools
Explore the full index of engineering calculators on this vertical site.