Quick Answer
Calculate EPB Shield Face Stability Safety Margin (Limit Equilibrium)
Calculator
Result Interpretation
EPB Shield Face Stability Safety Margin (Limit Equilibrium) Calculator computes Face Stability Safety Margin in dimensionless using the defined engineering formula and the input values provided.
Worked Example
Verified calculation
Given:
- Cover Depth = 15
- Soil Effective Cohesion = 15000
- Soil Effective Friction Angle = 0.523599
- Soil Unit Weight = 18000
- EPB Chamber Support Pressure = 250000
Expected Result:
- Face Stability Safety Margin = 1.427412295567
Engineering Interpretation:
Under the given input conditions, the calculated result is: Face Stability Safety Margin = 1.427412295567 dimensionless.
The actual numerical result is computed by the Runtime engine using the persisted tool definition. The values shown here come from automatically validated test cases.
Formula / Method
face stability safety margin = (epb chamber support pressure - (soil unit weight * cover depth * (1 - sin(soil effective friction angle)) / (1 + sin(soil effective friction angle)) + soil effective cohesion * cos(soil effective friction angle))) / (soil unit weight * cover depth * (1 - sin(soil effective friction angle)) / (1 + sin(soil effective friction angle)) + soil effective cohesion * cos(soil effective friction angle))Formula family: formula_tunneling_epb_shield_face_stability_safety_margin_checker
Variables
| Symbol | Label | Role | Description |
|---|---|---|---|
| support_pressure | EPB Chamber Support Pressure | INPUT | EPB Chamber Support Pressure |
| soil_unit_weight | Soil Unit Weight | INPUT | Soil Unit Weight |
| depth | Cover Depth | INPUT | Cover Depth |
| friction_angle | Soil Effective Friction Angle | INPUT | Soil Effective Friction Angle |
| cohesion | Soil Effective Cohesion | INPUT | Soil Effective Cohesion |
| face_stability_safety_margin | Face Stability Safety Margin | OUTPUT | Face Stability Safety Margin |
Calculation Steps
- Enter the epb chamber support pressure in Pa.
- Enter the soil unit weight in N/m^3.
- Enter the cover depth in m.
- Enter the soil effective friction angle in rad.
- Enter the soil effective cohesion in Pa.
- Step 1: Compute face stability safety margin.
- Read the face stability safety margin (dimensionless) from the results.
Engineering Summary
Calculate EPB Shield Face Stability Safety Margin (Limit Equilibrium)
Frequently Asked Questions
What does this calculator calculate?
The EPB Shield Face Stability Safety Margin (Limit Equilibrium) Calculator estimates Face Stability Safety Margin based on the input parameters you provide
Why is epb chamber support pressure important in this calculation?
epb chamber support pressure is directly proportional to face stability safety margin. When you enter epb chamber support pressure in Pa, the calculator uses it in the engineering formula to compute the output
How should I interpret the result face stability safety margin?
The calculator outputs face stability safety margin 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: EPB Chamber Support Pressure (Pa), Soil Unit Weight (N/m^3), Cover Depth (m), Soil Effective Friction Angle (rad), Soil Effective Cohesion (Pa). 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
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