1. What is Retaining Wall Stability?

The stability of a retaining wall is determined by the ratio of resisting moments to overturning moments. A factor greater than 1.5 is typically required for adequate safety against overturning.

2. How Does the Calculator Work?

The calculator uses the stability equation:

Where:

• \( Resisting\ Moment \) — Sum of moments resisting overturning (foot-pounds)
• \( Overturning\ Moment \) — Sum of moments causing overturning (foot-pounds)
• 1.5 — Minimum safety factor required

Explanation: The equation compares the forces trying to keep the wall upright versus those trying to topple it.

3. Importance of Stability Calculation

Details: Proper stability calculation ensures the retaining wall can withstand lateral earth pressures without failing. It's critical for structural safety and longevity.

4. Using the Calculator

Tips: Enter both resisting and overturning moments in foot-pounds. Values must be positive numbers. The calculator will determine if the wall meets the 1.5 safety factor requirement.

5. Frequently Asked Questions (FAQ)

Q1: Why is 1.5 the minimum stability factor?
A: This safety factor accounts for uncertainties in material properties, loading conditions, and construction variations.

Q2: What contributes to resisting moment?
A: Typically includes wall self-weight, any surcharge on the heel, and soil weight on the footing.

Q3: What causes overturning moment?
A: Primarily lateral earth pressure from retained soil, plus any additional horizontal loads.

Q4: Should other failure modes be checked?
A: Yes, sliding and bearing capacity must also be verified for complete wall design.

Q5: Are there code requirements for this?
A: Most building codes specify minimum safety factors for retaining wall design, typically 1.5-2.0 for overturning.