Alabama Contractors License Practice Exam

What safety factor is commonly used in the design of retaining walls?

1. 1.5

2. 2.5

3. 3

4. 3.5

The correct answer is: 1.5

The commonly used safety factor of 1.5 in the design of retaining walls is based on structural engineering principles that aim to ensure stability and safety under various conditions. This factor accounts for uncertainties in material properties, loads, and potential environmental effects. In the context of retaining walls, the safety factor is crucial because these structures must withstand lateral earth pressures, groundwater, and potential surcharge loads from adjacent structures or traffic. Using a safety factor of 1.5 means that the wall's design is based on a capacity that is 1.5 times greater than the expected maximum load. This level of safety helps to mitigate risks associated with failure, ensuring that even if loads exceed anticipated levels, the wall will still perform adequately. Retaining walls are critical for soil stabilization and preventing erosion or collapse, making this safety factor an essential guideline in engineering practices.