Concrete footings are used to stabilize the base of a retaining wall. A retaining wall is used to confine soil to a particular area. They are commonly found on the sides of main roads preventing grassy embankments from spilling out onto the road. If concrete footings were not used, then, over time, the retaining wall would tip with the pressure of the soil.
Overcoming Soft Soil
When pouring concrete footings, it is important that there are no soft soil patches because these areas can compromise the stability of the footing. If there are only one or two soft soil patches in otherwise well-conditioned soil, increase the depth of the concrete footing.
The trench for the concrete footing to be poured into should be at least eight inches/20 centimeters deep and six inches/15 centimeters wider than the retaining wall it is supporting. For retaining walls taller than three feet/one meter, it is necessary to make the depth of the concrete footing thicker.
Concrete can be made thicker or thinner. When it comes to concrete footings, a thicker mixture is better, as overly wet concrete can weaken the structure. If you are not comfortable mixing your own concrete, buy ready-mix concrete. While it is more expensive than making your own, it reduces labor time.
Even though concrete footings are beneath the surface, they can still be affected by weathering. If the weather is cold enough, the top few inches of a pond can freeze over, and the same applies with moist soil. So make sure the top of the concrete footing is below the soil that could freeze.