What differentiates a counterfort retaining wall from a buttress retaining wall?

A counterfort retaining wall is designed with vertical elements called counterforts that project inward from the wall to provide additional support. These counterforts effectively help resist the lateral pressure exerted by the soil behind the wall, enhancing the wall’s stability and structural integrity. In contrast, a buttress wall features sections that project outward away from the wall. This outward projection is meant to provide stability by transferring loads back to the earth and enhancing resistance against the forces acting on the wall, often used in scenarios where the wall must anchor into the soil more effectively.

The distinction highlighted in the correct choice accurately portrays the fundamental design characteristics and purposes of both types of retaining walls. This understanding is crucial for the correct application in engineering and construction practices, as each serve different conditions and structural requirements.