Which type of soil should be considered stable?

Solid rock is considered stable due to its inherent properties. It has a high load-bearing capacity and minimal compressibility, making it less susceptible to erosion or movement under load. Unlike other soil types, solid rock maintains its strength and structure even under varying environmental conditions, such as moisture changes or seismic activity. This stability is crucial in construction and engineering projects, where a stable foundation is essential for safety and longevity. In contrast, clay, sand, and loam can experience changes in strength and stability based on moisture content and compaction, which can create challenges in construction and landscaping. Understanding these differences helps in selecting appropriate materials and designing foundation systems for infrastructure projects.