$7855$ : $/$: "Explain the fundamental principles of soil mechanics in civil engineering. How do factors such as soil composition, moisture content, and compaction affect the behavior of soil under load? Discuss the significance of soil classification systems and their role in determining suitable foundation types for various structures. Additionally, elaborate on the concept of soil consolidation and its implications for settlement analysis in construction projects. How do engineers address soil$-$related challenges to ensure the stability and durability of civil infrastructure?"