$667$ "How does soil compaction influence the stability and performance of civil engineering structures? Explain the concept of soil compaction, including its process and factors affecting it such as moisture content and compaction effort. Discuss the significance of achieving proper compaction in various construction projects, such as roadways, embankments, and building foundations. Illustrate the consequences of inadequate compaction on structural integrity and long$-$term stability. Lastly, describe techniques and equipment used for effective soil compaction in civil engineering practice."