task : $8998$#"What are the fundamental principles governing the behavior of structural materials in civil engineering applications? How do factors like stress, strain, and elasticity influence the design and construction of buildings and bridges? Explain the concept of load$-$bearing capacity and its significance in structural integrity. How do engineers assess and mitigate risks related to material failure? Explore the role of material properties such as ductility, hardness, and toughness in construction projects. Discuss the importance of material selection in ensuring long$-$term durability and safety."