$6541$ : $46215$ : "What are the fundamental principles of structural mechanics in civil engineering, and how do they influence the design and analysis of buildings and bridges? Discuss the concept of load$-$bearing, stresses, and strains in materials, along with their implications for construction. How do factors like material properties, geometry, and environmental conditions affect the structural behavior of civil engineering systems? Explore the basics of static equilibrium, deformation, and stability in structures, highlighting their significance in ensuring safety and functionality."