$--$"What are the fundamental principles underlying structural analysis in civil engineering, and how do they inform the design process? Explain the key factors influencing material selection for construction projects and their impact on structural integrity and sustainability. Discuss the role of geotechnical engineering in assessing soil stability and foundation design, highlighting methods for mitigating risks associated with soil movement and settlement. How do environmental considerations influence the design and construction of infrastructure projects, particularly in terms of resilience to natural hazards and long$-$term sustainability?"