solve answer$\_\_\_\_\_\_\_\_\_$What theoretical frameworks underpin civil engineering principles? Explore concepts like structural analysis, fluid mechanics, and material science, elucidating their roles in designing infrastructure resilient to environmental factors and human needs. Discuss how theories such as Euler$-$Bernoulli beam theory or Navier$-$Stokes equations govern structural stability and fluid behavior, respectively. Delve into soil mechanics theories like Terzaghi's principles to address foundation design challenges. Moreover, examine sustainability theories driving civil engineering practices, integrating concepts like life cycle assessment and sustainable development goals. How do these theories inform decision$-$making processes and innovative solutions for infrastructure projects, ensuring durability, safety, and environmental responsibility?