task : $6\mathrm{.}11$##What are the foundational theories that underpin the field of civil engineering? How do principles like structural mechanics, fluid dynamics, and material science inform the design and construction of infrastructure such as bridges, roads, and buildings? Explore how theoretical frameworks such as Euler$-$Bernoulli beam theory, Navier$-$Stokes equations, and Hooke's Law contribute to understanding and predicting the behavior of civil engineering structures under various loads and environmental conditions. Additionally, discuss the role of theoretical modeling and simulation in optimizing designs for efficiency, durability, and safety in civil engineering projects, ensuring sustainable and resilient infrastructure development for society.