Q : $26$##How do theories in civil engineering provide a fundamental framework for understanding and addressing various aspects of civil infrastructure? Discuss the significance of theories in areas like structural mechanics, fluid dynamics, geotechnical engineering, and transportation. Explore how these theories serve as the basis for designing, constructing, and maintaining infrastructure projects such as bridges, dams, highways, and buildings. Additionally, delve into the role of theoretical models in predicting the behavior of materials and systems under different conditions, ensuring safety, efficiency, and sustainability in civil engineering practices.