What theoretical frameworks underpin civil engineering methodologies and practices? How do principles from disciplines like structural mechanics, fluid dynamics, and materials science contribute to the understanding and design of infrastructure? How do theories such as elasticity, plasticity, and finite element analysis inform structural engineering decisions? Additionally, what role do concepts like sustainability, resilience, and risk assessment play in modern civil engineering theories? Explore how these theoretical foundations shape the development of safer, more efficient, and environmentally conscious infrastructure projects, and how they adapt to emerging challenges like climate change and urbanization.