task : $58$##How do foundational theories in civil engineering underpin the design, construction, and maintenance of infrastructure? Discuss the pivotal role of classical theories such as structural mechanics, fluid dynamics, and materials science in shaping modern civil engineering practices. Explore how these theories inform decision$-$making processes in areas like structural design, transportation planning, and environmental sustainability. Analyze the interplay between theoretical frameworks and practical applications, considering advancements in computational methods and experimental techniques. Moreover, delve into how emerging theories, such as resilient infrastructure and sustainable development, are reshaping the discipline, addressing challenges like climate change adaptation and urbanization.