Civil engineering involves designing, constructing, and maintaining infrastructure such as roads, bridges, and buildings. One theoretical aspect is structural analysis, which assesses the ability of structures to withstand loads and forces. Another key area is geotechnical engineering, which focuses on soil and rock behavior to ensure stable foundations. Hydrology examines water flow and management to prevent flooding and ensure water supply. Additionally, transportation engineering optimizes the design and operation of transport systems for efficiency and safety. Understanding these theories is crucial for addressing challenges like environmental sustainability, urbanization, and climate resilience in civil engineering projects.