$233$What theoretical foundations underpin civil engineering practices? From fundamental principles in physics and mathematics to specialized knowledge in materials science and structural analysis, civil engineering relies on a robust theoretical framework. Theories such as mechanics of materials, fluid mechanics, and soil mechanics form the backbone of understanding for designing infrastructure like bridges, dams, and buildings. Additionally, theories in transportation engineering, environmental engineering, and geotechnical engineering contribute to the comprehensive knowledge base required for solving complex civil engineering problems.