Problem $($ KK $)==$ What are the foundational theories in civil engineering, serving as the bedrock for understanding structural stability, material properties, and environmental impacts? These theories underpin the design, construction, and maintenance of infrastructure like bridges, roads, and buildings. By grasping principles of mechanics, fluid dynamics, and material science, engineers ensure structures withstand various loads, weather conditions, and natural disasters. How do these theories inform practical applications, ensuring safety, sustainability, and efficiency in civil engineering projects worldwide?