Explore the principles of structural optimization in civil engineering, focusing on methods for designing structures that meet performance requirements while minimizing material usage and construction costs. Discuss the mathematical optimization techniques, including linear programming, genetic algorithms, and finite element optimization methods, for optimizing structural designs subject to constraints such as strength, stability, and serviceability criteria. Furthermore, examine the applications of structural optimization in conceptual design, form$-$finding, and design optimization of civil engineering structures to achieve efficiency, sustainability, and innovation in structural engineering practice.