Question $1$:Evaluate the fundamental principles and theoretical frameworks that underpin the design and analysis of structural systems in civil engineering. Discuss how these principles guide the development of models to predict the behavior of complex structures under various loads and stress conditions. Highlight the role of material properties, load combinations, and environmental factors in shaping these theoretical models. In your response, consider the balance between safety, functionality, and economic efficiency, and elaborate on how civil engineers address uncertainties and variabilities within these models to ensure the reliability and longevity of constructed structures. Furthermore, analyze the importance of incorporating advanced computational tools and simulation techniques in enhancing the precision and accuracy of structural analyses.