What are the underlying principles and methodologies governing the design and construction of suspension bridges in civil engineering? Explore the structural dynamics involved, including the considerations of load distribution, material properties, and environmental factors. Discuss how these factors influence the choice of materials, such as steel cables and concrete towers, and the overall geometric configuration of the bridge. Additionally, delve into the significance of tension and compression forces in maintaining stability and equilibrium within the bridge structure. Evaluate the role of advanced analytical techniques, like finite element analysis, in optimizing the design process and ensuring structural integrity. Finally, assess the implications of these theories on the safety, longevity, and economic viability of suspension bridge projects on a theoretical level.