How do soil mechanics and foundation engineering principles interplay in the design and construction of deep foundation systems for large$-$scale infrastructure projects, and how does the selection of appropriate foundation types impact the overall stability, safety, and longevity of civil engineering structures? Discuss the underlying theories governing soil behavior under load, including consolidation, shear strength, and settlement, and analyze how these theories inform the selection of suitable foundation types such as driven piles, drilled shafts, and caissons. Consider the influence of various site$-$specific factors such as soil type, groundwater conditions, and structural requirements on the decision$-$making process. Additionally, explore the role of advanced geotechnical analysis techniques, such as finite element modeling and dynamic testing, in optimizing foundation design and ensuring the structural integrity of complex civil engineering projects.