How do different soil types impact the design and construction of deep foundation systems in civil engineering projects? Evaluate the influence of factors such as soil composition, density, and moisture content on the behavior of various types of deep foundations, including pile foundations, drilled shafts, and caissons. Analyze the engineering considerations and challenges associated with selecting the appropriate deep foundation system for a given soil condition, taking into account factors such as load$-$bearing capacity, settlement, and lateral stability. Explore the methodologies used in site investigation and soil testing to assess soil properties and determine suitable foundation designs. Investigate the role of geotechnical engineering principles in optimizing deep foundation designs to ensure the safety, durability, and cost$-$effectiveness of civil engineering structures.