task $77===$How do varying soil compositions affect the stability of foundation structures in civil engineering? Specifically, how do factors such as soil density, moisture content, and particle size distribution impact the load$-$bearing capacity and settlement characteristics of different foundation types? Additionally, what theoretical models or analytical methods are commonly used to predict and mitigate potential soil$-$related issues in civil engineering projects? Understanding these theoretical foundations is crucial for designing resilient structures that can withstand environmental pressures and ensure long$-$term stability and safety in diverse soil conditions.