$!$@#$$\%^$&$*$: retaining walls function in civil engineering projects? Explain the fundamental principles governing their design and construction, including factors such as material selection, wall geometry, and soil characteristics. Discuss the primary types of retaining walls and their respective advantages and limitations$.$ Furthermore, explore the key considerations in determining the appropriate type of retaining wall for a given scenario, considering factors like soil type, slope angle, and required structural integrity. Finally, illustrate the importance of proper drainage and reinforcement techniques in enhancing retaining wall performance."