A three-story structure is to be constructed over an 8000 m² site. The initial subsurface exploration indicated the presence of sinkholes and voids due to the dissolution of lime stone formation. The predominant soil type is a silty fine sand grading to a fine sand with seams of sandy clay. The design indicates that shallow foundations can be used for this project provided the soils were made more homogeneous as far as load support and no voids were present within the depth up to 7.6 m below ground surface. Assume ground water is not a concern. Dynamic compaction was proposed to improve the ground. The local contractor doing dynamic compaction has a 15-ton tamper with a diameter of 2.0 m and thickness of 1.4 m. You are requested to conduct the preliminary design for this dynamic compaction project including drop height, spacing, number of drops, and settlement.