The document discusses several important engineering characteristics of soil that influence how soil performs under loads. These characteristics include: 1) Shear strength - the strength of soils determines its ability to support loads and remain stable on hillsides. Shear strength depends on factors like internal friction and pore water pressure. 2) Compressive strength - the tendency of soil to decrease in volume under load. Compressive strength predicts how much a soil will settle under loads. 3) Compaction - how closely soil particles are packed. Well-compacted soil with interlocking particles supports heavier loads with less settlement.