Soil compaction is a critical part of most engineered structures that use the earth or soil as a foundation or a base for support. The soil’s engineering properties, including strength, compressibility, and permeability, can be improved and become more predictable with the proper degree of compaction. The soil may also be a major structural component, as in the case of earth fill dams, levees or dikes, high road fills, and other embankments.

Unique to Manual 70 is the combination of established soil mechanics engineering fundamentals and the discussions on using the latest ASTM standards related to those fundamentals.

Manual users should be familiar with ASTM D2487 Standard Practice for Classification of Soils for Engineering Purposes (Unified Soil Classification System). This practice, included on the CD-ROM ASTM Soil Compaction Standards—A Companion CD to Manual 70 (sold separately) is found throughout Manual 70 in the narratives, the various figures, and the tables.