Earthworks and soil compaction

To appreciate that an earth structure can comprise a variety of material types each performing a different function. To understand the factors affecting the suitability of fill materials and the choice of criteria based on laboratory tests. To be aware of the factors that can affect the efficiency of an earthmoving operation including trafficability, softening and bulking. To understand the factors affecting the field compaction of soils and to be able to interpret the results of laboratory compaction tests. To understand the benefits of lime and cement stabilisation. Earthworks or earth structures are constructed where it is required to alter the existing topography. They comprise excavation and filling and are most commonly formed for highway works, such as cuttings and embankments but they may also consist of site levelling, such as for industrial or housing estates and excavation and backfilling of quarries, trenches and foundations. The stability of cutting and embankment slopes is discussed in Chapter 12. In this chapter the construction and compaction of the fill material to form an embankment structure is considered.