the, compaction, stabilization
The term compaction means the artificial increase of the density of a natural soil by mechanical means, that is, the densification. The natural soil may be compacted either in situ or after transportation in a new fill. For the compaction of clay fills, a sheep is foot roller is usually employed (sometimes it is called a tamping roller). Its construction: a steel drum has some steel studs welded to its surface (the shape of which is like the shape of a sheep is foot). The drum is empty for transportation, but it is filled with sand and water on the site where it must be used. All the weight of the drum is supported on a few of the sheep is fool studs at the same time. As a result of this, footprint pressures in developed. These pressures can crush and compact any lumps of lay. Individual drums can then be attached side by side and drawn all together by one caterpillar tractor. The modern light standard heep is-foot roller has a 43-in. diameter drum, a loaded weight varying from 6,000 to 15,000 lb. per 8-ft. width of a drum, and foot-print pressures varying from 60 to 300 psi. The heavy standard sheep is-footprint roller has a 60-in. diameter drum and footprint pressures from 300 to 600 psi. Stabilization — is an artificial method Used for the purpose of improving by special admixtures such properties of a soil which are important for the shearing strength and of the volume and the shape of the soil. It is necessary to consider the loading or climatic conditions which the soil may encounter when it serves as a foundation or construction material. Most soils can be effectively and economically stabilized by mixing them with cement. The amounts of cement Usually vary from 8 to 12 per cent of the soil by volume. Cement stabilization is not effective in soils with a high organic content or in soils containing substances, such as sulfur, which may produce a. disintegration of concrete. Bituminous-soil stabilization can be used under such, conditions, is one of its effects is waterproofing of the soil and the maintenance of the low water content necessary for continued stability of cohesive soils. The stabilization of soils by the addition of artificial resins and other chemicals is recommended as it produces effective waterproofing of the soil particles thus improving the soil quality.
