Pages: 13 Published: Jan 2011
A. DESCRIPTION OF THE TYPES AND TERMS FOR FILL COMPACTION Earthfill and/or compacted backfill are constructed using earthwork techniques that include excavating, hauling, spreading, soil processing, addition of water, and compacting earth (soil and/or rock). Earthwork has wide application in construction projects. Practically every construction project has a component of earth construction that buildings, structures, or other project components are founded on, supported by, or constructed partially or entirely of soil or rock. Structural stability is usually dependent on proper foundation preparation and the proper placement and control of the earthfill placement and compaction process. Generally, all earth fills must be compacted to a specified density and water content as determined by the design parameters. Controlled compaction is usually required for roads, airfields, highways, building foundations, parking lots and drainage features, pipelines, railways, embankment dams, canals, dikes and levees, clay-lined containment structures and caps, and other related structures. Fill sections must be compacted to reduce the potential for excessive settlement or differential movements between cut and fill segments. Earth is compacted adjacent to structures such as bridge abutments  and in subgrades for roads to achieve uniform compressibility. Subgrade materials that are too soft or weak may be removed and replaced with compacted materials. Several base courses or layers of select soil are compacted immediately below airfield and roadway pavements to improve or control, as much as possible, the compressibility, strength, and drainage characteristics of the subgrade. Building foundations frequently require several forms of compacted backfill to ensure design performance. Backfill is frequently needed for larger structures where excavation is used to provide a balanced loading of the foundation. Fill placement is required under structures where the site must be elevated for operational requirements or to reduce flooding or both. The perimeter of buildings is often backfilled to prevent undesirable settlements and in some cases to support the walls. Some structures, such as pumping plants, must have compacted, free-draining soils in the foundation to prevent erosion problems caused by leakage. Lightly loaded structures or soils on poor soils may require mat foundations that must have compacted subgrades and backfill to ensure uniform compressibility and maintain differential settlement less than 1 in. for structural integrity and appearance.
Paper ID: MNL12162M