Compaction of soil

Abstract

An area of soil having an initial low bearing strength, such as an alluvial or sandy area, or an area formed by hydraulic fill, is compacted to provide an improved area of high bearing strength by forming a plurality of granular particulate (e.g., crushed stone, pebbles or sand) columns in pre-compacted holes in the area. The pre-compacted holes are formed by vibratorily driving a hollow probe having openable closure means set in closed position at its lower end, vertically downwardly to form each vertical hole, the soil around the probe thus being compacted. Thereafter, the probe is vibratorily extracted and granular particles are passed downwardly through the probe with the adjustable closure means open. Desirably, the granular material is compacted, i.e., consolidated, thereby further enhancing the bearing strength of the area, either by introducing such material into the probe during vibratory extraction of the probe or by introducing this material before the probe is vibratorily extracted, the probe in either such event inducing vertical vibratory movement of the particles with resultant reduction in the mass volume and lessening of void volume. The area may be further treated by vibratorily tamping with a tamping device having a concentrated high mass.

Dependencies are inferred from the claim text.