Research on Vibratory Maximum Density Test for Cohesionless Soils

Abstract

The use of relative density as a method of control for compaction of cohesionless soils is hampered by lack of an adequate method for determining the maximum soil density. Previous investigations have shown that higher densities are obtained for most cohesionless soils by vibratory methods than by the standard impact compaction methods. This paper presents the results of an investigation of vibratory methods to determine the combination of variables which would give the highest density. Four electromagnetic table-type vibrators, an immersion-type concrete vibrator, and a pneumatic table-type vibrator were used in this investigation. The effect on the soil density of magnitude of surcharge, time of vibration, amplitude of vibration, and water content were studied for seven cohesionless soils representing a wide range in gradations. A summary of the Bureau of Reclamation's test procedure for determining the relative density of cohesionless soils using a vibratory table is included. For the range of amplitudes investigated, maximum densities were generally obtained at the higher amplitudes. Additional research is needed to determine the optimum deadweight surcharge. The increase in density was insignificant for times of vibration greater than 6 min, and 8 min seems to be a reasonable and sufficient time for the equipment and soils tested. The initial density of the soil prior to vibration did not have a significant effect on the final density. The difference between the densities obtained using oven-dried soil and initially saturated soil was not significant for most of the soils tested.

Effects of Soil Type and Compaction on the Growth of Ailanthus altissima Seedlings

“…The two soil materials used in this study were sandy loam topsoil and mason sand. Sand was chosen based on its use, along with gravel, for the construction of sidewalks and roadways (personal communication, New York State Department of Transportation), (8). The planting containers were 20 cm (8 in) diameter poly vinylchloride pipes with a height of 61 cm (24 in).…”

“…After draining and settling, more sand was added until the desired level and a bulk density of 1.67 gm/cc (102.3 Ib/ft 3 ) was obtained. For the compacted sand treatn1ent, a jackhammer with a flat disc was used (8). Four increments of dry sand, 15 cm (6 in) in height, were vibrated for one minute each to achieve a final bulk density of 1.88 gm/cc (117.3 Ib/ft 3 ).…”

“…But these methods are limited to spring, summer and fall months in the north ern and eastern regions. However, thermo-blanket tents have been used successfully to root stem cuttings out doors throughout the year (3,4,8).…”

A Study of Effective Soil Compaction Control of Granular Soils

“…Aside from the soil type, variables that influence the effectiveness of compaction using vibrating tables are water content, time of compaction, amplitude of vibration, surcharge, and mold size (Cumberledge and Cominsky, 1973;Pettibone and Hardin, 1965). In development of a vibrating table standard for the USBR, testing programs were conducted by Pettibone and Hardin (1965) on a variety of granular soils to determine the effect that these variables had on the maximum dry unit weight achieved during a vibrating table test. The highest dry unit weights were always obtained from either the oven-dry or saturated condition.…”

“…The corresponding standard that is commonly used to determine the maximum dry unit weight (or e min ) of a granular soil is ASTM D 4253. A soil-filled mold is fastened to a vertically-vibrating Aside from the soil type, variables that influence the effectiveness of compaction using vibrating tables are water content, time of compaction, amplitude of vibration, surcharge, and mold size (Cumberledge and Cominsky, 1973;Pettibone and Hardin, 1965). In development of a vibrating table standard for the USBR, testing programs were conducted by Pettibone and Hardin (1965) on a variety of granular soils to determine the effect that these variables had on the maximum dry unit weight achieved during a vibrating table test.…”