Concept of vibro stone columns ( GROUND IMPROVEMENT TEECHNIQUE

Concept of vibro stone columns

This technique introduces a coarse grained material as load bearing elements consisting of gravel or stone aggregate as a backfill medium.

The stone column and the in situ soil form an integrated system having low compressibility shear strength. The excess pore water pressure can dissipate through the stone column, which also acts as a vertical drain. The settlement expected for the treated soil is reduced while the rate of settlement is increased when compared with the untreated soils.

The following figure.2 illustrates the schematic of the installation procedure for Vibro Stone Columns. The grading of the stone usually falls into the range of 75mm to 12mm for Vibro Stone Columns

The above technique (vibro stone columns) ensures following applications:

Ø Improves bearing capacity of in-situ soils

Ø Mitigates liquefaction potential under the excitation of earthquake

Ø Reduces excessive settlements and minimises differential settlement.

Ø Allow rapid consolidation by providing radial drainage

Concept of vibro compaction

Vibro compaction is proposed as ground Improvement scheme to mitigate liquefaction potential of the loose to medium dense silty sands and to hence bearing capacity of the foundations up to 15T/m2

The basic principle behind the process is that particles of non-cohesive soils can be rearranged into a denser state by means of vibration. A schematic showing basic principle of Vibro compaction technique is presented in Figure 3

 

The above technique (vibro compaction) ensures following applications:

Ø Mitigates liquefaction potential under the excitation of earthquake

Ø Improves bearing capacity of in-situ soils

Ø Reduces excessive settlements and minimizes differential settlement