Deep vibratory compaction

The principle of all deep vibratory compaction techniques is based on the re-arrangement of grains into a more dense state as a result of vibrations transmitted by vibrating probes that are inserted into the ground. Deep vibratory 

Operational parameters such as the grid spacing of the compaction points, vibration time and the rate of withdrawal of the probe are in most cases determined during compaction trials undertaken at the project site itself. 

The main difference between the various techniques of deep vibratory compaction is the design of the probe. Based on this design deep vibratory compaction techniques can be divided into  

Some of these charts may work well for a specific machine type in specific soil conditions. However, the variations in soil conditions and compaction equipment are so large that the use of these charts for the purpose of designing and specifying a project is discouraged. Special precautions need to be taken with compressible 

As a consequence of the use of probes, the compaction method will create vertical columns of compacted material. The degree of compaction will decrease with increasing horizontal distance to the insertion point of the probe resulting in non-homogeneous compaction over the treated area. In situ tests, such as the Cone Penetration Test may be carried out to verify the required quality of the soil improvement. Other methods are described in the European Standard EN 14731 2005 Execution of special geotechnical works—aground treatment by deep vibration. 

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Massarsch, K.R. and Fellenius, B.H. Deep vibratory compaction of granular soils. Ground Improvement-Case Histories, Elsevier pubUdiers, B. Indranatna and C. Jian, Edt, 2005. 

Field procedures to decrease the void volume include static and dynamic compaction, pile driving and the use of surface and deep vibratory equipment. Explosives have also been used for this purpose. 

Massarsch, K.R. Deep Soil Compaction using Vibratory probes, ASTM symposium on design, construction and testing of deep foundation improvement stone columns and related techniques, ASTM STP, R.C. Bachus Edt, 297-319, 1991. 

Massarsch, K.R. Effects of vibratory compaction, Vibratory Pile Driving and Deep Soil Compaction— TRANSVIB2002, Holeyman, Vanden Berghe and Charue Edts., Swets and Zeitlinger, 33-42, 2002. 

Densify the loose, liquefiable soil layer. Stone column is often satisfactory if the loose layer is mostly sand. Other approaches, such as jet grouting, deep soil mixing with cementing agents and in situ vibratory densification can all be used. If the liquefiable soil layer is close to the ground surface, a complete excavation and replacement with compacted engineering fill is sometimes also feasible. 

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