Proceedings of DFI-India 2017: 7th Conference on Deep Foundation Technologies for Infrastructure Development in India, (DFI)
Advances in Desaturation of Sandy Soil to Mitigate the Liquefaction Hazard
Dhanaji S. Chavan, Research Scholar and Thallak G. Sitharam, Professor
It is well known that sites comprising of saturated loose sand undergoes large deformations, due to liquefaction, during seismic shaking. To cope with this, different mitigation techniques such as vibroflotation, deep dynamic compaction, compaction grouting, deep soil mixing etc. have been used in practice. However, as all these methods are costly, a new mitigation technique is required. Air injection has emerged as a new mitigation technique in which air is injected into the saturated loose sand. The introduced air makes the pore fluid mixture compressible and results into decrease in the generation of excess pore water pressure during seismic shaking. This paper reviews the laboratory and field studies performed to investigate the effect of air injection on liquefaction resistance. In addition to this, previous research in the direction of desaturation has evolved different techniques to generate gas in saturated sand. These techniques have also been discussed in the present paper. All the field and laboratory studies have shown that even a slight decrease in the degree of saturation increases the liquefaction resistance significantly.
|article #2756; publication #1035 (India2017)|