SKIRTED GRANULAR PILES

Stone columns are becoming popular for reinforcing clay deposits. Their use in non-ahesives soils is not so common as recourse has always been taken to techniques like vibro floatation, compaction piling, and use of explosive charges. As an alternative, skirted granular piles are now being advocated. 

The invention relates to an improved type foundation, which involves construction of skirted granular piles as a technique to. 

  • Reinforcing weak soils to improve strength and limit settlements and

  • Provide economical and technically feasible foundation in such soils.

The stress-deformation behavior of a loose to medium, non-cohesive soiled deposit reinforced with both plain and deformation behavior of granular pile soil systems demonstrated the benefits of reinforcing the non-cohesive weak sub-soil in terms of their capabilities for sustaining high loads for single piles and groups of 3 and 4 respectively. The improvement was found to be about 280 percent for 3 piles group and 375% for 4 piles group, when the piles were skirted. It was further noticed that the ultimate load was mobilized at a deformation of about 20 per cent of the pile diameter, whereas the transition of stress deformation behavior from elastic to elastoplastic seemed to occur at deformation of about 7.5% of pile Diameter. 

Non-cohesive sub-soils reinforced with granular piles may provide highly economical foundations not only for buildings but also for other complex modern constructions like industrial facilities. In situations where stringent settlement criterion is to be fulfilled and high loads must be sustained (building and heavy storage tank foundations), the granular piles may be skirted collectively in-groups. In situation where given loads are to be sustained with stringent restriction on amount of settlements (radar’s, transmission line towards, cyclostrones, machine foundations etc), additional to skirting the granular piles collectively, the ground outside the skirt may also be strengthened, and footings may be inter connected with skirt around it, ensuring safety against pull and lateral loads. Besides, the granular piles may be useful in reducing liquefaction potential in fine-to—medium, saturated cohesion less soils. If skirted in-groups the system (retrieval) type of foundations could be of great advantage for foundation for oilrigs. Also, buildings under distress due to excessive differential settlement could be strengthened by skirting to arrest.

 

 

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