Axial and Lateral Loading Behaviour of Pervious Concrete Pile

Abstract

Ground improvement is the process by which soil behaviour is altered mainly by physical means. Typical examples range from inclusion of structural elements such as piles or soil nails, to use of any compaction technique in which the bearing capacity of soil is enhanced. The use of stone columns in conjunction with soft or weak soils represents a very cost-effective way of improving bearing capacity. In addition, stone columns being highly permeable provide natural drainage, thereby accelerating consolidation. However, the physical behaviour of stone columns is affected by nature of the soil in which they are embedded. In particular, they offer little resistance to lateral loading generated by soil movement. This paper advocates the use of an innovative ground improvement technique, which involves partial cementation of granular columns resulting in Pervious Concrete Piles. This study includes formulation of mix design (1:1:4) for pervious concrete and detailed analysis of pile behaviour under axial and lateral loading. It was found that under same axial loading conditions, the load-carrying capacity of pervious concrete model pile exceeded four times that of a granular column with same dimensions. A series of lateral loading tests were conducted on 5-cm-diameter pervious concrete model piles with length/diameter ratios of 6, 10 and 14. The bending moment profile shows that pervious concrete pile behaves in the same way as flexible piles subjected to lateral loading. This type of behaviour has potential to transfer the load below failure surface without compromising on permeability criteria, thereby improving stability.