Enhancement of side resistance in bored piles with lime

A study was undertaken to investigate the effect of exposure to lime of pile boreholes in clay-rich soils on side load transfer. The study consisted of direct interface shear tests, full-scale field load tests, small-scale laboratory pullout tests and electron microscopy investigation. These inquiries suggested that the vertical sedimentation path of particulate lime in a vertical borehole does not permit it to invade the lateral surface of the clay in high enough concentration to affect granularization of the interface, whereas such an effect occurred clearly when the clay surface was horizontal (in laboratory direct shear studies), where lime particles collected on that surface. The presence of sand seams within the clay, however, allowed the lime from slurry to penetrate the clay and to stabilize it, suggesting that lime enhancement can produce substantial improvement of bored pile capacity in such stratigraphy.