Publication Abstract

Proceedings - Fourth International Conference - Piling and Deep Foundations, 1991, Stresa, Italy, (DFI)

Negative skin friction on coated and uncoated model piles
V.K. Puri & B.M. Das Southern Illinois University at Carbondale, Ill., USA U. Karna Lippincot Engineering Associates, Riverside, NJ., USA

This paper presents the results of tests conducted on instrumented aluminum piles in order to study the behavior of negative skin friction. Tests were conducted on uncoated model piles and also after applying a coating of asphalt. Different surcharge pressures were applied on the soil surface and the magnitudes of variation of the negative skin friction with depth and time were recorded. The adhesion between the pile surface and the soil was determined from pullout tests. The results of tests on uncoated piles show that, initially, the negative skin friction is more near the pile top and less at its bottom. As the surchere pressure increases, the value of the skin friction increases in the same fashion along the pile. It reaches its maximum value and then decreases in the course of time. The asphalt coating can be effectively used to reduce negative skin friction by as much as 80% of its value for uncoated piles.

 article #529; publication #37 (IC-1991-IT)