Question
What are major ways to undertake negative skin friction?
Answer
(i) Utilize slender pile sections since smaller pile area when subject to same working load would manufacture higher deformation, therefore increasing relative downward movement of piles.
(ii) In a sure region of H-piles for ground water table variation, painting is applied on surface of H-piles since rise and fall of water table contribute to corrosion of H-piles. On other hand, to reduce effect of extra loads brought about by negative skin friction, bitumen is practical on pile surface corresponding to region of soils that has negative skin friction. But, bitumen should not be applied to whole section of H-piles as it would be unable to derive designed frictional reaction from soils.
(iii) Designing of piles as end-bearing so that they are able to take up more loads.