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The following statements pertain to the occurrence of negative skin friction in piles. S1: It is developed when the pile is driven through a recently deposited clay layer. S2: It is developed when the pile is driven through a layer of dense sand S3: It is developed due to a sudden drawdown of the water table. Which of the above statement(s) is/are incorrect?

The following statements pertain to the occurrence of negative skin friction in piles. S1: It is developed when the pile is driven through a recently deposited clay layer. S2: It is developed when the pile is driven through a layer of dense sand S3: It is developed due to a sudden drawdown of the water table. Which of the above statement(s) is/are incorrect? Correct Answer S2 only

Concept:

Negative skin friction: It is usually a downward shear drag acting on a pile or pile group because of downward movement of surrounding soil relative to the piles.

This shear drag movements are anticipated to occur when a pile penetrates into compressible soil layer that can consolidate.

Negative skin friction for piles occurs:

When the pile is driven through a recently placed fill material on compressible soil before the completion of consolidation.

If fill material is loose cohesionless soil and when fill material is deposited over layer of soft soil or peat.

Sudden drawdown of groundwater table, increases the effective stress causing consolidation of soil with resultant settlement and friction force being developed on the pile.

∴ The statement 2 is the only incorrect statement here.

Related Questions

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