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Study the statements listed below (1) Negative skin friction is developed when the pile is driven through a recently deposited clay layer (2) Negative skin friction is developed when the pile is driven through a layer of dense sand (3) Negative skin friction is developed due to sudden drawdown of the water table Out of these statements

Study the statements listed below (1) Negative skin friction is developed when the pile is driven through a recently deposited clay layer (2) Negative skin friction is developed when the pile is driven through a layer of dense sand (3) Negative skin friction is developed due to sudden drawdown of the water table Out of these statements Correct Answer <span style=" line-height: 107%; background-image: initial; background-position: initial; background-size: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial;">1 and 3 are correct</span>

Concept:

Negative skin friction is a downward drag acting on a pile due to downward movement of surrounding compressible soil relative to pile.

Negative friction also occurs when settlement of surrounding soil is more than that of pile.

Negative skin friction reduces the load-carrying capacity of the pile.

Negative skin friction may develop under following conditions

  • It happens when the surrounding soil has been recently filled or formed. As the soil consolidates the earth fill moves downward developing friction forces on the perimeter on the perimeter of pile which tends to carry pile further into ground.
  • Negative skin friction may develop due to lowering of water table. When water table is lowered the effective pressure increases causing consolidation of soil, with the resultant settlement and friction force being developed on the pile.

Related Questions

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?
From the three typical cases C1, C2, C3 choose the combination, where one can expect occurrence of negative skin friction, on piles: C1 : An upward drag exists in the pile C2 : Develop if the filled material around pile is a loose sand deposit. C3 : Lowering of ground water table resulting in consolidation of soil
The following are certain operating problems of a rapid sand filter: 1. Sand depth should never be depleted by more than 10 cm. 2. Air binding results due to development of negative head and formation of air bubbles in the filter sand. 3. Water softening with lime-soda leads to incrustation of sand. 4. Bumping of filter bed is caused due to negative head. Which of the above statements are correct?
Some small cubes of same height 7 cm but variable length and width are put inside a large cuboid of height 21 cm. Length and width of cuboid is 32 cm and 24 cm, respectively. Small cubes are put such that cubes at the bottom most layer is of similar base area; second layer contains all the cubes of similar base area and third layer have all the cubes of similar base area. Which of the following statement(s) given below is / are TRUE? A: If side of each small cubes at bottom most layer is 8 cm, then maximum number of small cubes that can be put at bottom most layer is 12. B: If maximum of 48 cubes can be put at second layer, then side of each cube at second layer is 6 cm. C: If side of each small cubes at third layer is 1.6 cm, then maximum number of small cubes that can be put at third layer is 300.
Consider the following statements: 1. Effective stress in a sand layer below a lake with standing water does not alter as the water level fluctuates. 2. Regarding water table below the ground surface, any rise in the water table causes equal changes in both pore pressure and effective stress. 3. Capillary saturation will cause the effective stress to increase. Which of the above statements are correct?
Consider the following statements: 1. IS 3583 refers to Burnt Clay Paving Bricks. 2. IS 5779 refers to Burnt Clay Soling Bricks. 3. IS 3952 refers to Burnt Clay Hollow Bricks. 4. IS 2222 refers to Burnt Clay Lay Bricks. Which of the above statements are correct? 
Sentences of a paragraph are given below in jumbled order. Arrange the sentences in the right order to form a meaningful and coherent paragraph.   A. These kinds of sharks are known as obligate ram ventilators because they draw water in through their mouths and force it out through their gills. B. They use a method called buccal pumping, in which water is pulled in through the mouth and forced out through the gills by the cheek muscles. C. It is true that many types of sharks must keep moving in order to receive life-giving oxygen from the water passing through their gills. D. Other types of sharks are able to remain stationary because they possess special structures called spiracles, which force water out through their gills.
Assertion A: Slow sand filters are more efficient in removal of bacteria than rapid sand filters.Reason R: The sand used in slow sand filters is finer than that in rapid sand filtersSelect your answer based on the coding system given below:
Assertion A: Slow sand filters are more efficient in removal of bacteria than rapid sand filters.
Reason R: The sand used in slow sand filters is finer than that in rapid sand filters
Select your answer based on the coding system given below:
Consider the following statements and choose the correct answer:
1. The density of water varies inversely with temperature
2. The density of water varies inversely with the concentration of dissolved substances
3. Water is more dense at approximately 4° C and becomes progressively less dense as it is cooled below +4° C
4. When great evaporation occurs in a lake having no outlet, the lake may come to contain a higher percentage of salts than the ocear