Building Construction – foundation – Free PSC Quiz (15)

• Fender piles or dolphins are used to protect water front structures against impact of ships or other floating objects

• Sheet piles are commonly used as bulk heads or as impervious cutoff to reduce seepage and uplift under hydraulic structures

• Tension or uplift piles anchor down the structures subjected to uplift due to hydrostatic pressure or due to overturning moment

• Compaction piles are used to compact loose granular soils, thus increasing their bearing capacity

• Timber piles are prepared from trunks of trees. They may be circular or square. Diameters of piles are 30 to 50 cm and length not exceeding 20 times its top width. At bottom, a cast iron shoe is provided and at the top a steel plate is fixed. For a group pile each pile is brought at same level and concrete plate is provided to have common platform.
• Sand piles: These piles are formed by making hole in ground and fill with the sand and well rammed. The top of sand pile is filled with concrete.
• Concrete piles: Concrete pile can be precast or cast in situ type.
• Cast iron piles are strong in compression but weak in tension. Since caste iron is a brittle material,   it cannot resist impact loads and hence it is driven by a screw. It is generally of hollow cross section

• Sheet pile: They are used as bulk heads or as impervious cutoff to reduce seepage and uplift under hydraulic structures.

• Batter piles: These are used to resist large horizontal forces or inclined forces.

• Fender piles: These are used to protect water front structures against impact from ships or other floating objects

• Friction piles: Loose soil extends to a greater depth. Piles are driven at depth when friction resistance developed equal to load.

Friction piles are used to transfer loads to a depth of a friction load carrying material by means of skin friction along the length of piles.

Total friction resistance can be increased

• Increasing length and diameter
• Making Pile surface rough
• Placing closely or grouping of pile

A pier foundation consists of a cylindrical column of large diameter to support and transfer large superimposed loads to the firm strata below.

A pile is a slender structural member used to transfer loads to firm strata