The shell is inspected internally by using the light from a mirror or flashlight or drop light. When the Pile is driven to the desired depth mandrel is mechanically collapsed and withdrawn, leaving the shell inside the ground. The shell is driven into the ground with a collapsible steel mandrel or core in it having the same taper. It is one of the important types of pile foundations. The steel shell is reinforced with spirally wound hard drawn wire on an 8 cm pitch. The Pile consists of a thin corrugated shell (casing) closed at the bottom. The diameter of piles varies from 40 to 60 cm at the top and 20 to 30 cm at the bottom. The lengths of Reymond standard piles vary from 6 to 12 m. The piles with casing area known as eased cast-in-situ concrete Piles and those without casing are known as uncased cast-in-situ concrete piles. The casing may be kept in Position or it may be withdrawn. This bore is then poured with concrete after placing steel reinforcement if any. In the cast-in-situ concrete pile, a bore is dug into soil by inserting a casing. A concrete cover of at least 50 mm is provided. with lateral ties of 6 to 10 mm diameter at 100 mm c/c spacing for top and bottom lm length and 300 mm c/c spacing for the middle length. The reinforcement may consist of longitudinal steel bars of 20 mm to 40 mm in diameter, 4 to 8 nos. The size of the pile may vary from 30 cm to 50 cm in a cross-sectional dimension, and up to 20 m or more in length. transportation and lifting) the precast concrete piles are usually reinforced. Because of driving stresses and handling stresses (i.e. Precast Piles may be square, octagonal, or circular in cross-section and may be tapered or Parallel sided longitudinally.
Types of Pile Foundations Based on Their Function or Usesīased on function piles are classified as, The following factors should be considered while selecting types of pile foundation: Read More: Whi ch is Strongest & Best Foundation For A House (Types of Foundation for House)įactors Affecting the Selection of Pile Foundations Piles are used for the foundation of transmission towers, an off-shore platform that is subjected to uplift forces.Canal or deep drainage lines exit near the foundation.The structure is situated on the seashore or river bed, where there is a danger of scouring action of water.Where timbering to the trenches is difficult and costly.There are large fluctuations in the subsoil water level.pumping of water from the open trenches for the shallow foundations is difficult and uneconomical. The load of the superstructure is heavy and its distribution is uneven.Pile foundations are preferred in the following situations Read More: T ypes of Foundation and Footings & Their Uses in Building Construction
A Pile foundation usually consists of a number of Piles, which together support structure. The Piles may be driven or placed vertically or with a batter. It is in this respect they differ from columns. Piles are somewhat similar to columns in that loads developed at one level are transmitted to a lower level, but Piles obtain lateral support from the soil in which they are embedded so that there is no concern with regard to buckling.
There are different pile foundation types are used to transfer structural loads to a depth where the soil has the desired capacity to transmit the loads. The most common forms of deep foundations are : In case, the strata of good bearing capacity are not available near the ground, the foundation of the structure has to be taken deep with the purpose of attaining a bearing stratum that is suitable in all respects.