It usually forms part of the foundation of a building, typically a multi-story building, structure or support base for heavy equipment. The cast concrete pile cap distributes the load of the building into the piles. A similar structure to a pile cap is a “raft”, which is a concrete foundation floor resting directly onto soft soil which may be liable to subsidence.
- As per IS 2911 (Part I/ Sec 3) -2010, the pile cap may be designed by assuming
- that the load from column is dispersed at 45° from the top of the cap up to the mid
- depth of the pile cap from the base of the column or pedestal. The reaction from
- piles may also be taken to be distributed at 45° from the edge of the pile, up to the
- mid depth of the pile cap. On this basis the maximum bending moment and shear
- forces should be worked out at critical sections.
- (i) Pile cap is perfectly rigid.
- (ii) Pile heads are hinged to the pile cap and hence no bending moment is
- transmitted to piles from pile caps.
- (iii) Since the piles are short and elastic columns, the deformations and stress distribution are planer.
- (i) Shape of pile cap.
- (ii) Depth of pile cap.
- (iii) Amount of steel to be provided.
- (iv) Arrangement of reinforcement.
- DETERMINE NUMBER OF PILE
- PILE CAP ARRANGEMENT AND PLANE DIMENSION
- PILE CAP PRELIMINARY DEPTH
- CHECK FORCES IN PILES
- CHECK FOR PUNCHING SHEAR
- CHECK FOR SHEAR
- DESIGN OF MOMENT
- CHECK FOR BOND
- DETAILS FOR REINFORCEMENT