Table of Contents
What is pile cap reinforcement?
This process is known as shuttering and reinforcing. The materials used are long steel bars with longitudinal protrusions between the piles held in shape by thinner tie wires. Once this steel mat is laid, timber is attached around the perimeter to contain the wet concrete mixture.
Are pile caps reinforced?
A reinforced concrete slab known as a pile cap may be featured on top of foundation piles to evenly displace a load. The term “pile cap” may be used to describe a reinforced concrete slab constructed on top of a group of foundation piles to evenly displace or spread the load they are to carry.
What is punching shear in pile cap?
The punching shear in a pile is simply the axial compression force in a pile considering strength load combinations. The punching shear capacity is obtained via the ACI code equations, seen below. The code requires this value to be the minimum of these three values.
How do pile caps work?
Pile caps are constructed by excavating an area around the group of piles to enable formwork to be inserted. The pile tops may be trimmed to ensure they are at the same height. A reinforcement cage is then built and positioned in the formwork cast box and fastened to the piles.
How do you make pile caps?
Pile caps can be designed using the truss analogy or using the bending theories. Mostly, up to the four numbers of piles are connected by a pile cap to support the concentrated load from the superstructure, truss theory is used to design the pile caps.
What is the recommended reinforcement percentage in a pile?
(b) All piles shall be reinforced with not less than 4 longitudinal steel bars having an area of not less than 1.25 percent and not more than 4.0 percent of the gross cross-sectional area of the pile.
How is pile capacity calculated?
Step 2: compute the ultimate end bearing capacity (acting as individual piles). Ultimate end bearing capacity in clay = Nc × C × pile tip area (Nc = 9). Ultimate end bearing capacity in soft clay = 9 × 120 × π × diameter2/4 = 848.2 lbs/per pile. Total ultimate bearing capacity per pile = 76,920 + 848.2 = 77,768 lbs.
What is punching shear reinforcement?
The weight of a slab supported on a column induces shear stresses in the slab. These stresses, if sufficient and where additional reinforcement is not provided, would result in the column ‘punching’ through the slab.
Why do we give pile caps?
Pile caps create a stable foundation and offer a larger area for the distribution of the building load onto the piles. They act in a similar way to piled raft foundations, where a concrete slab rests on soil which may be susceptible to movement, above a group of piles. Rectangular (for all other number of piles).
What is pile cap design?
Pile caps are constructed to hold the pile and superstructure together at the ground level or below the ground level while transferring loads of the superstructure to the foundation. Pile caps can be designed using the truss analogy or using the bending theories.