Design Method

The design method tab provides options to set or control the design for the pile cap. The details of the design method employed are given in the Pile Cap design section above.

The layout of the Design Method area is shown below:

The input options are:

Beam Theory – the pile cap is designed as a rectangular concrete beam for bending.

Strut and Tie method – the pile cap is designed using the truss analogy using tension and compression elements.

Min of Beam & Truss – the pile cap design is carried out using both the Strut and Tie method and the beam method and the smaller reinforcement area required from each method is used.

Max of Beam & Truss – the pile cap design is carried out using both the Strut and Tie method and the beam method and the larger reinforcement area required from each method is used.

There are also three further options to control the design:-

Design Bending for Net ULS loads – the pile loads and bending moments in the pile cap are based on the applied column loadings only, no adjustment is made for the self-weight of the pile cap. This option applies to the beam theory only.

Design truss compression zone – for the strut and tie design to BS 8110 and SABS 0100, the design will use the check for a CCT node taken from the EC2 design code.

Deep Beam Theory – for use with the beam theory method. The design will treat the pile cap as a deep beam, using the method presented in the Concrete Designers’ Manual, Reynolds & Steedman, 10th Edition. This provides an alternative design method for deep beams as an alternative to the strut and tie method.