Pilecap design using strut and tie method

[Agent Coconut]

Good Morning,

I am doing a pilecap design and I trying to understand the concept as I am developing a generic spreadsheet to design a pilecap.
If we are using the old BS8110, clause 3.11.4.1 where it allows the pilcap to be designed using bending theory or truss theory.
Same goes to Eurocode 2, at clause 9.8.1 (2) where it allow the pile cap to be designed using flexural method or strut and tie method.

Can anyone give me an insight of when is appropriate to use truss/strut and tie and when to use bending/flexural method?

Also, if we design using strut and tie method, with reference to the thread here as well

is there anyone has pilecap design example base on eurocde? - Structural engineering general discussion

is there anyone has pilecap design example base on eurocde? or any spreadsheet? if possible, can anyone share with me for the design example for 2P--6P pilecap design by eurocode strut-tie method? by the way, under EC2 design, must the pile cap has vertical shear link ? thanks very much.

www.eng-tips.com

I found most of the reference book give example up to 2x2 pile cap only, where in real life we may have 5x5 or 6x3 pile arrangement, if anyone can share me the theory if we do by strut and tie method? or any reference. I looked the Mosley and it is up to 2x2 as well.

 

[HTURKAK]

Can anyone give me an insight of when is appropriate to use truss/strut and tie and when to use bending/flexural method?

The sectional or bending/flexural method assumes that the cap is considered to be a deep beam and is designed for flexure and shear at critical sections. This method can be adopted in reasonably shallow pile caps, where the shear span to effective depth ratio is more than 1.5 so that the bending action
will be more predominant than the truss action. IMO , it is good practice to provide transverse shear reinforcement even may not require .

I will suggest you to look ; Design Guide for Pile Caps ( By Concrete Reinforcing Steel Institute ,CRSI)