The primary two functions of a Grade/Tie Beam in spread footing and/or pile caps foundation system is to support the Slab-On-Grade (S.O.G) and/or to take the moment from eccentric footing (or moment from lateral loads example wind and seismic). While the pile cap level and depth may differ from one site and another the level of the slab-on-grade is fixed by architectural constraint.
My questions are:
- What is the most suitable level for a grade/tie beam is it at the slab-on-grade level or the footing level and what will happen if the beam is at the S.O.G level and the footing is subjected to moment?
- How to design such a beam, meaning what are the loads and how to calculate the lateral loads (especially shear and moment) from loads such as seismic and wind?
- In what Section of the ACI and Eurocode is the Tie/Grade Beam is mentioned and is it always required (meaning for all soil types and seismic zones ...)?