What are the best foundation type for a construction in the city and earthquake prone area? If bored pile foundation is the best, which type is the best, square, circle? what are the considerations of that type?
It is the right foundation type that is the best. Not necessarily pylons or any one size fits all solution.
Design of foundation is a process tightly tied to the type of soil, geology of the site, building usage and many more factors.
When all these factors are worked together and the loads on the foundation are determined, there is a determination as to the type of foundation.
This can be a combination of footings and grade beams, mat foundation, or if the competent soil strata is deep, pylons.
In some structures a combination of all these is used because either the geology is not uniform or the structure massing and height varies.