TABLE OF CONTENTS Foundations, contrary to the dreams of building owners, do not come prepackaged with metal building systems. The concept of single-source responsibility for pre-engineered buildings is qualified by the fact that the foundations are usually designed by outside engineers.
In this chapter we look into the differences between foundations for metal building systems and those for conventional construction and examine some common solutions. We will not deal with the basics of foundation design, a subject that should be familiar to any practicing structural engineer and, hopefully, to most architects. Similarly, we will not delve into the complex topic of establishing allowable bearing pressures for various soils, a task best left to geotechnical engineers.
As discussed in Chap. 9, poor soils found at the site might call for deep foundations, an expensive item that could explode the project s budget and suddenly make a competing site much more appealing. On a more positive note, an experienced geotechnical engineer might be able to justify a much larger allowable soil-bearing value than could be learned from the necessarily conservative tables of presumptive bearing pressures contained in the building codes. This recommendation could lead to substantial cost savings. As Ruddy1 has stated, An increase in an allowable bearing pressure from 3 ksf to 6 ksf can result in a savings of $0.08/s.f. for a shallow spread footing foundation system in a one-story facility.
The results of a geotechnical exploration program are of interest to all parties of the construction project.
