Abstract:
The International Building Code is a prescriptive code which often leads to deep foundation designs that are significantly more expensive to build than necessary to resist design loads and meet seismic performance objectives mandated by the code. On a positive note, the International Building Code allows engineers to use advanced design practices and alternate means and methods to economically modify or eliminate any design details that are too conservative or not applicable to the deep foundation element in question. Unfortunately, engineering budgets, lack of advanced analysis education or confidence, timing, separation of responsibilities between the engineer of record and the deep foundation delegated designer, and other issues limit the use of these approaches for most deep foundations.
This presentation focuses on the differences among value engineering, advanced design practices, and alternate means and methods applications related to the seismic design of deep foundations. Example applications where deep foundation elements are commonly overdesigned are discussed and example solutions are presented. An overview of relevant code requirements for different deep foundation elements is presented and the roles of the owner/engineer/contractor are also discussed in detail. PCI’s recent efforts to incorporate more performance-based approaches to seismic design are compared to shortcomings of the current language in the International Building Code. Seismic Design of innovate new foundation elements is also considered.