Proceedings of the 30th Annual Conference on Deep Foundations, 2005, Chicago, Illinois, USA, (DFI)
LRFD and Its Implications for QC/QA of Deep Foundations
Bernard Hertlein, M. ASCE, Chia K. Tan, Ph.D., P.E.
The move to LRFD methods for structural design by AASHTO, ACI, AISC, ASCE, and the FHWA has been a major change for the American construction industry. The deep foundations industry has arguably been placed most at risk by this situation, because of the need for, and the difficulty of providing, reliable quality assurance. LRFD is attractive for both the owner and the engineer because it promises cost reductions, but the assumption underlying LRFD is often overlooked – that the acceptable margin of safety can be rationally reduced, thus saving costs, provided that all the factors involved are closely controlled. This means that both the quality of the materials and the quality of the construction work must be closely monitored, and held to an acceptable standard. This paper describes the type of comprehensive quality management program that is needed in deep foundation construction projects based on LRFD. Case histories are used to illustrate the importance of both adequate inspection and reliable testing to a comprehensive quality management program.
|article #1302; publication #72 (AM-2005)|